CYGNSS Satellite Bistatic Radar Measurements for Ocean Surface Monitoring

Delay Doppler Maps (DDMs) calibrated into Power Received and Bistatic Radar Cross Section, collected by the eight-satellite CYGNSS constellation. The dataset includes daily files from up to 8 spacecraft, with a typical latency of approximately 6 days from measurement. This Version 2.1 science-quality release from NASA's POCLOUD supersedes Version 2.0 with improved calibration and coverage.

Use Cases

• Estimate ocean surface wind speed using calibrated Bistatic Radar Cross Section (BRCS) and Normalized Bistatic Radar Cross Section (NBRCS) measurements.
• Analyze signal scattering characteristics near the specular reflection point using the Delay Doppler Map Average (DDMA) of the NBRCS.
• Study waveform properties and signal leading edges using the Leading Edge Slope (LES) of the integrated delay waveform.
• Assess data quality and filter observations using the provided sets of quality flags, error estimates, and bias estimates.
• Perform spatiotemporal analysis of ocean conditions using geolocation, orbital, and timekeeping parameters alongside the core DDM data.

Strengths

• Data collection from a constellation of up to 8 satellites increases global coverage and temporal sampling.
• Version 2.1 includes significant improvements such as data availability during high beta-angle periods and more accurate coordinate frame corrections.
• Includes multiple calibrated geophysical observables (Power Received, BRCS, NBRCS, DDMA, LES) in a single record.

Limitations

• Receiver antenna pattern calibration is not applied per-DDM-bin in this version, which may affect fine-scale analysis.
• The typical 6-day latency from measurement limits near-real-time applications.
• Data volume and file structure (netCDF per spacecraft per day) require specific handling for large-scale analysis.

Provenance

Source

NASA CYGNSS mission, processed by POCLOUD.

Collection Method

Collected by the Delay Doppler Mapping Instrument aboard the CYGNSS satellite constellation using GNSS reflectometry.

Freshness

Data is produced daily with approximately 6-day latency from the last recorded measurement.

Geography

Global coverage, primarily over ocean surfaces between approximately 38° latitude.