For the detection of Travelling Ionospheric disturbances, eight complementary methodologies are applied in the TechTIDE project with real-time and historical data from Digisonde DPS4D ionospheric sounders, from the Continuous Doppler Sounding System and from GNSS receivers.
- HF-TID method
- CDSS-MSTID detection method
- GNSS TEC gradient algorithms
- Spatial and Temporal GNSS analysis
- The AATR indicator
- HF Interferometry method
- HTI technique to monitor wave activity
- TaD 3D mapping of the electron density
8. TaD 3D mapping of the electron density
(Kutiev et al., 2016)
The method for the reconstruction of the 3D electron density distribution (EDD) over Europe in real time is developed on the base of the TSM-assisted Digisonde (TaD) profiler. The TaD profiler, provides vertical electron density profiles (EDP) over Digisonde sounding stations operating in Europe, from the bottom of the ionosphere up to the GNSS orbit altitude. To obtain the 3D EDD, TaD profiler calculates first ED profiles over the European Digisonde locations. Using the Polyweight interpolation method the 2D maps of the basic ionospheric plasma parameters for the height of maximum electron density concentration, are developed. TaD profiler calculates ED profiles at each node and adjusts them to the GNSS-TEC values extracted from the GNSS TEC maps. Electron density at any arbitrary point within the 3D space is calculated by a linear interpolation from their respective values at the neighbouring grid nodes The EDD between any two points in the space is then obtained by calculating successive ED values with a defined step along the raypath (Figure 8). The model error based on the comparison of 3D EDD model values with vertical TEC (vTEC) and slant TEC (sTEC), calculated from individual GNSS receivers, is 10% for sTEC and 6% for vTEC. Belehaki et al. (2017) showed the sensitivity of the TaD EDD in TIDs and the model capability to detect the altitude of the maximum perturbation.
Kutiev, I., P. Marinov, and A. Belehaki (2016), Real time 3-D electron density reconstruction over Europe by using TaD profiler, Radio Sci., 51, doi:10.1002/2015RS005932.