Rongowai-CYGNSS: Airborne GNSS Reflectometry Data for Ocean Wind Sensing

New Zealand's Rongowai project collects airborne GNSS-Reflectometry data using a Next-generation receiver (NgRx) mounted on an Air New Zealand Q300 aircraft (tail number ZK-NFA). Each netCDF file contains geo-located Delay Doppler Maps (DDMs) calibrated into Power Received and Bistatic Radar Cross Section, with 20 DDMs per file split between left- and right-hand circular polarization. Measurements are reported at 1-second increments for flights typically lasting 45 to 90 minutes, with a median of 7 flights per day and a data latency of approximately one day.

Use Cases

• Calibrating and validating spaceborne GNSS-R wind speed algorithms based on airborne Delay Doppler Maps (DDMs).
• Studying ocean surface scattering properties using co- and cross-polarized Normalized Bistatic Radar Cross Section (NBRCS) measurements.
• Analyzing wind-wave interactions by examining the Leading Edge Slope (LES) of integrated delay waveforms.
• Assessing data quality and coherence for geophysical retrievals using the provided quality flags, error estimates, and coherence state metrics.
• Mapping Fresnel-zone geometry and spatial resolution estimates for specific reflection events over New Zealand's coastal and oceanic regions.

Strengths

• Data is collected via a dedicated airborne platform (Air New Zealand Q300) providing frequent, targeted coverage with a median of 7 flights per day.
• Includes calibrated scientific parameters like Bistatic Radar Cross Section (BRCS) and 20 Delay Doppler Maps (10 LHCP, 10 RHCP) per file for detailed polarization analysis.
• Low latency of approximately 1 day from measurement to availability supports near-real-time research applications.
• Dataset is supported by multiple agencies, including NASA and the New Zealand Space Agency, indicating institutional validation.

Limitations

• Column names and a complete data schema are not provided in the available metadata, complicating initial data exploration.
• Exact row counts, total file size, and a precise data license are not specified across the platforms.
• Geographic coverage is limited to flight paths within New Zealand, restricting global applicability.

Provenance

Source

University of Auckland (UoA) Rongowai Science Payloads Operations Centre, with support from NASA and the New Zealand Space Agency.

Collection Method

Data collected using a Next-generation receiver (NgRx) mounted on an Air New Zealand domestic Q300 aircraft (ZK-NFA).

Time Range

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Freshness

2026-04-09 23:00:25.043527

Geography

Flight paths between airports within New Zealand.