Advanced Spaceborne Thermal Emission and Reflection Radiometer

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ASTER image draped over terrain model of Mount Etna

ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is one of five remote sensory devices on board the Terra satellite launched into Earth orbit by NASA in 1999. The instrument has been collecting surficial data since February 2000.

ASTER provides high-resolution images of the Earth in 15 different bands of the m, ranging from visible to thermal infrared light. The resolution of images ranges between 15 to 90 meters. ASTER data are used to create detailed maps of surface temperature of land, emissivity, reflectance, and elevation.


ASTER image of Rub' al Khali (Arabia's Empty Quarter).
Band Label Wavelength
Nadir or
B1 VNIR_Band1 0.520–0.600 15 Nadir Visible Green/Yellow
B2 VNIR_Band2 0.630–0.690 15 Nadir Visible Red
B3 VNIR_Band3N 0.760–0.860 15 Nadir Near Infrared
B4 VNIR_Band3B 0.760–0.860 15 Backward
B5 SWIR_Band4 1.600–1.700 30 Nadir Short-wave Infrared
B6 SWIR_Band5 2.145–2.185 30 Nadir
B7 SWIR_Band6 2.185–2.225 30 Nadir
B8 SWIR_Band7 2.235–2.285 30 Nadir
B9 SWIR_Band8 2.295–2.365 30 Nadir
B10 SWIR_Band9 2.360–2.430 30 Nadir
B11 TIR_Band10 8.125–8.475 90 Nadir Long-wave Infrared
or Thermal IR
B12 TIR_Band11 8.475–8.825 90 Nadir
B13 TIR_Band12 8.925–9.275 90 Nadir
B14 TIR_Band13 10.250–10.950 90 Nadir
B15 TIR_Band14 10.950–11.650 90 Nadir

ASTER Global Digital Elevation Model

On 29 June 2009, the Global Digital Elevation Model (GDEM) was released to the public.[1][2] A joint operation between NASA and Japan's Ministry of Economy, Trade and Industry (METI), the Global Digital Elevation Model is the most complete mapping of the earth ever made, covering 99% of its surface.[3][4] The previous most comprehensive map, NASA's Shuttle Radar Topography Mission (SRTM), covered approximately 80% of the Earth's surface, [5] with a global resolution of 90 meters,[6] and a resolution of 30 meters over the USA. The GDEM covers the planet from 83 degrees North to 83 degrees South (surpassing SRTM's coverage of 56 °S to 60 °N), becoming the first earth mapping system that provides comprehensive coverage of the polar regions.[5] It was created by compiling 1.3 million VNIR images taken by ASTER using single-pass[7] stereoscopic correlation techniques,[1] with terrain elevation measurements taken globally at 30 meter (98 foot) intervals.[3]

Despite the high nominal resolution, however, some reviewers have commented that the true resolution is considerably lower, and not as good as that of SRTM data, and serious artifacts are present.[8] Some of these limitations have been confirmed by METI and NASA, who point out that the current version of the GDEM product is "research grade". [9]

See also


External links