Earthdata Forum

Hi - This should be simple, but I'm not getting it.  I want to create a scatter plot using bands from different files.  This was easy in SeaDAS6.4 but in SeaDAS7.x the scatter plot GUI apparently (at least as I've been using it) only allows selection of bands from a single file.  This is so fundamental I'm sure I'm missing something.  What? 

Thanks.  Barry

Barry,

It is relatively simple, but does require using the "Band Maths" function.  The products being compared need to have the same geolocation (or if not geolocated, the same dimensions).
You can add a band to one of the loaded products that is a virtual band linked to a band in the other product.  When creating this new band, the expression editor will show a product dropdown list at the top.  Select the appropriate product and then pick the band in the expression window.  The new virtual band will show up in the target product and can be used in all the band comparative tools.

Sean

Thanks, Sean.  Guess I finally have to try "Band Maths." :grin:  Should be no problem with common geolocation; I'm just checking for differences between outputs from smigen and l3mapgen.

Barry

Oftentimes with SeaDAS there are 2 or more ways of doing something.  Another approach would be to use the Collocation Tool.  This tool will create a new file which contains all the bands of your 2 source files.  If the source files contain differing projections then this tool will still work as it will reproject one of the source files to the projection of the other source file.  Then the statistics comparison tools such as Scatter Plot can be used in the new file to compare any of the bands.

Danny

Hi Danny.  Thank you.  In fact, I tried that but didn't get it to work, though it certainly seems like it should have.  Most likely operator error on my part (not uncommon, I'm afraid).  I appreciate you suggesting it.

Barry

Barry, this case study video tutorial illustrates the use of the Collocation Tool in comparing files and using statistics.
https://www.youtube.com/watch?v=5dIwCK7IDXE

More videos can be found here:
https://seadas.gsfc.nasa.gov/tutorials/video_tutorials/

Danny