摘要
The classical time and latitude observations are based on local vertical line. In principle, if the mass distribution around the point of observation and in the earth interior is asymmetric, the local vertical line deflection will be changed, thus affecting the results of time and latitude observations. Referring to a standard system (e.g. BIH, IPMS or the Jiont System), the time and latitude observations of every instrument contain systematical errors, which are represented by (A-O), where A is the adopted value of standard system and O the ob-
