Abstract：Tilt tide measurement data with digital water tube is collected at Hubei Shiyan seismostation from 2007-2010.The results of data analysis indicate that the tilt tide observation for 3 years werecontinuous and reliable，the instrument works normally and stably which has small annual zero drift and change amplitude and so it is with the low noise level. The overall quality nearly reach the international level in terms of data accuracy，continuity and applicability,though the data had been affected by the local station cave excavates in March,2009, which were highfrequency vibration and the shorttime drift. The earth tide returned soon to regular level very approximately and this shorttime Anomaly had been not believed firmly as an earthquake precusor. In the same time，it is revealed that in the tilt components evident signal occurs together with significant perturbations of load/unloadresponseratio(LURR) of earth tide before the Wenchuan \%M\%8.0 earthquakes．
Sun Lingli ,Luo Junqiu ,Lü Pinji et al. QUALITY EVALUATION OF TILT TIDE OBSERVATION WITH DIGITAL WATER TUBE AT SHIYAN SEISMOSTATION[J]. jgg, 2011, 31(Supp.): 59-63.
