NASA JASON-3: Near-Real-Time GPS Orbit and Sea Surface Height Anomalies

NASA's JASON-3 Project dataset provides near-real-time GPS-based satellite orbits and derived Sea Surface Height Anomalies (SSHA). It includes supplementary wet tropospheric corrections for historical observations to improve global sea level change estimates by 2-3 mm over 8 years. The data has a 5-hour latency due to orbit calculation and is distributed via AWS Open Data under a CC-BY-4.0 license.

Use Cases

• Monitoring global and regional sea level change based on near-real-time Sea Surface Height Anomalies.
• Improving historical sea level trend estimates by applying the provided wet tropospheric correction.
• Comparing GPS-based orbit accuracy against DORIS orbits for satellite positioning.
• Assimilating near-real-time altimetry data into ocean forecasting and climate models.

Strengths

• Provides a 2-3 mm error reduction in global sea level change estimates over 8 years via the supplementary correction.
• GPS orbits are described as more accurate than DORIS orbits for near-real-time applications.
• Data is near-real-time with a defined 5-hour latency for processing.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count and dataset size are unknown, which may limit suitability assessment.
• Last update date is unknown; freshness unverified.

Provenance

Source

NASA JASON-3 Project, with data similar to the NOAA-distributed Operation Geophysical Data Record (OGDR).

Collection Method

Satellite altimetry from the JASON-3 satellite, with GPS orbit calculation and SSHA derivation. Corrections use a method mapping SSMIS brightness temperatures to AMR equivalents.

Time Range

Includes historical Jason-3 observations and near-real-time data.

Freshness

Forward stream processing baseline updated to version 'G' in January 2025, indicating ongoing maintenance.

Geography

Global ocean coverage from satellite observations.