The research on the effect of dynamic tilt variation on the phase of cold atomic gravimeter

In recent years, absolute gravity comparison experiments between cold atomic gravimeter and traditional gravimeter have been carried out by combining cold atomic gravimeter with stable platform. Due to the working characteristics of the stable platform, the tilt angle of the cold atomic gravimeter will change slightly in the process of dynamic measurement, and the measurement noise will be introduced. In order to improve the accuracy of dynamic measurement, this paper first analyzes the trajectory of the mirror and atom in the atomic gravimeter combined with carrier motion information, obtains the phase expression of the atomic interferometer using the translation and rotation matrix, evaluates the main terms of the gravity deviation using the 20-min navigation data on the ship in the South China Sea, and simplifies the higher-order small-terms in the main terms to deduce the simplified form of the gravity deviation. Then, the Fourier transform is used to transform the simplified expression into the power spectrum expression of phase noise, the corresponding noise sensitivity function is used in the form of trigonometric. The 20-min data is divided into 10 intervals, the root-mean-square (RMS) value of the overall gravity deviation is 1.5–3 mGal using the power spectrum of the platform angle, angular velocity and carrier acceleration in each interval. The variation fluctuation of the RMS value is consistent with the fluctuation of solving the gravity deviation through the trajectory. The conclusion provides the calculation method of gravity noise caused by dynamic tilt change and horizontal acceleration, and also provides the basis for platform design.