Investigation of Displacement and Ionospheric Disturbance during an Earthquake Using Single-Frequency PPP

Currently, it is still challenging to detect earthquakes by using the measurements of Global Navigation Satellite System (GNSS), especially while only adopting single-frequency GNSS. To increase accuracy earthquake detection and warning, extra information techniques are required that lead high costs. Therefore, this work tries find a low-cost method with high-accuracy performance. The contributions our research twofold: (1) an improved earthquake-displacement estimation approach considering relation between ionospheric disturbance presented. For purpose, we propose undifferenced uncombined Single-Frequency Precise Point Positioning (SF-PPP) approach, in which both delay each observed satellite receiver Differential Code Bias (DCB) parameterized. When processing 1 Hz GPS data collected during 2013 Mw7.0 Lushan 2011 Mw9.0 Tohoku-Oki earthquake, proposed SF-PPP can provide coseismic deformation signals accurately. Compared results from GAMIT/TRACK, was not influenced common mode errors exist GAMIT/TRACK solutions. (2) Vertical Total Electron Content (VTEC) anomalies before investigated applying time-series analysis spatial interpolation methods. Furthermore, on long-term scale, revealed significant positive/negative VTEC appeared around epicenter day occurred compared about 4–5 days whereas, short-term emerged several-hours or after earthquake.