FPGA-based hardware/firmware co-design for real-time radiometric correction onboard microsatellite

Remote sensing images are inevitably produced with radiometric artifacts due to the photo-response non-uniformity of charge-coupled device (CCD) sensors. In situations where time constraints demand the prompt acquisition of imaging products, integrating an onboard radiometric correction system becomes essential. This paper advocates for a hardware–firmware co-design approach to achieve radiometric correction within the payload front-end electronics (FEE), leveraging the capabilities of field programmable gate array circuits (FPGA). The selection of an appropriate CCD sensor and optical device is guided by a thorough payload mission analysis, ensuring compliance with the specifications derived from Alsat-1B, the Algerian microsatellite launched in September 2016. Simulation results demonstrate that the designed FPGA firmware effectively controls the CCD sensor and configures its settings to achieve real-time radiometric correction of the acquired pixels in accordance with the mission requirements. To ensure efficient utilization during imaging operations, a hardware solution for onboard storage and in-orbit update of the radiometric coefficients has been considered for the radiometric correction system.