Retrieval of Atmospheric Water Vapor using Band Ratio Method and Its Validation with MODIS Satellite Data

This study focused on the retrieval and validation of Atmospheric water vapor (WV), an important parameter in studying surface-atmosphere interaction. We employed the MODTRAN RT model for simulations of at sensor radiance with varying WV values from extreme values. The retrieval of WV was accomplished by using the band ratio method, which relies on the ratio of WV absorption band to the window band to detect WV absorption of reflected solar radiation. Terra MODIS WV product for 8 February 2023 was utilized to validate the retrieved WV and the results were also validated with in-situ data obtained from a sun photometer. Validation of results with MODIS data show RMSE of 0.18 gm/cm
²
and R
²
of 0.67. Retrieval results also matches well with in-situ measurement. Overall, this study aimed to assess the accuracy and reliability of the retrieved WV content from Terra MODIS data and its validation with ground-based measurements