• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.56-66
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• 2012

The Recent Specialty Contractor in construction of the reduced quantity due to the recession, but competitive in order to increase the number of companies that are increasingly competitive. The field work of one person to perform the work of employees and multiple sites, workforce supply flow that occurs at each stage of information transfer is not made a late staffing. Therefore this research has proposed a new alternative that can overcome them and the entire industry in recent issue smart phone features that take advantage of GPS(Global Positioning System). This paper presents a Diligence and Indolence Management System using GPS of smart phone. offering the advantage of Web-based PMIS(Project Management Information System) through integration with real-time information transfer and smart phone applications for query by building a prototype of a professional construction company as their own on-site management measures are proposed to contribute time and attendance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.2
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• pp.134-141
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• 2013

This paper explores a real-time system implementation to couple tightly StrapDown Inertial Navigation System(SDINS) and Global Positioning System(GPS) mounted on the aircraft. When implementing the SDINS/GPS coupled system in real-time processor, we have to deliberate SDINS's unique characteristics based on the ring laser gyro, and besides, lever-arm, measurements, and error compensation method. The novel modeling method is applied to system the misalignment error term of gyro to estimate the cumulative heading attitude errors while the aircraft banking to turn repeatedly. Captive Flight Test results show that the proposed modeling strategy has good performance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2D
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• pp.317-324
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• 2006

This study deals with the precise GPS data processing refer to ITRF2000 through the calculation of absolute coordinates of cadastral satellite station which were established by purpose of cadastral surveying. We used the Gipsy-Oasis II software developed Jet Propulsion Laboratory to estimate daily position of GPS stations with orbital and atmospheric parameters. Especially, we carried out ionospheric delay, tropospheric delay, data existence whether or not and quality control check of observation data during pre-processing. The standard deviation of absolute coordinates was determined better than ${\pm}4mm$ from GPS precise analysis. The RMSE of difference between the result of this study and existing result by using Bernese s/w shows ${\Delta}X={\pm}0.079m$, ${\Delta}Y={\pm}0.019m$ and ${\Delta}Z={\pm}0.031m$.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.151-158
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• 2006

As GPS 'selective availability' was turned off in 2000, GPS related fields and markets are explosively extended. In mapping area, GPS/INS aided photogrammetry proved it is much cost and time effective method keeping enough accuracy as compared with traditional photogrammetry works. The advantage of GPS/INS integration is interdependence. Even if GPS signal was blocked in some time, the position accuracy is not affected. In this study, various GPS signal time gap was used in GPS/INS AT process. Field surveyed ground points were used in accuracy check with GPS/INS AT check points. And the result showed enough accuracy of photogrammetry work rule of NGII. y.

• Spatial Information Research
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• v.14 no.2 s.37
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• pp.211-221
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• 2006

GLONASS(Global NAvigation Satellite System) using the satellite information on 19,100km altitude supplies the location information similar method with GPS. Therefore, many researches study in combination GPS and GLONASS. This research compares with deciding coordination of one unit parcel using RTK-GPS and RTK-GPS/CLONASS. Then we examine the possibility of RTK-GPS/GLONASS for determining parcel coordinate.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.187-195
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• 2008

Generation of accurate ground coordinates from high resolution satellite image are becoming increasingly of interest. The primary focus of this paper is to compute satellite direct sensor model (DSM) and rational function model (RFM) for accurate generation of ground coordinates from high resolution satellite images. Being based on this we presented an algorithm to be able to efficiently ground coordinates about large area with introducing RFM(rational function model) method applied to rigorous sensor modeling standing on basis of satellite orbit dynamics and collinearity equation, and sensor modeling of high-resolution satellite data like IKONOS, QuickBird, KOMPSAT-2 and others. The general high resolution satellite measures the position, velocity and attitude data of satellite using star, gyro, and GPS sensors.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.21.3-21.3
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• 2011

이 논문에서는 육상교통 환경에서 GPS 가시 위성의 수가 부족할 경우 사용자 위치 결정 성능 향상을 위해 시각도움정보를 이용하는 방법을 제안하고자 한다. GPS를 이용하여 정확한 위치를 구하기 위해서는 위성으로부터 송출된 신호가 수신기까지 도달하는데 걸린 시간을 정확히 구하는 것이 가장 중요한다. 이를 위하여 위성과 수신기 간의 시각이 정확히 동기가 되어야 하지만 대부분 저가 발진기를 사용하는 수신기의 측정치에는 수신기 시계오차가 포함되어 있다. GPS 측정치로부터 정확한 위치결정을 위해서는 수신기 시계 오차가 고려되어야 하기에 최소 4개의 위성이 필요하지만 건물, 차량, 나무 등의 장애물의 영향을 받는 육상교통 환경에서는 4개 미만의 위성이 관측되는 경우가 종종 발생한다. 이러한 경우 정상적인 방법으로 수신기 시계오차가 계산되지 않아 위치 결정 성능이 떨어지게 되므로, 시각도움정보를 활용하여 위치 결정 성능을 향상시킬 수 있다. 제안한 방법의 시각도움정보는 가시 위성이 4개 이상의 경우 결정된 수신기 시계오차를 수신기 시계 고정법을 적용하여 생성하였다. 가시 위성수가 3개로 결정된 위치 결과와 시각도움정보를 적용하여 결정된 위치와의 비교를 통해 위치 성능이 향상됨을 확인할 수 있었다.

• Journal of Space Technology and Applications
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• v.2 no.2
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• pp.169-186
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• 2022

In this article, Russia's space threat assessment and space warfare in the Russia-Ukraine war (Russian invasion of Ukraine) were analyzed and summarized. Considering the probability that commercial satellites will also be potential targets of space warfare, it is suggested that not only military satellites but also commercial satellites develop and apply space technology that can be applied equally to space threats when developing space technology. Necessary space technologies is listed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1756-1758
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• 2016

Pseudorange is the pseudo distance between a GPS satellite and a GPS receiver to determine the receiver's position. The closer the distance between jammer and victim receiver is, the more effective a repeat-back jamming is. In this letter, we analyze the pseudorange difference between adjacent GPS receivers using real GPS pseudorange data to understand the effects by the repeat-back jamming.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.229-236
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• 2018

In this paper, we see the acquisition and tracking of L1 C/A signal on GPS receiver, do the research on GPS signal capture principle's foundation, and do the simulation of the GPS signals capture process for it's realizing and analyzing by Matlab. The simulation result, we can confirm this method's accuracy and the feasibility, and see that a satellite receiving ability play an important role in the efficiency of receiver.