The Instruments and Instrumental-error Evaluation Method for the Triangular Monitoring Network of Abnormal Changes in the Longitude and Latitude of an Observing Station

In order to set up the triangular monitoring network to derive the information of abnormal changes in the astronomical longitude and latitude of an observing station in the Yunnan Province, we discuss in this paper the requirements for the measuring instruments and propose a new model of instrumental errors so that various sources of systematic errors can be eliminated under its guidance, We give the overall scheme to design the measuring instruments and present the measuring method of instrumental errors through the comparison to the meridian circles used abroad.