Research On Soft Compensation And Forward And Inverse Problem Of Aeromagnetic Tensor Gradient Data

In recent years,breakthrough has been achieved in research and development of superconducting magnetometer for measurement of the full tensor gradient aeromagnetic data.SQUID has the characteristics of high sensitivity,low noise and wide band.It can effectively suppress background magnetic field,noise interference,improve data resolution and data accuracy,and has precise resolution of local magnetic anomaly targets.Combined with aeromagnetic prospecting,its wide range of detection not restricted by terrain effect,high detection efficiency,saving time and low operating cost per unit area at the same time,it also creates huge challenges for soft compensation work of aeromagnetic full tensor gradient data and research on theoretical algorithm for numerical calculation of forward and inverse problems.As a new generation of aeromagnetic measurement technology,aeromagnetic full tensor gradient measurement with magnetic prospecting,its wide range of detection is not restricted by terrain effect,high detection efficiency,saving time and unit area survey and low operating cost advantages at the same time,the core component of SQUID(superconducting quantum interferometer device)can effectively suppress the background magnetic noise,improve the data resolution ability and data accuracy,so it has unique advantages in geophysical exploration and military antisubmarine etc..This paper relies on the flight experimental data of the aeronautical superconducting full tensor magnetic gradient measurement device designed and developed by the Shanghai Institute of Microsystem and Information Technology.In this paper,the soft compensation technology of the aeromagnetic full tensor gradient data and the theoretical algorithm of the numerical calculation of the forward and inverse problems are systematically studied.In order to improve the aeromagnetic full tensor gradient data accuracy effectively,a forward compensation method is established in this paper based on characteristics of towed aeromagnetic measurement and combined with composition of magnetic interference and its changing principle.In the numerical calculation of the forward problem,the concept of node property is used to establish a more concise mathematical relationship between magnetic anomaly bodies and magnetic gradient tensor anomalies.This eliminates a lot of computational redundancy and improves the speed of complex magnetic forward calculation in essence under the premise of ensuring the precision of data.In terms of inverse problem,according to the good sparsity of grid node physical property model,inversion strategy of grid nodes magnetic susceptibility based on multiple components is proposed in this paper.On this basis,homologous characteristics between multiple components of magnetic total tensor gradient data are used for further improvement of this method by introducing structural consistency constraint and inversion strategy of grid node magnetic susceptibility based on structural similarity is proposed.For many kinds of geological and geophysical information,structural constraint information is introduced into inversion by node weight model and inversion strategy of grid node magnetic susceptibility based on geological and geophysical information constraints is proposed.Finally,the 3-D magnetic susceptibility structure in the study area is constructed by the measured aeromagnetic full tensor gradient data.The application of the theory is proved to be effective and practical.