研究大气反常折射的迫切性

就地球大气对天体测量观测的影响作了分类，介绍了对各类影响的传统处理方法，也介绍了低纬子午环的分别对待方法，特别强调了短周期的和不规则的反常折射影响对提高观测精度的限制，并提出了测定这些影响的可能途径。

The Urgency for the Study of the Abnormal Refraction

In the paper, the effects from the atmosphere of our earth on the astrometry are classified and some processing methods in the observations of traditional meridian circles are introduced. In comparision, the corresponding processing methods of the LLMC are also introduced. Since the LLMC can absolutely determine the normal refraction and the slope of the atmospheric isopyknic, it is pointed out that the short periodic and irregular refractions will be the main obstacle to raise the observational accuracy and the determination of the abnormal refraction in real time is urgent to clear away the obstacle of the refraction.