State Key Laboratory of Laser and Matter Interaction

As the lightwave passing through the atmosphere, the light’s path is not the uniform linear motion as well as the path has been bent, which causes the atmospheric refractive error of lightwave. As usual, two photoelectric theodolites are used to supply data for refractive error calculation. In the case of one photoelectric theodolite in the same time or the same area, the calculation method above is not suitable. This article proposes the calculation method of atmospheric refractive error based on single photoelectric theodolite which needs radar ranging to the flight target. First, station coordinate system is built and the station of photoelectric theodolite should be transformed to the system as well as the station of radar. Second, the original geocentric distance should be cut to L levels by lightwave refraction index from the station of photoelectric theodolite and the apparent distance between photoelectric theodolite and flight target is calculates. Third, the calculated geocentric distance should be cut to L levels by lightwave refraction index and the geocentric angle between photoelectric theodolite and flight target is calculated. At last, both the real elevation angle of photoelectric theodolite to the flight target and lightwave’s atmospheric refractive error are calculated by formula of elevation angle. The calculation method of atmospheric refractive error in this article only uses data of single photoelectric theodolite, as well as definite integral formulas of both apparent distance and geocentric angle are optimized, by which more accuracy error calculation of lightwave’s atmospheric refraction can be achieved.