Initial Operational Phase Radiometric Performance Verification of EOS-06 OCM-3 with Sentinel-3A/3B OLCI using Multipoint Targets

After the launch of any Earth Observation (EO) satellite, it is necessary to monitor the instrument’s performance to meet its specifications regularly. Cross-sensor verification is one such approach to check instrument radiometric performance concerning the available state-of-the-art instruments. In this work, the radiometric performance of Earth Observation (EOS-06) mission’s optical instrument Ocean Color Monitor (OCM-3) has been compared and verified with Sentinel-3A/3B Ocean and Land Colour Instrument (OLCI). To compensate for the difference in Relative Spectral Responses (RSR) of both instruments, the Spectral Band Adjustment Factor (SBAF) has been computed and applied to the data. To normalize the effect of time of imaging of the satellites, Top-of-Atmosphere (TOA) reflectance has been used for verification. In addition to that, OLCI products with close view angles with OCM-3 have been taken to minimize the difference in view angles of the satellites. The comparison shows a good spectral match between OCM-3 and OLCI TOA reflectance observations for various land and ocean targets.