The PO.DAAC is pleased to announce the public release of the historical science data records for the QuikSCAT’s Normalized Radar Cross Section data (also known as “sigma-0” or “sigma-naught”) for processing levels 1B and 2A (at 25 km and 12.5 km resolutions). This release marks the first time these data records have been provided with open access to the public. All three of these datasets are provided in the legacy HDF-4 format.

Data access and more detailed information on these datasets may be obtained at each of the respective dataset information pages:

• http://podaac.jpl.nasa.gov/dataset/QSCAT_LEVEL_1B_V2
• http://podaac.jpl.nasa.gov/dataset/QSCAT_LEVEL_2A_V2
• http://podaac.jpl.nasa.gov/dataset/QSCAT_LEVEL_2A_COMP_12

A comprehensive history of known instrument and data issues and the current status of the QuikSCAT mission is provided here:

• http://podaac.jpl.nasa.gov/OceanWind/QuikSCAT/SeaWinds-QuikSCAT_KnownProblems

Special note: QuikSCAT went into a "non-spinning" mode on 22 November 2009. The final rev number in the nominal operational "spinning" mode is 54296; the "non-spinning" mode of the instrument continued predominantly for the remainder of QuikSCAT operations. There were some brief periods of "spinning" in year 2013, which include the following days and rev numbers (identified in parenthesis):

1. 29 January to 5 February (7909-71011)
2. 14 March (71536-71549)
3. 18 March to 21 March (71590-71634)
4. 28 March to 31 March (71735-71769)

L2A data is not provided during the “non-spinning” operational mode; L1B is provided in both “spinning” and “non-spinning” modes through year 2014. L1B data for 2015 is expected to be produced and distributed in early 2016.
 
User advisory for L1B data: Data during the "non-spinning" mode is not consistently calibrated with data from the "spinning" mode. Furthermore, incidence angles change periodically during the "non-spinning" mode. It is therefore advised that only "expert" users attempt using the data during the "non-spinning" mode. For standard L1B data users who wish to access consistently calibrated L1B data during the "non-spinning" mode, please consider using the L1B Averaged Sigma-0 dataset as an alternative, which may be accessed by contacting podaac@podaac.jpl.nasa.gov.

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Physical Oceanography DAAC       Email: podaac@podaac.jpl.nasa.gov
Jet Propulsion Laboratory       WWW URL: http://podaac.jpl.nasa.gov

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