Variability of Vertical Total Electron Content Gradients in the Brazilian Sector

Author(s)

Espejo, Teddy Modesto Surco ; Costa, Emanoel ; de Paula, Eurico Rodrigues ; Moraes, Alison de Oliveira ; Monico, Joao Francisco Galera

• Document type: Journal article
• Source: IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS; v. 59, n. 3, p. 15-pg., 2023-06-01.

Abstract

Ground Based Augmentation Systems are designed to meet demanding requirements during airport approach and landing sections of aircraft routes. It computes corrected and smoothed differential corrections and other information. These messages are transmitted to aircraft, which may use the corrections to improve their position estimation. However, residual correction errors remain, due to ionospheric spatial and temporal gradients between Ground Based Augmentation System reference receivers and approaching aircraft. Large vertical ionospheric delay gradients detected during combinations of extreme geophysical environments indicate that there are problematic conditions for Ground Based Augmentation System operation over the Brazilian region. Motivated by the above conditions, data from Rede Brasileira de Monitoramento Continuo, the Brazilian public network of dual-frequency global navigation satellite system receivers operated by Instituto Brasileiro de Geografia e Estatistica were analyzed to estimate ionospheric vertical Total Electron Content (vTEC) gradients. The effects from different locations (represented by the dip latitude) and geophysical conditions (represented by solar activity, season, and local time) on variations of ionospheric vTEC gradients have been statistically quantified. The results from the present work provide information to more detailed performance assessments of Ground Based Augmentation System procedures under equatorial and low-latitude ionospheric regions, aimed at flexibly delimiting the conditions for feasible operation in such regions. (AU)

• FAPESP's process: 17/50115-0 - GNSS technology for supporting air navigation
• Grantee: Joao Francisco Galera Monico
• Support Opportunities: Research Grants - Research in Public Policies