中文摘要：

本文从L2C监测跟踪网的数据出发，分析了其中六个监测站的信噪比（SNR）数据。首先分析了未调制L2C码卫星的L1载波和L2载波的信噪比，得出此时的12的信噪比数值相对较小（L1载波的信噪比均值与L2的信噪比均值差异最大为19．1dB）且稳定性较差；随后分析了调制有L2C码的卫星的L1载波和L2载波的信噪比，得出现代化后的L2载波信噪比与L1载波的信噪比基本一致（两个信噪比之差基本上在5dB左右）；进而得出结论：调制有L2C码的L2载波具有更好的数据稳定性和抗干扰能力，且具有易于捕获的特点。

英文摘要：

In this paper, signal to noise ratio （SNR） of six test stations is analyzed using the data of L2C tracking test network. Firstly, by analyzing the SNR values on the L1 and L2 frequencies of the satellites unmodulated L2C, SNR values of L2 are smaller （ the most differences of mean SNR values of L1 and L2 is about 19. ldB） and instable, and then analyzing the SNR values on the L1 and L2 frequencies of the modernized satellites, SNR values of L2 are nearly conform with L1 （ the differences of SNR on the L1 and L2 are about 5 dB） , so the result is that the modernized L2 frequency has the futures of having more stabled data and better ability of anti-jamming and easily captured.