伪码信号辅助的CEI载波时延模糊度解算

摘要

针对连线干涉测量系统(CEI)在无模型时延或模型时延不准确条件下相位模糊度解算困难的问题,提出了利用伪码测距信号辅助的载波相位模糊解算方法.在测站距离约束下,根据两站所接收伪码信号的相对位置关系计算得到一个时延差作为解载波相位模糊的时延预报值.为了提高解模糊能力,引入了伪码捕获和跟踪的基本方法.仿真分析了不同信噪比下所能达到的最大精度,结果表明在信噪比高于0 dB时,可直接解算S频段的载波相位模糊;在信噪比较低时,可解算宽带群时延的相位模糊.在0 dB 和-30 dB 条件下重复试验1000次,正确率分别达到99.88%和99.91%,证明了算法的有效性.%It's difficult to get a precise ambiguity value of connected elements interferometry(CEI) when the model delay is not precise or there's no model delay.For this problem,a method with the auxiliary of pseudo-noise(PN) code ranging signal is given.Under the constraint of distance of two stations,a predic-tion value of differential-delay can be calculated according to the relative position relation of PN code re-ceived by two stations.In order to improve the ability of ambiguity resolution,the basic method of PN code acquisition and tracking is introduced.The maximum precision that can be achieved under different signal-to-noise ratio(SNR) is simulated and analyzed,the results show that when the SNR is higher than 0dB,no-ambiguity phase delay can be directly solved.When the SNR is low,the wideband group delay can be solved.The experiment is repeated 1000 times under the condition of 0dB and -30dB respectively,and the correct rates are respectively 99.88% and 99.91%,which proves the effectiveness of the algorithm.