The PO.DAAC is pleased to announce the public release of the CYGNSS Climate Data Record (CDR) Version 1.0 dataset. The Cyclone Global Navigation Satellite System (CYGNSS), launched on 15 December 2016, is a NASA Earth System Science Pathfinder Mission that was designed with the purpose to collect the first frequent space-based measurements of surface wind speeds in the inner core of tropical cyclones. Made up of a constellation of eight micro-satellites, the CYGNSS observatories provide coverage over the tropical oceans with a mean (i.e., average) revisit time of seven hours and a median revisit time of three hours. As a result of the CYGNSS constellation coverage, the CDR data is made available from 18 March 2017 to present with an approximate 1 to 2 month latency in the netCDF-4 formatted data files, where each file contains data within a 24-hour UTC period from a combination of up to 8 unique CYGNSS spacecraft. More information on CYGNSS can be found on the CYGNSS mission page.
Version 1.0 represents the first climate-quality release and is a collection of reanalysis products derived from the SDR v2.1 Level 1 data. Calibration accuracy and long-term stability are improved compared to the SDR v2.1 using a new trackwise correction algorithm which constrains the average value of the L1 data using MERRA-2 reanalysis wind speeds. Details of the algorithm are provided in the Trackwise Corrected CDR Algorithm Theoretical Basis Document. CDR Level 2 and 3 products (ocean surface wind speed and mean square slope) are generated from the CDR L1 data using the v2.1 SDR data processing algorithms. A more detailed explanation of the updates and improvements in the CDR data can be found within the respective dataset landing pages.
Datasets comprising this release include Level 1 and Level 2, both at an approximate binned spatial resolution of 25-km, followed by Level 3, which is regularly gridded with a binned 0.2° by 0.2° lat/lon spatial resolution. All datasets cover the global tropical oceans within a latitude domain of approximately 40° S to 40° N.
The CYGNSS CDR datasets are described and discoverable via the PO.DAAC data portal.