Error Correction Model and Uncertainty Analysis of the Shipborne Absolute Gravity Measurement System

  Objectives  The laser interference absolute gravimeters can only work in static conditions until now, and absolute gravity measurement in a dynamic environment is one of the hotspots for future technological development. The shipboard absolute gravity measurement can overcome the problems of zero drift, calibration, and error accumulation of the marine relative gravity instruments, and improve their efficiency and reliability.

  Methods  We present an absolute gravity measurement system from a ship, which consisted of an absolute gravity instrument, a gyro-stabilized platform, a force balance accelerometer and GPS (global positioning system).Firstly, Four types of interference sources that the vertical fluctuation, the pitch and roll, the horizontal fluctuation and the Eötvös effect, which cause the measurement errors of the shipboard gravity measurement system, were analyzed. Then, the limits of dynamic measurement, the error correction methods and their accuracy were given.

  Results and Conclusions  Under current technical conditions, the precision of the shipboard absolute gravimeter measurement system can be better than ±1.1 mGal. Therefore it provides theoretical support for further shipborne absolute gravity measurement experiments.