提出在低纬子午环上，对不同光谱型的天体测定出天文折射，以提高星位测定的精度。
In order to obtain higher measured accuracy of star's positions by the low-latitude meridian circle, it is needed to measure the astronomical refraction to the stars of different spectral types.
刻度盘的误差，是子午环固有的仪器误差之一，它直接影响了天体赤纬的测定精度。
The errors of the circle of a meridian circle will immediately affect the precision in determining celestial bodies' declinations.
本文论述了铁路上常用的太阳高度法测定天体真方位角各类误差的影响。
In this paper, all kinds of error's influence was expounded of the sun altitude method often used on the railway upon determining heavenly body azimuth.
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