Search found 150 matches

by avmehta
Fri Feb 12, 2021 12:30 pm America/New_York
Forum: All Questions/Comments
Question: gpt MosaicGeneral
Replies: 21

gpt MosaicGeneral

In the GUI I can see NaN where there is no data (Rhos =0  there show up as NaN) it is the NetCDF file that they stay 0s and no appear as NaN. I tried a number (-9999) instead of NaN but that does not work either!
Thanks much for your help.
Amita
by avmehta
Fri Feb 12, 2021 9:44 am America/New_York
Forum: All Questions/Comments
Question: gpt MosaicGeneral
Replies: 21

gpt MosaicGeneral

Hello George,  Thank you for the explanation. What I want to do is exclude land and cloud pixels from mosaic/composite and then set rhos to NaN or some missing value number if the value is 0. My par file looks like this:band1=rhos_412band1Expression=if (rhos_412 != 0) then rhos_412 else NaNqual...
by avmehta
Thu Feb 11, 2021 2:46 pm America/New_York
Forum: All Questions/Comments
Question: gpt MosaicGeneral
Replies: 21

gpt MosaicGeneral

Hello,  I am doing mosaic of a few mages and want to set certain value to NaN  I followed this statement in .par file:  band1Expression=if (Kd_490 != 0) then 1.3/Kd_490 else NaN   and have a statement that looks like:   band1Expression=if (rhos_443 != 0) then rhos_...
by avmehta
Tue Feb 09, 2021 8:43 am America/New_York
Forum: All Questions/Comments
Question: gpt MosaicGeneral
Replies: 21

gpt MosaicGeneral

Hello,     I am trying one flag at a time, in addition to LAND,  to see the impact. I tried qualityExpression=!l2_flags.LAND and  !l2_flags.CLDICE -- but I still see data when clouds are present. Should it be 'or' so that either land or cloudy pixel will be excluded?...
by avmehta
Mon Feb 08, 2021 6:52 pm America/New_York
Forum: All Questions/Comments
Question: gpt MosaicGeneral
Replies: 21

gpt MosaicGeneral

Thank you.
Amita
by avmehta
Mon Feb 08, 2021 4:37 pm America/New_York
Forum: All Questions/Comments
Question: MODIS 1640 nm band
Replies: 3

MODIS 1640 nm band

Thanks Don. But it is not so obvious in other bands -- just 1640 nm! Is that to be expected?
[img][/img].  and [img][/img].
Thanks.
Amita

by avmehta
Mon Feb 08, 2021 1:17 pm America/New_York
Forum: All Questions/Comments
Question: MODIS 1640 nm band
Replies: 3

MODIS 1640 nm band

Hello, I am processing MODIS L1 to L2 at 1) 1 km and at 2) 250 m. Please see the attached images - in 1 km image I see stripes. In my par file I did not specify any resolution -- considering that 1 km would be default. Can you please help with this? https://oceancolor.gsfc.nasa.gov/forumdata/attach/...
by avmehta
Mon Feb 08, 2021 1:03 pm America/New_York
Forum: All Questions/Comments
Question: gpt MosaicGeneral
Replies: 21

gpt MosaicGeneral

Thanks George.I am interested in just Rhos for all bands. If I did not specify PRODFAIL, according to you message it would it still exclude invalid pixels - correct?In my averaged image Rhos which are not valid show up as '0'. Is there a way to set them as NaN or other undefined value?Thanks...
by avmehta
Mon Feb 08, 2021 9:51 am America/New_York
Forum: All Questions/Comments
Question: gpt MosaicGeneral
Replies: 21

gpt MosaicGeneral

Hello,      I have been able to mosaic several images using gpt. I already have reprojected files so I use them to mosaic multiple images. I have the following questions I need help with.     1) Is it OK to use reprojected files and l2flags (for criteria to mosaic) for ...
by avmehta
Sun Feb 07, 2021 9:30 am America/New_York
Forum: All Questions/Comments
Question: gpt MosaicGeneral
Replies: 21

gpt MosaicGeneral

Thanks for reply George.
Initially I will not be merging images from MODIS and OLCI -  but merge them separately. I just looked at the link you sent -- great it explained what I was asking for!
Thanks a lot for your help.
Amita