SeaWinds on QuikSCAT: Level 1B Earth-Located Sigma-0 Measurements

QuikSCAT's SeaWinds instrument collected Level 1B data containing geo-located Sigma-0 (radar backscatter) measurements from 1999 until at least 2013. The dataset includes detailed antenna pulse geometries, with a complete 'egg' footprint of approximately 25 km by 35 km and eight constituent 'slices' each measuring about 25 km by 7 km. This is the second reprocessed version of the data, but users must note a significant calibration discontinuity after the instrument entered a 'non-spinning' mode on 22 November 2009.

Use Cases

• Calibrating wind vector retrieval algorithms based on the fundamental Sigma-0 (radar backscatter) measurements.
• Analyzing radar scattering properties of the Earth's surface using the detailed 'egg' and 'slice' pulse geometries.
• Studying long-term changes in ocean surface roughness by examining the time-series of Sigma-0 data.
• Developing new geophysical products by using the Level 1B data as input for custom processing chains.

Strengths

• Provides the fundamental, geo-located Sigma-0 measurements from a key satellite instrument with a documented spatial resolution of approximately 25 km by 35 km.
• Represents a second reprocessed version, suggesting improved quality and consistency over earlier releases.
• Has a long time series spanning over a decade, with specific operational details documented for expert use.

Limitations

• Data calibration is inconsistent between the primary 'spinning' mode (ending 22 November 2009) and the subsequent 'non-spinning' mode, requiring expert handling.
• Metadata completeness is low: column names, row counts, and exact file sizes are unknown across all platform entries.
• There is a conflict in the 'last updated' metadata, with one source showing 2026 and another showing 2015, casting doubt on maintenance currency.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Derived from ephemeris and Level 1A data collected by the SeaWinds scatterometer on the QuikSCAT satellite.

Time Range

1999 to at least 2013, with operational mode changes documented after November 2009.

Freshness

2026-04-09 22:12:27.964029

Geography

Global coverage from the QuikSCAT satellite's orbit.