Resourcesat2- Awifs Sensor On-Orbit Radiometric Consistency Assessment Using Radcalnet Data

Advanced Wide Field Sensor (AWiFS) onboard Resourcesat2 (RS2) has been successfully operating for more than a decade, supporting various applications related to land resource planning and management. Vicarious Calibration is the most proven method for evaluating the on-orbit radiometric stability of satellite data. The Committee on Earth Observation Satellites (CEOS) initiated Radiometric Calibration Network (RadCalNet) facilitates the vicarious calibration of satellite sensors with traceable and quantifiable accuracy. RadCalNet data from the Railroad Valley Playa, Nevada site was used to study the radiometric performance consistency of RS2-AWiFS data for a period of 5 years (2016-2020) with more than 70 match ups. The average bias value over the entire period of study was consistent in all the four spectral bands of the sensor. Except for the SWIR band, observed biases in the rest of the three bands were within ± 5%, with sun/view geometry constraints. Significant biases were observed for larger sun/view zenith angles which can be due to the non-lambertian nature of the RadCalNet Railroad Valley Playa site.