Search found 1466 matches
- 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 ...
- 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 ...
- 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 ...
- 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...
- 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
Sean
- 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
Regards,
Sean
- Fri May 31, 2024 4:00 pm America/New_York
- Forum: Home
- Question: CHLOROPHYLL A UNIT
- Replies: 3
Re: CHLOROPHYLL A UNIT
Yes, 50-100 is on the high end. What is your region of interest?
Sean
Sean
- Fri May 31, 2024 3:56 pm America/New_York
- Forum: Home
- Question: AQUA-MODIS, SNPP-VIIRS and NOAA20-VIIRS
- Replies: 1
Re: AQUA-MODIS, SNPP-VIIRS and NOAA20-VIIRS
Emanuele, We're still evaluating calibration updates for MODIS-Aqua and are hopeful that we can initiate a mini-reprocessing (yes, the issue extends back a couple years) sometime in the next month. I have to check with the team about the VIIRS sensors. I believe it is just waiting on the nod from th...
- Fri May 31, 2024 3:47 pm America/New_York
- Forum: Home
- Question: Help plotting future PACE orbits
- Replies: 2
Re: Help plotting future PACE orbits
There is an overflight prediction tool that can provide the times PACE instruments will view a location on the Earth, but we do not have the reverse (showing where PACE will view the Earth in the future). I will inquire with the Worldview team about adding the ability to plot the PACE orbits into th...
- Fri May 31, 2024 3:29 pm America/New_York
- Forum: Home
- Question: PACE L2 OCI wavelength bands
- Replies: 2
Re: PACE L2 OCI wavelength bands
Correct, the wavelength_3d is in the sensor_band_parameters group. Some background... The sensor_band_parameters group contains informational parameters and has been part of the L2 ocean color metadata since the days of SeaWiFS and includes a wavelength parameter that is the list of wavelengths for ...