Epoch-Wise Estimation and Analysis of GNSS Receiver DCB under High and Low Solar Activity Conditions

Zhang, Xiao; Xia, Lan; Lin, Hong; Li, Qianxia

doi:10.3390/rs15082190

Cited by 2 publications

(1 citation statement)

References 35 publications

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“…Indeed, the signal propagation error induced by the ionosphere can lead to substantial discrepancies in satellite navigation and positioning, spanning from several meters to hundreds of meters. As part of GNSS data processing, the DCBs and ionospheric model parameters are closely lumped [ 6 , 7 ], and their estimation is often performed simultaneously [ 8 , 9 , 10 ]. Hence, any inaccuracies in the ionospheric modeling may propagate into errors in the estimation of satellite DCBs using this approach.…”

Section: Introductionmentioning

confidence: 99%

Estimating BDS-3 Satellite Differential Code Biases with the Single-Frequency Uncombined PPP Model

Wu,

Gao,

2023

Sensors

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Differential Code Bias (DCB) is a crucially systematic error in satellite positioning and ionospheric modeling. This study aims to estimate the BeiDou-3 global navigation satellite system (BDS-3) satellite DCBs by using the single-frequency (SF) uncombined Precise Point Positioning (PPP) model. The experiment utilized BDS-3 B1 observations collected from 25 International GNSS Service (IGS) stations located at various latitudes during March 2023. The results reveal that the accuracy of estimating B1I-B3I DCBs derived from single receiver exhibits latitude dependence. Stations in low-latitude regions show considerable variability in the root mean square (RMS) of absolute offsets for satellite DCBs estimation, covering a wide range of values. In contrast, mid- to high-latitude stations demonstrate a more consistent pattern with relatively stable RMS values. Moreover, it has been observed that the stations situated in the Northern Hemisphere display a higher level of consistency in the RMS values when compared to those in the Southern Hemisphere. When incorporating estimates from all 25 stations, the RMS of the absolute offsets in satellite DCBs estimation consistently remained below 0.8 ns. Notably, after excluding 8 low-latitude stations and utilizing data from the remaining 17 stations, the RMS of absolute offsets in satellite DCBs estimation decreased to below 0.63 ns. These enhancements underscore the importance of incorporating a sufficient number of mid- and high-latitude stations to mitigate the effects of ionospheric variability when utilizing SF observations for satellite DCBs estimation.

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Section: Introductionmentioning

confidence: 99%

Estimating BDS-3 Satellite Differential Code Biases with the Single-Frequency Uncombined PPP Model

Wu,

Gao,

2023

Sensors

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An Analytical Study about Evaluation the Accuracy of Topographic Maps and Digital Elevation Models from Stereo Satellite Images

Madi,

Ali Al-Baghdadi,

Hamdoon

2024

IOP Conf. Ser.: Earth Environ. Sci.

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Topographic maps (TMs) play an essential role in spatial data collection. In remote and complex terrains, the importance of the data collected from topographic maps in various applications has led to the search for new techniques and accurate software to enhance mapping accuracy and efficiency. The accuracy of topographic maps and digital elevation models (DEMs) have been evaluated according to available techniques and modern instruments that served the success of this study, such as using the real-time kinematic technique (RTK), which combines with differential ground positioning system (DGPS), using remote sensing technique, by focusing on Leica photogrammetry suit (LPS) software to generate and analysis the results. This study addressed two case studies in the Makhoul Hills to Salah Din Governorate in northeast Iraq because it’s one of the most critical regions characterized by rugged terrain, and it is challenging to reach and get data from field surveying. Many factors highlight the significance of this study. The first factor used Pleiades stereo satellite images with very high resolution (VHR), with spatial resolution reaching (0.5m) for panchromatic images and (2 m) for multispectral images. The second is that overlapping between the adjacent images equals 90 %, in addition to all data available. Taking into account the Archive topographic maps that were published in 1957 by “Royal Dutch Airlines Koninklijke Luchtvaart Maatschappij” (KLM) were used as reference data when needed to compare the elevations of the surface extracted from DEM by using stereo images, the datum of KLM maps was universal transverse Mercator (UTM). the contour lines which were drawn from KLM maps with contour interval (CI) equal to (3m) and map scale 1:25,000 while photo scale 1:30,000, C. I represented the distance between the lines and indicated the accuracy of the maps on a large scale. As much as possible, the reasons behind collecting all data from multiple sources are as follows: To achieve the aim of this study and evaluate the topographic maps from stereo satellite images, (2). extracting high-accuracy DEMs from stereo satellite images, (3). assessing the accuracy of topographic maps and DEMs using ground control points (GCPs) collected in the field by the DGPS (4). the challenge of evaluating the accuracy of high-quality maps for hard-to-reach regions. Finally, A statistical analysis was performed to measure the differences in terrain elevations between rugged and flat areas to evaluate the accuracy of DEMs and TMs. This study concluded the differences were (0.992m) in flat regions and (1.482 m) in rugged areas, according to the computed values for the root mean square error (RMSE). Also, rugged and flat regions have standard deviations (STD) of (1.643 and 1.071) m, respectively. The results were within the allowable RMSE values of (1 m) for plain surfaces and (5 m) for rough terrain. That was extracted from stereo satellite images when running the LPS software. These results proved the work’s reliability and the maps’ accuracy. It is possible to verify the accuracy of the data by increasing the number of checkpoints for the study area so that they are used as GCPS to ensure the results and are not operated inside the block file while using the LPS program.

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Epoch-Wise Estimation and Analysis of GNSS Receiver DCB under High and Low Solar Activity Conditions

Cited by 2 publications

References 35 publications

Estimating BDS-3 Satellite Differential Code Biases with the Single-Frequency Uncombined PPP Model

Estimating BDS-3 Satellite Differential Code Biases with the Single-Frequency Uncombined PPP Model

An Analytical Study about Evaluation the Accuracy of Topographic Maps and Digital Elevation Models from Stereo Satellite Images

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