Create new Polar2Grid Reader for CSPP VIIRS Land Surface Temperature EDR

[kathys]

Please add a reader in support the CSPP VIIRS Land Surface Temperature Product. This should be very similar to if not identical to the CSPP Geo2Grid reader being added: #613

File prefix: LST_*.nc

Array: short VLST

units: Kelvin

Scale Factor: float LST_ScaleFact which is .005
Offset: float LST_Offset which is 200.

This will have to support a huge range of temperatures. We will have to work on the best color table with the GEO team too. The valid range is 213 to 343 K.

Test data can be found here:
bumi:/data/users/kathys/test_data/viirs_edr/j01/asci
bumi:/data/users/kathys/test_data/viirs_edr/npp/asci

[djhoese]

I don't see any "LST_*" files in the asci directory. Copy/paste error on the directory?

[kathys]

Looks like I was not successful in getting ASCI files for npp, but the j01 files are there. The LST software version is 2.0. For instance:

LST_v2r0_j01_s202306081924176_e202306081925403_c202306082036337.nc

[kathys]

I just copied some LST files for npp to the asci test file directory, although they will not match the date/time of the other products that are there.

[djhoese]

Ugh these files are different than the others. They aren't even semi-standard NetCDF files with a scale_factor and add_offset. They say they are CF 1.6 compliant, but defining scale/offset any other way is not CF compliant (at least I don't think so). Instead they have separate scalar variables:

        short VLST(Rows, Columns) ;
                VLST:_FillValue = -32768s ;
                VLST:coordinates = "Longitude Latitude" ;
                VLST:long_name = "VIIRS Land Surface Temperature (LST = LST data * LST_ScaleFact + LST_Offset)" ;
                VLST:units = "Kelvin" ;
        float LST_Offset ;
                LST_Offset:long_name = "VIIRS LST Offset" ;
                LST_Offset:units = "1" ;
        float LST_ScaleFact ;
                LST_ScaleFact:long_name = "VIIRS LST Scale Factor" ;
                LST_ScaleFact:units = "1" ;

Why?!?!?!

[djhoese]

...and it's called "VLST" because it is "VIIRS Land Surface Temperature"? 🤦‍♂️

[djhoese]

The initial version of this has been added now. Any future issues or changes will be in other issues or pull requests.