Updated: 17 May 2006

ERS-1 - Earth Resource Satellite

The following is a brief description of the European Space Agency's (ESA) Earth Resource Satellite (ERS).

The first satellite in this series, ERS-1 was launched on 17 July 1991 and ERS-2 on 20 April 1995. These satellites are designed to gather information about the earth's ocean, ice and land resources using a variety of sensors. Orbiting the Earth for nine years, over three times its planned lifetime, the ERS-1 mission was ended on 10 March 2000 by a failure in the on-board attitude control system. For more information visit the ESA's ERS Missions page.

ACRES acquires data from one of the instruments on board, the Synthetic Aperture Radar (SAR), which operates in C-band from the microwave region of the electromagnetic spectrum.

In addition to the Synthetic Aperture Radar, ERS-1 and ERS-2 carry other instruments:

The Radar Altimeter
The Along-Track Scanning Radiometer and Microwave Sounder
The Precise Range and Range Rate Equipment (functional only on ERS-2)
The Wind Scatterometer
The Laser Retro-reflector

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Sensor Parameters - Synthetic Aperture Radar (SAR)

The SAR is an active microwave sensor capable of imaging earth resource targets regardless of time of day, cloud, haze or smoke cover of an area. The instrument is classified "active" as it emits the energy necessary to image the earth's surface.

In contrast, "passive" or "optical" sensors rely on the sun's reflected energy to image the earth. More general information on SAR is available through NASA's Jet Propulsion Laboratory: What is Imaging Radar?

ERS SAR Characteristics

Frequency	5.3 GHz
Bandwidth	15.55 MHz
Band Name	C Band
Wavelength	56mm
Incidence Angle	23 deg (mid swath)
Polarisation	VV*
* V=vertical.

Generalised Applications

Meteorology	Interrelationship between oceanographic and climatic phenomena and their influence on global climatic change
Geology	Structural mapping, volcanism studies, coastal erosion studies
Vegetation Monitoring	Vegetation change, crop monitoring
Hydrology	Soil moisture studies, surface water body morphology, snow extent and condition
Land Use	Mapping, change assessment
Oceanography and Glaciology	Monitoring of polar ice sheets and sea ice; monitoring ocean circulation, currents and tides

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Enquiries and orders for ERS SAR data

To enquire about data availability or to order your ACRES ERS SAR data, please contact your preferred ACRES Distributor or our Customer Services on (tel) 02 6249 9779 or (fax) 02 6249 9938. Prices for ACRES ERS SAR data can be found in the ERS SAR Price List.

Copyright

ERS SAR data is subject to ACRES ERS Data End User Licence covering the use of ERS data.