The dual-frequency Synthetic Aperture Radar Altimeter (SRAL) on Sentinel-3 provides sea surface topography measurements in SAR mode, with a spatial resolution as narrow as 300 m.
SRAL is supported by a microwave radiometer for atmospheric correction and by a DORIS receiver, Global Navigation Satellite System, and laser retroreflector to determine its position in space with pinpoint accuracy.
Altimetry data can be used to determine sea and lake surface height, significant wave height, surface wind speed, and sea ice height and thickness.
The products will be available in:
- Near-Real-Time (NRT): products shall be available to the users within three hours after sensing.
- Short Time Critical (STC): products available to the users within 48 hours after sensing.
- Non-Time-Critical (NTC): products available to the users within one month after sensing.
The second table below lists the current operational altimetry products.
A full list of our ocean products can be found on our Ocean Products page.
|Processing Baseline Deployment date||Processing Baseline version||SRAL L1 product notice||SRAL L2 product notice|
|21 Jan 2020||2.61||Copernicus S3 Product Notice — Altimetry||Sentinel-3 Product Notice — STM L2 Marine|
|14 Feb 2019||2.45||Copernicus S3 Product Notice — Altimetry||Sentinel-3 Product Notice — STM L2 Marine|
|06 Dec 2018||2.33 (S3A)/1.13 (S3B)||Copernicus S3 Product Notice — Altimetry||Sentinel-3 Product Notice — STM L2 Marine|
|4 April 2018||2.33||S3 Product Notice — Altimetry||Sentinel-3A Product Notice — STM L2 Marine (NRT, STC and NTC)|
|14 February 2018||2.27||S3 Product Notice — Altimetry||Sentinel-3A Product Notice — STM L2 Marine (NRT, STC and NTC)|
|13 December 2017||2.24||S3 Product Notice — Altimetry||Sentinel-3A Product Notice — STM L2 Marine (NRT, STC and NTC)|
|12 April 2017||2.12||Sentinel-3A Product Notice — STM L1 Altimetry (NRT, STC and NTC)||Sentinel-3A Product Notice — STM L2 Marine (NRT, STC and NTC)|
How to get Altimetry data
Watch this video demonstration from our expert Bruno Lucas.
Users need to be registered to get access to the altimetry products. To do this you need to use our Earth Observation Portal (EOP). To access the Earth Observation Portal (EOP) for the first time, users need to create an account. Once the account has been created, you can log in to view and modify your profile, service subscriptions and licence arrangements.
Altimetry products are available:
- via our broadcast delivery system EUMETCast;
- by ordering from the EUMETSAT Data Centre;
- via Copernicus Online Data Access (CODA), an online rolling archive with http access.
All Sentinel data products are distributed using a Sentinel-specific variation of the Standard Archive Format for Europe (SAFE) format specification. The information is contained in a single package, with objects encoded in NetCDF format.
Full details can be found on the Sentinel Formats page.
How to use Altimetry data
|Product Data Format Specification - SRAL/MWR Level 2 Marine products||PFS||S3IPF.PDS.003.3||2.13|
|Product Data Format Specification - SRAL and MWR Level 1 products||PFS||S3IPF.PDS.003.1||2.11|
|Product Data Format Specification - SRAL/MWR Level 2 Marine products||PFS||S3IPF.PDS.003.3||2.12|
|Product Data Format Specification - SRAL and MWR Level 1 products||PFS||S3IPF.PDS.003.1||2.10|
|Surface Topography Mission (STM) SRAL/MWR L2 Algorithms Definition, Accuracy and Specification||CLS-DOS-NT-09-119||8|
|S3A STM Reprocessing - Spring 2018 (Level 0 to Level 2)||EUM/OPS-SEN3/REP/18/978053||1|
|Correspondence between the Sentinel-3 SRAL L2 Marine netCDF and BUFR formats||1|
|Sentinel-3 Altimetry User Guide||UG|