Comparative Studies on Methods to Overcome the Ionospheric Effects on GNSS Signals
Shreya Sarkar,
Anindya Bose
Issue:
Volume 9, Issue 2, December 2022
Pages:
28-32
Received:
10 July 2022
Accepted:
16 August 2022
Published:
31 August 2022
DOI:
10.11648/j.ajae.20220902.11
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Views:
Abstract: Global Navigation Satellite System (GNSS) signals are relatively weak in nature and are more difficult to detect under impaired visibility conditions. For an effective position solution accuracy measurement of pseudorange solving for three unknown positions (latitude, longitude, and altitude) using at least three satellites are possible. One more satellite is required as time is considered as another unknown for solving the receiver clock bias. Ionospheric delay can cause error in pseudorange measurements. This is caused due to free ions which interfere with the Global Navigation Satellite System (GNSS) signal. These free ions in the atmosphere are created by solar and cosmic radiation. The ionospheric delay/ phase advance depends on weather, geographic location, solar, geomagnetic activities etc. Therefore, ionospheric delay is unpredictable. Ionospheric delay is considered a significant source of error in measuring the position solution determined by the GNSS signals. This paper proposes two main ideas for overcoming the ionospheric effects. One idea establishes that the inclusion of more satellites or Multi-GNSS scheme could be useful for overcoming the ionospheric effects. The other idea is to deliberately choose ionofree data for obtaining a better solution accuracy. This paper shows the usability of two aforesaid processes in different scenarios. The paper identified the sources of error mentioned by the previous research groups. From this background study the motivation for this research had been identified. Then the paper is organized with research methodology, obtained results, their discussions. In the conclusion section the gaps and future scopes for study have been discussed.
Abstract: Global Navigation Satellite System (GNSS) signals are relatively weak in nature and are more difficult to detect under impaired visibility conditions. For an effective position solution accuracy measurement of pseudorange solving for three unknown positions (latitude, longitude, and altitude) using at least three satellites are possible. One more s...
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Digital Aircraft Assembly Process Technology Simulation and Visualization System
Md Helal Miah,
Jianhua Zhang,
Abdullah-Al Muin
Issue:
Volume 9, Issue 2, December 2022
Pages:
33-38
Received:
5 September 2022
Accepted:
4 October 2022
Published:
28 October 2022
DOI:
10.11648/j.ajae.20220902.12
Downloads:
Views:
Abstract: The main purpose of the digital aircraft assembly process is to ensure the high assembly accuracy of aircraft products, flexibility and reduce the assembly time. Also, reduce the assembly and manufacture error of tooling (Jig/Fixture) design for particular aircraft products. Generally, the aircraft product assembly process is complex, and it performs through the assembly and disassembly process. Regarding the complexity of the aircraft product assembly process, this research illustrates the systematic analysis of the simulation and visualization technology for the aircraft assembly process. This research introduces key technologies and solutions to realize the aircraft's assembly process visualization system. Then assembly simulation environment is implemented based on virtual reality modelling language (VRML), network, assembly process simulation, and visualization of assembly process documents. The digital aircraft assembly process technology has been divided into simulation and visualization systems in this research. The simulation process includes manufacturing factors, assembly objects, assembly sites, process equipment, tools, and devices. The visualization system visually processes the assembly simulation results and then outputs the processed results in the workshop workplace. It includes the related simulation results and adds necessary text technology to make it easier to understand the concept using visualization techniques to process the results. The research has practical value in the modern aircraft industry to propose an aircraft product simulation process based on computer-aided 3D design.
Abstract: The main purpose of the digital aircraft assembly process is to ensure the high assembly accuracy of aircraft products, flexibility and reduce the assembly time. Also, reduce the assembly and manufacture error of tooling (Jig/Fixture) design for particular aircraft products. Generally, the aircraft product assembly process is complex, and it perfor...
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