gis 地理信息系统，非常好用，功能超强,纯C++实现-gis geographic information systems, is very easy to use, powerful features, pure C++ implementation

过滤GPS信号中GSM协议，从而得到有效的纯GPS数据-Filter GPS signals in the GSM protocol, resulting in pure GPS data

采用实测数据实现纯惯导解算，整个程序完整，包含数据，可直接使用(Using measured data to achieve pure inertial navigation solution, the entire program integrity, including data, can be used directly)