We are pleased to announce the release of the Cyclone Global Navigation Satellite System (CYGNSS) Climate Data Record (CDR) Version 1.2 (v1.2) datasets. More information regarding the CYGNSS mission and instrumentation is available from PO.DAAC’s mission webpage. The CDR Version 1.2 collection provides a total of 3 unique datasets, each corresponding to processing Levels 1 (L1), 2 (L2) and 3 (L3), respectively. While there are a large number of variables and measurement parameters in each dataset, the primary measurement in L1 is the Bistatic Radar Cross Section (BRCS) and wind speed, expressed in units of meters per second in both L2 and L3. This version of CDR data is available from 1 August 2018 to present with an approximate 5-day forward production latency in netCDF-4 formatted data files, in which data are contained within a 24-hour UTC period. For L1 data, the files are separated according to the specified spacecraft identifier. For L2 and L3 data, the data files represent a daily aggregation from a combination of up to 8 unique CYGNSS spacecraft. The CDR v1.2 provides continuity to the CDR v1.0 that is available prior to August 2018.
This CDR V1.2 update was produced in response to the changes and improvements to the L1 data calibration recorded in Science Data Record (SDR) version 3.1 (v3.1). The update begins with 1 August 2018, corresponding to the start of production in the data time series. These datasets comprise a collection of reanalysis products derived from the SDR v3.1 Level 1 data (https://doi.org/10.5067/CYGNS-L1X31). Calibration accuracy and long term stability are improved relative to SDR v3.1 using the same trackwise correction algorithm as was used by CDR v1.1 (https://doi.org/10.5067/CYGNS-L1C11). Details of the algorithm are provided in the Trackwise Corrected CDR Algorithm Theoretical Basis Document. It is noted that the trackwise correction algorithm cannot be successfully applied to all SDR L1 data, so there is also some loss of samples in the CDR that are otherwise present in the SDR. Calibration accuracy and stability improvements in CDR v1.2 L1 also extend downstream to the L2 and L3 datasets (e.g., ocean surface wind speed and mean square slope).
As a result of improvements made to the SDR v3.1 L2 wind speed retrieval algorithm, the CDR v1.2 L2 dataset now includes a Young Seas with Limited Fetch (YSLF) wind speed product.
The Cyclone Global Navigation Satellite System (CYGNSS), launched on 15 December 2016, is a NASA Earth System Science Pathfinder Mission that was launched with the purpose to collect the first frequent space-based measurements of surface wind speeds in the inner core of tropical cyclones. The CYGNSS includes a constellation of eight micro-satellites. It provides a nearly gap-free Earth coverage between 40N and 40S with an average revisit time of seven hours and a median revisit time of three hours. As a result of the CYGNSS constellation coverage, this data is made available from 1 August 2018 to present with an approximate 1 week 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.
Access to the data as well as a complete listing of documentation resources, read software, and access information is available here:
- CYGNSS. 2022. CYGNSS Level 1 Climate Data Record Version 1.2. Ver. 1.2. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at https://doi.org/10.5067/CYGNS-L1C12
- CYGNSS. 2022. CYGNSS Level 2 Climate Data Record Version 1.2. Ver. 1.2. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at https://doi.org/10.5067/CYGNS-L2C12
- CYGNSS. 2022. CYGNSS Level 3 Climate Data Record Version 1.2. Ver. 1.2. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at https://doi.org/10.5067/CYGNS-L3C12
Ruf, C. S., S. Asharaf, R. Balasubramaniam, S. Gleason, T. Lang, D. McKague, D. Twigg, D. Waliser, 2019. In-Orbit Performance of the Constellation of CYGNSS Hurricane Satellites. Bull. Amer. Meteor. Soc., doi: 10.1175/BAMS-D-18-0337.1.
Download data using the PODAAC Data Subscriber:
- Source code: https://github.com/podaac/data-subscriber
- Example code:
podaac-data-subscriber -c CYGNSS_L2_CDR_V1.2 -d myData -sd 2018-08-01T00:00:00Z -ed 2018-08-10T00:46:02Z