关键词: 激光干涉型绝对重力仪, 绝对重力测量, 平台式, 自振, 传递函数

Abstract: Absolute gravimeter is an instrument used to accurately measure the gravitational acceleration,and it has a wide range of applications in many fields such as metrology,geophysics,geological exploration,and navigation.At present,the measurement accuracy of the split-type classical absolute gravimeter has reached the μGal level.On the other hand,the platform-type absolute gravimeter is greatly affected by its free vibration,resulting in an accuracy of several milligal.A set of vibration measurement system was built based on the NIM-3C absolute gravimeter,and the vibration data of the split and platform NIM-3C were collected,respectively.Through the analysis of the vibration transfer function,the key link to reduce the natural vibration was found,and a phased study was obtained.It is expected that the measurement accuracy of the platform-type absolute gravimeter will be improved to be several hundreds of microgal with better vibration control method applied in the gravimeter.

Key words: Laser interferometric absolute gravimeter, Absolute gravimetry, Platform, Self-vibration, Transfer function