Interpolation Algorithm of Global Ionospheric Map Product TEC

Abstract

Global Ionospheric Map (GIM) is an important ionospheric data product provided by the IGS working group, which can provide global real-time ionospheric delay error correction for satellite altimeters. In this study, temporal and spatial interpolation of Total Electron Content (TEC) that derived from GIM data products was performed, with the temporal and spatial resolution of Jason-3 altimeter. Two spatial interpolation methods, Kriging interpolation and Bilinear interpolation, were used in this study. The TEC obtained by these interpolation methods is compared and analyzed with the TEC value that converted from the dual-frequency delay correction of the smoothed Jason-3 altimeter cycle80 data. Results show that the mean bias between Kriging interpolation and processed dual-frequency delay correction is 0.94 TECU, the root mean square error is 2.73 TECU and the correlation coefficient is 0.91. As a contrast, these statistics between Bilinear interpolation and processed dual-frequency delay correction are 1.43 TECU, 6.85 TECU, and 0.61, respectively. This demonstrates that the accuracy of the Kriging interpolation is significantly higher than that of the * Ù ³ ½ ª Ó (62031005) Ì´Ó» ³ ª Ó (ZR2020MD097) ½ 2020-03-16