A Retrospective of Global Navigation Satellite System Ionospheric Irregularities Monitoring Networks in Brazil

Abstract

The use of Global Navigation Satellite System (GNSS) for air and terrestrial navigation and for many applications is increasing in the last decades. However, the Earth's ionosphere causes GNSS signal delay due to the total electron content (TEC) and scintillation in the signal phase and amplitude. This scintillation can give rise to deleterious effects in the GNSS positioning. So, it is important to assess the effects of the ionosphere over the GNSS signal. To achieve this goal, it is necessary to have a large spatial and temporal coverage of data from many different sounders, being the GNSS receivers of great importance due to their global coverage and availability. In this work, we present a retrospective of the scintillation monitoring networks in Brazil and their characteristics. As the RBMC network managed by the IBGE provides TEC and as rate of TEC index (ROTI) is well correlated with ionospheric irregularities, we present also the RBMC network description. These RBMC GNSS receivers provide data in regions with scarcity of scintillation monitors. The description of the Ionospheric Scintillation Monitoring Receivers (ISMR) Query Tool, that is a web software that has been supporting research on the ISMR data, is also presented.

Characterization of Scintillation Events With Basis on L1 Transmissions From Geostationary SBAS Satellites

“…(2022) and de Paula et al. (2023). The monitors were deployed at: (a) Fortaleza (close to the geomagnetic equator), receiving L1 transmissions from the EGNOS (European Geostationary Navigation Overlay Service) SBAS satellite Sirius‐5 (PRN number 136, located at 5.0°E in the geostationary orbit); and (b) Inconfidentes (close to the southern crest of the EIA), receiving L1 transmissions from the EGNOS SBAS satellite Inmarsat I‐3 F2 (PRN number 120, located at 15.5°W in the geostationary orbit).…”

“…The measurements were performed by two Septentrio PolaRx5S ground-based scintillation monitors, currently operated by the GNSS Technology to Support Air Navigation (GNSS NavAer) project, funded by the Brazilian Instituto Nacional de Ciência e Tecnologia (INCT). More details on the project can be found in Monico et al (2022) andde Paula et al (2023). The monitors were deployed at: (a) Fortaleza (close to the geomagnetic equator), receiving L1 transmissions from the EGNOS (European Geostationary Navigation Overlay Service) SBAS satellite Sirius-5 (PRN number 136, located at 5.0°E in the geostationary orbit); and (b) Inconfidentes (close to the southern crest of the EIA), receiving L1 transmissions from the EGNOS SBAS satellite Inmarsat I-3 F2 (PRN number 120, located at 15.5°W in the geostationary orbit).…”

PPP at Low Latitudes With Ionospheric Model Exclusively Based on Single Frequency GNSS Measurements

“…The model is executed using data from approximately 200 ground‐based receivers from the continuous operating GNSS stations throughout America, especially over the Brazilian region. The data from RBMC (Brazilian Network for Continuous GNSS Monitoring), IGS, GNSS NavAer (De Paula et al., 2022), LISN (Low latitude Ionospheric Sensor Network), and RAMSAC (Red Argentina de Monitoreo Satelital Continuo) are used. The location of the GNSS stations used in regional model are presented in Figure 1a.…”

A Simple and Effective Approach to Real-Time Ionospheric Monitoring at Low Latitudes and Its Applicability to GBAS

“…A few reference stations deployed by the Institute of Airspace Control (ICEA) were also used. A complete description of the networks used in this experiment can be found in Paula et al (2023). In all cases, the available data were collected by receivers with 15-s measurement intervals.…”