Investigating Ionospheric Scintillation Effects on Multifrequency GPS Signals

Author(s)

Salles, Lucas A. ^[1] ; Vani, Bruno C. ^[2] ; Moraes, Alison ^[3] ; Costa, Emanoel ^[4] ; de Paula, Eurico R. ^[5]

Affiliation

^[1] Inst Tecnol Aeronaut, Praca Mal Eduardo Gomes, Programa Posgrad Ciencias & Tecnol Espaciais ITA, Praca Mal Eduardo Gomes 50, BR-12228904 Sao Jose Dos Campos, SP - Brazil

^[2] Inst Fed Educ Ciencia & Tecnol Sao Paulo, Campus Presidente Epitacio IESP Pep, Rua Jose Ramos Jr 27-50, BR-19470000 Presidente Epitacio, SP - Brazil

^[3] Inst Aeronaut & Espaco, Div Eletron IAE AEL, Praca Mal EduardoGomes 50, BR-12228904 Sao Jose Dos Campos, SP - Brazil

^[4] Pontificia Univ Catolica Rio de Janeiro CETUC PU, Ctr Estudos Telecomunicacoes, Rua Marques de Sao Vicente 225, BR-22451900 Rio De Janeiro, RJ - Brazil

^[5] Inst Nacl Pesquisas Espaciais INPE, Ave Astronautas 1758, BR-12227010 Sao Jose Dos Campos, SP - Brazil

• Document type: Journal article
• Source: SURVEYS IN GEOPHYSICS; v. 42, n. 4, p. 999-1025, JUL 2021.
• Web of Science Citations: 2

Abstract

Over the last 15 years, the satellite constellation of the global positioning system (GPS) has been modernized for more precise applications, with the introduction of the L2C and L5 signals. However, among other effects, they are susceptible to severe ionospheric effects, particularly in the equatorial and low-latitude regions. Equatorial plasma bubbles, resulting from the combination of the ionospheric electrodynamics with plasma instability mechanisms and thermospheric coupling, may generate irregularity structures with scale sizes ranging from hundreds of kilometers to a few meters (or less). Ionospheric irregularities may cause deep amplitude fades and phase shifts to transionospheric signals. That is, they are responsible for amplitude and phase scintillation, which degrade receiver operations and may cause failures and unavailability to positioning and navigation services under extreme conditions. The objective of the present work is to analyze ionospheric scintillation effects on the L2C and L5 GPS signals, to compare their vulnerabilities with those of the L1 signal. The data used in this analysis were collected between November 2014 and March 2015, during the maximum solar activity of cycle 24 (a period of great scintillation incidence), by scintillation monitors deployed at four different sites in the Brazilian territory: Fortaleza, Presidente Prudente, Sao Jose dos Campos, and Porto Alegre. Intensity fades will be analyzed, considering different thresholds, to reveal their empirical probability distributions of scintillation occurrence, average fading occurrences and durations. The results will show that greater probabilities of strong scintillation occurrences are present in the modernized signals, reaching up to five times more events in the L5 signal in comparison with those in the legacy L1 signal. It will be shown that the L5 average fade duration is distinctly longer than the corresponding ones for the other frequencies, considering the same site, threshold, and L1 amplitude scintillation level. The results will also show that the average fade duration decreases according to the average ratio 0.6 s/3 dB within the threshold range from - 6 to - 15 dB, considering the same amplitude scintillation level and location. (AU)

• FAPESP's process: 06/04008-2 - GNSS: investigations and applications in geodetic positioning, in studies related to the atmosphere and precision agriculture
• Grantee: Joao Francisco Galera Monico
• Support Opportunities: Research Projects - Thematic Grants
• 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