The Advanced Microwave Scanning Radiometer for EOS (AMSR-E) is a twelve-channel, six-frequency, total power passive-microwave radiometer system. It measures brightness temperatures at 6.925, 10.65, 18.7, 23.8, 36.5, and 89.0 GHz. Vertically and horizontally polarized measurements are taken at all channels. The Earth-emitted microwave radiation is collected by an offset parabolic reflector 1.6 meters in diameter that scans across the Earth along an imaginary conical surface, maintaining a constant Earth incidence angle of 55° and providing a swath width array of six feedhorns which then carry the radiation to radiometers for measurement. Calibration is accomplished with observations of cosmic background radiation and an on-board warm target. Spatial resolution of the individual measurements varies from 5.4 km at 89.0 GHz to 56 km at 6.9 GHz.

Instrument Characteristics

  • Passive microwave radiometer, twelve channels, six frequencies, dual polarization, conically scanning.
  • Measures precipitation rate, cloud water, water vapor, sea surface winds, sea surface temperature, ice, snow, and soil moisture.
  • All-weather measurements of geophysical parameters supporting several global change science and monitoring efforts.
  • External cold load reflector and a warm load for calibration.
  • Offset parabolic reflector, 1.6 m in diameter, and rotating drum at 40 rpm.
  • Multiple feedhorns (6) to cover six bands from 6.9 to 89 GHz with 0.3 to 1.1 K radiometric sensitivity; vertical and horizontal polarization.
Instrument Facts
Responsible Agency: Japan Aerospace Exploration Agency (JAXA)
Heritage: Scanning Multichannel Microwave Radiometer (SMMR) on board Nimbus 7 and Seasat, Special Sensor Microwave Imager (SSM/I) on board the Defense Meteorological Satellite Program (DMSP), Advanced Microwave Scanning Radiometer (AMSR) on board the Advanced Earth Observing Satellite II (ADEOS II)
Accuracy: 1 K or better
Swath: 1445 km
Spatial Resolution: 6 x 4 km (89.0 GHz), 14 x 8 km (36.5 GHz), 32 x 18 km (23.8 GHz), 27 x 16 km (18.7 GHz), 51 x 29 km (10.65 GHz), 75 x 43 km (6.925 GHz)
Incidence Angle: 55°
Sampling Interval: 10 km for 6-36 GHz channels, 5 km for the 89 GHz channel
Mass: 324±15 kg
Duty Cycle: 100%
Data Rate: 87.4 kbps avg, 125 kbps peak
Thermal Control By: Passive radiator, thermostatically controlled heaters
Thermal Operating Range: -5 to 40°C
Pointing Requirements, design value (instrument only, 3σ)
Accuracy: 600 arcsec/axis for roll and pitch; NA for yaw
Knowledge: 300 arcsec/axis for roll and pitch; NA for yaw
Stability: 80 arcsec/sec/axis for roll and pitch; NA for yaw
Jitter: TBD
Physical Size: Sensor Unit: 139.7 x 77.5 x 76.2 cm (stowed), 139.7 x 151.2 x 76.2 cm (deployed)
Control Unit: 0.8 x 1.0 x 0.6 m