ATSR Total Water Vapour Content Retrieval and Comparison with GOME and ATSR Microwave Sounder Data

The Water Vapour estimation from satellite data has been widely discussed in past years and different IR based techniques have been approached by various authors. In our work we estimate the total content of water vapour over sea surface by using ATSR-2 (Along Track Scanning Radiometer) Infra Red imagery. Two different retrieval methods have been applied: one proposed by Ottlé [1] in 1997 and the other by Barton and Prata [2] in 1999. Taking advantage from the multisensor configuration of the ERS-2 platform, the computed total content of Water Vapour from ATSR data, has then been compared with the one derived by other two on-board instruments: GOME (Global Ozone Monitoring Experiment) and ATSR-MW (Microwave Radiometer). For performing the comparison analysis, we have selected data on different geographic locations, sensed at the same time by all three instruments. The results indicate a good agreement of ATSR-IR water vapour estimation with GOME and ATSR-MW when we use the retrieval method suggested by Barton and Prata.