Rotary table wobble error analysis and correction of a rotating accelerometer gravity gradiometer.

In a rotating accelerometer gravity gradiometer (RAGG), rotary table wobble refers to the shift in the direction of the spin axis during operation. This motion causes errors in the output of the RAGG, but the mechanism is not clear. The purpose of this paper is to analyze the relationship between rotary table wobble and RAGG errors and to propose a method for rejecting these errors. We consider the influence of attitude changes, angular velocity, and angular acceleration caused by the wobble on the specific force, and we describe the error transmission process based on the accelerometer configuration and its measurement principle. Furthermore, we show through a simulated experiment that when the angular velocity noise caused by the wobble is 1 μrad/s, this will produce errors of tens of E. We propose a post-error correction method that is based on the higher-precision RAGG model and motion measurement. The errors in the two channels of the RAGG are reduced to 3.69 E and 1.85 E after error correction. The error analysis of the effects of wobble on a RAGG and the proposed error correction method are of great significance for the development of high-precision gradiometers.