High-precision thermal control and verification of large-sized calibration blackbody for space remote sensors

Abstract Space infrared cameras perform non-uniformity correction of detectors through on-board calibration in orbit. Using the blackbody component inside the camera as a standard radiation source is a commonly used method. As the accuracy of calibration increases, there are also high requirements for the temperature stability and uniformity of the blackbody inside the camera. This article addresses the problem of thermal control of large-scale internal black bodies and proposes a hybrid temperature control method that relies primarily on radiation and is supplemented by thermal conduction. By modulating the thermal resistance of thermal conduction, the influence ratio of radiation and thermal conduction can be adjusted to ensure control capability while maximizing the temperature uniformity of the controlled black body. After flight verification, the blackbody temperature stability can reach ±0.1K, and the temperature uniformity can reach 0.2K, meeting the calibration accuracy requirements of remote sensing imaging. This article improves the traditional blackbody control scheme that relies solely on temperature control algorithms, introducing active and passive thermal control measures to meet the new requirements of large-scale blackbodies. The scheme adopted can provide a reference for temperature control of large-scale surface source blackbody.