Multi-Source Data Fusion for Global TEC Map Construction with VISTA Algorithm

The global total electron content (TEC) map based on the VISTA (Video Imputation with SoftImpute, Temporal smoothing and Auxiliary data) algorithm provides high-quality TEC estimation for both space weather and radio science and has been applied to the Madrigal ground-based TEC database in the past. While VISTA effectively leverages spatial smoothness and temporal consistency, its performance over the ocean is limited due to the sparse and uneven distribution of GNSS ground stations. To address this, we integrated complementary observations from optical remote sensing (GOLD), LEO satellites (COSMIC2; PlanetIQ), altimeters (Jason-3 / Sentinel-6) and Doppler orbitography and radio positioning (DORIS) with GNSS measurements into VISTA. Bias between different dataset and the Madrigal TEC has been removed based on each source’s unique observing and archiving characteristics. The effectiveness of the heterogenous data is tested by comparing the new results with the original VISTA results based on ground-based TEC only. The complete TEC maps show obvious improvement above ocean regions and preserve more observed meso-scale structures. It provides an advanced tool for space weather research and ionospheric correction in radio science.