The primary mission of ERS-1 and -2 is to perform remote sensing of the Earth's oceans, ice caps, and coastal regions. The satellites will provide systematic, repetitive global measurements of wind speed and direction, wave height, surface temperatures, surface altitude, cloud cover, and atmospheric water vapour levels. Data from ERS-1 will be shared with NASA under a reciprocal agreement for Seasat and Nimbus 7 data. Some land imaging will be performed with the satellites' SAR experiment. The satellites will be controlled from ESA's Darmstadt control centre, with a large number of other stations providing additional tracking coverage.
Spacecraft: 3-Axis stabilised, zero momentum bias with control to 0.11 deg (pitch/roll) and 0.21 deg (yaw). Single solar panel is 11.7 m x 2.4 m and supports peak payload power of 2600 W. Battery storage capacity is 2650 WHr. SAR antenna is 10 m x 1 m. S-Band communications with 2 kbps uplink. High-rate X-Band downlink provides 105 Mbps and 15 Mbps. On-board recorders store 6.5 Gbits. Payload: ERS-1 . Payload: AMI (Active Microwave Instrument) - includes a SAR (Synthetic Aperture Radar), Wave Scatterometer, and Wind Scatterometer; Radar Altimeter (RA); Scanning Radiometer and Sounder (ASTR-M); Laser Reflector (LRR) - used for precise orbit determination and RA calibration; Precision Ranging Equipment (PRARE) - used for orbit determination. ERS-2 . Payload: ERS-2 carries the same suite of instruments as ERS-1 with the addition of the Global Ozone Measuring Equipment (GOME) which measures ozone distribution in the outer atmosphere. AMI SAR.
Having given excellent service 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. Since its launch on 17 July 1991, ESA’s first sun-synchronous polar-orbiting mission, made 45 000 orbits, acquiring more than 1.5 million individual Synthetic Aperture Radar (SAR) scenes. ERS-1 SAR images, together with the data from other instruments on board, were delivered to a worldwide community of some 4000 users in science and applications. Surface winds derived from the scatterometer and altimeter were supplied to meteorological services worldwide since 1991. The duration of the mission also meant that scientists had already observed several El Nino phenomena through combined observations of surface currents, topography, temperatures and winds. The measurements of sea surface temperatures, critical to the understanding of climate change, made by the ERS-1 Along-Track Scanning Radiometer were the most accurate ever from space. All these critical measurements were continued and enhanced by the follow-on ERS-2 mission.
Design Life: 3 years . Total Length: 11.0 m. Total Mass: 2,450 kg.
Microwave, IR imaging of oceans, ice and land; SAR. ERS-1 is an Earth exploration satellite, using active and passive sensors for oceanography etc. Frequency plan: 2048.85/2225 MHz (TTC), 7225.2960/8489 MHz (PRARE), 8040, 8140 MHz (data transmission). Launch time 0146:31 UT. Designator ESA/91/02.
deg E.uropean Remote Sensing; carried SAR; ocean, land, ice, and atmospheric observations.