Aircraft hanging-type fluxgate magnetic gradient tensor instrument correction method

Abstract

The invention relates to an aircraft hanging-type fluxgate magnetic gradient tensor instrument correction method. The method comprises the following steps: 1) establishing a single fluxgate error model; 2) establishing a magnetic gradient tensor component error correction model; 3) collecting correction data in a uniform magnetic field region at high altitude; 4) correcting errors of tensor components; 5) collecting correction data in non-uniform magnetic field region on the ground; 6) solving scale factor error of the tensor components; 7) combining correction coefficients obtained through high-altitude correction and ground correction; and 8) fully calculating magnetic gradient tensor after correction. Compared with a conventional aircraft magnetic field gradient tensor correction algorithm, the correction method in the invention not only corrects a single tensor component, but also corrects the tensor as a whole, so that the tensor component and the whole correction results are allowed to be more accurate, and meanwhile, application conditions thereof meet actual aircraft magnetic gradient tensor detection region geological conditions better.

Description

Technical field: [0001] The invention relates to a correction method for an airborne geophysical and magnetic measuring instrument, in particular to a correction method for an aircraft-mounted fluxgate magnetic gradient tensor. Background technique: [0002] The magnetic gradient tensor measures the spatial change rate of the three components of the magnetic field along the orthogonal coordinate system. The magnetic gradient tensor is less affected by the geomagnetism and can obtain rich information. It is especially suitable for discovering shallow hidden mines and magnetic moving targets. It is one of the development directions of magnetic measuring instruments. In airborne magnetic gradient tensor measurement, in order to avoid the tensor instrument being subjected to the magnetic interference of aircraft such as helicopters, etc., usually the tensor instrument is mounted to a place far away from the aircraft, and then the magnetic field gradient of the target is measured...

AI Technical Summary

Problems solved by technology

This type of method has three main problems: first, in the region of uniform magnetic field, a single gradient component is zero is a necessary condition in the calibration of the magnetic gradient tensorometer, but not a necessary and sufficient condition

It can neither guarantee the correctness of the response to the non-zero gradient situation, nor can it guarantee the correctness of the whole after each gradient component forms a tensor

Second, it is difficult to reproduce the dynamic characteristics of the fluxgate during flight on the ground, so it is difficult to identify the inconsistency of the dynamic characteristics of multiple fluxgates

However, the airborne magnetic gradient tensor measurement is always in a state of motion, and the inconsistency of dynamic characteristics is also one of the reasons for the formation of motion noise and submersion of the target magnetic detection signal.

Third, in or near the target area of ​​the actual airborne magnetic field measurement, the ground magnetic anomaly is often large, and it is difficult to find an area with a uniform magnetic field for correction

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