Validation of INSAT-3D Atmospheric Motion Vectors

Satellite derived Atmospheric Motion Vector (AMV) is one of the most important sources of tropospheric wind information assimilated in numerical weather prediction (NWP) system. Earlier studies showed that the quality of Kalpana-1 AMVs was not comparable to that of other geostationary satellites and hence not used in NWP system. This was due to the error associated with empirical height assignment method used to derive Kalpana-1 AMVs. Recently the height assignment method and quality control scheme for deriving INSAT-3D AMVs have been modified. The validation of INSAT-3D AMVs against NCMRWF’s NWP short range forecasts (first guess) and in-situ observations has been carried out for January 2015, and compared with that of METEOSAT-7. Present study revealed noticeable improvement in the quality of INSAT3D AMVs. The root mean square vector difference (RMSVD) and bias of INSAT-3D AMVs computed against NWP first guess and in-situ observations are lower compared to that of METEOSAT-7.