Research On Magnetic Target Detection And Location Algorithm Based On Magnetic Gradient Tensor

With the development of noise reduction and shock absorption technology,the traditional sonar anti-submarine technology has been challenged.Therefore,the development of non-acoustic detection technology has become an urgent problem facing anti-submarine warfare.Magnetic anomaly detection technology as a non-acoustic detection technology because of its unique anti-submarine advantages,the world’s major military powers continue to pay attention to.Magnetic detection technology,which is widely used in petroleum,mineral exploration and military fields,is a technology to calculate the position of magnetic target by measuring magnetic quantity information by magnetic quantity acquisition system.Based on the theoretical basis of magnetic dipole,this paper studies the magnetic gradient tensor measurement array and three magnetic target positioning algorithms based on the magnetic gradient tensor,analyzes the main factors affecting the positioning accuracy of the algorithm,and conducts experimental verification.The main work is as follows:Based on tensor theory,magnetic gradient tensor is derived from the concept of tensor.The magnetic gradient tensor is applied in the field of magnetic exploration because it is not affected by coordinate system and reflects physical phenomena directly.Combining with the advantages of magnetic gradient tensor in magnetic field measurement,the advantages and disadvantages of three kinds of measuring arrays with different structures are analyzed successively.Finally,the planar measuring array of three-axis magnetic sensor is selected as the measuring array in this paper.Based on the theory of magnetic dipole model,three localization algorithms based on magnetic gradient tensor are studied.In this paper,the principle of the localization algorithm based on magnetic anomaly inversion,the invariant algorithm based on magnetic gradient tensor,and the localization algorithm based on magnetic moment are expounded in detail.the localization formulas of the three algorithms are deduced,and the solution of the multi-solution problem in the localization algorithm based on magnetic moment is given.In Matlab environment,the feasibility of the three positioning algorithms is verified by the establishment of algorithm model.Magnetic sensor noise and baseline array is analyzed,and three kinds of algorithm of positioning error measuring distance,provides guidance for array system to improve measurement precision and theoretical basis,which improve the effective detection range of array system should minimize the sensor noise,different detection range to choose the right baseline array.Under the same condition of sensor noise and array baseline,the localization effect of the inversion algorithm based on magnetic anomaly and the algorithm based on magnetic gradient tensor invariants is compared.In the outdoor environment,three algorithms are verified by the array system.The results show that the localization algorithm based on magnetic anomaly inversion,the localization algorithm based on magnetic gradient tensor invariants and the localization algorithm based on magnetic moment can be used to locate magnetic targets.