gps中利用sp3精密星历进行卫星位置解算、算法效率高-gps using the sp3 precision ephemeris satellite position solver algorithm efficiency

GPS NMEA协议处理框架，可从COM，Txt,TCP作为信号源，实现卡尔曼滤波，平均距离过滤算法-GPS NMEA protocol processing framework, as a source from COM, TXT, TCP, Kalman filtering, the average distance filtering algorithm