true north 真北 two-color laser ranger 双色激光测距仪 unbiased estimate无偏估计up-link station 注入站user segment 用户部分 variance of unit weight 单位权方差 variance-covariance matrix 方差-协方差阵 variance-covariance propagation law方差-协方差传播率 variance方差 vector data矢量数据 vertical angle 竖直...