Spectra in SeaDAS GUI

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avmehta
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Joined: Mon Feb 03, 2020 10:27 am America/New_York

Spectra in SeaDAS GUI

by avmehta » Sat Mar 05, 2022 10:00 am America/New_York

Hello,
I am using SeaDAS GUI for some analysis. I have collocated two images, resulting in two sets of band reflectance (for reference or master image and the other collocated with it. If I draw a box on a region, is it possible to get average spectra for this box?
Thank you for your help.
Amita

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OB SeaDAS - knowles
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Subject Matter Expert
Posts: 248
Joined: Mon Apr 07, 2008 4:40 pm America/New_York

Re: Spectra in SeaDAS GUI

by OB SeaDAS - knowles » Mon Mar 07, 2022 2:26 pm America/New_York

When you draw a vector box layer on a SeaDAS loaded image it creates an associated mask. This mask by default will be called "geometry".

To do statistics on this "geometry" region of interest, use the Statistic Tool (Menu > Analysis > Statistics)

Check the "Use ROI Mask" checkbox and check it's "geometry" checkbox. Then click the "Refresh View" button (which is at the top right corner of the Statistic Tool. This will limit your statistics to the ROI(s) instead of using the whole raster image.

Screen Shot 2022-03-07 at 2.20.32 PM.png
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avmehta
Posts: 179
Joined: Mon Feb 03, 2020 10:27 am America/New_York

Re: Spectra in SeaDAS GUI

by avmehta » Mon Mar 07, 2022 5:44 pm America/New_York

Thank you Danny.
I can do the statistics for the ROI I draw as you suggested, but for spectrum it only allows viewing spectrum at a cursor position! I see options for displaying spectra at all pixels and also to save the values in a file but as soon as I move the cursor -- the Spectrum View window goes blank. Selecting ROI and refreshing does not help fro spectrum. I must be missing something.
Thanks again.
Amita

OB SeaDAS - knowles
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Posts: 248
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Re: Spectra in SeaDAS GUI

by OB SeaDAS - knowles » Mon Mar 07, 2022 6:58 pm America/New_York

The Spectrum Plot is for single pixels. You can place pins and run it for all the pins and you will get a spectral line associated with each pin. So one line per pixel. If you don't use pins then it monitors the pixel directly beneath the cursor. So unfortunately it doesn't do what you want regarding a mean value of the ROI region's pixels.

avmehta
Posts: 179
Joined: Mon Feb 03, 2020 10:27 am America/New_York

Re: Spectra in SeaDAS GUI

by avmehta » Wed Mar 09, 2022 7:47 am America/New_York

Thanks Danny.
Amita

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