Atmospheric correction to IRS-P6 AWiFS data and its validation with ground measurements: A study over the semi-arid region

Abstract

In this study, we have implemented a fast atmospheric correction algorithm to IRS-P6 advanced wide field sensor (AWiFS) satellite data for retrieving surface reflectance under different atmospheric and surface conditions. The algorithm is based on MODIS climatology products and simplified use of Second Simulation of Satellite Signal in Solar Spectrum (6S) radiative transfer code. The algorithm requires information on aerosol optical depth (AOD) for correcting the satellite dataset. The atmospheric correction algorithm has been tested for IRS-P6 AWiFS False colour composites covering the International Crops Research Institute for the Semi-Arid Tropics Farm, Patancheru, Hyderabad, India, under varying atmospheric conditions. Ground measurements of surface reflectance representing different land use/land cover, i.e. red soil, chick pea, groundnut and pigeon pea crops were conducted to validate the algorithm. Terra MODIS AOD₅₅₀ validated with Microtops-II sun photometer–derived AOD₅₀₀ over the urban region of Hyderabad exhibited very good correlation of ∼0.92, suggesting possible use of satellite-derived AOD for atmospheric correction.

Keywords:

• atmospheric correction
• 6S code
• MODIS
• spectroradiometer
• sun-photometer

Acknowledgements

The authors thank the Director of NRSC and Deputy Director (RS&GIS-AA), NRSC for necessary help at various stages.