gps轨迹优化，gps采样的点显示轨迹的时候，由于gps漂移和定位精度的原因，地图上显示的轨迹不太理想，通过卡尔曼算法，是轨迹达到平滑的效果-gps trajectory optimization, gps sampling point display trajectory, because of drift and gps positioning accuracy reasons, the track displayed on the map is not ideal, through Kalman algorithm, is track to achieve the effect of smoothing