Thermal Analysis and Validation of GF-4 Remote Sensing Camera

Abstract

The Chinese GF-4 satellite remote sensor is the highest spatial resolution among the civil satellite on the geosynchronous orbit, which carries on a camera with spatial resolution of 50 meter in the bands of visible and near infrared red and 400 meter in middle infrared red band. The thermal design of the spacecraft was challenging because the high resolution and the sensitivity requirement to achieve the desired scientific objectives. This paper presents the thermal analysis and test of the GF-4 in GEO orbit. The major findings of the analyses are the following. The GF-4 experiences complex, alternating external heat flux and faces direct sunlight in most of the orbital period. By applying a finite element model, the predicted temperature variation of the components remains in the desired temperature regime even in the extreme conditions. Comparing the thermal analysis results, the difference between the predicted and measured temperatures was less than 3°C for most of the components. The thermal control system functioned properly and the thermal model simulated the actual thermal design of GF-4. This thermal design method realizes the high efficiency and precision thermal control of the first high resolution geostationary orbit camera in China, which can provide reference for the high precision and stability thermal control of large aperture optical camera.