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Instrument Overview

ERS-2 SAR imaged the Bay of Naples
ERS-2 SAR, Bay of Naples, including Phlegrean Fields to the west

The ERS-1 satellite launched on 17 July 1991 and ERS-2 followed on 21 April 1995, providing continuity for ERS-1. Both satellites carried a Synthetic Aperture Radar (SAR).

The ERS SAR operated in parallel with another instrument – the Wind Scatterometer (WS). Together the SAR/WS configuration was called the Active Microwave Instrument (AMI). AMI had three modes of operation, which allowed the instruments to image land during day or night or through clouds.

The ERS-1 mission ended on 10 March 2000, far exceeding its expected lifespan.

The last ERS-2 SAR data was acquired on 4 July 2011 and the ERS-2 mission itself ended on 5 September 2011.


Data Description

All ERS SAR products, in accordance with ESA Earth Observation Data Policy, are freely available to users. Read more about the available SAR products:

All products are provided in Envisat product format generated by the ESA ERS PF-SAR processor.

Processor Releases

It should be noted that for SAR, each product ordered is processed directly from the raw data, using the current version of the SAR processor. There is no archive of processed products except for the Level 1 ERS SAR Medium Resolution products (SAR IMM 1P) which have been bulk processed.

Data Tools

Tools available for visualising, processing and analysing ERS data:


The Sentinel Application Platform (SNAP) is a common architecture for all Sentinel Toolboxes (including the Sentinel-3 Toolbox). It is ideal for Earth Observation processing and analysis due to technological innovations.


Sentinel-1 Toolbox

Sentinel-1 Toolbox (S1TBX) consists of a collection of processing tools, data product readers and writers and a display and analysis application to support the large archive of data from ESA SAR missions including Sentinel-1, ERS-1 & 2 and Envisat.


Auxiliary Data

Auxiliary data from ground or airborne sources is sometimes used to help produce data products. Auxiliary data files for SAR data products are available to download.


The goal of SAR calibration and validation activities was to verify the accuracy and quality of data the instrument acquired. Details are available of the ERS SAR Cal/Val plan and of Calibration Activities.

Quality Control Reports

Quality Control is monitoring routinely the status of the spacecraft (payload and platform) and to check if the derived products meet the quality requirements along mission life-time. SAR Quality Control Reports are available for Product Anomalies, Quality Control Products Parameter Plots, Cyclic Reports, Taw Weekly Reports and AMI Telemetry Data.