Weight Factor Determination of Reverse Distance Weighting Method in Computation of Geomagnetic Diurnal Variation Data

A virtual geomagnetic diurnal station has been used to calculate the diurnal variation correction data in the regions where the ground magnetic surveying is difficult to be implemented, and this will provide diurnal variation correction data for the airborne geomagnetic measurement. The weight factors of reverse distance weighting (RDW) method usually use the empirical values, which have limitation in the application of different testing areas. The correlation coefficients are proposed and introduced to calculate the weight factors iteratively, which are more practical. The numerical experimental results show that the diurnal variation correction data, whose weight factors are calculated by correlation coefficients, have a higher precision. The precision of northern component X and horizontal component H are superior to 2.2 nT, eastern component Y and geomagnetic total intensity F are superior to 1.0 nT, vertical component Z is superior to 0.3 nT, and geomagnetic declination D and geomagnetic inclination I are superior to 10″. Therefore, the diurnal variation correction data in higher precision can be provided for the airborne scalar and vector geomagnetic measurement in the regions where the ground magnetic surveying is difficult.