自行研制的激光跟踪测量系统使用激光干涉和绝对测距两种方法进行精密测距,激光测距精度受大气折射率补偿精度的直接影响。以修正后的Edlen公式为基础,将最小二乘方法引入大气折射率计算公式,提出了使用大气压力(Pa)、大气温度(°C)和大气相对湿度(％)为参量的低阶分段大气折射率修正公式,经误差分析,新公式的不确定度为±3.5×10-8,满足精密激光测长的要求。

The laser interferometer and absolute distance meter for distance measurement are used for self-developing laser tracking measurement system. The measurement of air refractivity has a direct influence on the accuracy of laser ranging. A convenient formula using the air pressure (Pa), the air temperature (°C) and the air relative humidity (％) as parameters is presented based on the updated Edlen formula, which introduces the least squares method to calculate the relationship of the partial pressure of water vapor and the relative humidity. The uncertainty of the new formula is ±3.5×10-8, which agrees with the updated Edlen equation and satisfies the requirement of precision laser distance measuring.