Absolute gravity measurement method and apparatus thereof

Abstract

The invention discloses an absolute gravity measurement method and an apparatus thereof. The absolute gravity measurement method comprises the following steps that a time acquisition unit detects falling time t of a detected falling body and sends the t to a host computer; an optical interferometer detects a falling displacement signal d1(t) of the detected falling body relative to a reference prism and sends the signal d1(t) to the host computer; a vibration detection unit detects a displacement signal d2(t) of the reference prism which is vibrated along with ground and sends the signal d2(t) to the host computer; the host computer uses the signal d2(t) to compensate the signal d1(t) so as to acquire a displacement signal d(t) of the detected falling body relative to the ground; and the host computer acquires a gravitational acceleration g according to the signal d(t) and the t. In the invention, a ground vibration signal is compensated to a falling displacement of the detected falling body, measurement of a detected falling body displacement is accurate, measurement times can be greatly reduced and the accurate gravitational acceleration is acquired.

Description

technical field [0001] The invention relates to the field of gravity measurement, in particular to an absolute gravity measurement method and device. Background technique [0002] The principle of the current optical interference absolute gravimeter is to accurately measure the time and displacement of the measured falling object in the free fall in the gravitational field under high vacuum conditions, and then according to the formula (1): [0003] s(t)=s 0 +v 0 t+1 / 2gt 2 (1) Calculate g, where t is the falling time of the measured falling object, s(t) is the displacement of the measured falling object relative to the ground at time t, s 0 is the initial displacement of the measured falling body, v 0 is the initial velocity of the measured falling object. The principle of optical interference to detect the displacement of the measured falling body is as follows: figure 1 shown. The laser beam of the optical interferometer is emitted from the laser 101 and is divided...

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Problems solved by technology

However, if image 3 As shown, in this method, the low-frequency vibration sensor has different frequency responses to vibrations of different frequencies and directions, and there is attenuation and phase drift, which makes the vibration measurement inaccurate.

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