单词astronomical refraction
na.: 空中屈折
网络: 天文折射；大气折射；天文蒙气差
大气折射
The possibility of determining values of astronomical refraction in several directions at each station is discussed.
文章还论述了在各观测站多方向测定天文大气折射值的可能性。
Then the effect of vertical deflection and astronomical refraction on the precision for three-dimensional control network was studied.
再次，对影响工程三维控制网精度的大气折光和垂线偏差等问题进行了研究；