Intelligent Radiometric Calibration System for Ocean Color Satellite Sensors

• Published in: Journal of physics. Conference series Vol. 2829; no. 1; p. 012021
• Main Authors: Hu, Shixian, Chen, Shuguo, Wang, Junwei, Li, Sicong, Hu, Lianbo
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.09.2024
• Subjects: Aerospace environments; Calibration; GRACE (experiment); Lookup tables; Ocean color; Orbital stability; Performance degradation; Real time; Sensors
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/2829/1/012021

To achieve the integration of multiple ocean color (OC) sensors’ radiometric calibration tasks into a single system, we have developed an intelligent on-orbit radiometric calibration system called the Generalized Radiometric Calibration Entity for Ocean Color (Grace-OC). The system features real-time data downloading capabilities and integrates three calibration methods: onboard calibration, system vicarious calibration and cross calibration, enabling intelligent selection of on-orbit radiometric calibration methods tailored to the calibration sensors. Compared to other calibration systems, we have improved the universality and efficiency of the system by establishing high-spectral aerosols and Rayleigh lookup tables (LUTs) which are verified consistency through a comparative analysis with operational LUTs releasing by National Aeronautics and Space Administration (NASA) in this paper. Building upon this foundation, we have integrated a comprehensive analysis function for calibration coefficients to automatically construct degradation models of the radiometric measurement performance, and to achieve mutual verification between different calibration methods. We applied Grace-OC to HY1C/D and verified the feasibility of the intelligent selection calibration methods and the stability of the calibration system, achieving a calibration accuracy of up to 0.5%. Simultaneously, the precision of degradation models of the radiometric measurement performance is confirmed through Grace-OC, and the on-orbit radiometric calibration task was ultimately completed within 6 minutes for each per scene. Based on the above applications, Grace-OC has demonstrated its universality for various OC sensors, as well as the stability of on-orbit radiometric calibration tasks and the efficiency of operational speed.