Seasonal calibration for the simplified on-orbit external heat flux calculation method

Abstract

The MODTRAN-based external heat flux (EHF) calculation method provides greater accuracy than the simplified approach, which assumes a constant albedo for Earth. However, unlike the simplified method, the MODTRAN-based approach lacks the computational speed required for real-time applications. Therefore, this study investigated calibrating the simplified method using the Gaussian process regression (GPR) to align its results with the MODTRAN-based benchmark better. During the Spring Equinox, Summer Solstice, Autumn Equinox, and Winter Solstice, the maximum percentage absolute error of the calibrated simplified method was below 2 %, representing a 13 % reduction in error compared to the uncalibrated method. The EHF values obtained from the MODTRAN-based, simplified, and calibrated methods were used to simulate spacecraft temperature distributions. The results demonstrate that the calibrated method effectively reduced errors, producing temperature distributions closer to the benchmark and confirming the necessity and effectiveness of seasonal calibrations.