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SMAPEx-4 Archive
Soil Moisture Active Passive Experiment

The Advanced SCATterometer (ASCAT)

The ASCAT, operating at C-band, provides continuity to the ERS-1 and ERS-2 scatterometers. The ASCAT is onboard the Metop-A satellite, which was launched into a sun-synchronous orbit on 19 October 2006 and has been operational since May 2007. ASCAT operates at a frequency of 5.255GHz in vertical polarisation. Its use of six antennas allows the simultaneous coverage of two swaths on either side of the satellite ground track, allowing for much greater coverage then its predecessors. It takes about 2 days to map the entire globe. A 50 km resolution soil moisture product is now operational from ASCAT, available from EUMETSAT.


The features of ASCAT are summarized below.




Microwave radar



Launch date

19th, Oct. 2006

Design life

5 years


Polar orbit at an angle of 98.7° to the equator and at an altitude of 758km.

Spacecraft operations control centre

European Meteorological Satellite Organisation (EUMESAT)

Centre frequency (GHz)

5.255 (C-band)



Swath (km)

Two 520km swaths at each side, with 700km gap between them

Spatial resolution (km)


Temporal resolution

~2 days for covering global







Created: February 2016
Last Modified: June 2016
Maintainer: Xiaoling Wu, xiaoling.wu@monash.edu