The full magnetic gradient tensor （MGT） refers to the spatial change rate of the three field components of the geomagnetic field vector along three mutually orthogonal axes. The tensor is of use to geological mappin...The full magnetic gradient tensor （MGT） refers to the spatial change rate of the three field components of the geomagnetic field vector along three mutually orthogonal axes. The tensor is of use to geological mapping, resources exploration, magnetic navigation, and others. However, it is very difficult to measure the full magnetic tensor gradient using existing engineering technology. We present a method to use triaxial aeromagnetic gradient measurements for deriving the full MGT. The method uses the triaxial gradient data and makes full use of the variation of the magnetic anomaly modulus in three dimensions to obtain a self-consistent magnetic tensor gradient. Numerical simulations show that the full MGT data obtained with the proposed method are of high precision and satisfy the requirements of data processing. We selected triaxial aeromagnetic gradient data from the Hebei Province for calculating the full MGT. Data processing shows that using triaxial tensor gradient data allows to take advantage of the spatial rate of change of the total field in three dimensions and suppresses part of the independent noise in the aeromagnetic gradient. The calculated tensor components have improved resolution, and the transformed full tensor gradient satisfies the requirement of geological mapping and interpretation.展开更多
Aeromagnetic gradient data needs to be reduced to the pole so that it can be better applied to geological interpretation through theoretical derivation.In this paper,we conduct research on the morphological characteri...Aeromagnetic gradient data needs to be reduced to the pole so that it can be better applied to geological interpretation through theoretical derivation.In this paper,we conduct research on the morphological characteristics of the total and horizontal gradient modules before and after reduction to the pole and design models at different latitudes,with consistent and inconsistent magnetic field direction and geological body magnetization direction.We discuss how to use the total gradient module and horizontal gradient module in geological interpretation.The reduced-to-the-pole（RTP） method is required for the horizontal gradient module method but not for the total gradient module.Finally,the conclusions derived from the theoretical models are verified through analysis of real data.The position determination of a geological body using the total gradient method,gradient data,or total-field data works better without RTP,ensuring data primitive authenticity.However,the horizontal gradient module should be reduced to the pole to determine the boundary of the geological body.Finally,the theoretical model is verified by actual data analysis.Both the total and horizontal gradient methods can be applied to geological interpretation.展开更多
基金supported by the National High Technology Research and Development Program of China(863 Program)(No.2013AA063901 and No.2006AA06A201)
文摘The full magnetic gradient tensor （MGT） refers to the spatial change rate of the three field components of the geomagnetic field vector along three mutually orthogonal axes. The tensor is of use to geological mapping, resources exploration, magnetic navigation, and others. However, it is very difficult to measure the full magnetic tensor gradient using existing engineering technology. We present a method to use triaxial aeromagnetic gradient measurements for deriving the full MGT. The method uses the triaxial gradient data and makes full use of the variation of the magnetic anomaly modulus in three dimensions to obtain a self-consistent magnetic tensor gradient. Numerical simulations show that the full MGT data obtained with the proposed method are of high precision and satisfy the requirements of data processing. We selected triaxial aeromagnetic gradient data from the Hebei Province for calculating the full MGT. Data processing shows that using triaxial tensor gradient data allows to take advantage of the spatial rate of change of the total field in three dimensions and suppresses part of the independent noise in the aeromagnetic gradient. The calculated tensor components have improved resolution, and the transformed full tensor gradient satisfies the requirement of geological mapping and interpretation.
基金surpported by the National 863 Program(Grant No.2013AA063901)
文摘Aeromagnetic gradient data needs to be reduced to the pole so that it can be better applied to geological interpretation through theoretical derivation.In this paper,we conduct research on the morphological characteristics of the total and horizontal gradient modules before and after reduction to the pole and design models at different latitudes,with consistent and inconsistent magnetic field direction and geological body magnetization direction.We discuss how to use the total gradient module and horizontal gradient module in geological interpretation.The reduced-to-the-pole（RTP） method is required for the horizontal gradient module method but not for the total gradient module.Finally,the conclusions derived from the theoretical models are verified through analysis of real data.The position determination of a geological body using the total gradient method,gradient data,or total-field data works better without RTP,ensuring data primitive authenticity.However,the horizontal gradient module should be reduced to the pole to determine the boundary of the geological body.Finally,the theoretical model is verified by actual data analysis.Both the total and horizontal gradient methods can be applied to geological interpretation.
