A dual-satellite joint positioning method with improved CTSL for high-speed targets

High-precision space-based optical positioning contributes a lot to high-speed targets’ instantaneous and accurate tracking and trajectory prediction. However, because of the line-of-sight (LOS) calibrated errors of one single satellite, including the interior and exterior orientation elements, and the poor efficiency and precision of the position calculation method based on the measurements of dual-satellite, it is still problematic to promote the ability of the aerospace defense system through the space-based optical guidance information. To address the problems mentioned above, this paper proposes a novel space-based dual-satellite joint positioning method based on the constrained total least squares (CTSL) for locating the space high-speed targets. First, the LOS orientation determining method and the analysis of the associated measurement errors of one single satellite are constructed elaborately to provide a theoretical foundation for joint positioning. Subsequently, taking the solution of the common least-squares as the initial value, a novel iterative joint positioning method with CTLS of dual-satellite is presented to complete the location parameters estimation with the constraints of random measurement errors. Finally, the simulation strategy and data based on STK are presented to demonstrate the effectiveness of the proposed method. Experimental results show that the positioning accuracy and stability of the proposed method for the high-speed targets are better than that of the conventional LOS cross-positioning method.