基于相位条纹的高精度GPS码相位测量方法

GPS接收机在测量卫星到接收机的传播距离时，通常能得到码相位和载波相位2个基本测量值。虽然载波相位测量值比码相位测量值精度高，但存在整周模糊度的问题，在实际应用中比采用码相位的技术付出的代价高很多。因此，基于相位条纹技术，提出了一种高精度的码相位测量方法。在传统码跟踪环的基础上，通过提取互功率谱相位条纹的频率，得到高精度的码相位测量值，从而组装出高精度的码伪距。仿真实验结果表明:在信噪比为-15 dB的情况下，码相位测量误差均方差约0.37 m，优于传统延迟锁定环在相同条件下约1.82 m的跟踪精度。得到了比传统码跟踪环更高的码相位测量精度的同时，不需要解算载波相位的整周模糊度，对提高GPS定位精度具有研究意义和应用价值。 

High-precision GPS code phase measurement method based on phase stripe

When GPS receiver measures the propagation distance from satellites to the receiver, it can usually obtain two basic measurement values, code phase and carrier phase. Although the precision of carrier phase measurement is higher than that of code phase measurement, there exists the integer ambiguity problem, whose cost is much higher than that of using code phase technique in practical application. Therefore, based on the phase stripe technique, a high-precision code phase measurement method was proposed. On the basis of the traditional code tracking loop, the high-precision code phase measurement value is obtained by extracting the frequency of the phase stripes of the cross-correlation power spectrum, so as to assemble a high-precision code pseudo-range. Simulation results show that the precision of code phase measurement is about 0.37 m when the SNR is -15 dB, which is better than the tracking accuracy of 1.82 m under the same condition of traditional delay lock loop. At the same time of obtaining the higher-precision code phase measurements, the integer ambiguity of the carrier phase does not need to be solved, which has research significance and application value for improving the GPS positioning precision.