oa Наличие безоблачных снимков Landsat TM и ETM + и последствия для мирового производства данных Landsat

The NASA funded Web‐enabled Landsat Data (WELD) project generates 30m composited Landsat 7 Enhanced Thematic Mapper Plus (ETM+) mosaics of the conterminous United States and Alaska using terrain corrected (Level 1T) data. Recent WELD prototyping has demonstrated the feasibility of generating global Landsat monthly products. In this paper the global availability of cloud‐free Landsat ETM+ and Thematic Mapper (TM) data and the monthly probability of acquiring a cloud‐free land surface observation for the two instruments independently and fused together are reported for climate year 2010. The analysis uses more than 90,000 Landsat Level 1T scene metadata records obtained from the US Landsat archive. The results demonstrate the utility of fusing both Landsat data streams which increases the mean monthly global probability of a cloud‐free land surface observation by up to 37% relative to using Landsat ETM+ data only. Recommendations for global Landsat processing and implications for global Landsat data fusion with similar polar orbiting high spatial resolution sensors are described.