基于QZSS L1信号的岸基GNSS-R码延迟海面测高

为了探究GNSS L1波段中信号不同调制方式的GNSS-R码相位延迟海面的测高性能，开展了双天线岸基GNSS-R海面测高实验，收集了采样率为40 MHz的原始中频数据。利用自主开发的GNSS-R测高软件接收机和反演软件对实验数据进行了处理分析，同时获得了基于QZSS L1C/A码和L1C码的GNSS-R海面测高结果，并分别与岸基同步观测的雷达高度计的测高值进行对比，以对反演结果进行精度评定。实验结果表明:基于QZSS L1C/A码和L1C码的海面测高精度最优可达0.63 m和0.4 m，L1C码的延迟GNSS-R测高精度明显高于L1C/A码。此外，GNSS-R测高精度会随着卫星高度角的增加而有所增加。 

Coastal GNSS-R ocean altimetry based on code delay of QZSS L1 signal

In order to explore the altimetry performance of GNSS-R code phase delay measurement with different modulation methods in GNSS LI band signals, a coastal dual-antenna GNSS-R ocean altimetry experiment was carried out, and the original intermediate frequency data with a sampling rate of 40 MHz was collected. The experimental data was processed using the self-developed GNSS-R altimetry software receiver and inversion software, and the GNSS-R ocean altimetry results of QZSS L1C/A code and L1C code were obtained simultaneously. Then we compare them with the measured values of the radar altimeter that were simultaneously observed coastally, and used to evaluate the accuracy of the GNSS-R inversion result. The experimental results show that the ocean altimetry accuracy based on L1C/A code and L1C code is about 0.63 m and 0.4 m, respectively. It can be seen that the GNSS-R measurement accuracy of the L1C code delay is significantly higher than that of the L1C/A code. In addition, the accuracy of GNSS-R will be improved as the satellite elevation increases gradually.