Progress of research on anomalies of astronomical time and latitude observations before earthquake

This paper introduces the discovery of the phenomenon that short-term anomalous fluctuations appeared in residuals of astronomical time and latitude observations before earthquakes and the progress of related researches carried out for many years.The relations between the anomalous variations of time and latitude residuals of astronomical time and latitude instruments in different regions and the earthquakes around these instruments as well as the characteristics of residuals’ anomalous variations are analyzed.The significance of the anomalous fluctuations in residuals of astronomical time and latitude caused by the anomalous variations of the local plumb line before earthquake and detecting the vertical variation with astronomical time and latitude observations as well as the importance of carrying out further researches are discoursed.The possibility that the phenomenon will become an effective short-term earthquakes precursor,the current situations and the problems to be solved,are discussed.Also we offer the proposals to develop new roboticized astrometric instruments with high-precision and set up test observation networks in earthquake-prone areas in order to do research in-depth,optimize methods of observing and extracting anomalous information for short-term earthquake prediction,and so on.