SRAL

SRAL stands for Synthetic Aperture Radar Altimeter, an advanced radar altimeter instrument aboard the European Space Agency’s Sentinel-3 series (notably Sentinel-3A and Sentinel-3B). It uses synthetic aperture radar processing to achieve higher along‑track resolution than traditional pulse‑limited altimeters, improving measurements of the ocean surface and coastal areas.

The SRAL instrument operates primarily in the Ku-band and can operate in both conventional low-resolution mode and high-resolution SAR mode. The SAR mode generates finer spatial detail, enabling better retrievals of sea surface height, significant wave height, and wind speed, especially near coastlines where traditional altimetry faces limitations. SRAL data are complemented by on‑board processing and by accompanying instruments, such as a microwave radiometer for atmospheric corrections and precise orbit determination systems, to deliver accurate geophysical measurements.

Sentinel-3 carries SRAL together with a suite of sensors to support oceanography, meteorology, and climate monitoring. The mission, with its twin satellites (S3A and S3B), provides near-global, frequent observations of sea surface height, ocean surface wind, wave height, and related parameters. SRAL data contribute to sea level monitoring, ocean state estimation, and coastal change studies, supporting applications from weather forecasting to climate research and maritime safety.

Data from SRAL are distributed through Copernicus services and open data repositories, enabling researchers and operational agencies to access level-1 radar echo measurements and level-2 geophysical products such as sea surface height, sea surface height anomaly, significant wave height, and wind speed at 10 meters.