AATSR IPF improvements, Land Surface Temperature Retrieval adn Cloud Clear
ing Over Land
Improvements to the AATSR IPF relating to Land Surface Temperature Retrieval and Cloud Clearing over Land
This Technical Note describes the improvements to the cloud clearing over land, and the LST algorithm, which were included in IPF v6.0. The information contained in this document is applicable to versions 6.0 or greater of the IPF. The specific changes to the products are given below. For Level 1B products these are: the implementation of gross cloud test over land; the disabling of spatial coherence test over land, by clearing resulting flag if pixel over land and two new flags in the cloud flag words of the L1B ATS_TOA_1P products, introduced at bits 13 and 14. For Level 2 products these are: flagging of marginal cloud land pixels, where LST retrieved anyway, bit 11 of Level 2 confidence word, previously used for sea pixels only; the flagging of inland lakes, using bit 12 of Level 2 confidence word previously used for sea pixels only and extended land flag (bit 4) [Note: the combined fields contain NDVI for lake pixels], and also the implementation of averaged LST, replacing the 11 micron BT placeholder.