The variability of low-latitude ionospheric amplitude and phase scintillation detected by a triple-frequency GPS receiver

If any Global Positioning System (GPS) receiver is operated in low latitude regions or urban canyons, the visibility further reduces. These system constraints lead to many challenges in providing precise GPS position accuracy over the Indian subcontinent. As a result, the standalone GPS accuracy does not meet the aircraft landing requirements, such as Category I (CAT-I) Precision Approaches. However, the required accuracy can be achieved by augmenting the GPS. Among all these issues, the predominant factors that significantly influence the receiver position accuracy are selecting a user/receiver position estimation algorithm. In this article, a novel method is proposed based on correntropy and designated as Correntropy Kalman Filter (CKF) for precise GPS applications and GPS Aided Geosynchronous equatorial orbit Augmented Navigation (GAGAN) based aircraft landings over the low latitude Indian subcontinent. The real-world GPS data collected from a dual-frequency GPS receiver located in the southern region of the Indian subcontinent (IISc), Bangalore with Lat/Long: 13.021°N/ 77.5°E) is used for the performance evaluation of the proposed algorithm. Results prove that the proposed CKF algorithm exhibits significant improvement (up to 34%) in position estimation compared to the traditional Kalman Filter.

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Study of equatorial low-latitude ionospheric irregularities during a recent geomagnetic storm of 03 August 2010 using GPS receiver

2011 XXXth URSI General Assembly and Scientific Symposium ◽

10.1109/ursigass.2011.6050917 ◽

2011 ◽

Cited By ~ 1

Author(s):

S. Priyadarshi ◽

A. K. Singh

Keyword(s):

Geomagnetic Storm ◽

Ionospheric Irregularities ◽

Gps Receiver ◽

Low Latitude

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Study of Equatorial Plasma Bubbles Using ASI and GPS Systems

Geographic Information Systems in Geospatial Intelligence ◽

10.5772/intechopen.85604 ◽

2020 ◽

Author(s):

Dada P. Nade ◽

Swapnil S. Potdar ◽

Rani P. Pawar

Keyword(s):

Electron Content ◽

Gps Receiver ◽

Plasma Bubble ◽

Low Latitude ◽

Total Electron ◽

Plasma Irregularities ◽

Plasma Bubbles ◽

F Region ◽

Equatorial Plasma Bubbles ◽

Background Density

The plasma irregularities have been frequently observed in the F-region, at low latitude regions, due to the instability processes occurring in the ionosphere. The depletions in electron density, as compared to the background density, is a signature of the plasma irregularities. These irregularities are also known as the “equatorial plasma bubble” (EPB). These EPBs can measure by the total electron content (TEC) using GPS receiver and by images of the nightglow OI 630.0 nm emissions using all sky imager (ASI). The current chapter is based on the review on the signature of the EPBs in TEC and ASI. measurements. We have also discussed the importance of the study of EPBs.

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Nature-Inspired Biogeography-Based Optimization for Estimation of GPS Receiver Position in Low Latitude Regions of the Indian Subcontinent

Lecture Notes in Electrical Engineering - Microelectronics, Electromagnetics and Telecommunications ◽

10.1007/978-981-15-3828-5_25 ◽

2020 ◽

pp. 241-249

Author(s):

N. Ashok Kumar ◽

G. Sasibhushana Rao

Keyword(s):

Indian Subcontinent ◽

Gps Receiver ◽

Low Latitude

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On the Choice of the Third-Frequency Galileo Signals in Accelerating PPP Ambiguity Resolution in Case of Receiver Antenna Phase Center Errors

Remote Sensing ◽

10.3390/rs12081315 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1315

Author(s):

Shaoming Xin ◽

Jianghui Geng ◽

Jiang Guo ◽

Xiaolin Meng

Keyword(s):

Ambiguity Resolution ◽

Convergence Time ◽

Gps Receiver ◽

Dual Frequency ◽

International Gnss Service ◽

Phase Center ◽

Triple Frequency ◽

Antenna Phase ◽

Signal Combination ◽

Antenna Phase Center

Rapid precise point positioning ambiguity resolution (PPP-AR) is of great importance to improving precise positioning efficiency. There is an expectation that Galileo multi-frequency (three or more frequencies) data processing will offer a promising way to accelerate PPP-AR. However, the performance of different combination observables out of raw Galileo multi-frequency data is still unclear, and the adverse impacts of missing receiver antenna phase center corrections have not been quantified in detail. We therefore studied uncombined Galileo PPP-AR by contrasting three typical triple-frequency combinations, which are E1/E5a/E5b, E1/E5a/E6, and E1/E5/E6 signals, using 30 days of data from 15 stations across Australia. We carried out triple-frequency PPP-AR by separately applying the official GPS receiver antenna phase centers, as currently employed in most relevant literatures, as well as the pilot Galileo receiver antenna phase centers preliminarily measured by the International GNSS Service. We found that, compared to dual-frequency (E1/E5a) PPP-AR, triple-frequency PPP-AR based on E1/E5a/E5b signals shortened the convergence time by only 7.6%, while those based on E1/E5a/E6 and E1/E5/E6 increased unexpectedly the convergence time by 17.6% and 12.7%, respectively, if the GPS receiver antenna corrections were presumed for Galileo signals. However, after using the pilot Galileo phase center corrections, triple-frequency PPP-AR based on E1/E5a/E5b, E1/E5a/E6, and E1/E5/E6 signals could speed up the convergence on average by about 16.2%, 30.3%, and 17.7%, respectively. Therefore, we demonstrate the critical impact of correct Galileo receiver antenna phase centers on multi-frequency PPP-AR convergences. Moreover, the triple-frequency signal combination E1/E5a/E6 is advantageous over others in achieving rapid triple-frequency Galileo PPP-AR.

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Progress report on 21-cm observations at low latitude between longitudes (l 11) 0° and 66°

Symposium - International Astronomical Union ◽

10.1017/s0074180900100907 ◽

1967 ◽

Vol 31 ◽

pp. 177-179

Author(s):

W. W. Shane

Keyword(s):

Preliminary Report ◽

Progress Report ◽

Galactic Centre ◽

Low Latitude ◽

The Third ◽

Introductory Lecture ◽

Centre Region

In the course of several 21-cm observing programmes being carried out by the Leiden Observatory with the 25-meter telescope at Dwingeloo, a fairly complete, though inhomogeneous, survey of the regionl11= 0° to 66° at low galactic latitudes is becoming available. The essential data on this survey are presented in Table 1. Oort (1967) has given a preliminary report on the first and third investigations. The third is discussed briefly by Kerr in his introductory lecture on the galactic centre region (Paper 42). Burton (1966) has published provisional results of the fifth investigation, and I have discussed the sixth in Paper 19. All of the observations listed in the table have been completed, but we plan to extend investigation 3 to a much finer grid of positions.

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