Observability of Airborne Passive Location System with Phase Difference Measurements
With a pair of antennas spaced apart, an airborne passive location system measures phase differences of emitting signals. Regarded as cyclic ambiguities, the moduli of the measurements traditionally are resolved by adding more antenna elements. This paper models the cyclic ambiguity as a component of the system state, of which the observability is analyzed and compared to that of the bear- ings-only passive location system. It is shown that the necessary and sufficient observability condition for the bearings-only passive location system is only the necessary observability condition for the passive location system with phase difference measurements, and that when the system state is observable, the cyclic ambiguities can be estimated by accumulating the phase difference measurements, thereby making the observer able to locate the emitter with high-precision.
作 者： Deng Xinpu Wang Qiang Zhong Danxing 作者单位： College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China 刊 名： 中国航空学报（英文版） ISTIC 英文刊名： CHINESE JOURNAL OF AERONAUTICS 年，卷(期)： 2008 21(2) 分类号： V2 关键词： passive location phase difference observability accuracy