INSAT-VHRR based measurements and interpretation of sunglint signatures for the estimation of near-surface wind speeds over oceans

Presents the results estimation of wind speeds over oceanic regions based on the analysis of SUNGLINT signatures observed in INSAT-VHRR visible band images. Wind speed estimates are derived using the observed intensity gradients across the glinted area. Which is observed to cover a very large region. Sometimes approaching a few million sq. kms. Analysis of sunglint signatures recorded simultaneously on VHRRs onboard INSAT-1D and INSAT-2A satellites, located 10° apart on the equator on Feb. 17, 1993 at 0600 GMT is presented and discussed. The estimated wind speed values over the glint region are compared with the monthly mean wind speed climatological values over the region of interest at well at with near-simultaneous wind speed and wave height measurements from radar altimeter onboard ERS-1. The results indicate the good possibility of estimation of wind speeds using sunglint signatures observed in geostationary VHRR images with an estimated accuracy of ±1.5 m/sec