Search found 1496 matches

by OB.DAACx - SeanBailey
Mon Aug 05, 2024 10:15 am America/New_York
Forum: Home
Question: Cloud mask for CZCS
Replies: 3

Re: Cloud mask for CZCS

The threshold is 0.027 as stated.

Sean
by OB.DAACx - SeanBailey
Fri Aug 02, 2024 1:09 pm America/New_York
Forum: Home
Question: l1bgen failed with exit code 1
Replies: 4

Re: l1bgen failed with exit code 1

The l1bgen_generic code does not support PACE OCI. You should simply download the L1B files we distribute, rather that the L1A. However, if you have L1A files, you can run l1bgen_oci on them to generate the L1B...but it'd be faster to download them :D https://search.earthdata.nasa.gov/search/granule...
by OB.DAACx - SeanBailey
Fri Aug 02, 2024 12:15 pm America/New_York
Forum: Home
Question: Cloud mask for CZCS
Replies: 3

Re: Cloud mask for CZCS

I can see how that would be confusing, since CZCS doesn't have an 865band :D The value listed for cloud_wave is the "requested" value (what was input to the code). The code finds the closest wavelength to the requested value. If you run l2gen on the parent L1A file, you would see this repo...
by OB.DAACx - SeanBailey
Mon Jul 29, 2024 9:46 am America/New_York
Forum: Home
Question: Navigating PACE imagery
Replies: 5

Re: Navigating PACE imagery

Dirk,
Using your link to Earthdata I was able to see data over the Gulf of Mexico just fine...it's there :)
PACE-gulf-of-mexico.png
PACE-gulf-of-mexico.png (470.36 KiB) Not viewed yet
by OB.DAACx - SeanBailey
Mon Jul 15, 2024 5:42 pm America/New_York
Forum: Home
Question: Calculating geophysical products with Sentinel 2
Replies: 1

Re: Calculating geophysical products with Sentinel 2

A while ago (rather a long while) the Sentinel-2 SAFE format changed. It was a minor change, but one that impacts the ability for l2gen to properly read the data. We have not had time to figure out how to make l2gen happy with the new format and until we do, it will not work. The Sentinel-2 support ...
by OB.DAACx - SeanBailey
Tue Jul 02, 2024 6:24 pm America/New_York
Forum: Home
Question: Low/Negative SST values in tropical region
Replies: 1

Re: Low/Negative SST values in tropical region

Check the flags. If the SST seems unreasonably low, it is likely a cloud. The data are not masked at L2, only flagged. When binnng SST, the code selects qual_sst of 2 or greater (keeping the highest quality data for the bin). If the qual_sst is a 3 for the pixels you find low SST, that means it's a ...
by OB.DAACx - SeanBailey
Wed Jun 05, 2024 7:15 am America/New_York
Forum: Home
Question: Questions about the level3 remote sensing reflectance data of MODIS images
Replies: 2

Re: Questions about the level3 remote sensing reflectance data of MODIS images

The Rrs data are stored in the L3 mapped netCDF files as scaled short integers. If your software does not apply the scale_factor and add_offset information (contained in the variable attribtues) to convert the scaled integers into floating point values, you will need to do so after reading the data ...
by OB.DAACx - SeanBailey
Tue Jun 04, 2024 4:20 pm America/New_York
Forum: Home
Question: How can i obtain the MODIS Rayleigh correction reflectance from SeaDAS L2gen?
Replies: 1

Re: How can i obtain the MODIS Rayleigh correction reflectance from SeaDAS L2gen?

The rhos product is Rayleigh and gaseous absorption corrected reflectance. If you want a product that only removes the Rayleigh radiance component, you'll have to output Lt and Lr (and likely the Rayleigh transmittances, t_sen and t_sol) and do the math. The rhos that l2gen ouputs is: rhos = pi / Fo...
by OB.DAACx - SeanBailey
Tue Jun 04, 2024 3:22 pm America/New_York
Forum: Home
Question: MODIS/Aqua-derived PAR data have many plaids
Replies: 3

Re: MODIS/Aqua-derived PAR data have many plaids

It is everywhere, but the color palette "hides" it. Look a the lower portion of your image and you will see the blocky pattern in the western side as well.

Sean
by OB.DAACx - SeanBailey
Mon Jun 03, 2024 10:40 am America/New_York
Forum: Home
Question: MODIS/Aqua-derived PAR data have many plaids
Replies: 3

Re: MODIS/Aqua-derived PAR data have many plaids

The PAR algorithm uses a coarse ancillary data field (9km resolution), and given the different grids of L2 and the L3 ancillary, the result can show as as bit patchwork. As for the magnitude differences, you should verify the inputs match exactly what our production system used.

Regards,
Sean