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Up Topic Special Topics / Ocean Color Reprocessing / VIIRS Ocean Color Reprocessing 2014.0 (locked)
- By bryanfranz Date 2014-11-05 16:27
VIIRS Ocean Color Data Users:

The VIIRS ocean color products have now been reprocessed to version 2014.0, and the new products are now available through the ocean color web portal.  General details on the reprocessing changes are available here:

  http://oceancolor.gsfc.nasa.gov/cms/reprocessing/OCReproc20140.html

with specific details on impact to VIIRS here:

  http://oceancolor.gsfc.nasa.gov/cms/reprocessing/OCReproc20140VN.html

This is a major change to the VIIRS ocean color products quality, as well as the product data formats, including transition to netCDF4.  We recognize that this data format change has significant impact to data users engaged in routine forward stream data acquisition and analysis.  To mitigate this impact, we have taken some extra steps to allow for a "transition period of 1 month", ending on 8 December 2014, during which time we will be making available "and continuing to produce" both the old HDF4 and new netCDF4 products in parallel.  In general, the new netCDF4 files can be distinguished by the filename, which has a .nc extension.

During the transition period:

1) The Level-1 & 2 browser will show links to the old ocean color (OC) Level-2 file, as well as the two new Level-2 OC and IOP netCDF4 files.

2) The Level-3 browser will show the new Level-3 files as "Standard" VIIRS products, but the old HDF4 files will still be accessible by going to the "Test" tab on the browser.

3) The direct access archive will show both file types for all Level-2 and Level-3 products, with the new files identified via the .nc extension.

4) Perhaps most important for routine users, all subscriptions will provide links for both the old and the new .nc files.

5) Bulk data orders, however, will only serve the new data.

We hope this will help to ease the pain of transition to a new data format, and that you will take the opportunity to make any changes needed to support this change as soon as possible, and before 8 December.

It should also be noted that the old HDF4 products, even in the forward stream, are not using the full set of improved calibration and algorithm updates associated with this R2014.0 reprocessing, so you must transition to the netCDF4 file format to take advantage of the enhanced data quality, which is significant.

Also note that refined processing in the forward stream will now be delayed up to 45 days while we wait for availability of refined ancillary meterological data from NCEP.  See the above links for details.

If you have any questions or see any problems, please to this forum.

Best Regards,
Bryan Franz and the Ocean Biology Processing Group
- By tufillaro Date 2015-01-15 15:35
Hi

In the latest version of SeaDas how do you 'turn off' the
stripe processing for the l2gen from L1 to L2 VIIRS data?

thanks
nick
nbt.osu@gmail.com
- By SeanBailey Date 2015-01-15 15:49
Nick,

If you are referring to the corrections we're making for detector-to-detector differences, the answer is to set the xcal_opt=0
Keep in mind that there is still are detector- and mirror-specific calibrations that account for the some of the striping that is
convolved with the calibration tables (the F-LUTs).  These you can't turn off.

Regards,
Sean
- By pgarnesson Date 2015-06-18 08:49
Dear Bryan,
when you have announced the switch of VIIRS to netCDF4, you have explained that Refined products will be delayed up to 45 days (also explained in http://oceancolor.gsfc.nasa.gov/cms/reprocessing/OCReproc20140.html).
In practice, it seems that refined products are now systematically updated about 16 days after acquisition.
Do you confirm? and confirm it will be the same for netCDF MODIS?

Thank you in advance.

Philippe
- By SeanBailey Date 2015-06-18 09:31
Philippe,

The statement was "Refined Level-2 products will increase to 15 - 45 days."
16 is within that window.  The reprocessed MODIS data use the same ancillary
inputs as VIIRS and will therefore be similarly affected. 

Regards,
Sean
- By pgarnesson Date 2015-06-18 09:45
Dear Sean,
I agree this in within the window... but in http://oceancolor.gsfc.nasa.gov/cms/reprocessing/OCReproc20140.html it is said that NCEP data "become available monthly on the 15th day of the next month".
From my understanding it perfectly explain the 15-45 days (15 days for last days of previous month but 45 for the first days of the previous months).
For the last products, I have observed that refined data are updated 16 days after acquisition, it means the NECP data are now daily updated?
Regards.
Philippe
- By SeanBailey Date 2015-06-18 19:07
Philippe,

There was a change in the requirements we have for post processing the ancillary data from the source.
So, yes, the lag should be less than the nominal month.  Data faster is better, right :grin:

Sean
Up Topic Special Topics / Ocean Color Reprocessing / VIIRS Ocean Color Reprocessing 2014.0 (locked)

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