Search found 1464 matches

by OB.DAAC - SeanBailey
Mon Jun 05, 2023 9:16 pm America/New_York
Forum: Home
Question: OCM3 processing error, please help me
Replies: 1

Re: OCM3 processing error, please help me

SeaDAS does not support OCM3.

Sean
by OB.DAAC - SeanBailey
Mon Jun 05, 2023 9:13 pm America/New_York
Forum: Home
Question: Rayleigh-corrected reflectance
Replies: 1

Re: Rayleigh-corrected reflectance

Yes, rhos is Rayleigh corrected reflectance.

Sean
by OB.DAAC - SeanBailey
Mon Jun 05, 2023 9:08 pm America/New_York
Forum: Home
Question: Processing Landsat 8 images with L2gen
Replies: 4

Re: Processing Landsat 8 images with L2gen

You seem to be attempting to process a L2 file. This will not work, as l2gen expects a L1 file as input.

Sean
by OB.DAAC - SeanBailey
Wed May 31, 2023 5:58 pm America/New_York
Forum: Home
Question: l2gen algorithm - source code error
Replies: 4

Re: l2gen algorithm - source code error

Fabio, When the Hu algorithm is above 0.25 mg m^-3, but below 0.35 mg m^-3, we blend Hu with OCx. As Lachlan pointed out: The decision point in the function chl_oci that selects chl_hu, chl_ocx, or a blend of the two, is dependent only the magnitude of chl_hu (i.e., chl1). The code is correct. Sean
by OB.DAAC - SeanBailey
Wed May 31, 2023 8:29 am America/New_York
Forum: Home
Question: ATMWARN not used in VIIRS PIC l2bin flags
Replies: 1

Re: ATMWARN not used in VIIRS PIC l2bin flags

Julien,

Indeed, there is a discrepancy with the VIIRS PIC flaguse parameter. The good news is that the impact is insignificant. There is an extremely small number of pixels flagged as ATMWARN that are not also flagged by another of the flags in use as masks for the product.

Regards,
Sean
by OB.DAAC - SeanBailey
Mon May 22, 2023 7:42 am America/New_York
Forum: Home
Question: Geolocation shift for Chesapeake Bay scenes
Replies: 1

Re: Geolocation shift for Chesapeake Bay scenes

Sami, Geolocation of the Hawkeye imagery is a bit of a challenge: https://oceancolor.gsfc.nasa.gov/data/hawkeye/geolocation/ While we do our best to minimize the geolocation errors, we cannot completely eliminate them. Some scenes are worse than others. (or if you take an optimistic view, some scene...
by OB.DAAC - SeanBailey
Thu May 18, 2023 3:30 pm America/New_York
Forum: Home
Question: Level 1&2 browser - scenes not available for ordering
Replies: 2

Re: Level 1&2 browser - scenes not available for ordering

Fabio, This issue is related to the change in filename for the MLAC data with the recent reprocessing. Unfortunately, there is no longer a direct link (by way of the filename) between the L1 files and the L2 files and the old browser was expecting that, at least for the data ordering. Unfortunately,...
by OB.DAAC - SeanBailey
Thu May 18, 2023 8:44 am America/New_York
Forum: Home
Question: SeaDAS cannot reproduce OBPG l2 product
Replies: 3

Re: SeaDAS cannot reproduce OBPG l2 product

Make sure you are using the same ancillary inputs that were used in the OBPG processing. With NRT files, the OBPG processes with the best available at the time of processing. If you process a file later, is it possible - actually quite likely - that the ancillary files obtained via getanc will not b...
by OB.DAAC - SeanBailey
Thu May 18, 2023 8:28 am America/New_York
Forum: Home
Question: PIC netCDF files - scale and offset values for pic variable
Replies: 2

Re: PIC netCDF files - scale and offset values for pic variable

The data are stored as signed short integers, so, if you are seeing floating point values, the function you used to read the PIC product applied the scale and offset values. The scale_factor and add_offset values are applied to the data using this simple equation: geophysical_value = scale_factor * ...
by OB.DAAC - SeanBailey
Mon May 15, 2023 1:23 pm America/New_York
Forum: Home
Question: SeaWiFS L1a and L2 Filename Datetime Discrepancy
Replies: 2

Re: SeaWiFS L1a and L2 Filename Datetime Discrepancy

The issue stems from how the filenames are defined, and for SeaWiFS this most impacts the MLAC data. MLAC are merged files with all of the HRPT (direct broadcast) and on board recorded LAC (local area coverage) data. When the MLAC files were developed, we needed a way to ensure we didn't have duplic...