Near-real-time VTEC maps: new contribution for Latin America Space Weather

TL;DR

This paper presents a near-real-time system for generating high-resolution VTEC maps over Latin America using multiple GNSS constellations, achieving low bias and RMS error, and enabling ionospheric W-index mapping for space weather monitoring.

Contribution

The authors develop and validate a regional VTEC mapping system utilizing multi-constellation GNSS data with minimal latency, a novel approach for Latin America.

Findings

Mean bias lower than 1 TECU compared to reference maps.

RMS error better than 1 TECU against independent measurements.

VTEC maps generated every 15 minutes accurately reflect ionospheric conditions.

Abstract

The development of regional services able to provide ionospheric vertical totalelectron content (VTEC) maps and ionospheric indexes with a high spatialresolution, and in near-real-time, are of great importance for both civilianapplications and the research community. We provide here the methodolo-gies, and an assessment, of such a system. It relies on the public GlobalNavigational Satellite Systems (GNSS) infrastructure in South America, in-corporates data from multiple constellations (currently GPS, GLONASS,Galileo and BeiDou), employs multiple frequencies, and produces continen-tal wide VTEC maps with a latency of just a few minutes. To assess theability of our system to model the ionospheric behavior we performed a year-round intercomparison between our near-real-time regional VTEC maps, andVTEC maps of verified quality produced by several referent analysis centers,resulting in mean biases lower than 1 TEC units (TECU). Also, the evalua-tion of our products against direct and independent GNSS-based slant TECmeasurements shows RMS values better than 1 TECU. In turn, ionospheric W-index maps were generated, for calm and disturbed geomagneticscenarios, solely employing our quality verified VTEC maps. The spatial rep-resentation of these W-index maps reflects the state of the ionosphere, with aresolution of 0.5x0.5 degrees. Finally, we conclude that our products, com-puted every 15 minutes, do provide an excellent spatial representation of theregional TEC, and are able to provide the bases for the possible computationof ionospheric W-index maps, also in near-real-time