Minimize Mission Summary


ERS was the first ESA program in Earth observation with the overall objectives to provide environmental monitoring, in particular in the microwave spectrum.

The ERS program was composed of two missions, ERS-1 and ERS-2, and it was a pioneering character in the field of instrument development (active sensors).

The mission introduced and demonstrated advanced observation technologies and is a fine example of a European success story.

ERS-1 mission duration: ERS-1 was launched by Ariane-4 on 17 July 1991 and failed on 10 March 2000 after 9 years of activity.

ERS-2 mission duration: ERS-2 was launched by Ariane-4 on 21 April 1995 and was ended and then de-orbited on 5 September 2011 after 16 years of activity.

The ERS-1 satellite carried five sensors: an Active Microwave Instrument (AMI) including a radar imager (SAR) and a scatterometer, a radar altimeter (RA), a radiometer (ATSR), a microwave sounder (MS) and range equipment (PRARE) - as described in the table below. The ERS-2 satellite carried an additional sensor, the Global Ozone Monitoring Instrument (GOME).

The ERS-1 and ERS-2 missions were mainly operated in a 35-day repeat cycle. In addition, a 3-day cycle (ice phase) was followed by ERS-1 in 1992 and 1994 and by ERS-2 in 2011. ERS-1 had also a 168-day repeat cycle (geodetic phase) in 1994 and 1995. Both ERS-1 and ERS-2 were operated in a 1-day difference (known as tandem mode) from 1995 to 2010 to develop SAR interferometry applications.

On-board sensors
AMI Active Microwave Instrument Consisted of a Synthetic Aperture Radar and a wind scatterometer (both in the C-band)
RA Radar Altimeter Took precise measurements of the distance from the ocean surface and of wave heights
ATSR Along-Track Scanning Radiometer Operated in the infrared and visible ranges. Measured sea surface temperatures and the vegetation cover of land surfaces.
GOME Global Ozone Monitoring Experiment An absorption spectrometer which measured the presence of ozone, trace gases and aerosols in the stratosphere and troposphere
MS Microwave Sounder Supplied data on atmospheric humidity
PRARE Precise Range And Range-Rate Equipment ERS orbit and trajectory determination
LRR Laser Retro-Reflector Determined satellite position using ground-based laser stations

More information on the ERS-1 and ERS-2 satellites can be found in the Directory of the eoPortal which is operated by ESA.