Advanced Along-Track Scanning Radiometer (AATSR)

Source:http://www.naturalsciences.be	Source: http://mtp.jpl.nasa.gov

Advanced Along-Track Scanning Radiometer (AATSR) is one of the Announcement of Opportunity (AO) instruments on board the European Space Agency (ESA) satellite ENVISAT. It is the most recent in a series of instruments designed primarily to measure Sea Surface Temperature (SST), following on from ATSR-1 and ATSR-2 on board ERS-1 and ERS-2. AATSR data have a resolution of 1 km at nadir, and are derived from measurements of reflected and emitted radiation taken at the following wavelengths: 0.55 µm, 0.66 µm, 0.87 µm, 1.6 µm, 3.7 µm, 11 µm and 12 µm. Special features of the AATSR instrument include its use of a conical scan to give a dual-view of the Earth's surface, on-board calibration targets and use of mechanical coolers to maintain the thermal environment necessary for optimal operation of the infrared detectors. AATSR coverage for the SMAPEx study area is summarised in the table below. AATSR data can be downloaded from ESA.

Mission	AATSR
Sensor	Advanced Along-Track Scanning Radiometer (AATSR)
Spacecraft	Envisat
Launch date	1st, Mar. 2002
Design life	3 years with a goal of 5 years
Orbit	Sun-synchronous polar orbit (SSO): Nominal reference orbit of mean altitude 800km, 35 days repeat cycle, 10:00am mean local solar time (MLST) descending node, 98.55°. inclination. [envisat.esa.int]
Spacecraft operations control centre	ESA
Accuracy	Sea surface temperature: <0.5K over 0.5 deg x 0.5 deg (lat/long) area with 80% cloud cover Land surface temperature: 0.1K (relative)
Swath (km)	500
Waveband	VIS - NIR: 0.555, 0.659, 0.865 micrometers, SWIR: 1.6 micrometers, MWIR: 3.7 micrometers, TIR: 10.85, 12 micrometers
Spatial resolution (m)	IR ocean channels: 1km x 1km, Visible land channels: 1km x 1km
Temporal resolution	35 days repeat cycle