Temporal analysis - burned area

EO Products / Scripts
21

Sorry for the question, but I can’t make this step to download the data.
could you help me if you know a tutorial.
I should do a task but I don’t know the construction of the API very well.
Thanks for your help

22

Hi,Thank you for the script. I tried running it for my area but it returned a black image. @pierre.markuse ,@fcbasson and @gmilcinski could you please give me ideas on how to customize it to fit my area. What parameters do I need to change/add on the script?

Please note I have no programming skills, I am still trying to teach myself programming.

23

Hi Nokukhanya, ive noticed to get it working you must do a few things in playground.

  1. Zoom in to your area of interest (hint this is only likely to work if your in one Row/Path ie square of satelite imagery, but they are large should you are mostly right
  2. Click on the date selector in playground find before and after dates for which images were taken that day (you can tell by the light grey circle that pops up.
  3. Select the after date from this menu
  4. Also change the dates in the script to those dates
  5. Note the current image displayed (controlled by the date selector in playground can be anytime after but not before or during the dates inputed into the script
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24

Im trying to get this working in EO Hub as WMS service, can anyone help what programing tweaks are required?

25

Hi @alex.clark,
can you be a bit more specific into what exactly you want to do? Not sure I know what is EO Hub.

That being said, in order to make it work through WMS, you will have to tweak the dates of the data to be compared in the Custom script, then Base64 encode this script and send it to the WMS end-point as an EVALSCRIPT parameter.

26

Thank you so much for your response, I was able to fit the script to my area and show the fire.

I have been trying to take it to ArcGIS online using WMS service by copying and pasting the script on custom script editor on my WMS templates but it doesn’t work. Please assist on how to get this working

27

Hi @Liphakamile,

I checked the custom script in your WMS collection and realised that you are using an outdated evalscript. Read all about the transition to Evalscript V3 in the documentation and the corresponding forum posts.

Now, to solve your problem you need to take care of two things:

  1. You should use this updated and fixed V3 script for burned area visualisation.
  2. Make sure that there is data available in your area of interest for the dates you specify in line 26 of the updated script. Looking at your collection that line would read var allowedDates = ["2019-08-22","2019-09-11"]; in your case.

This worked for me when I tested it in QGIS with the dates and AOI from the custom script example. For other interesting custom scripts for fire detection, wildfire visualisation or burn scar detection please check out our custom scripts repository, which you can also contribute to and share your scripts with other users.

I hope that helps!

Cheers, Max

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