Novel relative navigation for small satellite formation based on antenna arrays using impulse response

For small satellite formation, it is essential to determine precisely the position and velocity of a deputy satellite relative to a chief satellite. However, the traditional relative navigation systems that consist of many sensors have usually large volume and high cost. Considering the miniaturization of small satellites and their highly integrated functional modules, cost-effective relative navigation method is required. In this paper, a novel approach is proposed, called Relative Navigation using the Multi-dimension Channel Impulse Response (RNMCIR). A formation of several deputy vehicles (DVs) and one chief vehicle (CV) is considered. In RNMCIR, the existing communication systems and antenna arrays on flying vehicles are utilized and different DVs broadcast orthogonal spectrum spread sequences which can be received by the CV, simultaneously. First, by utilizing the code division multiple access (CDMA) scheme, the signals from different DVs can be separated, and the Channel Impulse Response (CIRs) are obtained by sliding-correlation. Based on the CIRs, the distances and angle-of-arrival (AoAs) of the line-of-sight (LOS) signal propagation paths from the DVs to the CV can be calculated. Then the observation equation of the EKF can be derived. Based on which, the relative position and velocity between the CV and DVs can be estimated iteratively. RNMCIR is theoretically proved and also validated by the simulation results in this paper. The signal transceiver architecture for inter-vehicle communications and the RNMCIR method are also presented for implementation in a real vehicle.