• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.84-91
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• 2007

As GPS equipments improve, one can acquire GPS data easily in the field. To obtain precise and accurate coordinates, however, post processing is additionally required and the processing needs high degree of skills. Besides, it is very common that we cannot operate processing softwares in the field because the required system environment is usually not prepared. The aim of this study is the development of an internet-based GPS data processing service. For post processing, we used GIPSY developed by JPL. It has many advantages such as obtaining coordinates quickly by using precise or predicted ephemeris. This service proceeds as following orders by interlocking GIPSY software and internet service which is operated on a Linux platform: Users upload the raw data file on the internet, then GIPSY runs automatically and then the user gets the result in the field. We use an Apache web server as the hosting program and PHP scripts are used in coding web pages. The total processing time including data-uploading was around 30 seconds for a 24-hour data with a 30-second sampling rate.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.65-71
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• 2004

The Development of GPS practical using and systematic fixing for GPS Quality Control System on On-Line. Developed the program that can prove GPS quality about GPS permanent observation stations or user GPS data in server client system environment of Web-Based objectively Developed Save-module of graph display of analysis result data and reporter form. Developed the program for making an estimate of GPS satellite information in server client system environment of Web-Based. Designed that the Display can be possible and store estimate result can expresses the form such as Sky Plot, DOPs, Satellite Elevation, satellite number cf predict-time and then the result can be preserved for report form.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.187-190
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• 2010

GPS survey came into wide use, but there are inefficient parts in related laws and regulations. Especially, to get GPS surveying results under 1.5cm permissible error the observation time must be longer than 8 hours in triangulation points surveying regulations. However, GPS surveying technology is developing now, so results could be acceptable under 4 hours observation time. Therefore, this study made a stable standard of observation time in GPS survey by comparing the errors due to observation time, and used PAJU, DOND and YANP's GPS data and 6 cadastral points' survey data. Also, to analyze the variations of results due to baseline distance, applied each GPS site as a fixed point and compared the positions. As a result, the stable satisfactory results were calculated under 4 hour survey, when the baseline distances were under 30km.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.1
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• pp.63-71
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• 2004

This research is to reconstruction of railway alignment using GPS data, an investigation is made on the method of optimum simplification for reduction of unnecessary linear data, improve the accuracy by using four simplification algorithms among the methods. By applying two measured of displacement between observed data and it's simplification methods have been evaluated. The results showed that the complexities of lines is not practical to investigate simplification algorithms, the Douglas-Peucker method produced a little displacement between observed data and it's simplification. Its by using the Douglas-Peucker method to observed linear GPS data in railway track, design elements of horizontal alignment have been calculated. Then we could know that obtain the good results fur reconstruction of alignment elements through the methods and algorithns of this study.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.9 no.3
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• pp.92-101
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• 2010

Energy efficiency and safe mobility are the two key constituents of the future automobile. The technologies that enable these features are now heavily dependent upon information and communication technology rather than traditional auto-mechanical technology. This paper presents an exploratory project 'Smart&Green Vehicle Project' at Western Michigan University which is to improve the geographical location accuracy of vehicles and to study various applications of making such location data available. Global Positioning System (GPS), Inertial Navigation System (INS), Vehicular Ad-hoc Network (VANET) technology, and data fusion among these technologies are investigated. Testing and evaluation is done on systems which will gather vehicular positioning data during GPS signal loss. Vehicles in urban settings do not acquire accurate positioning data from GPS alone; therefore there is a need for exploration into technology that can assist GPS in urban settings. The goal of this project is to improve the accuracy of positioning data during a loss of GPS signal. Controlled experiments are performed to gather data which aided in assessing the feasibility of these technologies for use in vehicular platforms.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.27-31
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• 2003

It can be classified in various methods to get the geoidal heights. It can be achieved geometric geoidal heights if we do GPS surveying in leveling point. The aims of this paper are calculation of geometric geoidal heights using GPS/leveling data in study area and evaluation of the global and local geoid models in and around Korean peninsula. For this study, study area was selected in the leveling line from Kunsan to Chonju city and GPS surveying was accomplished in the leveling line. And, also spherical harmonic analysis was made on the three global geopotential models, OSU91A, EGM96, EGM96m under same condition and KOGD2002, Korean gravimetric geoid model was made in this study The results shows that EGM96m is the best model because the differences between geoidal heights of EGM96m and geometric geoidal heights of GPS/Leveling data appear the smallest value among them.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2382-2386
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• 2003

The Global Positioning System(GPS) is a satellite based precise positioning system avaliable worldwide. The GPS have many error sources. The earth's ionosphere and atmosphere cause delays in the GPS signal that translate into position errors. Some errors can be factored out using mathematics and modeling. The configuration of the satellites in the sky can magnify other errors. The problem of accuracy on GPS measurement data can be meaningful. In this study, we propose the method for GPS positioning accuracy improvement. The FUZZY set theory on PDOP(Position Dilution of Precision) and SNR(Signal to Noise Ratio) provide improved for measured positioning data. The accuracy of positioning has been improved by selecting data from original using the FUZZY set theory on PDOP and SNR.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1409-1415
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• 2017

The navigation and EDR(Event Data Recorder) have a different roles but also a lot of similar or common functions and elements. A representative element is a GPS. The GPS of navigation is a more higher than the that of EDR in performance. The high performance GPS has a very short initialization time and more accurate than the GPS of EDR. And the informations of OBD(On Board Diagnostics) is able to be shared in navigation and EDR. But these inter-working product between the navigation and EDR has been not yet shown. So, this paper is aimed to show how to interwork in two devices. We utilize USB bulk communication in two devices for inter-working. It is very simple ways and it could interwork in GPS, event video and ODB II data. It could be effective in cost competence and convenience. These was implemented by hardware and software and proved by the standard test.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.33.1-33
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• 2002

The INS provides high rate position, velocity and attitude data with good short-term stability while the GPS provides position and velocity data with long-term stability. By integrating the INS with GPS, a navigation system can be achieved to provide highly accurate navigation performance. For the best performance, time synchronization of GPS and INS data is very important in GPS/INS integrated system. But, it is impossible to synchronize them exactly due to the communication and computation time-delay. In this paper, to reduce the error caused by the measurement time-delay in GPS/INS integrated systems, error compensation methods using separate bias Kalman filter are suggested for both the...

• Information Systems Review
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• v.11 no.1
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• pp.181-196
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• 2009

New domains in the analysis of the behavior of moving objects, particularly within human social settings, are generating research interest due to significant advances in the accuracy and production cost of global positioning system (GPS) devices. However, although potential applications have been described in multiple research areas, practical and viable business implementations of GPS technology remain challenging. This paper combines the potential of GPS capabilities with the analytical power of OLAP and data visualization to examine data on the movements of visitors in a zoological garden. Based on this example, the benefits and limitations of the application of GPS technology to the analysis of human spatial behavior are discussed.