NASA ARSET_ Techniques for Plotting and Analyzing ATL24 Coastal Bathymetry Part 2
The Story
Welcome to Part 2 of our specialized series on coastal remote sensing and altimetry data: "NASA ARSET: Techniques for Plotting and Analyzing ATL24 Coastal Bathymetry Part 2."In this episode of the NASA Live Video Podcast, we advance from our foundational overview into the practical, hands-on programming and analytical workflows required to process coastal data. Mapping the shallow waters of our global coastlines is critical for marine navigation, habitat conservation, and coastal vulnerability assessments—and NASA's ICESat-2 ATL24 product provides some of the most precise spaceborne LiDAR bathymetry data available today.
Through the framework of NASA’s Applied Remote Sensing Training (ARSET) program, we dive deep into the technical methods used to plot and analyze these complex photon-return profiles. We discuss how to handle the ATL24 HDF5 data structure, utilize open-source Python libraries (such as h5py, pandas, and matplotlib) for visualization, isolate sea-surface vs. sea-floor returns, and account for water column refraction to ensure highly accurate depth measurements along dynamic coastal zones.
Whether you are a marine scientist, a coastal engineer, a GIS developer, or a space enthusiast eager to see how advanced laser altimetry maps the ocean floor from orbit, this second installment delivers essential technical insights. Subscribe to the NASA Live Video Podcast to catch up on Part 1 and stay connected with the absolute frontier of space exploration, remote sensing, and cutting-edge earth science!
Speaker 1: Welcome to part two of the ARSET training NASA's satellite
Speaker 1: laser altimetry for coastal and nearshore bathymetry. My name is
Speaker 1: Sean McCartney from NASA's Goddard Space Flight Center in Maryland,
Speaker 1: serving as your ARSET instructor wherever you are joining from. Welcome.
Speaker 1: The following slides provide an overview of the two part
Speaker 1: webinar series. So why would somebody want to take this training?
Speaker 1: Nearly eighty percent of the world's oceans are unexplored and unmapped.
Speaker 1: Successful coastal management depends on monitoring and mapping. Coastal bathymetry
Speaker 1: is essential for navigational hazards for vessel operations, tidal modeling
Speaker 1: and prediction, tsunami risk assessment and forecasting, underwater cultural heritage preservation,
Speaker 1: and environmental change monitoring. Satellite drive pathymetry enhances capacity for
Speaker 1: collecting high resolution, accurate depth data supporting varied applications. By
Speaker 1: the end of this two part training, participants will be
Speaker 1: able to identify NASA bathymetry data used for global coastal
Speaker 1: and nearshore bathymetry mapping for risk reduction relating to shipping
Speaker 1: and navigation, identify the applications and limitations of IAT tube
Speaker 1: athymetry data or ATL twenty four for coastal and nearshore
Speaker 1: bathymetry mapping, Plot and download IAT tube athymmetry data using
Speaker 1: slide roll web client in analyze IAT tube bathymetry data
Speaker 1: using the slide roll Python client. The prerequisites for the
Speaker 1: training are two are SET courses, the Fundamentals of Remote
Speaker 1: Sensing Course and the Mapping and Monitoring Lakes and Reservoirs
Speaker 1: with satellite observations. From December two to December fourth, there
Speaker 1: will be two one and a half hour sessions which
Speaker 1: will include presentations, demonstrations, and question and answer sessions. All
Speaker 1: materials and recordings from each session will be available from
Speaker 1: the training web page. If you are not able to
Speaker 1: attend one part, a recording will be made available within
Speaker 1: forty eight hours on the RSET training web page. Homework
Speaker 1: opens today December fourth and will be due on December
Speaker 1: thirty first. A certificate of completion will be awarded to
Speaker 1: those who attend all live sessions and complete the homework
Speaker 1: assignment before the given due date. Part two of the
Speaker 1: training is focused on techniques for plotting and analyzing ATL
Speaker 1: twenty four coastal bathymetry. The objectives for part two of
Speaker 1: the training follows. By the end of today, participants will
Speaker 1: be able to identify the applications and limitations of i
Speaker 1: AT two pathymetry data for coastal and nearshore bathymetry mapping
Speaker 1: plot and download i AT two pathymetry data using slideral
Speaker 1: Web client in analyze i AT two pathymetry using slide
Speaker 1: rule Python client. Please put your questions in the questions
Speaker 1: box and we will address them at the end of
Speaker 1: the webinar. Feel free to answer your questions as we go.
Speaker 1: We will try to get to all the questions during
Speaker 1: the Q and A session. After the webinar, the remainder
Speaker 1: of the questions will be answered in the Q and
Speaker 1: A document, which we will be posted to the training
Speaker 1: website about one week from today's training. It is not
Speaker 1: my pleasure to introduce the guest trainers for today's webinar,
Speaker 1: Doctor Christopher Parrish, Joseph Paul Swinsky, Gretchen Imohori, and Keana Kief.
Speaker 1: Doctor Parrish is a professor of geomatics in the College
Speaker 1: of Engineering, School of Civil and Construction Engineering at Oregon
Speaker 1: State University. He also serves as director of the Geospatial
Speaker 1: Center for the Arctic and Pacific, a university led advancing
Speaker 1: research and education in geodesy, geomatics, and geospential geospatial engineering.
Speaker 1: He is past president of the America Society for Photogrammetry
Speaker 1: and Remote Sensing. Prior to joining Oregon State University, he
Speaker 1: held a position of lead Physical Scientists in the Remote
Speaker 1: Sensing Division of Noah's National Geodetic Survey. He also serves
Speaker 1: as an affiliate faculty member in the Center for Coastal
Speaker 1: and Ocean Mapping Joint Hydrographic Center at the University of
Speaker 1: New Hampshire. JP Swinsky is a twenty four year NASA
Speaker 1: Goddard software developer who spent most of his career creating
Speaker 1: flight software for spacecraft and science instruments. He led flight
Speaker 1: software development for the Atlas instrument from twenty ten until
Speaker 1: twenty sixteen. In twenty eighteen, he transitioned to cloud based
Speaker 1: data processing solutions, and in twenty twenty co developed slide
Speaker 1: role with the ice AT two Project scientist and University
Speaker 1: of Washington, a public web service providing fast cloud access
Speaker 1: to ice AT two data. Gretchen Imohori is estabbed scientist
Speaker 1: and Satpathy Project manager at Noah's National Geodetic Survey with
Speaker 1: twenty six years at NOAH, she supports hydrographic and remote
Speaker 1: sensing operations. She holds a Bachelor of Science and Chemistry
Speaker 1: from State University of New York, Buffalo and a Master
Speaker 1: of Science in Earth Science Ocean Mapping from University of
Speaker 1: New Hampshire. Keana Keith is an analyst programmer with two
Speaker 1: plus years experience working Chris Parish's research group at Oregon
Speaker 1: State University. She has a Bachelor of Science and Computer
Speaker 1: Science from Oregon State University. She is a lead developer
Speaker 1: for noah's Comprehensive Bathometric LIGHTAR Uncertainty Estimator, SATPATHY Photogrammatic Shoreline
Speaker 1: Uncertainty Estimator, and a contributing developer of NASA's ATL twenty four.
Speaker 1: Chris over to you.
Speaker 2: Thanks Sean, and hi everyone again. My name is Chris Parrish.
Speaker 2: I'm with Oregon State University and I'm really honored to
Speaker 2: give a demo on ATL twenty four and how we're
Speaker 2: going to use ATL twenty four and Sentinel two spectral
Speaker 2: imagery alongside each other for mathemetric analysis and also maybe
Speaker 2: looking at mathemmetric change. So to set the stage for this,
Speaker 2: if you're going to follow along with me. There are
Speaker 2: some things that you need to set up ahead of time.
Speaker 2: So first of all, there are a couple of files
Speaker 2: that you should have been able to find on the
Speaker 2: training website. There's a shape file which is called hyannas AOI,
Speaker 2: and then there's also a Python script which is called
Speaker 2: psdblinear aggression dot PI. So you want to go and
Speaker 2: download those two files if you haven't already done. So,
Speaker 2: you also need to set up an EU Copernicus account
Speaker 2: in order to be able to download Sentinel two imagery.
Speaker 2: You'll also need to download and install qgis also known
Speaker 2: as QGIS. That's free and open source GIA software that
Speaker 2: we're going to use in this demo. And there's three
Speaker 2: sites that you want to go ahead and bookmark. Once
Speaker 2: is the Copernicus Browser, the second is the slide Rural
Speaker 2: Earth web client, and then the third is the Noah
Speaker 2: Webmap Tile Service Electronic Navigational Chart. So here's our project site.
Speaker 2: This is where we're going to be working for this demo.
Speaker 2: This is Hyhana's Harbor in Cape Cod, Massachusetts. This is
Speaker 2: a site that is meaningful to me because it's actually
Speaker 2: where I started my career. At the very beginning of
Speaker 2: my career, I worked on a Noah Hidrographic Service ship
Speaker 2: and this is where I first met the ship and
Speaker 2: where we spent a few weeks working before transmitting down south.
Speaker 2: So just to kind of take a quick look at
Speaker 2: the site here, one thing that you might notice is
Speaker 2: that there's a lot going on in terms of where
Speaker 2: we are. So this is on the south shore of
Speaker 2: Cape Cod you can see in the in the image
Speaker 2: up in the upper left where we are relative to Boston.
Speaker 2: But in terms of things going on in the harbor,
Speaker 2: there are a lot of coastal engineering project you know,
Speaker 2: engineered structures, some of them going back nearly two hundred years,
Speaker 2: such as the breakwater, the original breakwater. We've also got
Speaker 2: a jetty grindfield, other shoreline protection structures. There's a dredged
Speaker 2: channel that's used by the ferry. And then there are
Speaker 2: also a lot of storms that impacts this area, including
Speaker 2: a lot of times large no o' easters. So really
Speaker 2: a lot of different reasons why there could be changes
Speaker 2: to the bathymetry and the site and why we might
Speaker 2: be interested in monitoring with bathemetric change over time, and
Speaker 2: just to make the point that bathymetry in this area
Speaker 2: has been of interest for a long long time. Here
Speaker 2: we're looking at an eighteen ninety four US Coast and
Speaker 2: Ganetics Survey chart of Hyannas Harbor. So quickly, this is
Speaker 2: the workflow that we're going to go through. We're going
Speaker 2: to start with just a visual analysis of our project site.
Speaker 2: We'll do that in QGIS. I'm just a kind of
Speaker 2: gain familiarity with the site. Then we're going to go
Speaker 2: into the slide role web client, and this is where
Speaker 2: we're going to be able to view and download ATL
Speaker 2: twenty four with imetry. So I set to withymetry from
Speaker 2: our new ATL twenty four data products that Laurie talked
Speaker 2: about in the earlier session, and then we're going to
Speaker 2: integrate that ATL twenty four with inmetry with satellite drive
Speaker 2: with imetry from sentinel to imagery and generate final bathometric
Speaker 2: data layers for visual assessment. Before I jump into actually
Speaker 2: doing the dewnload, there's one step that I just want
Speaker 2: to talk about briefly so that it doesn't confuse anyone
Speaker 2: when we get to this step. So there's going to
Speaker 2: be a step where we're going to do this integration
Speaker 2: of the ATL twenty four with inmetry with Stanel two imagery,
Speaker 2: and the way we're going to do that. We're going
Speaker 2: to run a widely known algorithm known as the Stumf algorithm.
Speaker 2: This is actually going to parallel in some ways, I
Speaker 2: think a workflow that Gretchen is going to show and
Speaker 2: demonstrating the no asatpathy tool. I'll just say the version
Speaker 2: that we're going to do, it's going to be a
Speaker 2: little bit basic compared to what Gretchen is going to show,
Speaker 2: So we're not going to make use of some of
Speaker 2: the new elements that just compositing in the switching model
Speaker 2: and acolyte and other things that Gretchen might mention, But
Speaker 2: for visual analysis, this should be a pretty good workflow.
Speaker 2: So we're going to start by generating what's called pseudobythymmetry
Speaker 2: or PSDB, and that's going to be the logarithms the
Speaker 2: ratio of logarithms of two different spectral bands. We're going
Speaker 2: to use blue and green, and then in the next
Speaker 2: step we're going to do a linear regression of that
Speaker 2: pseudobythymmetry on ATL twenty four or regression of ATL twenty
Speaker 2: four reference pythymetry on this pseudobythymmetry, and that's going to
Speaker 2: give us the parameters of the linear transformation that we
Speaker 2: can use to transform that pseudopythymmetry to actual depths. So
Speaker 2: with that, let me go ahead and at this point
Speaker 2: and just start in on the demo. And the first
Speaker 2: thing we want to do is, I'm just going to
Speaker 2: bring up qgis. Again, this is free and open source
Speaker 2: GIS software. The version I've got is three point four zero,
Speaker 2: but any recent version should work reasonably well. And I'm
Speaker 2: going to go ahead and just open a new empty project.
Speaker 2: And at this point, I want to navigate to those
Speaker 2: files that I mentioned were on the training website and
Speaker 2: so hopefully you had a chance to download those. If
Speaker 2: you did. Some of the files that you grabbed, what
Speaker 2: point were the ones called hs AOI shape file. And
Speaker 2: in this case, I can just kind of drag and drop.
Speaker 2: I'm going to take the one with the extension of
Speaker 2: dot SHP and I'm just gonna drag and drop that
Speaker 2: right into qgis. There you can see it opened up.
Speaker 2: The first thing I want to do is probably just
Speaker 2: change the symbology. I'm going to double click that to
Speaker 2: bring up the symbology, and I want to change it
Speaker 2: to just a red outline something like that and say, okay,
Speaker 2: so there's my project site. The next thing I want
Speaker 2: to do is, let's see if I can move that
Speaker 2: screen move that screen sharing box out of the way. Okay.
Speaker 2: The next thing I want to do is just like
Speaker 2: usual and a gis I want to bring up some
Speaker 2: base map imagery, and so to do this, I'm actually
Speaker 2: going to bring up some Google imagery. If you're if
Speaker 2: you haven't set this up already, what you want to
Speaker 2: do is you want to go into plugins manage and
Speaker 2: install plugins, and that should pop up this list of
Speaker 2: plugins that are both installed and not installed. So in
Speaker 2: my case you can see this one called quick Map
Speaker 2: Services that's already been installed. If you don't have that yet,
Speaker 2: you want to go not installed, search for it in
Speaker 2: the search bar and install it. Because I've already got it.
Speaker 2: I'm gonna go ahead and just close this and then
Speaker 2: hopefully at this point you'll see over here on the
Speaker 2: on the right hand side of the screen, the search
Speaker 2: next gis q MS. If you don't see that, the
Speaker 2: way to get that to pop up is you want
Speaker 2: to go into UH. You should be able to go
Speaker 2: into just Web Quick Map Services and search next gis QMS.
Speaker 2: So in this box, I'm just gonna type Google Satellite
Speaker 2: and the one I want to pick is the one
Speaker 2: called Google Satellite Hybrid, and I'm gonna.
Speaker 3: Say ad.
Speaker 2: So that one ahead and opened up the imagery for
Speaker 2: my site. And at this point I can just kind
Speaker 2: of explore a little bit. I'll turn off the the
Speaker 2: project side outline just so we can see what's going on.
Speaker 2: Here are some of those engineered structures that I've talked about,
Speaker 2: the jetty, the breakwater, and then over here we've got
Speaker 2: a grind field. There are also some private revetments that
Speaker 2: have been installed for shoreline protection, the dredged channel that's
Speaker 2: used by the ferry, and so, like I mentioned, just
Speaker 2: a lot going on in a lot of reasons why
Speaker 2: the symmetry and the site might be changing and might
Speaker 2: be of interest. So in terms of looking at existing
Speaker 2: with mmetry, one thing we want want to do at
Speaker 2: this point is go ahead and bring in some Noah
Speaker 2: Medical chart data e n C data, and so to
Speaker 2: do this, I'm going to go up here and click
Speaker 2: on Layer Data Source Manager, and I'm going to scroll
Speaker 2: down here until I see w MS that stands for
Speaker 2: Webmap Service w MTS Webmap Tile Service. I'm going to
Speaker 2: do that and just click on new and I think
Speaker 2: I've already got this set up, but it shouldn't hurt.
Speaker 2: I'll go ahead and do it anyway. I'll call this.
Speaker 2: I'll call this Noah Webmap Tiles Service e n C.
Speaker 2: And then I'm going to need to put the U
Speaker 2: r L in here and to do that again. This
Speaker 2: was one of the three links that should have been
Speaker 2: available on the on the trending website, so it's actually
Speaker 2: this one here that starts with GIS chart Tools. I'm
Speaker 2: just going to grab that, that whole U r L
Speaker 2: and go ahead and put that in here and say, okay.
Speaker 2: It looks like I had already set that up, so
Speaker 2: it says do you want to overwrite it? And I'll
Speaker 2: just go ahead and say sure, overwrite okay, and then
Speaker 2: I can I can close out of this box and
Speaker 2: then back over here. Now when I scroll down in
Speaker 2: this in this browser, I scroll down to where I
Speaker 2: see w MS w MTS. Expand that pick the one
Speaker 2: that I just added. I want to expand it and
Speaker 2: expand it again until I see something called default zero
Speaker 2: two eight milimeter, and I'm going to write click that
Speaker 2: and say add layer to projects. And that worked, and
Speaker 2: went ahead and popped up the elect electronic navigational chart
Speaker 2: for this area, so we can zoom in and look
Speaker 2: at what the chart soundings look like for this area.
Speaker 2: One thing we might see. I found this kind of
Speaker 2: interesting just in exploring the e and say, if we
Speaker 2: get close to shore and for example, close to this
Speaker 2: breakwater here, you see that there are a lot of
Speaker 2: these rock awash symbols. But actually it looks like in
Speaker 2: the very shallowest areas maybe not a great density of sounding.
Speaker 2: So hopefully we'll be able to use ATL twenty four
Speaker 2: and Sentinel too withthymmetry to get a good idea of
Speaker 2: what's going on in those areas. So within mind, let's
Speaker 2: go ahead and just jump into the next part of
Speaker 2: this where I'm going to show you how to get
Speaker 2: I set to ATL twenty four with ymmetry, and to
Speaker 2: do so, I'm going to go to the next of
Speaker 2: the links that we shared and the demo and the
Speaker 2: training website, and so this time I want to go
Speaker 2: to the one that's called slide Rural Earth. That's going
Speaker 2: to take me to this website here. So this is
Speaker 2: how we're going to be able to get NASA ATL
Speaker 2: twenty four data through through slide rule and this web client.
Speaker 2: So I want to click on the link that says
Speaker 2: web client it's going to pop up. I want to
Speaker 2: make sure this is something that I sometimes forget to do. Actually,
Speaker 2: I want to make sure that I've selected the table
Speaker 2: it's called I set to coastal mathymmetry, and then we're
Speaker 2: going to be able to just zoom into our area
Speaker 2: and take a look at pathymmetry in that site. Before
Speaker 2: we do that, I just wanted to make a quick
Speaker 2: point here. So in picking out the site for this demo,
Speaker 2: I very specifically chose a site that was someone on
Speaker 2: the challenging side. So at mid latitude site, a lot
Speaker 2: of times when you see people do Sili drigathymmetry or pathymmetry,
Speaker 2: a lot of times we're focused on the very clear
Speaker 2: tropical waters where we just know things are gonna work great.
Speaker 2: So I purposefully tried to pick a little bit of
Speaker 2: a more typical project site. But just while we're here,
Speaker 2: I do kind of want to take this opportunity just
Speaker 2: to show you what it looks like if we you know,
Speaker 2: if we were to select a site that was in
Speaker 2: a uh a really you know, sort of amazing tropical area. Here,
Speaker 2: it looks like I thought I had a site selected,
Speaker 2: so I might have to do this kind of on
Speaker 2: the fly. So I'm just assuming in here on Turks
Speaker 2: and Caicos, and I'm just going to draw a project box.
Speaker 2: We'll do one maybe that goes about like maybe something
Speaker 2: like that, and I'm gonna we'll click ahead, run slide
Speaker 2: while this process is again the reason I'm doing this,
Speaker 2: This is not our site. I just want to show
Speaker 2: what it looks like when we've got a site where
Speaker 2: uh here. What's gonna happen is when it gets processing,
Speaker 2: we're going to see that it's selected all of the
Speaker 2: different track lines of I said to you, bothymetry, and
Speaker 2: for a side like this, what we should see is
Speaker 2: that throughout the entire site we've got really amazing pathymetry.
Speaker 2: I'll give this a second to just finish processing. Okay,
Speaker 2: there we go. So that worked. That came up and
Speaker 2: we can see it found all these different tracks of bythymmetry,
Speaker 2: and in any given track, I'm going to change the
Speaker 2: color scheme. I'm going to change it to this coool scheme.
Speaker 2: So any track that's within this site, I'm going to
Speaker 2: see this really just nice bathmetric profile. I'll see the
Speaker 2: depths dropping off to greater than fifteen meters depending on
Speaker 2: where where I am in the profile. I can pick
Speaker 2: another line. Basically, any line I pick, I imagine it's just
Speaker 2: going to look like pretty amazing pythymmetry. And in this case,
Speaker 2: another thing that I can put the actually do here
Speaker 2: is I can go to this three D v and win.
Speaker 2: This's loads if I can get this to work. But
Speaker 2: it should do is oh yeah, there we go. I
Speaker 2: should be able to just sort of drag this up
Speaker 2: and kind of rotate this around and look at the
Speaker 2: bathymetry for that site in three D. And in a
Speaker 2: case like this, I couldn't even made my side a
Speaker 2: bit bigger. In a case like this, you can imagine
Speaker 2: that we could generate a pretty good bathymetric DM even
Speaker 2: without incorporating any additional data. Okay, with that in mind,
Speaker 2: let's go ahead and go back to requests. And now
Speaker 2: I'm going to go up to the site that we
Speaker 2: actually are interested in for this demo. So I'm gonna
Speaker 2: I'm gonna scroll all the way back up to New
Speaker 2: England and to Cape Cod and to our Highness Project site.
Speaker 2: So here we are, here's our here's our actual side
Speaker 2: of interest. I'm gonna do the same thing. I'm gonna
Speaker 2: draw a box. I can make it pretty big. I
Speaker 2: just basically want to make sure I'm covering the whole
Speaker 2: area so I can do something. Maybe I'll do something
Speaker 2: maybe about like that, and then same process before I'm
Speaker 2: gonna run slide rule. It's going to go through and
Speaker 2: process again. It's finding all the tracks of I SAT
Speaker 2: to bathymmetry. So this one in this case, if you're
Speaker 2: to spend some time investigating these different track lines, basically
Speaker 2: what you'll see is it's not as amazing as when
Speaker 2: we were just looking at turks and caicos, but we
Speaker 2: do seem to have some pretty good bathymetry going through
Speaker 2: the going through the harbor, and so I can, you know,
Speaker 2: just try try a different couple of different track lines,
Speaker 2: and so it looks like we've got some good pometry.
Speaker 2: This is all great at this point. Let's go ahead
Speaker 2: and and and download it. And there's a few different
Speaker 2: ways I can do this. One way, if I want
Speaker 2: a little bit more control, What I could do is
Speaker 2: I could go ahead and select these individual track lines
Speaker 2: one at a time, and I could click on this
Speaker 2: thing that says three D view. Oh excuse me, not
Speaker 2: the three D V sorry, that table. I could click
Speaker 2: on table, and when this pops up. At this point,
Speaker 2: I can actually edit the commands that's shown here, and
Speaker 2: I can do things like I can pick exactly what
Speaker 2: parameters I want to export. I can I can pick
Speaker 2: different you know, filters, or do things in different ways. However,
Speaker 2: for the sake of this demo, I'm going to do
Speaker 2: things in an easier way. I'm just going to go
Speaker 2: kind of right in the middle of my screen. If
Speaker 2: you see this button that says export, I'm just going
Speaker 2: to go ahead and click that, and I'm gonna choose
Speaker 2: an export format, and I want to make that CSV
Speaker 2: comma separated values and say export. And I'm gonna go
Speaker 2: ahead and put this into the folder that I created
Speaker 2: for this training. So I created this g Hyannas Harbor
Speaker 2: Aziel twenty four demo. I'll make a new subfolder that
Speaker 2: I will call ATL twenty four, and I will put
Speaker 2: this CSP file right in that folder. Something I should
Speaker 2: point out at this point because I was kind of
Speaker 2: I wasn't very discriminate in picking out exactly what tracks
Speaker 2: I want. I just grabbed them all. That was the
Speaker 2: easiest way to go and grab the data. I am
Speaker 2: going to pay a slight price for that later, and
Speaker 2: I'll talk about that when I get there. For now,
Speaker 2: we're actually done in slab role, though, so I can
Speaker 2: go ahead and close the web browser and get back
Speaker 2: over into QGIS and back to our project site. And
Speaker 2: at this point, since I just grabs that ATL twenty
Speaker 2: four data layer, why don't I just go ahead and
Speaker 2: bring that into QGIS. So the way I'm going to
Speaker 2: do that is, I'm going to click on layer and
Speaker 2: under layer, I'm going to do AD layer, and there
Speaker 2: should be one that's called ad to limit text layer,
Speaker 2: so I'll click that. Now I want to just browse
Speaker 2: to find that file, so it's the file that I
Speaker 2: just created. There, I'm going to go to AHL twenty
Speaker 2: four folder, select that CSP file and say, okay, if
Speaker 2: I want, I can scroll along down here in the
Speaker 2: bottom and see the individual fields that came in in
Speaker 2: that file, so all the different information refraction corrected orthometric height,
Speaker 2: so all of the pothometry has been refraction corrected. It's
Speaker 2: got a confidence interval. I think that's something that Lori
Speaker 2: covered in her talk. But basically the confidence and the
Speaker 2: and the bathymetry classifications, spot granule, et cetera. Everything basically
Speaker 2: auto populated. It said that my ex field is longitude
Speaker 2: phyfield is latitude pH. I can go ahead and set
Speaker 2: my Z field to ortho underscore H that's my Z
Speaker 2: and I can go ahead and just say AAD and
Speaker 2: at that point I you'd be able to close this window.
Speaker 2: And if you can see all these orangeish dots that
Speaker 2: just got added, that's the ATL twenty four data. If
Speaker 2: I want to can change it symbol. I kind of
Speaker 2: like doing this as a blue dot. I think that
Speaker 2: looks pretty good. There's my ATL twenty four data. So
Speaker 2: at this point we're really doing well. I would make
Speaker 2: an observation here, though, and that is that even though
Speaker 2: this brought in a lot of ATL twenty four data,
Speaker 2: it still is kind of sparse in terms of you know,
Speaker 2: there's areas of the harbor where if we're interested in
Speaker 2: looking at nearshore withythymmetry, all we've got is these individual
Speaker 2: discrete tracks. So this is the point where we want
Speaker 2: to see how we can combine ATL twenty four pythymmetry
Speaker 2: with specially drive pathymetry from SEVENEL two. So to do this,
Speaker 2: I'm going to go to the third of the weblinks
Speaker 2: that we're shared in the trending website, and the third
Speaker 2: link it's the one that's called Pernicus Browser. So I'm
Speaker 2: gonna open this up. You'll need to create an account
Speaker 2: for this. It's free, uh so free to create an account,
Speaker 2: and then you'll have to log in. I happen to
Speaker 2: already be logged in, and you can tell that because
Speaker 2: it's got my name listed up here. But go ahead
Speaker 2: and sign in if you need to. Okay, So the
Speaker 2: next thing I want to do is just go over
Speaker 2: to our project site. So I'm gonna scroll over to
Speaker 2: Cape cod and into our Hynas Harbor project site. At
Speaker 2: this point, I want to draw an AOI and so
Speaker 2: I'm going to use this little polygon tool, and then
Speaker 2: once I select that, I want to grab the tool
Speaker 2: next to it. It looks like the pencil icon. I'll
Speaker 2: select that and I might scroll it a little bit,
Speaker 2: and I'm just gonna I'm just gonna go ahead and
Speaker 2: and digitize something it doesn't. It doesn't have to be perfect,
Speaker 2: and it's okay if I make this a little bit
Speaker 2: big than what it actually needs to be, so I'll
Speaker 2: maybe do something and just finish it up off like that. Okay,
Speaker 2: Now we want to put in a date, and this
Speaker 2: is the point where you can actually spend a lot
Speaker 2: of time looking through the different dates trying to find
Speaker 2: imagery that looks good. Cloud free, water looks reasonably clear.
Speaker 2: I'm going to do a little bit of a shortcut.
Speaker 2: I've already done some analysis and i found a data
Speaker 2: that looks good, so I'm just going to go ahead
Speaker 2: and put that in. The day that I found is
Speaker 2: twenty twenty three, twenty twenty three oh three, twenty twenty
Speaker 2: three oh three, twenty all right there, it is right there,
Speaker 2: so it brought up that date. I want to make
Speaker 2: sure I'm in the visualize tab here, and at this
Speaker 2: point over on the right hand side of the screen,
Speaker 2: I've got this download icon, so I'll click that download icon,
Speaker 2: and then here I want to click on the tab
Speaker 2: that says analytical, and I want to be careful with
Speaker 2: the settings here. I want my image format to be
Speaker 2: tiff thirty two bit float. I want to change my
Speaker 2: resolution to high. I'm gonna go ahead and keep the
Speaker 2: court the default coordinate system. And then I'm going to
Speaker 2: select three different images to download. I'm going to do
Speaker 2: true color, so that's going to be the RGB, and
Speaker 2: then I'm gonna pick just two of the bands. I'm
Speaker 2: going to do BAN two, which is blue, and BAN three,
Speaker 2: which is green, and I can just click the click
Speaker 2: the download icon, so that should be saving them to
Speaker 2: my downloads folder. I can go ahead and open that
Speaker 2: up there it is, it just downloaded. I'm going to say,
Speaker 2: we'll just do cut and I'm going to paste this
Speaker 2: into the to the folder that I set up specifically
Speaker 2: for this demo. We'll do a subholder. My new subholder
Speaker 2: will just be called Sentinel two.
Speaker 4: No.
Speaker 2: Two and copy in that ZIP file. I'll go ahead
Speaker 2: and extract all of the different images that are in
Speaker 2: that in that. Okay, So that worked, it extracted all
Speaker 2: the images. I'm going to do one more thing, just
Speaker 2: because these are fairly long and cumbersome file names. I'm
Speaker 2: going to rename these the thing that says banned too.
Speaker 2: I'm just going to rename that to S two for
Speaker 2: Sentinel to blue. The one that says banned three, I'm
Speaker 2: going to rename that to be S two winterscore green.
Speaker 2: And then the final one that's the true color RGB,
Speaker 2: I'm going to rename that to be S two underscore RGB.
Speaker 2: So I've got those three three different images, all redn ends.
Speaker 2: At this point, I can get out of that Copernicus
Speaker 2: browser and I can actually just, uh, this is another
Speaker 2: case where I can just drag and drop this, So
Speaker 2: I'll just I'll just drag and drop those right in. Whoops,
Speaker 2: So it looks pretty good here. I am back in
Speaker 2: in QG. I S I've got my uh my RGB
Speaker 2: image up at the top. If I want, I can
Speaker 2: go ahead and take my ATL twenty four both imagery
Speaker 2: and drag that up to the up to the very
Speaker 2: top so that we can see where the where the
Speaker 2: I saw two pythymmetry is on top of the Sentinel
Speaker 2: two imagery. Okay, at this point, we're going to move
Speaker 2: on to the next step, which is, uh that some
Speaker 2: prestio that I showed you earlier on the slides, and
Speaker 2: we're going to create that pseudo bythymmetry layer. So this
Speaker 2: is going to be the ratio of the logarithms of
Speaker 2: the two different spectral bands, the blue band and the
Speaker 2: green band. So the way I'm going to do this
Speaker 2: is I'm going to click on raster and then raster calculator,
Speaker 2: so that brings me up here to raster a calculator.
Speaker 2: I'm going to create an output layer, and I want
Speaker 2: to give this a name, so I'm going to put
Speaker 2: it right back in my in my demo folder, I'll
Speaker 2: do a new subfolder called PSDB. Again, that stands for pseudopathymmetry,
Speaker 2: and that denotes the fact that we're not going to
Speaker 2: have actual depths. It'll just be sort of pseudodepths or pseudobythymmetry.
Speaker 2: So I'm going to go in there and I'm going
Speaker 2: to make my file name. I'm going to do stb
Speaker 2: dot tef save, and then the next thing I want
Speaker 2: to do is I just want to go ahead and
Speaker 2: create that stump pray show. So this is going to
Speaker 2: be natural log of one thousand times blue band. So
Speaker 2: S two blow in parentheses divided by natural log of
Speaker 2: one thousand. I'ms the green band. This might look a
Speaker 2: little funny, what what is this again? This is just
Speaker 2: this is just the stump rash show that that we
Speaker 2: saw earlier back in the in the slide. So we've
Speaker 2: done log of blow over log of green. That factor
Speaker 2: of a thousand, that's just a constant that is designed
Speaker 2: to keep the keep the logarithms positive and linear linearly
Speaker 2: related to depth. So I'm just gonna go ahead and
Speaker 2: run this. I'm gonna say, okay, and it worked. It
Speaker 2: already generated my pseudopythymmetry later. All right. The next step
Speaker 2: I want to do at this point is, like I
Speaker 2: mentioned earlier, our ultimate goal here is we want to
Speaker 2: use the ISAT tubeothymmetry from ATL twenty four to calibrate
Speaker 2: our pseudopythymmetry. And so to do this, we need to
Speaker 2: create a layer that has both values. We want to
Speaker 2: We want a layer that has the at L twenty
Speaker 2: four heights. I should have mentioned, by the way, uh
Speaker 2: in the at L twenty four the heights or orthometric
Speaker 2: heights best on the e g M O eight GID model.
Speaker 2: So those are you know, actual datam best heights, and
Speaker 2: then the pseudopythymmetry that's not those are just sort of
Speaker 2: relative values. But what I want to do is create
Speaker 2: a layer that has both of those together and so two. Uh,
Speaker 2: to do this, I'm going to go up to the
Speaker 2: processing toolbox. I'm gonna to go processing toolbox. I've already
Speaker 2: got this up. So in this search window for the
Speaker 2: processing toolbox, I'm going to search for clip raster by
Speaker 2: mass layer, clip raster by mass layer. And in this case, uh,
Speaker 2: my input layer is going to be let's see, I
Speaker 2: want to do uh, I want to do It looks
Speaker 2: like I made a mistake. I called the thing that
Speaker 2: I wanted to be set up with the matory actually
Speaker 2: called SDB. That should say PSDB. But that's okay. My
Speaker 2: input layer is going to be just my SDB layer,
Speaker 2: and my mask layer is going to be Wait, I'm sorry,
Speaker 2: I say what I've done. I've done the I've done
Speaker 2: the wrong tool here, the tool that I actually wanted. Sorry,
Speaker 2: back in this search box. The tool that I want
Speaker 2: here is the sample raster values. That's the one that
Speaker 2: I meant to bring up sample raster values. So my
Speaker 2: input layer is going to be my Hotel twenty four data.
Speaker 2: My raster letter layer is going to be SDB, and
Speaker 2: again I should have called that PSDB. I'm going to
Speaker 2: create an output column. I'm going to call that sample
Speaker 2: sample underscore PSDB and just go ahead and run that
Speaker 2: and I can close and that ran, and that created
Speaker 2: this layer called sampled, which now that has all the
Speaker 2: ATL twenty four heights and it also has the pseudopythymmetry.
Speaker 2: So at this point we're actually really close to being
Speaker 2: able to generate our final SDB layer. We just need
Speaker 2: to do a linear regression in order to calculate linear
Speaker 2: transformation coefficients that are going to allow us to transform
Speaker 2: or pseudo bythymmetry to actual withymetry. So to do this,
Speaker 2: there's a Python script. I'm going to go plug ins
Speaker 2: Python console and then open up the Python editor and
Speaker 2: there's the scripts that's for me already open. But if
Speaker 2: you don't have this open, you just want to click
Speaker 2: on the open script and want to browse and finds
Speaker 2: the scripts that was made available on the Trening website.
Speaker 2: It's the PSDB linear regression dot pile, and go ahead
Speaker 2: and open that up. That will open up the scripts.
Speaker 2: The only thing that you should actually have to change
Speaker 2: here is if you go down to this it's line seven,
Speaker 2: and you'll see this path to where the where that
Speaker 2: CSV file lives that you created. Again, that's the CSV
Speaker 2: file that we need, the one that has the ATL
Speaker 2: twenty four data in the pseudo bythymetry. You want to
Speaker 2: change that to your path and make sure you've got
Speaker 2: your slashes going in the right direction. And at that
Speaker 2: point you should just be able to hit this s
Speaker 2: green run script icon and hopefully this will run and okay.
Speaker 2: So that went ahead, and that finish running, and it
Speaker 2: gave me the scatter plot. So what I see here
Speaker 2: is on the x axis, those are my pseudo pythymmetry values.
Speaker 2: On the why I that's my I saw to bithymetry
Speaker 2: from ATL twenty four and then it fit a linear
Speaker 2: aggression line. The first thing I want to note in
Speaker 2: this case is that our our square value is actually
Speaker 2: fairly lost, so we've got an R squared of point
Speaker 2: five to four. Usually in my research group, we wouldn't
Speaker 2: move on with using this for bathymetry unless we had
Speaker 2: an R squared of about point seven or higher. The
Speaker 2: reason that I happen to know that this is okay
Speaker 2: in this case is if you'll remember that there was
Speaker 2: that step when we were in the slab real Web
Speaker 2: client and I said that we could have been a
Speaker 2: little bit more selective and just picking out exactly which
Speaker 2: tracks we wanted to download, but we didn't do that.
Speaker 2: We went ahead and just sort of grabbed everything. So
Speaker 2: I know, because I actually tried this, that if I'd
Speaker 2: spent a little more time in that step of grabbing
Speaker 2: just the tracks that I knew had the best bathymetry,
Speaker 2: and or if I'd done a little bit of cleanup afterwards,
Speaker 2: I could get a much better our square value here.
Speaker 2: But actually it doesn't really change the presameters of this
Speaker 2: linear transformation the sloping and intercept constant. So that's what
Speaker 2: we're really interested in here, So we're not going to
Speaker 2: worry too much about the kind of lowish R square.
Speaker 2: We just need these the values the sloping intercept constants.
Speaker 2: So at this point we are actually very close. Uh,
Speaker 2: this is a point where we're going to go back
Speaker 2: into raster calculator. Let me see if I can do
Speaker 2: it this way. I need to keep this scatter plot
Speaker 2: up because I need to be able to see these numbers.
Speaker 2: So I'm going to go back to raster calculator and
Speaker 2: what I'm basically going to do is I'm just going
Speaker 2: to apply a linear transformation that is going to transform
Speaker 2: my pseudo bythymmetry to actual byth inmetry. So I'm going
Speaker 2: to do an output layer. I will call this. I'll
Speaker 2: create a new folder here that's just going to be
Speaker 2: called sdb SDB, and I'll give this file a file name.
Speaker 2: And because I accidentally called the other one SDB, I'm
Speaker 2: going to call this one. I'll just do something like
Speaker 2: SDB final, SDB final dot tif and I'll say save.
Speaker 2: And now I'm going to create an equation to compute this,
Speaker 2: and it's going to be I'm just going to look
Speaker 2: over here. This is why I keet the scatter plot up.
Speaker 2: I want to look at uh at the two constants.
Speaker 2: So I'm going to do negative twenty five point eight
Speaker 2: five zero times SDB, which really again that should have
Speaker 2: been our pseudo athymetry minus oh, I'm sorry, not minus
Speaker 2: plus plus twenty one point five to three zero, where
Speaker 2: those two constants again are just from overhearing our scatter plot,
Speaker 2: I can say you okay, and it looked like that
Speaker 2: that one ahead ran. So I've got a layer that's
Speaker 2: now called sd be final. I do probably want to
Speaker 2: clip that to just our project site so we can
Speaker 2: and I can I can get rid of the Python
Speaker 2: script at this point, this is where I want to
Speaker 2: clip it. So this is the point where I actually
Speaker 2: want to do the tool that I started to show
Speaker 2: last time. I'm gonna do this clip raster by mass
Speaker 2: player and I'll do I'm going to clip SDB final
Speaker 2: and the mass Player is going to be the hynas
Speaker 2: AOI and just let that run. Oh oh, I guess
Speaker 2: it didn't select it. Try one more time. Run. Okay,
Speaker 2: that ran. Now I can get rid of this one
Speaker 2: and I can turn off that and that, and I've
Speaker 2: just got my final SDB layer and if I want
Speaker 2: to change the symbology, I can double click it. I
Speaker 2: can change from single band great to single band pseudo
Speaker 2: color and just pick out a color ramp. I kind
Speaker 2: of like this one. This one looks kind of like pytymetry.
Speaker 2: Go ahead and apply and close. And so now I've
Speaker 2: got a bathymetric DM for this project site. And that
Speaker 2: was created using the combination of I set two bathymetry
Speaker 2: from ATL twenty four and centaal two values. It looks
Speaker 2: pretty interesting. I can clearly see the dredge channel through there.
Speaker 2: I can see some of the deeper areas like in
Speaker 2: the anchor in the in the anchorage behind the breakwater.
Speaker 2: Over here, I can see some of the really shallow
Speaker 2: areas that are closer to shore. So everything looks pretty good.
Speaker 2: Uh So at this point, if I wanted to, if
Speaker 2: I were interested in in bathymetric change and kind of
Speaker 2: seeing how the pathymmetry in this site changes over time,
Speaker 2: I could just repeat that process using multiple dates, multiple
Speaker 2: epics of Sentinel two imagery and then I could do
Speaker 2: differences of the d ms or just sort of look
Speaker 2: visually at how pathymmetry in this area is changing over time.
Speaker 4: So that's it.
Speaker 2: That is the uh that's the end of the demo.
Speaker 2: But I just wanted to say thanks and if you
Speaker 2: want to reach me, my contact information is here, Christopher
Speaker 2: dot Parrish at Oregon State dot ADU.
Speaker 1: Thanks Chris, thank you for the excellent demonstration of ATL
Speaker 1: twenty four integration with Sentinel two and generation of mathymetric
Speaker 1: data layers. We will now transition to JP Swinsky, who
Speaker 1: will provide a demonstration of slide roll Python client. JP
Speaker 1: over to you.
Speaker 5: Great well, thank you.
Speaker 6: I'm going to be talking about slide rule worth again
Speaker 6: and just as a refresher from what we talked about
Speaker 6: a couple of days ago. Slide Rule is a public
Speaker 6: web service with rest like APIs for processing and accessing
Speaker 6: science data. And specifically what we're talking about here is
Speaker 6: accessing the ATL twenty four with inmetry data. Last time
Speaker 6: we talked about the web browser and I gave a
Speaker 6: demo of that web client. Today we're going to be
Speaker 6: talking about the Python client that typically runs inside a
Speaker 6: jubiterin notebook, and I'm going to be given an example
Speaker 6: of how to access to ATAIL twenty four data from
Speaker 6: a jubiteren notebook using the side rule Python client. Now
Speaker 6: before I do that, though, I want to just show
Speaker 6: our landing page of our website. So the Python client
Speaker 6: can be a little intimidating. It's not as easy to
Speaker 6: use as the web client, and so we provide a
Speaker 6: lot of documentation to go along with it to help
Speaker 6: to help you out, to help you get started. So
Speaker 6: if you navigate to side rule worth do io in
Speaker 6: your browser, find you'll come here. And the first thing
Speaker 6: I want to point out is this contact us page,
Speaker 6: so you should always feel free to reach out to us.
Speaker 6: Here's this email here goes directly to me. I'm always
Speaker 6: excited when users email us and we do our best
Speaker 6: to get back to you as soon as possible. You're
Speaker 6: also free for people a little bit more on the
Speaker 6: developer side, if you want to go to GitHub and
Speaker 6: open up an issue if you find anything wrong, or
Speaker 6: want to feature requests. And certainly we're an open source
Speaker 6: project and we invite collaborations, so you're also free to
Speaker 6: open pool requests and start discussions on features that you'd
Speaker 6: like to see. But now about the documentation. So clicking
Speaker 6: on the documentation link takes you to our documentation site
Speaker 6: and this is it here on the left. You can
Speaker 6: kind of walk through it in the order of which
Speaker 6: you would typically want to approach it if you're a
Speaker 6: new user. So getting started, the first thing you're going
Speaker 6: to want to do is know how to install the
Speaker 6: Python client, and this is instructions on how to install it.
Speaker 6: We support Conda and pie Pie. You can also directly
Speaker 6: install it from GitHub. Then we have a really short,
Speaker 6: the simple Hello World type Python program that can just
Speaker 6: get you started and make sure everything is installed correctly
Speaker 6: and you're running okay, and then we move into examples.
Speaker 5: I don't know about you, but I learned best from example.
Speaker 6: So here's some examples that we've put together, and the
Speaker 6: one we're actually gonna be going through today is this
Speaker 6: ATL twenty four example. But then as you progress you
Speaker 6: can go through the user's guide. You're gonna find out
Speaker 6: all the different parameters and APIs that are available. There's
Speaker 6: some more information for specific to ice at two right here,
Speaker 6: and then going down even further, we have our developer's guide.
Speaker 6: So if you're really interested in how this all works,
Speaker 6: we have a map of our project why we develop
Speaker 6: side rule. Here's an under the hood. So here's an
Speaker 6: eye chart on all the different components and an explanation
Speaker 6: of those. But just wanted to let you know this
Speaker 6: is where to go when you have questions about using
Speaker 6: the Python client. So now I'm going to switch over
Speaker 6: and actually look at our ATL twenty four example.
Speaker 5: So this is just check. I've checked out the repository.
Speaker 6: And I've opened it up in vs code, and so
Speaker 6: under the slide rule repo from GitHub, I go to
Speaker 6: clients Python examples, and then under the examples you'll find
Speaker 6: this notebook that I'm going to walk through right here.
Speaker 6: So I've set this all up, so I'm gonna just
Speaker 6: run through this out. So this is I'm importing the
Speaker 6: slide rule client into my kind of environment. Well, I
Speaker 6: should point out this file right here is all of
Speaker 6: the packages you need to run all of our examples.
Speaker 6: You don't have to use it, but if you're wondering, man,
Speaker 6: I wish I had a quick way to get all
Speaker 6: the dependencies.
Speaker 5: This is what you do.
Speaker 6: Okay, So now I'm going to initialize the client. You
Speaker 6: will find one difference here. I'm running against a private
Speaker 6: developers cluster. Just so I don't pound the public cluster.
Speaker 6: This organizational setting is absent in the in the version
Speaker 6: that is on our repository, and it would go right
Speaker 6: to the public cluster. Here are some helper functions. I'm
Speaker 6: not going to talk too much about those, but you'll
Speaker 6: see them being used. It's really just to plot the
Speaker 6: data that we get back from the server. So I
Speaker 6: have functions to plot ATAIL twenty four, ATAIL six, and
Speaker 6: atil oh three. And now I'm also going to define
Speaker 6: an area of interest. It's just on the north shore
Speaker 6: of the Dominican Republic. And this is There are many
Speaker 6: ways that you can find an area of interest using
Speaker 6: our Python client.
Speaker 5: This is the simplest.
Speaker 6: It's just creating a list of lat longs. You can
Speaker 6: also use Goojson and shape files. But I've done this
Speaker 6: this way here for clarity. So now if you just
Speaker 6: want I just you just want all the data ATAIL
Speaker 6: twenty four data in this area of interest. This is
Speaker 6: one line here you run it it's going to it
Speaker 6: says that there's one hundred and ten ATAIL twenty four
Speaker 6: granules that are intersect this area of interest.
Speaker 5: Ran in eight seconds.
Speaker 6: It processed all one hundred and ten of those granules
Speaker 6: in parallel on the server. So so just to talk
Speaker 6: through what's happening here, the Python client built a request
Speaker 6: when you hit this run, and it's sent that request
Speaker 6: to the server. The server is sending back status messages
Speaker 6: which we see displayed here, and then it sends back
Speaker 6: a data frame encoded as a geopark file that the
Speaker 6: Python client then opens up. And so that's all what
Speaker 6: happened right there. And now I'm just going to look
Speaker 6: at that data frame and has forty four thousand rows.
Speaker 6: That means it's got forty four thousandthymmetry photons. And these
Speaker 6: are the columns that come back by default when you
Speaker 6: just do a simple access of the ATL twenty four
Speaker 6: data so you'll see here that each photon has the
Speaker 6: same classification. It's all withymetry. This is an encoding for
Speaker 6: which groundtrack it is. This is the height of the surface,
Speaker 6: the rithmetric height of the surface. This is the reference groundtrack.
Speaker 6: If you know anything about ice A two, all of
Speaker 6: the tracks are labeled and so it's reference groundtracks seven
Speaker 6: to fifty eight. Here's the rithmetric height of each of
Speaker 6: these photons. So this has a depth of about twenty
Speaker 6: meters here, and here's the confidence level that the ATAIL
Speaker 6: twenty four algorithm assigned to it. This is which spot
Speaker 6: it was on the six spots of the ice AT
Speaker 6: two ATLAS instrument. Here's the along track coordinate, a cross
Speaker 6: track coordinate. And then this source ide is allows you
Speaker 6: to look up which granule the data came from. So
Speaker 6: embedded in the metadata of the geodata frame is a
Speaker 6: dictionary that links source IDs to granule names. And then lastly,
Speaker 6: this is which cycle the data was collected at. Oh,
Speaker 6: and we have the time and the lat long and
Speaker 6: if you're familiar with geodata frames, that this lat long.
Speaker 5: Isn't coorted as a point geometry.
Speaker 6: So let's plot this and see what it looks like. Okay,
Speaker 6: this is just a quick view of what it looks like.
Speaker 6: And so I can see here underneath where it's white,
Speaker 6: this is probably land. And then this is where we
Speaker 6: get a lot of good pathymetry near to the shore.
Speaker 6: And then the algorithm is doing its best to find
Speaker 6: bathymetry as it goes farther offshore.
Speaker 5: So this is a lot of data. Now let's say, you.
Speaker 6: Know what, there's actually a particular track that I'm interested in,
Speaker 6: and so I've preconstructed this. So now instead of pulling
Speaker 6: all of the data, I just want the ground track
Speaker 6: three the right beam. I want the reference groundtrack to
Speaker 6: be two two, and I want it to be from
Speaker 6: cycle twelve of the ICE two collection. So now let's
Speaker 6: run that. It's gonna the client's going to construct a request,
Speaker 6: send it out to the server. The server is going
Speaker 6: to process that request and send the data back in.
Speaker 6: It happened now in three seconds. So I'm gonna look
Speaker 6: at this data frame. And so now I've only got
Speaker 6: eight hundred and sixty one but THEMTRY photons. So this
Speaker 6: set of photons is a subset of this one up here,
Speaker 6: and the subset is defined by these parameters here the beam,
Speaker 6: the reference groundtrack, and the cycle.
Speaker 5: You can use others.
Speaker 6: You can include just one or include others that are
Speaker 6: in the data set, all of which are going to
Speaker 6: be explained in our documentation.
Speaker 5: Okay, so now let's plot this. Ah.
Speaker 6: Okay, so this is now a side view of the photons.
Speaker 5: Let's go back up here again.
Speaker 6: This is a top down view looking plotting them all
Speaker 6: of the bathymetry based on its lat long coordinate and
Speaker 6: kind of color coding it to show some depth. But
Speaker 6: now we're turning this on its side and looking at
Speaker 6: just one of the tracks, and we defined which one
Speaker 6: of those tracks are and we get this nice plot here.
Speaker 6: So this is a profile of the seafloor. Okay, So
Speaker 6: now I'm like, oh, I really like this. I want
Speaker 6: to I want to dig in and get more information
Speaker 6: about it. So now I'm going to do a detailed
Speaker 6: access of this single track, similar to what we talked
Speaker 6: about a couple of days ago with the web client.
Speaker 5: I'm turning the compact flag off so I get all
Speaker 5: of the data.
Speaker 6: I'm going to now say I don't want you to
Speaker 6: I don't want the server to threshold on confidence at all.
Speaker 6: Give me all of the bathymetry, even if it's very
Speaker 6: low confidence, and then give me all the different classifications.
Speaker 5: So let's run this.
Speaker 6: It's going to construct this request, it's going to send
Speaker 6: it to the server. Serve is going to respond with
Speaker 6: the results. And it just didn't. And now we have
Speaker 6: thirty five thousand photons. Again, the reason we have thirty
Speaker 6: five thousand photons. So now we have thirty five thousand photons.
Speaker 6: The reason we have thirty five thousand photons instead of
Speaker 6: the eight hundred some up here is because we're asking
Speaker 6: for all the photons, not just the bithymmetry. So we're
Speaker 6: getting a lot of sea surface and unclassified photons.
Speaker 5: So let's plot that.
Speaker 6: And here you see it, so you can see the
Speaker 6: gray is the unclassified. This looks like land, and then
Speaker 6: we come down there's a little drop to the ocean,
Speaker 6: and then we've got the sea surface in blue, and
Speaker 6: we've got that same track now in red in the
Speaker 6: context of the other photons.
Speaker 5: Let's look at this based on confidence.
Speaker 6: And you can see here we have a bunch of
Speaker 6: different confidence values spread throughout the bothymmetry being identified there. Okay,
Speaker 6: so again something that we talked about a couple of
Speaker 6: days ago was using the web client. We were able to,
Speaker 6: instead of going directly to a TAIL twenty four, go
Speaker 6: to ATL three and use ATL twenty four to classify it.
Speaker 6: So this is a more sophisticated request. The ATAIL twenty
Speaker 6: fours is run against the release six ATLO three, so
Speaker 6: I have to manually specify that in the request parameters.
Speaker 6: I'm going to ask for everything because this is an
Speaker 6: ATL three request. I'm gonna turn off any filtering based
Speaker 6: on its own confidence values, and I'm going to ask
Speaker 6: for the same beam reference, groundtrack, and cycle.
Speaker 5: So this is going to go out and grab that.
Speaker 5: And we got that there.
Speaker 6: And so now this is all of the ATLO three
Speaker 6: data classified with the.
Speaker 5: ATL twenty four.
Speaker 6: You notice it's a bigger area here, and there's more
Speaker 6: data data that wasn't used by the classifier because it
Speaker 6: was outside of a band considered outside of the band
Speaker 6: in which there'd be valid bathymetry. So that's why there's
Speaker 6: even more data. Now I'm ATLO three, But I also
Speaker 6: want to point out back up here, we're going to
Speaker 6: get different fields. So now we get what the spacecraft
Speaker 6: velocity was at each of these photons. We get what
Speaker 6: the solar elevation is. See, we get the background rate
Speaker 6: and we get the quality pH flags. These are all
Speaker 6: fields that come in the ATLO three product but do
Speaker 6: not come in the ATL twenty four product. So therefore,
Speaker 6: if you want those fields, this is an easy way
Speaker 6: to get that data and overlay.
Speaker 5: The ATL twenty four classifications. Okay, now.
Speaker 6: Let's combine some features of ATLO three and again combine
Speaker 6: it with ATL twenty four to do some filtering at
Speaker 6: the ATLO three level. So here I'm going to do
Speaker 6: the same request as before, except I'm going to do
Speaker 6: two new filters. I'm gonna say, only give me ATLO
Speaker 6: three that has a high confidence.
Speaker 5: According to the ATLO three algorithm.
Speaker 6: And the ATLO three has this classifier called yapsy, yet
Speaker 6: another photon classifier which gives us score based on the
Speaker 6: local density of the photon how many photons are near it.
Speaker 6: And so I'm gonna say, only give me photons that
Speaker 6: have a high density. So this is saying filter the
Speaker 6: ATIL of three with these parameters and then overlay the
Speaker 6: ATL twenty four classifications. And so we run that request
Speaker 6: and we get the data back. Took a little bit longer,
Speaker 6: A second longer because it's it had to do some
Speaker 6: more processing with the A and the confidence filtering, and
Speaker 6: now we have much less photons than before, and we see, interestingly,
Speaker 6: we see some gaps here now where there were photons
Speaker 6: that were filtered out by the ETL three filtering but
Speaker 6: were classified by ATL twenty four. And we do see
Speaker 6: though some more photons that were classified by ATL twenty four.
Speaker 6: And then it cleans up all of this, all of
Speaker 6: the photons if you look back up here, all of
Speaker 6: this stuff that was obviously not a surface reflection. Some
Speaker 6: of these filters very quickly cleaned up all of that.
Speaker 6: And here we're now taking the same plot and we're
Speaker 6: overlaying color coding it with the yapsy score, so you
Speaker 6: can see what the aapsy score is of some of
Speaker 6: these photons that were identified as bothymetry. Okay, so here
Speaker 6: is now a final step to this process of using
Speaker 6: ATLO three, and that is we're going to take ATLO
Speaker 6: three data, we're going to classify it with ATL twenty
Speaker 6: four data, then we're going to specify to only use
Speaker 6: the bathymetry photons, and then we're going to run the
Speaker 6: ATLO six surface surface finding algorithm on it to produce
Speaker 6: an aggregated surface elevation of the bothymmetry photons. And we're
Speaker 6: all going to do that on the server making this
Speaker 6: request here. So this request is constructed. You can see
Speaker 6: I talked through what it's doing, and this is the
Speaker 6: magic to tell the server to use the ATL three
Speaker 6: surface finding algorithm. And so it ran. It took three
Speaker 6: seconds to run. And now this is the this is
Speaker 6: the data. We're going to get different fields in this
Speaker 6: data set because it's this is really now like an
Speaker 6: ATLO six product, but we've fooled it by giving it
Speaker 6: bathymetry instead of land ice elevator photons. So we get
Speaker 6: you know, number of fit photons, we get the surface window,
Speaker 6: we get the misfit, the armist of the misfit, we
Speaker 6: get the slope here.
Speaker 5: And so forth.
Speaker 6: Okay, so now let's plot this and we get a
Speaker 6: very nice smooth return of this of the seafloor. Now
Speaker 6: again you may say, well, there's some things here that
Speaker 6: that aren't right. You can go back and tweak the
Speaker 6: parameters here and say, oh, you know what, let me
Speaker 6: get rid of low confidence photons, or let me do
Speaker 6: an atail twenty four confidence level.
Speaker 5: That's that's higher.
Speaker 6: I only want the really high confidence photons based on
Speaker 6: ATAIL twenty four and you and you can tweak that
Speaker 6: to get a very clean But even just with these parameters,
Speaker 6: we've gotten a very clean surface that's easy to work
Speaker 6: with and is only a handful right eighty one. Right,
Speaker 6: this this data set represents the same surface, but as
Speaker 6: much smaller and easier to work with.
Speaker 5: And then, lastly, for.
Speaker 6: Power users that you just want access to the raw data,
Speaker 6: here's a request that does some different filters, just based
Speaker 6: on ATAIL twenty four. So again, now we've moved past
Speaker 6: the talking about the ATAIL of three. We're back to
Speaker 6: talking about ATL twenty four and some of the more
Speaker 6: corner case features that we support this set. Here, I've
Speaker 6: just chosen to turn off the low confidence filter. You
Speaker 6: could turn on a night filter. Say you want, say
Speaker 6: you have an area of interest and you're just interested
Speaker 6: in pathymetry that was collected at night, Well you could
Speaker 6: turn this on and then we'll only return pothymetry accepted.
Speaker 5: That was collected at night.
Speaker 6: Or there's we have a calculation of what the maximum
Speaker 6: sensor depth is for the Atlas instrument when measuring bothymmetry.
Speaker 6: Sometimes we get we think the algorithm will find bothymmetry
Speaker 6: beyond that sensor death. But if you want to just
Speaker 6: reject all of that, you can turn this one and say,
Speaker 6: if the sensor depth is exceeded, turn it to false,
Speaker 6: and that way you'll only get photons in which the
Speaker 6: sensor depth is not exceeded. So let's take a look
Speaker 6: at this and you'll see now fewer photons because we've
Speaker 6: done some filtering here.
Speaker 5: Just for completeness, I'll plot that there. Now. Lastly, an exciting.
Speaker 6: Feature that we've just added is the ability to directly
Speaker 6: query for AHL twenty four resources from the client, just
Speaker 6: hitting the Python, just hitting.
Speaker 5: The slide rule servers.
Speaker 6: So these are requests that do not use CMR in
Speaker 6: order to querry ATL twenty four resources, and therefore we
Speaker 6: expose some additional query parameters.
Speaker 5: So here is an area of interest. I'm gonna build a.
Speaker 6: Polygon string from that, and now I'm gonna make a
Speaker 6: request for retail twenty four granules with this polygon, and
Speaker 6: I'm gonna say I want the maximum. I want to
Speaker 6: have a maximum mean depth of ten meters. So nothing
Speaker 6: should have a max a mean depth of greater than
Speaker 6: ten meters, so only mean depths for granules less than
Speaker 6: ten meters, and I only want granules that are collected
Speaker 6: in the fall. So there's an encoding for which season.
Speaker 6: Winter is zero, spring is one. Actually, this is the
Speaker 6: that wrong, this is the this is the summer. I
Speaker 6: only want to collect in the summer. Summer's two and
Speaker 6: the fall is three. So I'll run this request. It's
Speaker 6: gonna go out to the servers. It's gonna make that query.
Speaker 6: And now this is all of the granules, have found
Speaker 6: fifty three tracks, and it's returning the granule names with
Speaker 6: the beam that meets this criteria, have.
Speaker 5: Mean depth, mind depth, max depth season.
Speaker 6: We have the number of bathymetric photons and a few
Speaker 6: other things that you can look at. And then also
Speaker 6: now if you want more information about a granule itself,
Speaker 6: we have an API that allows you to say, give
Speaker 6: me information just about this granule. And so we'll run that.
Speaker 6: It went out very quickly, ran out. It made a
Speaker 6: request to the server of the server queried our own
Speaker 6: database and said, okay, for this granule here it has
Speaker 6: these beams. This beam was collected in the summer. Oh,
Speaker 6: there's no bothymetry in any in that beam okay, beam
Speaker 6: three it was collected in the summer, had four photons
Speaker 6: and this was the mean depth, mind depth and max
Speaker 6: depth for that and so forth.
Speaker 1: Thank you, JP. Great demonstration for participates wanting to explore
Speaker 1: the slide roll Python client. Next, we'll hear from Gretchen
Speaker 1: and Kana, who will present on Noah's Satpathy tool and
Speaker 1: integration of NASA's ATL twenty four product. Gretchen and Kiana
Speaker 1: over to you.
Speaker 7: Thank you pretty much.
Speaker 4: We're very excited to talk about our work today on
Speaker 4: noah Stat Value Tool and the integration of NASA's ATL
Speaker 4: twenty four. To begin with, we're going to give a
Speaker 4: little background talk about sat baby and what SDB is
Speaker 4: and its importance, and then give a few examples from
Speaker 4: our SAT value desktop tool. I'll run through a quick
Speaker 4: demo and then pass that off to Canna to talk
Speaker 4: about our ATL ATL twenty four integration and her demo,
Speaker 4: and then if we have time, we'll talk about the
Speaker 4: future of sapathy. So, Noah Stat BATHI Testktop Tool version
Speaker 4: three point one is now official. This is the interface.
Speaker 4: The whole purpose of the value tool is to automate
Speaker 4: the creation of satellite dry bythymmetry. And I should say
Speaker 4: that this desktop tool is for Noah internal use only
Speaker 4: at this point, but I will talk about the future.
Speaker 4: So for those that did not catch Chris Parrish's talk
Speaker 4: in the morning, Satellite dry pathymmetry or SDB is an
Speaker 4: indirect method of bathometric measurement. And while it is not
Speaker 4: the most direct compared to multibede sonar and vathametric lighter,
Speaker 4: SDB is more direct than the gravity based pythymmetry. But
Speaker 4: given that, why do we care about STAB? The example
Speaker 4: on the left or the right give a good example
Speaker 4: of why it's important. The top right image is the
Speaker 4: batometric lighter example from our group and wrote sunsing division
Speaker 4: in the National g JIC Survey, and this is a
Speaker 4: saint shows if you look at the lower SDB example
Speaker 4: that doctor Rick Stump created, it fills in the gaps
Speaker 4: of the bathymetric lighter. So there are some uses for him.
Speaker 4: But what is Sallee drieth inventary in detail? For our
Speaker 4: purposes today and sat pathy, we use the method of
Speaker 4: using sentinel two resolution of ten meters and updated research
Speaker 4: from doctor Rick Stump and doctor Isabel Camelero and I
Speaker 4: should note that all SDBA methods can be grouped into
Speaker 4: three method major character categories. The first one is spectral
Speaker 4: SDP special radiance for example, radio transfer equation or RTE optimization,
Speaker 4: RTE empirical and VAN ratio. The second is photochrometric and
Speaker 4: the wave and the third is wave kinematics. For our
Speaker 4: purposes today, we're going to focus on the band ratio approach,
Speaker 4: which is based on a relationship between reflectance and depth
Speaker 4: and it often requires but not always, which I'll explain
Speaker 4: a little bit when we talk about our simplified calibration
Speaker 4: requires a known dep depth data to calibrate the composed
Speaker 4: compositing approach for the data. The compositing approach for the
Speaker 4: Van ratio solution inherently removes a lot of the faulty data.
Speaker 4: So we're asked a lot of times is why do
Speaker 4: we need u s dB for our purposes at NAWA,
Speaker 4: it's for intermonautical chart updates, hydrographic survey planning and reconnaissance
Speaker 4: change analysis, and to fill in atometric glider caps in
Speaker 4: non navigationally stigific areas. And then image below as an
Speaker 4: example from our NOAH chart. These areas of unsurveyed locations
Speaker 4: still exist in areas like Alaska, but I'm going to
Speaker 4: focus on the hydrographic survey planning in Wisconsin. The reason
Speaker 4: i SDB is so important, as we've been using it
Speaker 4: quite a bit, is it's become a vicious cycle where
Speaker 4: hydrographic survey data sometimes doesn't exist. We need the data,
Speaker 4: then the hydro data. The hydro vessels need to collect
Speaker 4: the data. However, if they're an area where there isn't
Speaker 4: any data to operate safely, it becomes very dangerous. This
Speaker 4: is where SDB is very has become very important to
Speaker 4: provide some amount of data so the surveys can be
Speaker 4: as safe as possible. So my first example is of
Speaker 4: Saint Matthew's. Saint Matthews is off of in Alaska, off
Speaker 4: the coast, and the e n C or Electronic Navigation chart.
Speaker 4: While it does.
Speaker 7: Show some areas where there are rocks and areas of.
Speaker 4: Danger, where to the a survey of vessel like the
Speaker 4: Fairweather need to stay away from.
Speaker 7: We were asked when the nose ship.
Speaker 4: Fairweather had to survey this area, we could run the
Speaker 4: sad bady tool to provide reconnaissance data. The pseudopathymetry read
Speaker 4: examples on the left and it shows some areas that
Speaker 4: are not captured in the E n C current chart.
Speaker 4: This helps keep the noise ship fair weather safe to
Speaker 4: the best extent possible. Another example is in Kotsubu, Alaska.
Speaker 4: That's in the northern part of Alaska, and if you
Speaker 4: can take a look at the E and C on
Speaker 4: the left, there's a lot of gray areas that basically
Speaker 4: says there are no charted depths here, So you're basically
Speaker 4: working blind when you're serving in this area.
Speaker 7: Very dangerous.
Speaker 4: Again, we were asked to run the sad Bady tool
Speaker 4: and to provide data that would provide some information on
Speaker 4: the thethymmetry. What we found was not just the thethymmetry,
Speaker 4: but channels, multiple channels, two channels to show where they
Speaker 4: can navigate somewhat safely. So the next I'm going to
Speaker 4: run into the sat patty dust optimum. So this is
Speaker 4: the the sat patty desktop tool interface, and I'm going
Speaker 4: to zoom in on our area of interest, which should
Speaker 4: be around the area of Miami.
Speaker 7: Each of these.
Speaker 4: Squares are the set of two tiles, and I will
Speaker 4: select the tile that I'm interested in and zoom in
Speaker 4: further intro and the area of interest. You can also
Speaker 4: provide an AOI that's a ZIP shape pile, and then
Speaker 4: I'm going to select the project directory. Next, we're going
Speaker 4: to figure out what start date we want. So for
Speaker 4: the Miami area it's relatively clear in Florida most of
Speaker 4: the year, except when there's hurricanes. We're going to go
Speaker 4: up to January to January first, and we'll do it
Speaker 4: in data a couple of weeks earlier. For the cloud cover,
Speaker 4: we'll just leave it as default as twenty percent. You
Speaker 4: can move it to eight, ten percent or less cloud shadows.
Speaker 4: We'll talk a little bit about that as we're processing
Speaker 4: some of the data. It's no and nice you don't
Speaker 4: have to worry about. And I'll show example of the
Speaker 4: no data cover what I mean by that. It's now
Speaker 4: we're set. We're going to search for the imagery. The
Speaker 4: little dial shows that it's searching, and while we're doing that,
Speaker 4: I'm going to talk a little bit about well, it's
Speaker 4: already finished. Actually, let's look at our search results.
Speaker 7: It was pretty clear.
Speaker 4: So this is what it looks like after the imagery
Speaker 4: is run through, and we can go through and select
Speaker 4: which ones are the least turbid have the least amount
Speaker 4: of clouds. This is quite a bit turbid, so we
Speaker 4: don't want to use something like that. We don't want
Speaker 4: to use the stuff with all the clouds. I'll explain
Speaker 4: a little bit more about them. I'm going to go
Speaker 4: back to the first one. This looks pretty clear compared
Speaker 4: to this one looks pretty turbid still in this area, So.
Speaker 7: I hadn't selected.
Speaker 4: In a perfect world, if we had more time, we
Speaker 4: would select ideally six to eight images to create the composite.
Speaker 7: And I'll talk a little bit more about that.
Speaker 4: But the interesting time one was going to select one
Speaker 4: and then I'm going to submit the scenes. The SAT
Speaker 4: value workflow and composite product procedure for a given area
Speaker 4: interest or AOI Multiple sentinel two alwe scenes are collected
Speaker 4: and atmospherically corrected to remote sensing reflectance or RSS. Red, green,
Speaker 4: and blue bands are used as inputs to the band
Speaker 4: ratio models PSDB red and PSTV green which stands for
Speaker 4: pseudo STP. In addition, turbidity proxies are specified in the
Speaker 4: red edge seven O four band and the OC three
Speaker 4: based chlorophylla A product. So this is the PSD red
Speaker 4: in the psd green, so the red edge For each scene,
Speaker 4: individual pseudopithymmetry layers are generated and then composited along the
Speaker 4: temple dimension by selecting the maximum PSTV value per pixel
Speaker 4: representing the deepest least turbid observation. The temporal index of
Speaker 4: this maximum pseudo SDP is recorded and applied to extract
Speaker 4: corresponding values from the red edge and chlorophyl a letters,
Speaker 4: producing composite turbity turbidity peroxy maps. These composite products provide
Speaker 4: context for any residual tibidity and service inputs to the
Speaker 4: subsequent steps within the SAP value processing cheap. As they
Speaker 4: spoke about before, when you're selecting imagery, there are free
Speaker 4: things you need to take into consideration. We want low turbidity.
Speaker 4: When there's turbidity in the water column, the calculated DUFF
Speaker 4: is going to be more shallow than the actual value,
Speaker 4: so that's important to know. They also want little or
Speaker 4: no sunland sunglint, or the reflection of the sun off
Speaker 4: the water surface obscures the ability of the satellite sensor
Speaker 4: to properly capture reflectance and then see little or no
Speaker 4: little or no shadows due to clouds. Those are the
Speaker 4: stark areas here, shadows cast by clouds obscure the finalized
Speaker 4: DEBA product by goverestimating death values and then d little
Speaker 4: or no clouds. In the AOI we talked a little
Speaker 4: bit about that the presence of clouds also affects the
Speaker 4: final STV results by underestimating death values. Snow and ice.
Speaker 4: There's another one, little or no snow and ice. Snow
Speaker 4: and ice on or near the shore line affects the
Speaker 4: final STV results and also underestimates the death results. So
Speaker 4: I'm going to see if it's ready and it is
Speaker 4: process is incomplete. Take a look at our map results.
Speaker 4: As you can see there is our items take off.
Speaker 7: Some of these a little easier to see. So this
Speaker 7: is the s the.
Speaker 4: PSP red, and the PSDB green. We're going to focus
Speaker 4: on the PSDB red first. So now I'm going to
Speaker 4: walk into the walkay through the simplified calibration procedure. I
Speaker 4: think that there we go, so Stafady's simplified calibration procedure.
Speaker 4: As you recall I said, you normally need the charted
Speaker 4: soundings or reference survey to help tie the the PSDB
Speaker 4: down to to have actual UH true drops and meters.
Speaker 4: So we're going to convert the pseudo SDB drive from
Speaker 4: spectral ratios into true drops intometers. This option is beneficial
Speaker 4: for areas where we can't we don't have reconnaissance, or
Speaker 4: we lack recent high quality reference data. And the relationship
Speaker 4: is defined by PSDB red I'm sorry. SDB equals m one,
Speaker 4: which is the slope times PSDB e minus m not
Speaker 4: which is the offset here, where M one represents the
Speaker 4: slope and m not represents the offset. Okay, all right,
Speaker 4: so the next thing I'm going to talk about it
Speaker 4: is the offset parameter or I'm not just a side,
Speaker 4: I'm here. The offset parameter is selected by sampling a
Speaker 4: near ship pixel of the landwater interface, which serves as
Speaker 4: an approximate local data. It represents the PSD value at
Speaker 4: depth of zero and serves this initial reference point for
Speaker 4: the relationship between PSDB and water depth. When tidal information
Speaker 4: is available, the offset parameter can be further refined with
Speaker 4: a well with a known vertical reference such as local
Speaker 4: sea level. Okay, so we're going to take the magnifying
Speaker 4: glass to hover over these area along the shoreline. We'll
Speaker 4: see these values here will change through our research we
Speaker 4: know that the PSDB offset range is between point nine
Speaker 4: three and one point zero three ahead towards the interior,
Speaker 4: not the channel. See if we can find something, looks
Speaker 4: pretty good.
Speaker 7: Okay.
Speaker 4: So they now that I've clicked the offset, it fills
Speaker 4: in automatically. We're going to do the same thing for
Speaker 4: the PSDB green. Put this down to PSD green. You
Speaker 4: can usually pick the same from the same areas. The
Speaker 4: range the research for the PSB green offset is between
Speaker 4: point eight five.
Speaker 7: And point nine five.
Speaker 4: See that looks pretty good, okay. So now that's filled
Speaker 4: into the offset, so point nine to eight. We're going
Speaker 4: to go ahead and submit the parameters zum out a
Speaker 4: little bit.
Speaker 8: Okay, so a little bit more slow parameters M one.
Speaker 8: The slope M one value is roughily indicative of how
Speaker 8: strongly light it tenuates with depth in the water column.
Speaker 8: Higher tenuation, for example, more turbid or scattering waters requires
Speaker 8: a steeper slope, while lower tenuation and clear water corresponds
Speaker 8: to a short, shallower slope. An initial value is provided
Speaker 8: based on the mean of slope estimates reported by publications
Speaker 8: from doctor Rick Stump and doctor Isabel cabell Aro, which
Speaker 8: drive the calibration parameters to the regression with reference slid
Speaker 8: our data sets and or charted sellings.
Speaker 7: Go ahead and something.
Speaker 4: Because the optical properties and water clarity can read very regionally,
Speaker 4: users can fine tune the slope in plus or mine
Speaker 4: plus or minus five percent increments to better match local
Speaker 4: water conditions. Adjustment is constrained within specific ranges where the
Speaker 4: PSDB red is between four point eight eight and sixty
Speaker 4: point five and SDB green is between forty two point
Speaker 4: seven and eighty eight point four five. Supporting tubidity indicate
Speaker 4: caters such as the seven O four reddit good band,
Speaker 4: which is here in our those literary products.
Speaker 7: There we go. So that's the red edge. This is
Speaker 7: our chlorophyll. Oops, there we go. Red edge in chlorophyll.
Speaker 4: Can guide this adjustment by providing context on prevailing water quality,
Speaker 4: for example clear, moderately turbid or extremely turbid. Okay, so
Speaker 4: now that we have that, we're gonna we'll now have
Speaker 4: the We should now have the STB red and the
Speaker 4: SDV green players not available. Okay, so now you'd want
Speaker 4: to do a quick check of the SDB red make
Speaker 4: sure there's no negative values.
Speaker 7: It's pretty good.
Speaker 4: We're going to just stick to the shore between zero
Speaker 4: and five because that's really SDB red generally where the
Speaker 4: limits are and it works the best. And then the
Speaker 4: green we're going to do the same thing. Everything from
Speaker 4: probably about five meters to on should be in the
Speaker 4: positive reade. You just want to do a double check.
Speaker 4: That looks pretty good, Okay, So that's the firstness we'll
Speaker 4: check on that. So the area in Miami has basically
Speaker 4: a low tithe that is optimal first as satpathy. So
Speaker 4: in this side, I'm going to talk about the importance
Speaker 4: of tides and macro and macro tidal areas. These red
Speaker 4: points that we created represent the tie aid stations and
Speaker 4: their values are calculated through NOASV data tooled by subtracting
Speaker 4: the mean mobile water value from the mean high water
Speaker 4: value for that station. The difference between the two value
Speaker 4: represents the tide range of that location. If the tide
Speaker 4: range is a meter or less, it simplifies things for sappathy.
Speaker 4: This means and what is case dependent and general tide
Speaker 4: adjustment is not necessary because it falls within the vertical
Speaker 4: uncertainty of STB generated through satpathy. When the tide range
Speaker 4: is larger than one meter, locations require a tide adjustine
Speaker 4: because the potential difference between the title stages exceeds inherent
Speaker 4: uncertainty of SAP badie. We'll talk more about this when
Speaker 4: we discuss the time model.
Speaker 7: I'm going to go back to.
Speaker 3: Our tool.
Speaker 4: And to select the different options. I'm going to add
Speaker 4: the reference data. That's another way to kind of see
Speaker 4: if we're in the ballpark. So this is remote sensing,
Speaker 4: our Remote Senstensing Division Topo Batty data under the National
Speaker 4: Genetic Survey, and that.
Speaker 7: Will show up when I select.
Speaker 3: There we go.
Speaker 4: So let me take off our interim products so you
Speaker 4: can see this. So this is a little snippet of
Speaker 4: our data reference data.
Speaker 7: I'm gonna expand this.
Speaker 4: Because okay, so the SDB red, so the auxilliary grid
Speaker 4: the values are shown here. That's for the reference data.
Speaker 4: And I'm gonna flip this s t BE red and
Speaker 4: as they move across to see that the numbers change.
Speaker 4: So I'm gonna stick to probably close to the shore.
Speaker 4: I'm just gonna run around and see how close we are,
Speaker 4: so we don't anything like a half a meters between
Speaker 4: is okay that's roughly okay, Okay, we'll do the same
Speaker 4: thing for the SDB green. Oops again, we're gonna go
Speaker 4: a little farther out for the green. We do sometime
Speaker 4: after five meters. We're just doing a cursory glance here,
Speaker 4: all right, So those values look generally okay, We're go ahead,
Speaker 4: and you can always come back and adjust it again,
Speaker 4: but we're going to go ahead and submit those parameters.
Speaker 4: So before I hand this over to Kenna, I'm gonna
Speaker 4: talk about our motivation at Noah for integrating the ATL
Speaker 4: twenty four into SATPATHI first, also an entirely independent reference
Speaker 4: data source.
Speaker 7: It's near global coastal.
Speaker 4: Coverage is ideal for US well. It has a maximum
Speaker 4: depth ranges which are generally quite comparable to one seci
Speaker 4: up and occasionally slightly deeper and are The ATL twenty
Speaker 4: four actually tests confirm and stability for STB calibration and melidation. So,
Speaker 4: like I was talking about with the the future of
Speaker 4: SAP ABBY, the reason why we're interested in things like
Speaker 4: near global coastal coverage is because we were asked to
Speaker 4: expand the sat AALBI, to not just create a themetry
Speaker 4: just for United States, but to go globally, to work
Speaker 4: with our federal partners and with cost survey, so the
Speaker 4: global coverage is very advantageous, as well as the accuracy
Speaker 4: tests to make us assured that we're using reference data
Speaker 4: that's suitable. So that's a really incredible option and we
Speaker 4: are working on Although the desktop tool is just available
Speaker 4: for Noah at this point, there is a public site
Speaker 4: that's going to be that's in work now that's going
Speaker 4: to take advantage of the A TALE twenty four. So
Speaker 4: we'll talk about that hopefully in another presentation. Now i'd
Speaker 4: like to pass this off to Canon to talk about
Speaker 4: her ATL twenty four demo, and yeah, thank you Canon,
Speaker 4: Thank you Gretchen.
Speaker 9: So we get ATL twenty four data in side role
Speaker 9: using side rules Python API, which allows us to request
Speaker 9: granule data from October twenty eighteen to November twenty twenty four,
Speaker 9: when release one of ATL twenty four was published. In
Speaker 9: satbathy we use a greater confidence threshold than the default
Speaker 9: value of zero point six, and this is to prevent
Speaker 9: some false pathymetry that occurs, especially around the SA surface,
Speaker 9: where the bottom of the sea surface can get falsely
Speaker 9: identified as pathymetry. The ATL twenty four implementation takes the
Speaker 9: satellite derived bathymetry photon data and then it regrids that
Speaker 9: photon data into a ten meter resolution raster to match
Speaker 9: the resolution of satbathy. This is to make it easy
Speaker 9: for use with Brian Eaters valalidation code, which produces air
Speaker 9: analysis heat scatters and histogram plots for SDB red, SDB green,
Speaker 9: and SDB merged. These values can be used to validate
Speaker 9: results or can be used to recalibrate the shoreline. If
Speaker 9: we go to an example here, I have set up
Speaker 9: a sat bathy run that is very similar to what
Speaker 9: Gretchen showed us just a moment ago. I've got a
Speaker 9: similar area of interest selected. I've gone through the tile
Speaker 9: selection and calibration steps, and so now all you need
Speaker 9: to do to get ATL twenty four products is check
Speaker 9: this ATL twenty four comparison checkbox before you click create
Speaker 9: final Products. If you look at the terminal while this
Speaker 9: is happening, you'll see the request to satbathy start to generate.
Speaker 9: It's going to return photons in a random temporal order,
Speaker 9: just due to the nature of how side rule gathers
Speaker 9: the data, So we do a sort on that data
Speaker 9: from oldest to newest. That way, if a photon shares
Speaker 9: a pixel in the final raster. It'll use the newest
Speaker 9: photon to generate that pixel's value. This can take a
Speaker 9: moment to process, so I will just go and take
Speaker 9: us to an already completed folder. So to get to
Speaker 9: your data, you're going to go into your output folder.
Speaker 9: You're going to go into the prod folder and into
Speaker 9: the ATL twenty four sub folder. In here you're going
Speaker 9: to see the aristatistics, heat scatter and histogram results for
Speaker 9: your SDB green, SDB merged, and SDB red. You're also
Speaker 9: going to have a data subfolder, and in here will
Speaker 9: both be the ATL twenty four dot TIF raster that
Speaker 9: we use in satbathy, but also a CSB file that
Speaker 9: contains all the photon data retrieved for this request. That way,
Speaker 9: because it is slightly lossy to generate the raster, you
Speaker 9: can access all of the ATL twenty four data, including
Speaker 9: any of those photons that didn't make it into the
Speaker 9: final raster. This ATIL twenty four TIF, for example, can
Speaker 9: be used to pull it into qgis. I've already loaded
Speaker 9: the data just by taking the file and dragging and
Speaker 9: dropping it onto qgis with a base map already loaded in,
Speaker 9: and then I've set the colors to go from shallow,
Speaker 9: which is a yellow color, to a darker color in purple,
Speaker 9: and we can zoom in and see these lines. Here
Speaker 9: are our granule tracks that relate to the photon data
Speaker 9: that we've returned. Just an example of what this output
Speaker 9: file looks like. We'll go ahead and look at the
Speaker 9: merged values. So in merged we have air statistics, and
Speaker 9: so this will give you the median absolute air, the
Speaker 9: mean absolute air, the bias, and then the number of
Speaker 9: photons relating to that bin that we've done for the statistics.
Speaker 9: So from zero to ten meters, the bins are in
Speaker 9: two meter increments, and then from ten meters onward the
Speaker 9: bins are in five meter increments, just because in those
Speaker 9: deeper values you can see like ten six and one
Speaker 9: photon returns, the returns just get smaller. This is an
Speaker 9: example of what the heat scattering looks like. On the
Speaker 9: y axis, we have the reference data set, which in
Speaker 9: this case is ATL twenty four, and on the X
Speaker 9: axis we have SDB merged, which is the SDB merged
Speaker 9: results from our satbaty run. As we can see, there's
Speaker 9: fairly good correlation on this one to one axis, which
Speaker 9: generally means that the ATL twenty four data is validating
Speaker 9: the results from Sabbath and then we can look into
Speaker 9: these histograms that give us an idea of how the
Speaker 9: photon spread is within those bins. Alrighty, and then that's
Speaker 9: my person and I'll pass it back to Gretchen.
Speaker 4: All right, So thank you Kenna. Now I'm gonna give
Speaker 4: some major updates for tak a little bout our major
Speaker 4: updates for the SATPADI desk top version three point one. So,
Speaker 4: as Kana mentioned, we have the validation code that should
Speaker 4: be ready to show you and our actual data. So
Speaker 4: I'm gonna that's in our validation folder and we can
Speaker 4: see how we did. Let's take a look at the
Speaker 4: sv merged heat scatter PT this.
Speaker 7: Okay, so this looks pretty good.
Speaker 4: This is the generally from like I said, the zero
Speaker 4: to four is the SDB red so they get merged.
Speaker 4: The green STB, which is from about five meters to
Speaker 4: looks like it's about a little over eight. So this
Speaker 4: aligns pretty well. The reference data is not we used
Speaker 4: was again our remote sensing division to a badly lighter
Speaker 4: under the nest g n X survey. And Noah, we
Speaker 4: have a lot more data compared to the ATL twenty four,
Speaker 4: but so you can see a lot of more data points,
Speaker 4: which is nice.
Speaker 7: So it looks like it lined up pretty well.
Speaker 4: So the items, the the values we picked looked like
Speaker 4: it was on. But if it is a little off,
Speaker 4: you would do adjustment in the in the tool, you
Speaker 4: can use the multiplier. Let's say the greening was a
Speaker 4: little the dark spot was a little below that line,
Speaker 4: you would to the adjustment for the green here down here,
Speaker 4: and we probably do the minus and and you can
Speaker 4: always go back. That's the nice ability of the tools
Speaker 4: to be able to like adjust and recreate the products.
Speaker 7: It's a nice manifit.
Speaker 4: Okay, I go back to So that's and then can
Speaker 4: I already talked about the histogram and the aero statistics.
Speaker 4: I won't go over that, but it's very similar.
Speaker 7: And then.
Speaker 4: I'll talk a little bit about the tide module is
Speaker 4: I spoke about earlier. For areas like Miami and Hatteras,
Speaker 4: those are below one meter tied our water level. But
Speaker 4: for areas in Alaska that we've been working quite a bit,
Speaker 4: sometimes it can be five meters. So in these cases,
Speaker 4: in other areas where we don't have information on tide
Speaker 4: we can use the on datum SDB composite product using
Speaker 4: the Vizio tide model. So the workflows as follows. We
Speaker 4: extract a sentinel two scene gradual sensing time, query the
Speaker 4: tide model at each x y t point, create gridded
Speaker 4: water level rasters at local means level, and composite the
Speaker 4: water level of rasters according to maximum PSD RAD or green,
Speaker 4: and then finally we adjust the calibrated sd B red
Speaker 4: or SDB green products using the water level grid composite.
Speaker 4: The examples that we have to the right are for Hatterus.
Speaker 4: That's one of our test regular test locations to make sure.
Speaker 7: Everything was working correctly.
Speaker 4: Normally, we already know what the tides are for Hatteras,
Speaker 4: but for places outside that don't or uh maybe globally
Speaker 4: that we may not know is that will be very helpful.
Speaker 7: And there is plans to update to the most recent
Speaker 7: of the ZIO.
Speaker 4: So going back to where everything is, if you want
Speaker 4: to access that, that's in the SDB UH composites folder.
Speaker 4: So if you see the local mean sea level and
Speaker 4: at the beginning of the tiff and the water level,
Speaker 4: I have that already up along with the final project
Speaker 4: SDB merged, so this is the SDB merged this is
Speaker 4: indicates deeper water.
Speaker 7: Here and then.
Speaker 4: The tie module local mean Sea level adjusted. That is
Speaker 4: the product for my the MIAMI so resources going forward
Speaker 4: for folks that are looking for more information on sat
Speaker 4: pavvy and actually the research that all went into it.
Speaker 4: These are papers from doctor Cabellero and doctor Rick Stump,
Speaker 4: and I really like to do a special thanks to
Speaker 4: the SAUT Valley team, especially Brian Atter who has been
Speaker 4: a huge help for all their continued support, and thanks
Speaker 4: to NASA for allowing us to do this presentation and training.
Speaker 1: Thank you Gretchen and Keana for the terrific presentation and
Speaker 1: demonstration on satpathya. The following slides provide a summary of
Speaker 1: the concepts covered in part two of the webinar series.
Speaker 1: ATL twenty four can be integrated with optical bands blue
Speaker 1: and green green wavelengths for driving satellite drive pathymetry. Slide
Speaker 1: roll is a public web service with low latency access
Speaker 1: to on demand data products stored in S three. Slide
Speaker 1: role provides on demand processing next to the data for
Speaker 1: generating customized data products using parameters supplied in the user's request.
Speaker 1: Slide roll Python client can be used to access ATL
Speaker 1: twenty four. Slide roll provides documentation for the Python client,
Speaker 1: including example scripts, user guide, and developers Guide. SATPATHI is
Speaker 1: a hybrid web desktop tool created by Noah for automating
Speaker 1: automating satellite derived pathymmetry. Satpathy utilizes ten meter resolution satellite
Speaker 1: imagery from the Copernicus Sentinel two mission, Amazon Web service
Speaker 1: and Acolyte Atmospheric Correction processor. Satpathy integrated the ATL twenty
Speaker 1: four product as an independent reference data source. The following
Speaker 1: is a summary of topics covered over both days of
Speaker 1: the training. NASA's i AT two carries a photon counting
Speaker 1: laser altimeter named Atlas. Atlas provides near contiguous a long
Speaker 1: track sample using six individual beams of green light at
Speaker 1: five hundred and thirty two nanimeter wavelength, providing high vertical resolution.
Speaker 1: Every photon detected by Atlas has a latitude, longitude, and
Speaker 1: elevation associated with it. National Snow and Ice Data Center
Speaker 1: provides access to ATL twenty four data metadata and tools.
Speaker 1: Slide roll is a public web service with low latency
Speaker 1: access to on demand data products stored in S three.
Speaker 1: Slide roll Python Api can be used to access ATL
Speaker 1: twenty four. Satbathi is a hybrid web desktop tool created
Speaker 1: by Noah for automating satellite drive bathymetry. Satpathy utilizes ten
Speaker 1: meter resolution satellite imagery from the Copernicus Sentinal two mission
Speaker 1: Amazon Web service and Acolyte. Satpathy integrates the ATL twenty
Speaker 1: four product as an independent reference data source. Before we
Speaker 1: transition to the Q and A session, I want to
Speaker 1: remind you there will be one homework assignment accessible from
Speaker 1: the training page starting today. Answers must be submitted by
Speaker 1: Google Form with a due date of December thirty first.
Speaker 1: To receive a certificate of completion, you must attend all
Speaker 1: live webinars and complete the homework assignment by the deadline.
Speaker 1: You will receive a certificate via email approximately two months
Speaker 1: after the completion of the course. We want to thank
Speaker 1: once more doctor Christopher Parish from Oregon State University, JP
Speaker 1: Swinskey from NASA's Goddard Spaceflight Center, Gretchen Emilhore from Noah,
Speaker 1: and Keana Key from Oregon State University for their presentations
Speaker 1: and instructive demos. Below is the contact information for Chris, JP,
Speaker 1: Gretchen and Keana, along with links to the urset website
Speaker 1: and social media. If you enjoyed today's webinar, we hope
Speaker 1: you will sign up on the r set list serve
Speaker 1: to receive notifications of future trainings, and please follow us
Speaker 1: on social media for other relevant announcements pertaining to NASA's
Speaker 1: Earth Sciences. We will now transition to the question and
Speaker 1: answer portion of today's training.
Speaker 3: Okay, can you guys hear me?
Speaker 1: Okay, yes, Gretchen, Yes, we can hear you.
Speaker 3: Yes, thank you. I can start on the questions, starting
Speaker 3: with the question nineteen. Does that sound okay?
Speaker 1: Actually we start from the first, so we're going to.
Speaker 3: Jump Oh, I beg your pardon.
Speaker 2: So yeah.
Speaker 1: So question one, When integrating ATAIL twenty four data sets
Speaker 1: from ice AT two for shallow water but symmetry, do
Speaker 1: you typically use machine learning approaches? If yes, which techniques
Speaker 1: are most frequently applied example given random forest, convolutional neural
Speaker 1: network XG, BOOST, et cetera. And why are they preferred
Speaker 1: over traditional methods?
Speaker 2: I think that was my answer to that question, and
Speaker 2: then sorry, my answer ended up in a couple of
Speaker 2: different pluses on the on the screen there. That's a
Speaker 2: really active research topic. It seems like their paper is
Speaker 2: being published every month on looking at different machine learning
Speaker 2: methods for STB, So I would just point to a
Speaker 2: couple of recent review papers that were published on STB.
Speaker 2: And also we did a recent I st to bothymmetry
Speaker 2: review paper that was by John at All, just published
Speaker 2: this year. It contains a lot of references.
Speaker 1: Hey, Chris, thank you so much. Question number two, could
Speaker 1: you suggest some case studies or I sad to ETL
Speaker 1: twenty four imagery has been applied for ecosystem monitoring or
Speaker 1: restoration projects, for example, chloral refmapping, seagrass monitoring, or coastal
Speaker 1: habitat restoration.
Speaker 2: Yeah, I can take that one too. There was a
Speaker 2: paper bile Aqualic at All. Mike Sinskay of NASA was
Speaker 2: also a co arthor on that. Sorry, I was trying
Speaker 2: to pull up the exact reference for it, but that
Speaker 2: was a paper specifically looking at I said tube pothymetry
Speaker 2: for benic habitat mapping. And then our research group is
Speaker 2: actually currently looking at use of INTL twenty four for
Speaker 2: core refrustration site monitoring in the Florida case. That's a
Speaker 2: collaboration with gender Extra at the University of New Hampshire.
Speaker 2: Center for coastalin Ocean Mapping.
Speaker 1: Okay, Chris, thank you so much. Question number three. If
Speaker 1: we are integrating I said to Atail twenty four data
Speaker 1: sets with multi spectral remote sensing data such as sentinels
Speaker 1: the imagery, what are the best practices to improve accuracy,
Speaker 1: Which remote sensing data sets are most frequently used for
Speaker 1: this purpose? And why are there any tips for pre processing, filtering,
Speaker 1: or modeling that can enhance the symmetry estimates.
Speaker 2: I can keep going because I put the first part
Speaker 2: of the answer in the chat, but maybe Gretchen or
Speaker 2: others will want to chat in here as well, so
Speaker 2: and I think this was covered in part in Gretchen's presentation.
Speaker 2: But careful selection of the input scenes, trying to find
Speaker 2: scenes that avoid clouds, turbidity, artifacts, compositing of several scenes
Speaker 2: can improve the accuracy or blessed atmospheric correction, which was
Speaker 2: a step that Gretchen mentioned. And then another thing that
Speaker 2: we recommend is performing accuracy tests and using independent reference data.
Speaker 2: We're available as shown and Gretchen's and Cannas demos.
Speaker 1: Chris, thank you again. Question number four, Will this work
Speaker 1: for the purpose of archaeological diving?
Speaker 2: I can keep going, but obviously anybody else jump in
Speaker 2: at any time. Archaeological marine archaeology is potentially a really
Speaker 2: interesting application of issatude with tymmetry and ATL twenty four,
Speaker 2: and it's one that I've heard mentioned in the peer
Speaker 2: reviewed literature. To date, I haven't seen a published study
Speaker 2: dedicated to marine archaeology, but I know that again, it's
Speaker 2: an area that people are interested in and I think
Speaker 2: are maybe currently actively working on. Very cool.
Speaker 1: I look forward to reading some of his papers when
Speaker 1: they're published. Question number five, Are I too ATL twenty
Speaker 1: four data sets used for applications like natural resource exploration
Speaker 1: or disaster monitoring, such as tracking sediment deposition and can
Speaker 1: they be applied in hydrocarbon exploration as well?
Speaker 2: I can take just the first part of that. Are
Speaker 2: the second part I guess on disaster monitoring. So a
Speaker 2: former student, John Herman, did an excellent study on use
Speaker 2: of solely satellite based methods. So I set to you
Speaker 2: with tymmetry and specially drive pathymetry or looking at a
Speaker 2: hurricane change analysis. And in Joe's study it was shown
Speaker 2: that we could actually see sort of at least broad
Speaker 2: patterns of special change, for example, moving sandbars that occurred
Speaker 2: to the hurricane. I think the resource exploration again, that's
Speaker 2: another kind of topic that I think people are interested
Speaker 2: in right now. It's one that I've certainly heard people mention.
Speaker 2: I don't have any studies to point to off the
Speaker 2: top of my head.
Speaker 1: Chris, thank you so much again. Question number six, how
Speaker 1: does the vertical accuracy of HL twenty four compare to
Speaker 1: standard single beam hydrographic surveys in clear water? Can I
Speaker 1: use ATL twenty four to validate or even correct my
Speaker 1: existing field data?
Speaker 2: This one was also my response, and again anybody else,
Speaker 2: any of the other panelists this time, and I was
Speaker 2: trying to answer some of the questions in the in
Speaker 2: the chats as other four presenting my answer to this one,
Speaker 2: I said, too, is generally not as accurate as a
Speaker 2: single beam or multi beam ecosounding. We did a study
Speaker 2: of ATL twenty four accuracy and that was just published
Speaker 2: in a paper an Earthen Space Science earlier this year.
Speaker 2: What we found from the ATL twenty four pothymetry we
Speaker 2: had eight different test sites. The RMSS of the ATL
Speaker 2: twenty four pythymmetry was zero point six eight or sixty
Speaker 2: eight centimeters using all points, and if we filtered by
Speaker 2: just high confidence points. It was point four to three
Speaker 2: meters or forty three centimeters, So I think you know,
Speaker 2: half meter or better than half is really quite good
Speaker 2: for a lot of applicussions, but still not approaching what
Speaker 2: you can get from sonar.
Speaker 1: Great Chris, thank you again. Question number seven, did you
Speaker 1: use Sentinel two data instead of Lance hat for this
Speaker 1: for the spatial resolution for the model? Does this improve
Speaker 1: the model?
Speaker 2: We've used both. We've used both Lance eight nine and
Speaker 2: Sentinel two both can both can be great sources of
Speaker 2: input data for for SDB. The Sentinel two special resolution
Speaker 2: is a little bit better in the in the red,
Speaker 2: grin and blue spectral bands, which can be helpful.
Speaker 1: Hey, great Chris, thank you. Question number eight, My area
Speaker 1: of interest is a coral reef with high morphological complexity
Speaker 1: such as rough slopes, seven drop offs, and narrow values.
Speaker 1: Since the ice that two laser footprint is roughly eleven
Speaker 1: to seventeen meters, does it effectively capture these sharp changes
Speaker 1: or does it smooth out the the athymmetry too much
Speaker 1: for precise coastal mapping.
Speaker 2: Yeah, that one again was a great question, and that's correct.
Speaker 2: I said two footprint is around eleven meters, and that
Speaker 2: can be a limiting factor and extracting a really high
Speaker 2: frequency spatial detail. Something that's important is that the along
Speaker 2: track special resolution of I said two is quite good.
Speaker 2: Points in the along track direction and nominal points spacing
Speaker 2: is about seventy centimeters, so that can help and resolving features.
Speaker 2: But really my main suggestion here is just investigated and
Speaker 2: several of these talks by you know, JP and others,
Speaker 2: you saw examples of using that slide real web client.
Speaker 2: That's a really fast and easy way to go in
Speaker 2: and visually grab some ATL twenty four data for your site,
Speaker 2: and I would just start there in terms of looking
Speaker 2: at how good the resolution is and if it's going
Speaker 2: to support your needs.
Speaker 1: Awesome, Chris, thank you so much. Question number nine, when
Speaker 1: do you change when you do the change analysis when
Speaker 1: Sentinel two? Do you calibrate the reflectance with ATL again
Speaker 1: or use the regression coefficient from the original calculation and
Speaker 1: apply it to all the sentinel imagery.
Speaker 2: My recommendation is if you're doing multi temporal analysis, so
Speaker 2: change detection or something like that where you've got input
Speaker 2: scenes from different times, I would, if at all possible,
Speaker 2: I would do the calibration separately for each epic, but
Speaker 2: if you wanted to, you could start with the calibration
Speaker 2: parameters for the first from the first epic and and
Speaker 2: just rEFInd them as needed.
Speaker 1: Awesome, thanks Chris. Question number ten data collection model for
Speaker 1: water turbidity based on size, weight, composition, settling rate, overlay
Speaker 1: with world currents and closest coastal impact. Question mark does
Speaker 1: it need to include baseline TURBIDIV levels possible to make
Speaker 1: moving animated data overlay over seasonal title and trade wind
Speaker 1: change prediction models for cumulative impacts?
Speaker 2: My answer here was this sounds like an amazing tool.
Speaker 2: To the best of my knowledge, that's not something that
Speaker 2: currently exists, but if there are people who want to
Speaker 2: take the lead on developing something like that, I can
Speaker 2: see it being beneficial to a lot of different people.
Speaker 3: Great.
Speaker 1: Thank you again, Chris. Question number eleven, how can tide
Speaker 1: be applied or moved from pseudo satellite drive asymmetry.
Speaker 2: I'll give my answer here and Kretschener theres may want
Speaker 2: to jump in, so regarding tide correction, and if you're
Speaker 2: doing single scene STV, so you're not compositing multiple scenes,
Speaker 2: and if your calibration data are already reference to a
Speaker 2: vertical data, then your output STB are going to be
Speaker 2: in cparently a reference to that same vertical datam as
Speaker 2: the reference data that you're using for calibration. And so
Speaker 2: for that reason, in that specific case, you don't need
Speaker 2: a TI a dedicated tide correction step. And to kind
Speaker 2: of explain that if you're doing if you're doing a
Speaker 2: linear transformation from your pseudo SDB to SDB and the
Speaker 2: transformation parameters come from something that's already referenced to a
Speaker 2: vertical datam any kind of vertical shift, for example, digit
Speaker 2: tides is just going to be inherently accounted for the
Speaker 2: time that you do need a tide correction is if
Speaker 2: you're using if you're sort of compositing or pulling together
Speaker 2: multiple stands collected at multiple different stages of tide.
Speaker 1: Hey, Chris, thank you. Question twelve, Since the interest is
Speaker 1: in the symmetry, would you want to sample satellite data
Speaker 1: just after ice off to avoid photoplankton that might be
Speaker 1: growing in the water column in the later spring and
Speaker 1: summer which could mask the bethymmetry.
Speaker 2: Quite possibly, Yes, I would monitor global turbidity or you
Speaker 2: know kdie four ninety data sets to try to find
Speaker 2: optimal times for optimal water clarity. That is generally going
Speaker 2: to be the driving factor and whether you get good
Speaker 2: with ymmetry.
Speaker 5: Or not.
Speaker 1: Gay question number thirteen. Does the stump approach only work
Speaker 1: with the ratio of the log of blue and green
Speaker 1: or could other band ratios be applied?
Speaker 2: Absolutely, you can do other band ratios, and I think
Speaker 2: this was shown in Gretchen and Cannis talks for example,
Speaker 2: they're SDB green and SDB red. Those refer to, respectively,
Speaker 2: ratios of log blue to log green and then log
Speaker 2: blue to log red. So those are those are both
Speaker 2: combinations that can be used and really any any other
Speaker 2: combination essentially as well, if you're working with hyperspectrol imagery
Speaker 2: for example.
Speaker 1: All right, Chris, thank you again. Question fourteen. Have you
Speaker 1: tried to compare your depth data or the data source
Speaker 1: being discussed against real world bethymmetry data products such as
Speaker 1: the Noah Blue topo to assess its accuracy?
Speaker 2: We have in that accuracy test that I think I
Speaker 2: put in the in the chat that was a comparison
Speaker 2: against Noah data. A lot of it was a lot
Speaker 2: of it was airborne Tobo Bethy Ladder data available on
Speaker 2: Noah Digital Coast, and a lot of that same data
Speaker 2: is available in Blue Topo. For the next release, we're
Speaker 2: going to try to do an automated accuracy test using
Speaker 2: all of the Blue Topo, all the Blues, all the
Speaker 2: Noah Blue TEPA data, but the development of that is
Speaker 2: something that's still on the works.
Speaker 1: Okay, thank you, Chris. Question fifteen, what quality criteria in
Speaker 1: ATL twenty four would you specify to filter out and
Speaker 1: noisy data? Since I we'll be working with an inland
Speaker 1: water body, can you specify a comparable quality criteria for
Speaker 1: ATL thirteen data?
Speaker 2: For ATL twenty four, we've typically recommended a confidence threshold,
Speaker 2: So one of the parameters is that confidence parameter It
Speaker 2: was discussed in Laurie mcgroder's presentation that provides a confidence
Speaker 2: of the symmetry classification. We've used a threshold of point
Speaker 2: six as a good starting point for filtering out some
Speaker 2: of the lower confidence data, but that's kind of site specific,
Speaker 2: so you might want to sort of play around with
Speaker 2: that and fine tune it. The second part of the
Speaker 2: question is correct ATL thirteen is the is the corresponding
Speaker 2: products for inland waters thirteen provides a lot of other parameters,
Speaker 2: but there is a there is a pythymmetry parameter. To
Speaker 2: the best of my knowledge, there is not a similar
Speaker 2: confidence parameter. But I would definitely encourage rating the algorithm.
Speaker 2: Theoretical Basis document which provides all the technical specifications for
Speaker 2: ANTIL thirteen data product.
Speaker 1: Terrific. Question number sixteen, how would you integrate the SDB
Speaker 1: layer with the point the themetry data?
Speaker 2: This may have been where Gretchen was going to step
Speaker 2: step into this. Gretchen or somebody else want to want
Speaker 2: to pick up the questions from this point or would
Speaker 2: you all like me to keep going?
Speaker 5: Allright?
Speaker 3: Not hearing anyone else, I'm sorry because I was muted.
Speaker 3: Go ahead, I was going to pick up at nineteen.
Speaker 2: Okay, all right, I'll I'll turn it over. You integrate
Speaker 2: the STB layer with the point the theymmetry.
Speaker 4: I'm not.
Speaker 2: I'm not totally sure I understand the question. But if
Speaker 2: it's referring to how do you actually how do you
Speaker 2: take your pseudobythymmetry and then integrate that with the individual
Speaker 2: points from ETL twenty four, that was one of the
Speaker 2: steps that I should how to do that in my
Speaker 2: demo just using QGIS and and basically it was using
Speaker 2: that sample raster values tool to have the pseudo SDB
Speaker 2: and then just at each at each raster or each
Speaker 2: location of ATL twenty four point to sample the corresponding
Speaker 2: pseudo STB value.
Speaker 1: Okay, Question seventeen, what about the difference in pseudo STB
Speaker 1: per S two detector?
Speaker 2: Yeah, I think that's I think that's interesting. One of
Speaker 2: my recent students, Art mcculluugh, I looked at actually using
Speaker 2: small sets where you've got you know, each each individual
Speaker 2: satellite has its own imaging sensor on it, so you've
Speaker 2: got just differences between the different sensors. I think that's
Speaker 2: just a I don't have detailed information other than I
Speaker 2: think that's a great question and most definitely an area
Speaker 2: for ongoing research.
Speaker 1: Great question number eighteen. I've collected hydrographic survey data across
Speaker 1: my steady area. How should I combine field based hydrographic
Speaker 1: data with ice AT to a long track measurements to
Speaker 1: create a more robust validation data set. What are the
Speaker 1: trade offs between them?
Speaker 2: My answer to this one just in terms of things
Speaker 2: to consider, you know, need to pay attention to different
Speaker 2: special resolutions and accuracies. Different datums can definitely be a
Speaker 2: factor when you're trying to combine data. So for data
Speaker 2: collected in the US knows vertical datum transformation utility be
Speaker 2: datum can be a useful utility for that.
Speaker 1: Great question number nineteen, Where can I access the satpathy tool?
Speaker 3: Okay, yeah, Now the satvati tool is for noah internal use.
Speaker 3: Is a desktop tool, but we are working on a
Speaker 3: larger cloud effort, public cloud effort. This will incorporate lessons
Speaker 3: we have learned over the years as we've worked with
Speaker 3: Noah's Office of cod Survey for our reconnaissance projects with
Speaker 3: them and our other federal mapping partners. But I think
Speaker 3: you gave my sean as my information on the slide,
Speaker 3: so folks that are interested, you can feel free to
Speaker 3: contact me for updates on our status.
Speaker 1: Great Gretchen, thank you so much. Question twenty the example
Speaker 1: in Alaska was fascinating. Have there been any studies looking
Speaker 1: at the efficacy of these approaches in polar regions in
Speaker 1: particular given the challenge is presented by snow and ice.
Speaker 3: Yeah, that's a really good question. We've found that working
Speaker 3: in Alaska has been very challenging and we have been
Speaker 3: trying to do, where possible some parallel research along with
Speaker 3: the SDB reconnaissance operational work for NOS office A coast survey.
Speaker 3: Alaska alone is challenging areas, so there's more work needed
Speaker 3: there as well as the other northern areas and polar regions.
Speaker 1: Okay, christ thank you. Last question twenty one, I missed
Speaker 1: the definition of SDB underscore merged and SDB on the
Speaker 1: score read. Could you explain.
Speaker 5: H questions?
Speaker 2: Should I answer this?
Speaker 3: Yeah, Brian, thanks, that'd be great.
Speaker 2: Great.
Speaker 10: So, S tob red and SB green are the two
Speaker 10: products that are created from the or else SDB algorithm
Speaker 10: or s A coach. We found the S to b
Speaker 10: read typically works better in shallow regions, while SMB green
Speaker 10: is more suited for deeper water. So s to be
Speaker 10: merged us as a combination of those two algorithms, relying
Speaker 10: on s tob red for the shallow water and then
Speaker 10: transitions to s tob green for the deeper areas. More
Speaker 10: information about how that works could be found in some
Speaker 10: of the publications that were listed.
Speaker 1: Brian, thank you and thank you to everybody that asked questions,
Speaker 1: and I want to thank everybody that attended today's training,
Speaker 1: actually both parts of the training. Today was the last
Speaker 1: day of this two part webinar series, so for wherever
Speaker 1: you were joining from, thank you so much. We also
Speaker 1: want to thank once again our amazing presenters, Doctor Christopher
Speaker 1: Parish from Oregon State University, JP Swinsky from NASA's Goddard
Speaker 1: Space Light Center, Gretchen Imohorami from NOAH, and also Key
Speaker 1: from Oregon State University. We also want to thank subject
Speaker 1: matter expert Brian Edter from NOAH from joining today to
Speaker 1: help as a subject subject matter expert answering some of
Speaker 1: the questions, and also want to thank Amy Neely from
Speaker 1: NASA Goddard Space Flight Center as well for her vision
Speaker 1: in having this training take place. So thank you to
Speaker 1: all the wonderful presenters and we look forward to seeing
Speaker 1: you in the future at an upcoming our set training.
Speaker 1: Thank you
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