Satellite Observations
Satellite observations can be used to directly assess the state of the HMA region, and they form the basis of inventory products that document land cover states, for example the location and timing of landslides or the extent of glaciers. These observations are also a vital component of all modeling efforts because they provide a means for calibration. This is particularly important for those physical processes that are poorly understood and must be parameterized within existing models. Observations are also used to validate model simulations, providing an independent measure of model. Finally, satellite observations enable statistical assessment of model quality and are assimilated into many modeling schemes to improve regional assessments.
It is important to note that many remote sensing products must themselves pass through ground validation phases before they can be used in the larger HiMAT effort. For example, many satellite products use radiative transfer algorithms to convert radiance values to meaningful land surface properties.