Research On Misalignment Correction Method Of Magnetic-Attitude Coordinate System Based On Plane Vector Constraint

Mineral resources are an important material basis for national economic construction and social development,and more than 95% of China’s energy and more than 80% of industrial raw materials come from mineral resources.Therefore,ensuring the stable and sustainable supply of mineral resources plays a crucial role.In order to accelerate the construction of a new energy system and improve the national strategic material reserves,China is carrying out a new round of strategic prospecting operations,and scientific prospecting is an important link to break through this strategic action.As an efficient geophysical exploration method,aeromagnetic method is widely used in scientific prospecting operations.With the continuous development of magnetic exploration theory and technology,magnetic parameters are evolving from total field strength or total field gradient to vector,and three-component magnetic measurement has become one of the main directions of the current development of aeromagnetic surveying.The three-component magnetic measurement system changes the attitude of the system during the working process,and the three-component magnetic field data under the coordinate system of the magnetic sensor is directly measured,and it is also necessary to synchronously collect three-dimensional attitude data such as heading angle,pitch angle and roll angle,so as to correct the magnetic measurement data to the geographic coordinate system for subsequent data processing and inversion interpretation.However,due to the non-alignment error of the coordinate system between the three-component magnetic sensor and the inertial guidance system for measuring attitude in the process of integrating into the magnetic measurement system,the accuracy of attitude correction will be seriously affected,and the accuracy of three-component magnetic measurement will be affected.In this paper,aiming at the problem of non-alignment error of the coordinate system between the magnetic sensor and the inertial guidance system in the aviation three-component magnetic survey system,the correction method of plane vector constraint is studied based on Euler’s rotation theorem,and the correction effect of the method is verified by simulation experiments and the field.The main research contents are as follows:1)The causes of the non-alignment error between the coordinate system of the magnetic sensor and the coordinate system of the inertial guide system in the aviation three-component magnetic survey system are analyzed,and the transformation relationship of the space rotation coordinate system is derived based on Euler’s rotation theorem.The non-alignment error correction model of the magneto-pose coordinate system is established,and the method principle based on plane vector constraint is studied.2)A method for solving parameters of non-alignment error correction of magneto-pose coordinate system based on cuckoo search algorithm is proposed.Through simulation experiments,the correction effect of the method is verified and evaluated.3)A three-component magnetic measurement ground simulation experimental system was built and field experiments were carried out,and the non-alignment error correction process was carried out on the measured three-component magnetic measurement data,and the peak-to-peak value was used to evaluate the calibration performance of the method.The results showed that the peak-to-peak values of the three-component magnetic measurement data before correction were 3127.7n T,1897.1n T and 1857.6n T,respectively,and decreased to 17.9n T,24.4n T and 18.6n T after correction,with improvement rates of 99.42%,98.71% and 99.16%,respectively.