次程序用来仿真叠加了地杂波和高斯白噪声的回波信号-Second program is used to simulate the ground clutter superimposed Gaussian white noise and the echo signal

NMEA语句读取程序，实现了GPZDA\SDDBS\等解释- NMEALINEREAD currently supports the following NMEA sentences: $GPGGA Global positioning system fixed data $GPGLL Geographic poition [latitude, longitude & time]