Model of the Ionospheric Delay Correction Based on CORS for Vehicle Navigation and Positioning

CICTP 2012 ◽  
2012 ◽  
Author(s):  
Lei Wang ◽  
Wu-Sheng Hu
Keyword(s):  
Ionospheric Delay ◽  
Vehicle Navigation ◽  
Delay Correction

scholarly journals On Global Ionospheric Maps based winter-time GPS ionospheric delay with reference to the Klobuchar model

Pomorstvo ◽  
2019 ◽  
Vol 33 (2) ◽  
pp. 210-221
Author(s):  
David Brčić ◽  
Renato Filjar ◽  
Serdjo Kos ◽  
Marko Valčić
Keyword(s):  
Ionospheric Delay ◽  
Single Frequency ◽  
Electron Content ◽  
Ground Truth Data ◽  
Local Pattern ◽  
Satellite Positioning ◽  
Klobuchar Model ◽  
Global Ionospheric Maps ◽  
Winter Time ◽  
Delay Correction

Modelling of the ionospheric Total Electron Content (TEC) represents a challenging and demanding task in Global Navigation Satellite Systems (GNSS) positioning performance. In terms of satellite Positioning, Navigation and Timing (PNT), TEC represents a significant cause of the satellite signal ionospheric delay. There are several approaches to TEC estimation. The Standard (Klobuchar) ionospheric delay correction model is the most common model for Global Positioning System (GPS) single-frequency (L1) receivers. The development of International GNSS Service (IGS) Global Ionospheric Maps (GIM) has enabled the insight into global TEC dynamics. GIM analyses in the Northern Adriatic area have shown that, under specific conditions, local ionospheric delay patterns differ from the one defined in the Klobuchar model. This has been the motivation for the presented research, with the aim to develop a rudimentary model of the TEC estimation, with emphasis on areas where ground truth data are not available. The local pattern of the ionospheric delay has been modelled with wave functions based on the similarity of waveforms, considering diurnal differences in TEC behavior from defined TEC patterns. The model represents a spatiotemporal winter-time ionospheric delay correction with the Klobuchar model as a basis. The evaluation results have shown accurate approximation of the local pattern of the ionospheric delay. The model was verified in the same seasonal period in 2007, revealing it successfulness under pre-defined conditions. The presented approach represents a basis for the further work on the local ionospheric delay modelling, considering local ionospheric and space weather conditions, thus improving the satellite positioning performance for single-frequency GNSS receivers.

scholarly journals Long-term Performance Evaluation for Ionospheric Delay Correction of BeiDou Navigation Satellite System

2019 ◽  
Vol 131 ◽  
pp. 01075
Author(s):  
Chen Liu ◽  
Yi Jiang ◽  
Ye Chen ◽  
Ao Xu ◽  
Junpeng Li ◽  
...  
Keyword(s):  
Satellite System ◽  
Ionospheric Delay ◽  
Navigation Satellite ◽  
Dual Frequency ◽  
Correction Model ◽  
Beidou Navigation Satellite System ◽  
Correction Rate ◽  
Klobuchar Model ◽  
Delay Correction ◽  
Ionospheric Grid

Ionospheric delay is one of the main errors in the satellite navigation and positioning system. At present, ionospheric delay correction model and grid ionospheric information are provided to correct the error in BeiDou Navigation Satellite System (BDS). The ionospheric delay correction model is the Klobuchar model with 8 parameters at the geographic latitude for basic navigation. Grid ionospheric information is the ionospheric grid map covering China region for enhanced services. The dual-frequency pseudo-range combination data and ionospheric data from 2013 to 2018 have been used to make comprehensive assessments of the correction performance of BDS Klobuchar model and ionospheric grid information. The average correction rate of ionospheric grid information is about 85%, and the average correction rate of BDS Klobuchar model is about 73%. The correction accuracy of BDS Klobuchar model varies little, and the ionospheric grid information has a single-peak structure. The correction accuracy in summer and autumn is slightly higher than that in winter and spring. Changes in solar activity have a greater impact on BDS Klobuchar model correction bias. Ionospheric grid information owns relatively strong anti-disturbance ability, and BDS Klobuchar model also has a definite anti-disturbance capability compared with the GPS Klobuchar model.

scholarly journals Evaluation of Seasonal Variability of First-order Ionospheric Delay Correction at L5 and S1 Frequencies Using Dual-frequency Navic System

2021 ◽  
Author(s):  
Sharat chandra Bhardwaj ◽  
Anurag Vidyarthi ◽  
Bhajan Singh Jassal ◽  
Ashish kumar Shukla
Keyword(s):  
Seasonal Variability ◽  
Ionospheric Delay ◽  
Electron Content ◽  
Dual Frequency ◽  
Satellite Constellations ◽  
Total Electron ◽  
First Order ◽  
Seasonal Characteristics ◽  
Geosynchronous Satellites ◽  
Delay Correction

Abstract For the precise positioning application it is important to determine and eliminate the positioning error introduced by various sources such as the ionosphere. To develop a standalone precise navigation system, India has launched the seven satellite constellations of NavIC (Navigation with Indian Constellation) system to provide precision positioning over India and surrounded landmass. Since the ionospheric delay depends on the frequency of the satellite signal and NavIC systems work at different frequencies (L5 and S1) than GPS systems (L1 and L2), it is not possible to use the GPS data-driven study for NavIC based location calculations directly. Thus there is a need for a specialized ionospheric study for NavIC systems. In addition, the ionospheric delay is directly proportional to Slant Total Electron Content (STEC) which is dependent upon diurnal and seasonal solar activity. To achieve accurate positioning facilities, there is also a need for evaluation for seasonal variability of ionospheric delay correction for NavIC receivers. This paper deals with the STEC estimation; its smoothing, and removal of instrumental biases from STEC. The determined true STEC has been used to determine first-order ionospheric delay at L5 and S1 frequencies. The delay at S1 has been found less (2 to 7m) as compared to L5 (10 to 30m). Furthermore, the seasonal variability of ionospheric delay has been analyzed using about 19 months of data (from June 2017 to December 2018) and found that the ionospheric delay follows unique seasonal characteristics which can be utilized for delay modeling. It has been also observed that the geostationary satellites of the NavIC system are more appropriate than geosynchronous satellites for ionospheric related studies.

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