Research on the eleventh generation IGRF

This paper expounds in detail the modeling principle, data sources, spherical harmonic coefficients and error sources of the 11th generation international geomagnetic reference field model (IGRF11). Taking the NOAA/NGDC candidate geomagnetic model as an example, an analysis is made on the data selection principle and calibration method. Under MATLAB environment, a visual software of the model was developed, providing the most possible and convenient way for making a geomagnetic reference map. This enables the effective use of international open data, and reduces the workload and cost of geomagnetic measurements, therefore, it is valuable for geomagnetic navigation. Comparing the test and measured values with the calculated value shows that the calculation results of the software are correct and reliable; and comparing IGRF11 with WMM2010 for their similarities and differences reveals that WMM2010 has higher accuracy and a wider scope of application than IGRF11. Finally, by estimating long-time variation, the reason for low calculation accuracy of IGRF11 is analyzed.