Passive Ranging Based on Observability Analysis and Receding Horizon Filter

In angle-only target tracking, the aim is to estimate the relative distance of a target and platform by using measurement of elevation and azimuth. In the case that both of the target and platform travel with constant velocity, the angle measurements cannot provide any information of the range between the target and the platform. The platform has to maneuver in order to estimate the range of the target. The observability of passive ranging is analyzed based on singular value decomposition of observable matrix. The relationship between the observability and aerocraft maneuver is obtained. Based on observability and Cramer-Rao lower bounds (CRLB), the maneuver strategy for improving observability is derived. To estimate the relative distance of the target and the platform, an algorithm of passive ranging is given using the receding horizon filter method. The simulation results show that the proposed method has a high estimation accuracy.