This directory contains data for the ISS-RapidScat Level 2B 12.5km science-quality Version 1.2 netCDF dataset. ************************************************** Dataset description: (as shown here: http://podaac.jpl.nasa.gov/dataset/RSCAT_LEVEL_2B_OWV_COMP_12_V1.2) This dataset contains the RapidScat Level 2B 12.5km Version 1.2 science-quality ocean surface wind vectors, which are intended as a replacement and continuation of the Version 1.1 data forward from orbital revolution number 5127, corresponding to 19 August 2015; the overlapping time period starting on 19 August 2015 corresponds to the first time period of the recorded low signal-to-noise ratio (SNR). The Level 2B wind vectors are binned on a 12.5 km Wind Vector Cell (WVC) grid and processed using the Level 2A Sigma-0 dataset. RapidScat is a Ku-band dual beam circular rotating scatterometer retaining much of the same hardware and functionality of QuikSCAT, with exception of the antenna sub-system and digital interface to the International Space Station (ISS) Columbus module, which is where RapidScat is mounted. The NASA mission is officially referred to as ISS-RapidScat. Unlike QuikSCAT, ISS-RapidScat is not in sun-synchronous orbit, and flies at roughly half the altitude with a low inclination angle that restricts data coverage to the tropics and mid-latitude regions; the extent of latitudinal coverage stretches from approximately 56 degrees North to 56 degrees South. Furthermore, there is no consistent local time of day retrieval. This dataset is provided in netCDF-4 "classic" format and made available via FTP and OPeNDAP. For data access, please click on the "Data Access" tab above. This Version 1.2 dataset differs from the previous Version 1.1 dataset as follows: 1) L1B sigma-0 has been re-calibrated during the periods of low signal-to-noise ratio (SNR) and 2) during low SNR periods the L1B sigma-0 calibration is determined using re-pointed L1B QuikSCAT data. It is advised for users to avoid using the "wind_obj" variable in this dataset since it is minimally applicable and meant primarily for quality assurance; for users who wish to access the objective function values for each ambiguity, it is suggested to use only the "ambiguity_obj" variable. The "wind_obj" variable contains DIRTH probabilities (which are derived form the "ambiguity_obj" objective function values) in the range of 0 to 1 indicating the conditional probability that the true direction is within + or - 2.5 degrees of the retrieved wind direction given the observed backscatter measurements in the cell. ************************************************************************************* Cautionary Notes: 1) It is advised for users to avoid using the "wind_obj" variable since it is minimally applicable and meant primarily for quality assurance; for users who wish to access the objective function values for each ambiguity, it is suggested to use only the "ambiguity_obj" variable. 2) Due to the multi-operational roles of ISS, disruptions in the data flow and data retrieval for RapidScat occur much more frequently than stand-alone remote sensing platforms. Users depending on the availability of data within the last 14 days are therefore advised to defer to the near-real time updates provided by the following link at NOAA for adequate and timely information regarding any planned or ongoing data outages: http://manati.star.nesdis.noaa.gov/rscat_images/monitor/RapidScat_Scheduled_Outages.txt ************************************************************************************* Note: for users who wish to gain more information on instrument/spacecraft anomalies and outages, please refer to: http://manati.star.nesdis.noaa.gov/rscat_images/monitor/RapidScat_Scheduled_Outages.txt ************************************************************************************* Directory contents (data files partitioned according to 4-digit years): /2015.../2016 Note: The actual data files are contained within an additional layer of 3-digit day-of-year directories. File naming convention: rs_l2b_v1.2_RRRRR_YYYYMMDDHHmm.nc.gz rs_l2b Instrument/Level Identifier: RapidScat Level 2B RRRRR 5-digit orbital revolution number v1.2 Version ID: v1.2 = version 1.2 YYYY 4-digit year of data file creation date MM 2-digit month of data file creation date DD 2-digit day of month of data file creation date HH 2-digit hour of 24-hour day of data file creation time mm 2-digit minute of hour of data file creation time nc File extension: nc = netCDF gz GNU Zip file extension ************************************************************************************* Please send any comments or questions to https://podaac.jpl.nasa.gov/forum/. Last modified on 4 May 2016.