Experimental validation of a novel radiation based model for spacecraft attitude estimation

Attitude Determination (AD) is one of the key requirements of many current and emerging remote sensing missions. As such AD has been traditionally accomplished through a variety of algorithms and measurement models pertinent to sensing mechanisms. The current paper addresses conceptual validation and utility of a novel radiation based heat (measurement) model for space application. The proposed new Heat Attitude (HA) model utilizes temperature data to relate the Satellite Surfaces' (SS) Net Heat Flux (NHF) to attitude assuming that the satellite navigational data are available. As Sun and the Earth are considered the main external sources of radiation, their effects are modeled for the SS temperature changes via a novel measurement model and sensing mechanism. In this respect and in order to experimentally validate the capability of the proposed HA model, a Cubic Laboratory Satellite (CLS) with three orthogonal copper coated surface plates is constructed. Next, Non-Contact Thermopiles (NCT) are installed to measure the SS radiative temperatures in a vacuum chamber equipped with a Sun simulator. Subsequently, the CLS is tested under static and dynamic scenarios where the temperature data are used for error analysis and model validation via an Extended Kaman Filter (EKF). Comparison of the CLS true and HA model EKF estimated attitudes demonstrate a good accuracy. In this sense, the proposed novel HA model is promising and paves the way for a new low cost alternative approach for space AD applications.