ESA Echoes in Space - Hazard: Flood mapping with Sentinel-1
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- Опубликовано: 30 сен 2024
- Dr. Chris Stewart explains how to derive a flood map from Sentinel-1 images, using SNAP.
SNAP: step.esa.int/ma...
Download Sentinel images: scihub.coperni...
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Echoes from space will take you on a journey through the exciting world of Radar Remote Sensing. Learn the basics that will help you to understand where this technology is coming from, how the images are acquired and which manifold applications already use Radar Remote Sensing to help protect our planet.
which polarization is good for flood mapping? is there any preference?
Covered here: Subset, Multilook, Calibration, Terrain Correction, Create Stack, Layer Manager (overlay/transparency), RGB composite image, KMZ export (Google Earth).
Wow. Thank you so much for this video. You are such a good teacher, I finally understand some concepts concerning this type of study. How you explained everything was simply meticulous. 😊😊😊😊
Very good. Thank you.
How can I classify the area in red that represents the floodplains? I tried supervised sorting but it didn't work.
I want to generate a shape only from the floodplain areas.
How to prepare sediment map please?
Now, it was successful. Thanks for your sharing video about Flood mapping.
I need to export inundate areas only. How can i do that?
Please explain a bit on how phase polarity and entropy affects the identification process, what is the physics behind it?
Dear Sir, very good material- I could follow it. However, after Terrain Correction for my case, it appear "no data" background. How do I remove it?
did you ever figure out how to remove it?
Thanks 🎉❤
Hi, I am a new user of SNAP toolbox.
I am using sentinel 1 GRDH data for flood area identification. I have done everything until export file.
After masking, I am trying to export data (view as Google Earth KMZ) but there have shown like this;
SNAP-Error
the image could not be exported .
Could you please help me to finish this work?
Dear Sir, It took along time to run Geometric\Terrain Correction. I do not why ? please provide me an advices.
So downloading the products has been a bit confusing to me, should I download SLC or Grid data?
Hi. I have a problem when stacking the 2 images. Error: org.jblas.NativeBlas.daemm (CIIIDDIDIDII). I have searched for the solution and found that I should install the libgfortran. I did that but the error still appears, Does anyone know how to solve it?
PLZ, I want to know how to add the ٍِSARscape tool to my ENVI 5.3?
I used the valuable satellite data of Sentinel-1.
If possible, guide me to fix the problem of image reversing
How important is the order of these operations? What if you do terrain correction before calibration?
Great...
thank you! this was incredibly useful.
How do we go about the same with Sentinel-2 images using SNAP
Hello, what is the hardware recommended for an effective snap process?
What is the best polarization to detect water below the canopy of trees in flooded forest?
It must be bands that cross the canopy to improve the estimate.
thank you very much. it helps me a lot to analyze the flood areas of the flood event of July 2021 in Germany
Is there any way to deal with the scalloping seen at 8:50 and 11:45 without converting to db?
the product does not exist with the coordinate system when I use Terrain Correction Tool. I need your help
Hello, I am doing the practice with an area of Formosa (Argentina) that had floods in 2019. Now, I cannot perform the terrain correction, I give RUN and the machine keeps turning and it does not give me the result that I am expecting.
No selecciones la opción de mascara
I do not know why? it took long time.
What happens exactly when you calibrate sigma0?
I am very interested in the explanation and totorial you create.
but because in my place of college still no one uses radar image for research final project. so I have to learn by myself about this image, see the explanation and totorial that you make make me lighter to learn it. I hope to discuss with you.
thank you sir
Dear Sir, very good material- I could follow it. However, after Terrain Correction for my case, it appear "no data" background. How do I remove it?
did you figure out how to remove it?
can you help me to get snaphu the phase unwrapping and the procedure for géocoding
thanks for those videos
hi Dr Stewart, what overall name is given to the method used in the video
Stewart's
Why is my laptop when using SNAP, the laptop is frozen and does not work ??
SNAP requires a lot of RAM memory to work properly. It happened to me too, and i had to borrow a laptop from friend :D
Quoc Nguyen It depends what are your laptop specifications like RAM & the processor type...these are the key determinants
Amazing
Go ahead
Not really impressed! :?
17:32 wow❤
thanks this was very helpful after flood of 2018/oct/07 here at south of Honduras
twitter.com/eo_college/status/1052483421006639104
haha thanks!
Sir, what does the mst and slv conveys in d stack image ?.
I think they are master and slave images. When I went through the tutorial, I had them reversed.
@@paulsponagle3754 no clue...
Highly intituive
Hi sir, I have 1 question. How to calculate how much area are effected in flood.
You can multiply the number of true pixels by the square of the nominal pixel size.
@@Andreandthepenguin How can i calculate the number of pixels that represent the area that is flooded?
@@andrijamitrovic7120 To extract the areas of flooding, you can use either a thresholding method, a classification method, or you can manually digitize the areas of flooding. I prefer a simple fixed thresholding, using band math for a single flood event. If it's a time series, I use something like intermeans thresholding in a script. After that, there are multiple ways to calculate area. The quick and dirty way is to look in the metadata/properties of the output image to find the pixel count and nominal pixel resolution. Raster area = pixel count * pixel size (the area of one pixel). So, if you were working with landsat the area would be: [pixel count] * 30 * 30. I hope this helps.
@@Andreandthepenguin Thanks for your reply. I really appreciate it. I understood it. I was thinking about other method like if i have a area (raster picture in, lets say GEOTIFF format) of water during the flood and and area (raster) before the flood event. Could I open those images in Qgis and just use some operations in order to get a new raster that represents the area that is flooded (above lake level).
Update. Actually, in SNAP, this is a way to create water masks before and during the flood and then we can apply difference so we can get a new mask that is the flooded area only and then use raster-masks-mask area to calculate the surface that is flooded
Thanks!
Hi mate! Can I Use Sentinel-2 or Sentinel-3