不知道它的误差估计算法是怎样的? 准确度怎么样?
//$pgrme,45.3,m,,m,45.3,m*00
//$pgrme,45.3,m,,m,45.3,m*00
//estimated error information (pgrme)
//the garmin proprietary sentence $pgrme reports estimated position error
//information.
//$pgrme,<1>,m,<2>,m,<3>,m*hh<cr><lf>
//<1> estimated horizontal position error (hpe), 0.0 to 999.9 meters
//<2> estimated vertical position error (vpe), 0.0 to 999.9 meters
//<3> estimated position error (epe), 0.0 to 999.9 meters