Satellite characteristics

Launch Date - End 798415200 - 1309903200

Status Decommissioned

Orbit type Sun-synchronous polar orbit

Altitude 780

Orbit inclination 98.5

Equatorial crossing time 10:30:00

Orbit period 100

Satellite family: ERS (European Remote-Sensing Satellite)

The European Remote Sensing satellite ERS-1, launched in 1991, carried a comprehensive payload including an imaging synthetic aperture radar, a radar altimeter and other powerful instruments to measure ocean surface temperature and winds at sea. ERS-2, which overlapped with ERS-1, was launched in 1995 with an additional sensor for atmospheric ozone research.

At their time of launch the two ERS satellites were the most sophisticated Earth observation spacecraft ever developed and launched by Europe. These highly successful ESA satellites collected a wealth of valuable data on Earth’s land surfaces, oceans, and polar caps and were called upon to monitor natural disasters such as severe flooding or earthquakes in remote parts of the world.

Both ERS satellites were built with a core payload of two specialised radars and an infrared imaging sensor. The two were designed as identical twins with one important difference: ERS-2 included an extra instrument to monitor ozone levels in the atmosphere.

Shortly after the launch of ERS-2 in 1995 ESA decided to link the two satellites in the first ‘tandem’ mission which lasted for nine months. During this time the increased frequency and level of data available to scientists offered a unique opportunity to observe changes over a very short space of time, as both satellites orbited Earth only 24 hours apart.

The ERS-1 mission ended on 10 March 2000 and ERS-2 was retired on 05 September 2011.

    Sensor characteristics

    Sensor name AMI SAR (Active Microwave Instrument Synthetic Aperture Radar)
    Sensor short description
    Sensor type Imaging microwave radar
    Resolution class High (5 - 30 m)
    Swath width (at nadir) 100 km
    Max look angle 23 °
    Sensor name AMI WS (Active Microwave Instrument Wind Scatterometer)
    Sensor short description
    Sensor type Imaging microwave radar
    Resolution class Very Low (> 1 km)
    Swath width (at nadir) 500 km
    Max look angle 47 °
    Sensor name ATSR IRR (Along Track Scanning Radiometer Infra-Red Radiometer)
    Sensor short description
    Sensor type Imaging radiometer (Vis/IR)
    Resolution class Very Low (> 1 km)
    Swath width (at nadir) 500 km
    Max look angle 47 °
    Sensor name ATSR MWS (Along Track Scanning Radiometer Microwave Sounder)
    Sensor short description
    Sensor type Imaging microwave radar
    Resolution class Very Low (> 1 km)
    Sensor name GOME (Global Ozone Monitoring Experiment)
    Sensor short description
    Sensor type Atmospheric instrument
    Resolution class Very Low (> 1 km)
    Swath width (at nadir) 960 km
    Max look angle 31 °
    Sensor name MWR (Microwave Radiometer)
    Sensor short description

    MWR is a nadir-viewing, two-channel Dicke-type radiometer (passive sensor). The main objectives of MWR is the measurement of atmospheric humidity as supplementary information for tropospheric path correction of the RA-2 signal, which is influenced by the integrated atmospheric water content and by liquid water. In addition, MWR measurements are useful for the determination of surface emissivity and soil moisture of land, for surface energy budget estimations, investigations to support atmospheric studies, and for ice characterization.

    Sensor type Imaging radiometer (passive microwave)
    Resolution class Very Low (> 1 km)
    Spectral bandwidth 23.8 (K-band) and 36.5 (Ka-band) GHz
    Swath width (at nadir) 20 km
    Max look angle 47 °
    Sensor name RA (Radar Altimeter)
    Sensor short description
    Sensor type Radar altimeter
    Resolution class Very Low (> 1 km)