Dataset to accompany manuscript "Assessment of Ionospheric TEC Performance among Multi-GNSS Dual-Frequency Combinations based on ROTI"

This dataset accompanies the manuscript "Assessment of Ionospheric TEC Performance among Multi-GNSS Dual-Frequency Combinations based on ROTI".  The data can be used to reproduce figures 1-8 in the main text. All files are in .mat format and are easily readable.  The abstract for the associated paper is as follows:

The dual-frequency combination of Global Navigation Satellite System (GNSS) signals plays a crucial role in ionospheric monitoring. At present, the majority of GNSS satellites emit multiple signals across various frequency bands. This offers the opportunity of estimating the ionospheric total electron content (TEC) from multiple dual-frequency combinations. The Rate of TEC index (ROTI) is calculated from dual-frequency phase measurements and it serves to quantify the dynamic variations in the slant TEC (STEC) by reducing datum deviations through differencing. This study assesses the ionospheric TEC performance among multiple dual-frequency combinations based on ROTI for the BeiDou Navigation Satellite System (BDS), Global Positioning System (GPS), and Galileo constellations. The results indicate that, ROTI is significantly correlated with the accuracy and quality of the TEC. The ROTI values derived from different dual-frequency combinations exhibit inherent differences, which remain consistent over a long-time scale. The intra-combination frequency difference and the performance of individual signals are factors that influence the TEC performance. The optimal dual-frequency combinations are L2I-L5P for BDS, L1C-L2W for GPS, and L1C-L8Q for Galileo, respectively. Moreover, ROTI could also be affected by the satellite orbit plane change, which is quantified by the solar beta angle of the satellite orbital plane.