Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a sensor onboard the Terra satellite (pictured right), launched in December 1999. The Terra satellite also carries the MODIS sensor and follows a similar orbit to Landsat 7. ASTER is the result of a cooperative effort between NASA and Japan's Ministry of Economy, Trade and Industry (METI) and the Earth Remote Sensing Data Analysis Center (ERSDAC).
ASTER data may be used for a range of applications including land-use studies, mapping, geology, water resources, coastal resources, environment and generation of digital elevation models (DEM).
ASTER user advisory change in status alert - January 12, 2009.
ASTER SWIR detectors are no longer functioning due to anomalously high SWIR detector temperatures. ASTER SWIR data acquired since April 2008 is not useable, and show saturation of values and severe striping. All attempts to bring the SWIR bands back to life have failed, and no further action is envisioned. VNIR and TIR data continue to show excellent quality, meeting all mission requirements and specifications. More information.
ASTER's spectral bands and spatial resolution are generally more detailed than those of Landsat, meaning it is particularly useful for geological studies as well as environmental monitoring. However, unlike Landsat, repeat coverage by the ASTER sensor is more infrequent. This can be addressed to some extent by customers placing General Programming Requests (GPR) through Geoscience Australia.
The ASTER instrument consists of three separate instrument subsystems:
ASTER has 14 bands of information according to the following table:
| Instrument | VNIR | SWIR | TIR |
|---|---|---|---|
| Bands | 1-3 | 4-9 | 10-14 |
| Spatial resolution | 15m | 30m | 90m |
| Swath width | 60km | 60km | 60km |
| Cross track pointing | ± 318km (24 deg) |
±116km 8.55 deg) |
±116km (8.55 deg) |
| Quantisation (bits) | 8 | 8 | 12 |
| Note: Band 3 has nadir and backward telescopes for stereo pairs from a single orbit. |
The spectral range of each band is shown in the following diagram and table (courtesy NASA):
| Characteristic | VNIR | SWIR | TIR |
|---|---|---|---|
| Spectral Range | Band 1: 0.52 - 0.60 «m (visible green) Nadir looking |
Band 4: 1.600 - 1.700 «m | Band 10: 8.125 - 8.475 «m |
| Band 2: 0.63 - 0.69 «m (visible red) Nadir looking |
Band 5: 2.145 - 2.185 «m | Band 11: 8.475 - 8.825 «m | |
| Band 3: 0.76 - 0.86 «m (near infra-red) Nadir looking |
Band 6: 2.185 - 2.225 «m | Band 12: 8.925 - 9.275 «m | |
| Band 3: 0.76 - 0.86 «m (near infra-red) Backward looking |
Band 7: 2.235 - 2.285 «m | Band 13: 10.25 - 10.95 «m | |
| - | Band 8: 2.295 - 2.365 «m | Band 14: 10.95 - 11.65 «m | |
| - | Band 9: 2.360 - 2.430 «m | - |
To enquire about data availability or to order your ASTER satellite data, please contact Earth Observation Client Services.