A Radiometric Calibration Method for Defined Lunar Areas Based on SP Model

The Moon is an attractive target for radiometric calibration. The integrated signal from the lunar disk has been used to derive several empirical irradiance models, which are particularly useful for tracking instrument responsivity over time. Historically, numerous lunar exploration missions have performed photometric corrections on lunar surface observations, enabling comparison across diverse datasets. In this context, very little work has been done to utilize the photometric knowledge of specific lunar surface regions as a reference for the optical instruments of Earth-observing satellites. In this letter, we introduce a method for instrument calibration using the radiance of a defined surface portion through a photometric model developed based on spectral profiler (SP) data on board the SELENE Lunar Orbiter and conduct calibration experiments using lunar views captured by the panchromatic and multispectral sensor 2 (PMS2) of the JiLin-1 GuangPu02 (GP02) satellite operating in low-Earth orbit. Finally, the applicability and reliability of the calibration method are verified by comparison of disk reflectance and radiance. The method can be extended to other similar sensors and is beneficial for the development and application of lunar radiance models.