I want to download global VIIRS L1A and geo data from the NASA Ocean Color L1 & 2 brower. But the ordered data only included L1A data. I found that if the data I downloaded no need order, I could download both L1A and geo data. So I wonder how to access global VIIRS L1A and geo data?
That same list can then be used to get the GEO files by replacing the string "L1A" with "GEO-M" in the file name in the URL.
Thank you for your reply. The URL I used to download VIIRS L1 data did not include L1A. For example: https://oceandata.sci.gsfc.nasa.gov/cgi/getfile/requested_files_1.tar?h=ocdist305&p=/data1/a000d322b38f2e67/requested_files
All the L1A files are in the folder of requested_files_1.tar. I tried to replace the folder name with L1A file name, but the revised URL could not be opened.
So could you explain more details about how to access GEO data?
Thank you for your reply. I tried to download DEM files for VIIRS from the NASA OBPG server, but I did not figure out how to register for "samoa.gsfc.nasa.gov". So could you tell me how to register for this server?
In addition, I think it is easier to use your first approach. Could you tell me what is the URL and how to get it?
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You can generate a geolocation file from the extracted L1A using SeaDAS.
Thank you for your reply. I selected "Do not" extract my order when ordered data, but the URL included in the http_manifest.txt file stilled did not contain "L1A":
Do you know what happened?
Thank you for passing my samoa question to your web admins. They told me to creat Geo files using Seadas following the page you supplied: https://seadas.gsfc.nasa.gov/help-8.2.0/processors/ProcessGeolocate_viirs.html
According to that page, DEM files from the NASA OBPG FTP server are required. However, your web admins said that I did not need to register for the samoa access. If so, I cannot get the DEM files.
By the way, I could generate Geo files without DEM files using Seadas. But those Geo files were different from that downloaded directly from the L1 & 2 browser. So I think DEM files are necessary when generate Geo files.
I am sorry that I could not generate Geo files with either of your methods. Could you give me more hints?
Thank you in advance.
In addition, I could generate Geo files without DEM files using Seadas. But those Geo files were different from that downloaded directly from the L1 & 2 browser. So I think DEM files are necessary when generate Geo files.
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The documentation on the "ProcessGeolocate_viirs" page needs to be updated (thanks for alerting us to that discrepancy). The required DEM files are no longer distributed using the samoa FTP server (it, in fact, no longer serves as an FTP server - as we no longer support FTP distribution). When you install the processing components of SeaDAS (OCSSW) and select VIIRS as a sensor you wish to be able to process, the installer will pull the required software and support files - including the DEM files.
As for the files in your extracted order request (f0f0c271ef862168), those were Level 2 files, which include the geolocation information internal to the netCDF file, so no need to generate a GEO file from a L1A file.