Analysis of Several Years of DI Magnetometer Comparison Results by the Geomagnetic Network of China and IAGA

The comparison of absolute geomagnetic instruments is an important component of geomagnetic observation. To promote high quality standards in geomagnetic data acquisition, the International Association of Geomagnetism and Aeronomy (IAGA) organizes an international comparison every two years. In China, this comparison is part of quality control process for geomagnetic observation data, and is organized by the Geomagnetic Network of China (GNC). In this paper, the comparison results from several years are analysed in detail, and some useful information is presented that will help to guide the observatory's future observation work and improve data quality. In addition, the quality of the absolute observation data of GNC and IAGA is evaluated using a statistical method. This should aid scientists who use these data to understand their research results.