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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Ionospheric scintillation impact on ambiguity resolution using ADOP in closed form

Texto completo
Autor(es):
Silva, C. M. [1] ; Alves, D. B. M. [1] ; Souza, E. M. [2] ; Setti Junior, P. T. [1]
Número total de Autores: 4
Afiliação do(s) autor(es):
[1] Sao Paulo State Univ, UNESP, Sch Technol & Sci, Presidente Prudente - Brazil
[2] Univ Estadual Maringa, UEM, Maringa, Parana - Brazil
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Fonte: Advances in Space Research; v. 64, n. 4, p. 921-932, AUG 15 2019.
Citações Web of Science: 0
Resumo

The Ambiguity Dilution of Precision (ADOP) is a well-known scalar measure that can be used to infer the strength of the Global Navigation Satellite System (GNSS) model of the carrier phase ambiguities involved in precise relative GNSS positioning. Odijk and Teunissen (2008a) derived closed-form expressions for single-baseline GNSS models that allow verifying the factors affecting the ambiguity resolution as well as the probability of its correct resolution as integer values. However, this weighted-ionosphere ADOP closed form assumes that the standard deviation of the ionosphere delay is dependent on a function associated with the baseline length. This means that a baseline of the same length at different locations around the world and in different moments in time would have the same standard deviation, which in practice is not true. This becomes even worse in regions like Brazil, where the ionospheric anomalies are more intense and frequent, especially in periods of high solar activity. In this work, a new method for calculating the ionospheric delay standard deviation that considers the ionospheric scintillation S4 index is proposed to improve the closed-form ADOP performance. Experiments with a baseline of 280 m located in Presidente Prudente, Brazil (magnetic latitude of around -13 degrees), were carried out. The results showed that in periods of both weak and strong ionospheric scintillation, the introduction of S4 into the ionospheric delay standard deviation was beneficial for ADOP. The average improvement of the ADOP closed form was of around 72% in the analyzed period of weak scintillation and of 35% in the period of strong scintillation. In addition, the results showed that in periods of strong scintillation, relative positioning accuracy is around 100 times worse, up to 30 m, when compared to periods of weak ionospheric scintillation. (C) 2019 COSPAR. Published by Elsevier Ltd. All rights reserved. (AU)

Processo FAPESP: 12/19906-7 - Avaliação robusta do impacto da modelagem atmosférica no posicionamento baseado em redes
Beneficiário:Daniele Barroca Marra Alves
Modalidade de apoio: Auxílio à Pesquisa - Regular
Processo FAPESP: 13/06325-9 - Solução das ambiguidades no posicionamento baseado em redes
Beneficiário:Crislaine Menezes da Silva
Modalidade de apoio: Bolsas no Brasil - Mestrado
Processo FAPESP: 16/24861-3 - Posicionamento por ponto GNSS: implementação e avaliação de novos modelos, sistemas e sinais
Beneficiário:Paulo de Tarso Setti Júnior
Modalidade de apoio: Bolsas no Brasil - Mestrado