Terra / ASTER
NASA's Terra satellite is mounted in 1999. It operates in a polar sun-synchronous orbit at 705 km above the Earth's surface, crossing the equator on descending passes at 10.30 AM. There are five seperate modules on the satellite. It has 14 bands which have high spatial, spectral, and radiometric resolution. The image size is 60 x 60 km.
| Band | Spectral Range ( µm) | Spatial Resolution (m) |
|---|---|---|
| 1 | 0.52-0.60 | 15 |
| 2 | 0.63-0.69 | 15 |
| 3 | 0.78 - 0.86 | 15 |
| 3N | 0.78 - 0.86 | 15 |
| 4 | 1.60-1.70 | 30 |
| 5 | 2.145-2.185 | 30 |
| 6 | 2.185-2.225 | 30 |
| 7 | 2.235-2.285 | 30 |
| 8 | 2.295-2.365 | 30 |
| 9 | 2.360-2.430 | 30 |
| 10 | 8.125-8.475 | 90 |
| 11 | 8.475-8.825 | 90 |
| 12 | 8.925-9.275 | 90 |
| 13 | 10.25-10.95 | 90 |
| 14 | 10.95-11.65 | 90 |
Stereoscopic Image
ASTER is capable of stereoscopic imaging in the near infrared band. One of the 2 sensors which is in near-infrared spectral range looks backwards, while the other is perpendicular to the ground. With this feature stereoscopic viewing is obtained.
Digital Elevation Model
It is possible to generate digital elevation model (DEM) by means of sensors which have different perspectives.
Short-Wave Infrared
6 Short-wave infrared (SWIR) bands are used directly or indirectly in lithological mapping in earth science studies.
Thermal Infrared
Thermal Infrared (TIR) encompasses 5 band ranges. In addition to information on surface temperature, it is also used in lithological mapping. Thermal imaging is based on the principle of heat dissipation of all objects that is over the value of absolute zero temperaturte value