Radiometric Cross-Calibration of an Aerial Sensor with Satellite Top-of-Atmosphere Reflectance

Surface reflectance (SR) is essential for many remote sensing applications, but retrieving it from aerial images is challenging due to the lack of in-flight radiometric calibration and varying acquisition conditions. We propose a novel method for radiometric cross-calibration of aerial imagery using satellite Top-of-Atmosphere (TOA) reflectance. The method involves estimating at-sensor reflectance at the airborne altitude from satellite TOA reflectance, followed by spectral band adjustment and spatial alignment between satellite and airborne imagery. A linear radiometric model is derived to relate the Digital Number (DN) to the at-sensor reflectance from a selected subset of robust aerial-satellite pixel correspondences. The radiometric calibration parameter was retrieved using linear regression. The method is particularly suitable for airborne campaigns that lack onboard or in-situ radiometric calibration equipment. An ablation study is presented to analyze the selection of reliable reference pixels.