基线比值法相位解模糊算法

Unwrapping Phase Ambiguity Algorithm Based on Baseline Ratio

研究了由N-1个等比值双基线系统组成的N基线测向系统的相位解模糊算法。对每个双基线系统(Pnλ20,Pn+1λ20)在(-p/2,p/2),(-q/2,q/2)范围内进行一维整数搜索,寻找出一组相位模糊解(k0n,l0n),根据二元一次不定方程,得到该双基线系统的模糊解,解的组数为Pn,Pn+1的最大公约数(Greatest common divisor,GCD),然后寻找由(P1λ20,P2λ20,P3λ30)构成的三基线系统的相位模糊解,解的组数为P1,P2和P3的最大公约数。以此类推,可得N基线系统的相位模糊解,如P1,P2,…,PN的最大公约数为1,那么就可得到惟一解,实现相位无模糊。该算法的计算量小,便于工程实现,仿真结果表明了算法的有效性。

The unwrapping phase ambiguity algorithm of N-baseline direction finding system including N-1 constant ratio double-baseline direction-finding subsystem is studied. One-dimensional integer search is made to find a pair of phase ambiguity number（k0n,l0n） within the scope of（-p/2,p/2）, （-q/2, q/2）for each double-baseline direction finding system （Pnλ0/2,Pn＋1λ0/2）. The pairs of phase ambiguity numbers of the double-baseline are acquired according to two variables first-order indefinite equation, which are equal to the greatest eommon divisor（GCD） of Pn and Pn＋1. The pairs of phase ambiguity numbers of the triple-baseline are the GCD of P1, P2 and P3 through the triple-baseline system composed of （P1λ0/2,P2λ0/2＋P3λ0/2）. The rest can be deduced by analogy, and the sets of phase ambiguity numbers of the N-baseline are obtained. The unique set of phase ambiguity numbers can be obtained if the GCD of P1, P2, …, PN is equal to unit. The algorithm has a low computation, thus it is suitable for real-time processing. Finally, simulation results verify its validity.