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.
Source: http://www.meted.ucar.edu, accessed on 28th, Apr. 2010
Mission |
ASCAT |
Sensor |
Microwave radar |
Spacecraft |
Metop-A |
Launch date |
19th, Oct. 2006 |
Design life |
5 years |
Orbit |
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) |
Polarisation |
VV |
Swath (km) |
Two 520km swaths at each side, with 700km gap between them |
Spatial resolution (km) |
50 |
Temporal resolution |
~2 days for covering global |
ASCAT overpass time
The ASCAT overpass times for the SMAPEx study area have been determined from a Fortran program based on NORAD data, and are provided in the table below. Date and time are in UTC.
●=full ASCAT coverage of airborne box; ○=partial ASCAT coverage
●=concurrent; ●=non concurrent
Date (UTC) |
ASCAT overpass start time (UTC) |
Durations (s) | Flight Type |
| 05/09/2011 |
|
59 |
|
| 05/09/2011 |
|
176 |
|
| 07/09/2011 |
|
241 |
|
| 07/09/2011 |
|
204 |
|
| 10/09/2011 |
|
148 |
|
| 13/09/2011 |
|
- |
|
| 15/09/2011 |
|
109 |
|
| 18/09/2011 |
|
- |
|
| 19/09/2011 |
|
201 |
|
| 19/09/2011 |
|
239 |
|
| 21/09/2011 |
|
180 |
|
| 21/09/2011 |
|
73 |
|
| 23/09/2011 |
|
- |
|