Effect of self-vibration on accuracy of free-fall absolute gravity measurement with laser interferometer

2015 ◽  
Author(s):  
Jin-yang Feng ◽  
Shu-qing Wu ◽  
Chun-jian Li ◽  
Duo-wu Su ◽  
Mei Yu
Keyword(s):  
Laser Interferometer ◽  
Free Fall ◽  
Gravity Measurement ◽  
Absolute Gravity ◽  
Absolute Gravity Measurement

Free-fall absolute gravity measurement based on double interferometers

2015 ◽  
Vol 23 (10) ◽  
pp. 2740-2746
Author(s):  
冯金扬 FENG Jin-yang ◽  
吴书清 WU Shu-qing ◽  
李春剑 LI Chun-jian ◽  
粟多武 SU Duo-wu ◽  
于梅 YU Mei
Keyword(s):  
Free Fall ◽  
Gravity Measurement ◽  
Absolute Gravity ◽  
Absolute Gravity Measurement

A Vibration Compensation Method for Absolute Gravimeters

2016 ◽  
Author(s):  
Guan Wang ◽  
Hua Hu ◽  
Kang Wu ◽  
Lijun Wang
Keyword(s):  
Transfer Function ◽  
Laser Interferometer ◽  
Compensation Method ◽  
Gravity Measurement ◽  
Absolute Gravity ◽  
Absolute Gravimeter ◽  
Broadband Seismometer ◽  
Vibration Isolators ◽  
Vibration Compensation ◽  
Absolute Gravity Measurement

The laser interferometer is used to track the falling object in a freefall absolute gravimeter, which could be disturbed by the vibration from the ground. Thus, the vibration compensation method is often used to reduce the influence of the vibration. Typically, a sensor (broadband seismometer) is used to record the vibration. But the measured ‘vibration’ Nm(t) does not equal the motion of the reference corner cube N(t). Because there exists a transfer function G(s) making Nm(s) = G(s)N(s). Traditionally, G(s) is assumed to be equal to the transfer function of the sensor, which can be achieved with the help of other equipment. But the assumption is not reasonable and the process of calculating the transfer function is complicated. A novel vibration compensation method without any other equipment is proposed in this paper. In this method, G(s) is simplified to estimate N(t) using N′(t) = ANm(t − τ), which is used for compensation. The gain A and delay τ can be obtained by analysis of the data acquired by the absolute gravimeter. The experiments are conducted with the homemade absolute gravimeter T-1 and repeated for 75 times. The standard deviation of the uncompensated results is 3276 μGal (1 μGal = 1 × 10−8 m/s2), while that of the compensated results is 167 μGal. The compensation method not only achieves a reduction by nearly a factor of 20, but also can be simply used without any other equipment. The results indicate that the method basically meets the demands of absolute gravimeters. In the future, it may be applied to dynamic absolute gravity measurement and take the place of vibration isolators.

A Compound Recoil-Compensated Chamber Design for Free-Fall Absolute Gravimeters

2020 ◽  
Author(s):  
Yi Wen ◽  
Kang Wu ◽  
Meiying Guo ◽  
Lijun Wang
Keyword(s):  
High Precision ◽  
Free Fall ◽  
Test Mass ◽  
Precision Measurements ◽  
Gravity Measurement ◽  
Absolute Gravity ◽  
Systematic Bias ◽  
Chamber Design ◽  
Measurement Results ◽  
Gravity Measurements

Abstract The ballistic free-fall absolute gravimeters are most commonly-used instruments for high-precision absolute gravity measurements in many fields, such as scientific research, resource survey, geophysics and so on. The instrumental recoil vibrations generated by the release of the test mass can cause troublesome systematic bias, because these vibrations are highly reproducible from drop to drop with coherent phase. A compound counterbalanced design of chamber using both belt-driven mechanism and cam-driven structure is proposed in this paper. This structure is designed to achieve excellent recoil compensation as well as long freefall length for high precision measurements. Simulation results show that the recoil vibration amplitude of the compound recoil-compensated structure during the drop is about 1/4 of that with only belt-driven counterbalanced structure. This confirms the feasibility and superiority of the new design. And it is believed that the absolute gravimeter based on this newly proposed chamber design is expected to obtain more precise gravity measurement results in the future.

The first repeated absolute gravity measurement for geothermal monitoring in The Kamojang Geothermal Field, Indonesia

Geothermics ◽  
2015 ◽  
Vol 53 ◽  
pp. 114-124 ◽  
Author(s):  
Yayan Sofyan ◽  
Yunus Daud ◽  
Jun Nishijima ◽  
Yasuhiro Fujimitsu ◽  
Yustin Kamah ◽  
...  
Keyword(s):  
Geothermal Field ◽  
Gravity Measurement ◽  
Absolute Gravity ◽  
Absolute Gravity Measurement

scholarly journals Experiment on dynamic absolute gravity measurement based on cold atom gravimeter

2022 ◽  
Vol 71 (2) ◽  
pp. 026701-026701
Author(s):  
Cheng Bing ◽  
◽  
Chen Pei-Jun ◽  
Zhou Yin ◽  
Wang Kai-Nan ◽  
...  
Keyword(s):  
Cold Atom ◽  
Gravity Measurement ◽  
Absolute Gravity ◽  
Absolute Gravity Measurement

scholarly journals Absolute gravity measurement based on atomic gravimeter under mooring state of a ship

2021 ◽  
Vol 70 (4) ◽  
pp. 040304-040304
Author(s):  
Cheng Bing ◽  
◽  
Zhou Yin ◽  
Chen Pei-Jun ◽  
Zhang Kai-Jun ◽  
...  
Keyword(s):  
Gravity Measurement ◽  
Absolute Gravity ◽  
Absolute Gravity Measurement
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