ABSTRACT
There are many Earth observation satellite-based sensors, both active and passive, currently in orbit or planned for the near future. Representative of these, we describe briefly the multispectral ASTER system (Abrams et al., 1999) and the TerraSAR-X synthetic aperture radar satellite (Pitz and Miller, 2010). See Jensen (2005), Richards and Jia (2006) and Mather and Koch (2010) for overviews of remote sensing satellite platforms. The Advanced Spaceborne Thermal Emission and Reflectance Radiometer
(ASTER) instrument was launched in December 1999 on the Terra spacecraft. It is being used to obtain detailed maps of land surface temperature, reflectance and elevation and consists of sensors to measure reflected solar radiance and thermal emission in three spectral intervals:
• VNIR: Visible and near-infrared bands 1, 2, 3N, and 3B, in the spectral region between 0.52 and 0.86 µm (four arrays of charge-coupled detectors (CCDs) in pushbroom scanning mode).
