Minimize Look up Surface Biome

Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals and soil organisms, and are often referred to as ecosystems.

In SLSTR Level-2 processing, a biome map is stored as an auxiliary data file containing a high spatial resolution map of vegetation type. The number of biomes is that of GLOBCOVER, i.e. 22, but for flexibility in likely processor updates, should be assumed to be a maximum of 50. However, the number of biomes in the biome map should be matched by the number of types of coefficients which are to be applied in the LST processor.

The appropriate biome for analysis for a given pixel should be selected as the biome which is the nearest neighbour. Studies indicate that the number of mixed pixels without a majority biome is only a few percent.

For each biome, six base retrieval coefficients must be supplied (two per class of coefficient), corresponding to the fully vegetated and bare soil states. The retrieval coefficients will be supplied for both day and night (making 12 retrieval coefficients in all) for each biome. There are also two constant parameters per biome, the values of which will be supplied as auxiliary parameters and are the same for both detector elements.

The process also finds the biome GEOTIFF grid of the cell containing the pixel Field Of View (FOV) centre and looks up the biome index for the corresponding tabulated coefficients.