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TABLE 
ERS-1 onboard instrumentation and the main geophysical measurement objectives 
J3p3Quugap|Boc 
  
  
  
  
MAIN INSTRUMENT MAIN GEDPHYSICAL PARAMETER RANGE ACCURACY 
Wind field 
Wind scatterameter  - Velocity 4-24 m/s + 2 ms or 10% 
& Altimeter whichever is greater 
Wind scatterameter ^ - Direction 0-360* + 20° 
Wave field 
Altimeter - Significant wave height 1-20 m + 0.5 or 10% 
whichever is greater 
Wave mode — Wave direction 0-360° +15° 
Wave mode - Wavelength 50-1000m 20% 
Earth surface imaging 
SAR imaging mode - Land/ice/coastal zones etc. 80 KM Geometric/radiometric 
(minimum resolutions: 
swath width) a) 30 m/2.5 dB 
b)100 m/1 dB 
Altitude 
Altimeter - Üver ocean 745-825 km 2 m absolute 
+ 10 cm relative 
PRARE Satellite Range + 10 cm 
ATSR (IR) Sea surface temperature 500 km swath — - 0.5 K 
W sounder Water vapour in 25 km spot 105 
  
  
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