A New Algorithm for Ill-Posed Problem of GNSS-Based Ionospheric Tomography

Ill-posedness of GNSS-based ionospheric tomography affects the stability and accuracy inversion results. Truncated singular value decomposition (TSVD) is a common algorithm reconstruction. However, TSVD method usually has low reconstruction efficiency. To resolve above problem, truncated mapping (TMSVD) presented to improve reconstructed computational authenticate effectiveness advantages TMSVD algorithm, numerical test scheme devised. Finally, temporal–spatial variations selected region are studied using GNSS observations under different geomagnetic conditions. The results can accurately reflect semiannual anomalies, diurnal variations, storm effects. In contrast with ionosonde data, it found that profiles more consistent than those IRI 2016. study suggests an efficient for tomographic electron density (IED).