CYGNSS Level 1 Science Data Record Version 3.0

This Level 1 (L1) dataset contains the Version 3.0 geo-located Delay Doppler Maps (DDMs) calibrated into Power Received (Watts) and Bistatic Radar Cross Section (BRCS) expressed in units of m2 from the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation. This version supersedes Version 2.1; https://doi.org/10.5067/CYGNS-L1X21 . Other useful scientific and engineering measurement parameters include the DDM of Normalized Bistatic Radar Cross Section (NBRCS), the Delay Doppler Map Average (DDMA) of the NBRCS near the specular reflection point, and the Leading Edge Slope (LES) of the integrated delay waveform. The L1 dataset contains a number of other engineering and science measurement parameters, including sets of quality flags/indicators, error estimates, and bias estimates as well as a variety of orbital, spacecraft/sensor health, timekeeping, and geolocation parameters. At most, 8 netCDF data files (each file corresponding to a unique spacecraft in the CYGNSS constellation) are provided each day; under nominal conditions, there are typically 6-8 spacecraft retrieving data each day, but this can be maximized to 8 spacecraft under special circumstances in which higher than normal retrieval frequency is needed (i.e., during tropical storms and or hurricanes). Latency is approximately 6 days (or better) from the last recorded measurement time. Here is a summary of improvements the calibration and processing changes to the Version 3.0 data: 1) the transmitted GPS signal strength in the direction of the DDM scattering surface is determined in real time from measurements of the direct signal from the GPS satellite to the CYGNSS navigation receiver, allowing for the BRCS calibration to be corrected for variations in GPS transmit power; 2) the NBRCS has been validated using comparisons with a large population of modeled values derived from coincident ocean surface roughness spectra produced by the NOAA WAVEWATCH-3 oceanographic wave model; 3) L1 calibration parameters have been adjusted to produce a best fit to the model population.

Data and Resources

Additional Info

Field	Value
Maintainer	Earthdata Forum
Last Updated	August 25, 2026, 10:57 (UTC)
Created	April 1, 2025, 15:18 (UTC)
accessLevel	public
bureauCode	{026:00}
catalog_conformsTo	https://project-open-data.cio.gov/v1.1/schema
harvest_object_id	3922da94-78e8-4214-8f0b-ec99f4392973
harvest_source_id	b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title	Science Discovery Engine
identifier	10.5067/CYGNS-L1X30
license	https://www.usa.gov/government-works
modified	2026-08-17T22:16:03Z
programCode	{026:000}
publisher	NASA/ESSP/UMICH/CYGNSS;NASA/JPL/PODAAC
resource-type	Dataset
source_datajson_identifier	true
source_hash	faf2cb66b278654dcab18be0c851b7cd10cccb221e51955f0ff8619e616715e9
source_schema_version	1.1
spatial	["CARTESIAN", [{"NorthBoundingCoordinate": 40.0, "WestBoundingCoordinate": -180.0, "EastBoundingCoordinate": 180.0, "SouthBoundingCoordinate": -40.0}]]
temporal	2018-08-01/2022-08-07
theme	{"Earth Science"}