In-orbit calibration of the pyramid coarse sun sensor using Lyapunov-based conical maneuvers of the satellite: A new framework

Abstract

Due to the lightweight, inexpensive, and simplicity, coarse sun sensors (CSS) are an interesting part of the small satellites with low-earth orbit. However, the CSS drawbacks such as low accuracy and nonlinear distribution of the error contours through the sensor Field of View (FOV) apply a notable limitation in its application. This forces the literature to focus on laboratory or in-orbit calibration methods. The excellence of the in-orbit calibration in comparison with the laboratory cases is clear; however, the difficulty is to achieve enough data when the satellite is launched. To solve that, in this paper, a conical maneuver based on the Lyapunov theory is designed which causes the sunlight to cover the sensor FOV. After that, using the achieved rich data pack, the CSS calibration process, including the sensor misalignment, solar cells misalignment, and solar cells characteristic curve (Fresnel effect), is accomplished. Moreover, the results show that the combination of the new calibration methods with the iterative least square (ILS) algorithm leads to 0.89° accuracy through the FOV of 120°.