Research On Accelerometer Field Calibration Method Of Strapdown Airborne Gravimeter

In recent years,the strapdown airborne gravity measurement technology has become mature gradually and become one of the most important means of measuring Earth gravity field.The error caused by accelerometer has a significant effect on the accuracy of the gravimeter.And accelerometer has long-term changes even in a sophisticated temperature-controlled environment.Field calibration techniques can compensate for accelerometer errors.Therefore,it can improve the actual accuracy of the gravimeter.The main content of this paper consists of the following three parts:(1).Based on the basic theory of airborne gravity measurement,the requirements of accelerometer measurement accuracy are analyzed.When establishing the accelerometer error model,installation error,the scale factor error and zero offset error are mainly analyzed.(2).The error model of strapdown inertial navigation is established,including position error model,velocity error model and attitude error model.The Kalman filter model of accelerometer is established,and the observability of state variables is analyzed.(3).The design of calibration path is carried.The observability of state variables changes at different poses.Therefore,it is possible to use a combination of different poses to design an appropriate calibration path.This can improve the observability of system and ultimately improve the calibration result.