Design and Verification of an Integrated Panoramic Sun Sensor atop a Small Spherical Satellite

Abstract

This paper proposes an integrated panoramic sun sensor (IPSS) for the small spherical satellite Q-SAT that has been working in orbit since 2020. IPSS is essentially a set of temperature-compensated photoelectric cells distributed on the spherical surface of Q-SAT. Compared with traditional sun sensors, IPSS has full spherical coverage of 4π so that the sun vector from any direction can be inversed. The mechatronic design and mathematical model of the proposed IPSS are presented. In-depth error analyses in terms of albedo effect, sampling error, parameter deviation, etc. are carried out. IPSS can provide a sun vector inversion accuracy of 1.5∘ where albedo disturbance does not dominate. Simulation results show that the measurement of IPSS together with a COTS magnetometer can support the three-axis attitude determination of satellites in various orbits and can adapt to the seasonal variations of subpolar points. Ground experimental results and on-orbit data have also verified the feasibility and performance of IPSS. Although the panoramic sun sensor is designed for the small spherical Q-SAT, it can also be applied to other satellites with limited power budgets.

An All-Day Attitude Sensor Integrating Stars and Sun Measurement Based on Extended Pixel Response of CMOS APS Imager

“…Results show that the orientation accuracy from sun measurement is better than 9" (3σ), and the attitude accuracy from star measurement is better than 5" (3σ) for pointing and 11" (3σ) for rolling respectively. Existing conventional sun sensors have the highest accuracy up to about 0.01° [44]. It can be seen that while maintaining the high-precision stars measurement function, the integrated sensor also has the ability to measure the sun in the daytime, and the accuracy is significantly better than the existing camera-based sun sensors.…”

Power Generation Calculation Model and Validation of Solar Array on Stratospheric Airships

“…Several studies have reported such a reduction in photovoltaic conversion efficiency with the angle, which has been referred to as angular loss or Kelly cosine characteristics [26,[35][36][37][38][39]. Angular loss typically occurs when the radiation incidence angle surpasses about 47.5 • , diminishing to zero beyond 80 • [40]. The photovoltaic conversion efficiency decay factor (PCEDF) µ is introduced to correct the impact of the radiation incidence angle on the photovoltaic conversion efficiency of the solar cells, and the solar radiation incidence angle θ in determines its value, as follows:…”