Evaluation Method for Airborne Full Magnetic Gradient Tensor Data Measured Over a Survey Area

Abstract

Airborne surveys of the full magnetic gradient tensor have been established as a powerful method in environmental, engineering, exploration and lithospheric studies. However, the accuracy limitation of the gradiometer, the inevitable interference from the carrying platform, and the complexity of the flight environment could degrade the quality of the airborne full magnetic gradient tensor (AFMGT) measurements. High-quality measurements are essential to obtain reliable data for subsequent analysis and robust interpretations, but there is currently no method for evaluating accuracy of the AFMGT measurements. Therefore, we propose an evaluation method for AFMGT data measured over a survey area, constrained by the harmonicity property for all tensor components, without the necessity for independent referencing data. Considering that one of the features of the AFMGT measurements is high-order and spatial correlation, we represent them by tensors that are data structures in multilinear algebra. The accuracy and utility of our method have been tested and verified by simulations and field experiments. Our work can serve as a groundwork for instrument manufacturing and quality control.