• Journal of the Korea Society of Computer and Information
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• v.21 no.6
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• pp.71-76
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• 2016

In this paper, we propose the mobile visual inspection information system using DGPS and portable range finder for levee safety inspection. Instead of existing visual inspection management method that is stored hand-written data, this system is designed to manage directly the visual inspection information using mobile devices in the field of levee. And through extracting accurate DGPS coordinates information about damage location of levee, this system is developed to ensure efficiency for the main task arising from the levee site such as inspection, maintenance and reinforcement. Furthermore, when damage has occurred at the point that inspector is not able to approach, this system can record the damage site data correctly, by converting data such as position, orientation and height of the damage point into the World Geodetic System coordinates. The position, orientation and height data was extracted automatically through the DGPS and portable range finder. And by applying the augmented reality method, this system was implemented for inspector to revisit the point of damage easily in order to perform the management, maintenance and reinforcement of the levee later.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.5
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• pp.393-398
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• 2007

According to the Korean datum change to a world geodetic system, the EDM area should be readjusted to provide consistent product over the country. The data set for EDM area is extracted from the previous KTN1987 DB and checked for the moved markers in XY network adjustment which provides quality verification. Then, EDM data set for the seven areas are rebuilt for the adjustment. Since the data is still based on the old datum, the coordinates of the data are transformed by applying the coordinate transformation parameters. Here, the transformation parameters, which were determined for the conversion of 1:50,000 topographic maps by NGII, were used. For each EDM point, the geoidal height from EGM96 model is applied to obtain the ellipsoidal height based on the GRS80. The measured distance projected onto GRS80 is adjusted using BL network adjustment by fixing 2nd order or 3rd order GPS control points. The results from the readjustment show the minimum standard error of 1.37" and the maximum standard error of 2.13". Considering the measurement accuracy of EDM (1.6" corresponding to about 2cm) and GPS position for fixed points (2cm), this result is considered to be reasonable and it is good for the practical use.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.405-410
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• 2008

세계적으로 세계측지좌표계의 도입이 확대됨에 따라 우리나라도 2001년 측량법의 개정을 통해 현재의 지리정보 좌표계변환을 위한 노력을 시행하고 있다. 이러한 측면에서 본 연구에서는 세계측지좌표계 변환방법론, 변환사례 등을 검토 후 한국토지정보시스템 데이터를 대상으로 시범지역을 선정하여 변환실험을 실시하였다. 그 결과 변환 후의 데이터는 국가GIS활용 및 업무지원을 위한 참조적 데이터로서 충분히 이용이 가능한 수준으로 도출되었다. 하지만 한국토지정보시스템 데이터의 세계측지좌표계로의 변환을 위해서는 각 지역별 변환계수를 산정할 필요가 있으며, 지적데이터가 가지고 있는 다양한 원점을 통일원점으로 변환되어야 할 것으로 판단된다. 또한 마지막으로, 기존의 지적데이터가 가지는 다양한 문제점을 그대로 내포하는 수준으로 변환되었다. 따라서 한국토지정보시스템의 세계측지좌표계 변환을 위해서는 본 연구의 결과를 기초로 하여, 더 많은 대상지역에 대한 변환을 통해 오차와 오류의 유형별 원인 분석 후 한국토지정보시스템의 세계측지좌표계 변환의 체계적이고 계획적인 전략을 수립할 필요가 있다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.346-350
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• 2008

본 연구의 목적은 국가기준점체계의 세계측지계 전환에 따른 인천 연안지역의 환경지리정보 변환 방안을 연구하는데 있다. 이를 위해 세계측지계 변환 방안과 관련된 각종 자료를 수집 분석하여 환경지리정보의 세계측지계 변환을 위한 방안을 연구하였다. 환경지리정보들을 다양한 구축방법에 따라 다양한 형태로 제공되고 있어 일괄적은 변환에는 어려움이 있을 것으로 판단된다. 환경지리정보들을 변환하기 위해서는 우선 국토지리정보원의 수치지도의 세계측지계 변환 지침을 기준으로 원시자료부터 변환을 수행하여 환경지리정보를 다시 구축하는 방안과 기존에 구축된 환경지리정보를 변환하는 방안이 있음을 알 수 있었다. 새로운 측지좌표계 도입에 따른 환경지리정보의 세계측지계 변환 방안을 제시하고, 환경지리정보에 대하여 국가기준계의 세계측지계 전환에 능동적으로 대응하고 세계측지계 도입에 따라 예상되는 초기 혼란을 최소화 하고 향후 구축될 환경지리정보들의 정확도 향상의 기반을 조성 할 수 있을 것으로 기대된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4D
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• pp.545-551
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• 2008

The MOCT(Ministry of Construction & Transportation) gave a order named as "The guideline for computerization and application of geotechnical investigation result" to an affiliated organization in March 2007. Today, pilot project of construction of geotechnical information database is in process to be stable for its system after applying this guideline, and discipline how to input investigated data for related users. We have developed standard for geotechnical investigation result-format, metadata for distribution of geotechnical information and to coordinate based on world geodetic system. Also, We had a introduce to status with respect to use the input system, collect a statistics of input contents. At a result, improvement items of input system is proposed. It was analyzed that most users put to practical use easily as a result of education for making use of on the spot of the developed GIIS. But There were problems with the GIIS as well as complexity of metadata formation, such as error of moving part of information window, and a part of recognition error of install program in accordance with computer OS circumstances. Particularly, to improve some parts of GIIS is needed, because of use of or KNHC (Korea National Housing Corporation)-specific format and difference of input process followed by MOCT's guideline. In this study, it is planning to make up for occurred problems, and improvements when operating and managing the Geotechnical Information DB center in 2008.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.12
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• pp.1103-1111
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• 2016

Korea Astronomy and Space Science Institute (KASI) has been operating SLR (Satellite Laser Ranging) system with 2kHz repetition rate for satellite precise orbit and spin determination as well as space geodesy. But the SLR system was improved to be capable of laser ranging with high repetition rate, up to 10kHz by developing new operation software and novel range gate generator, called HSLR-10. The HSLR-10 will contribute to the accurate spin rate determination of geodetic satellites and geodetic research due to its largest repetition rate in the world. In this study, the development methodology and configuration of operation software are addressed, and its validation results are also presented.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.3
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• pp.267-275
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• 2007

Nowadays, it grows bigger the importance of water resource management, and so, hydrographic surveying technology in river is important because it serves basic data about river environment. And, also, the application field of GPS has been increased and expected to be more increased because of the change of the geodetic reference system to World Geodetic System. In this study, hydrographic surveying in Hwang river in Geochang is accomplished by RTK GPS and Total Station and they are compared and analyzed the both results. The section profile in river is made by Hec-Ras program and CAD. The results show it can be saved 15.3% in surveying times and the amount of surveying works can be enlarged 42.5%. And the standard error between RTK results with calibration and the results without calibration turned out as 2.1 cm. So we have a conclusion that RTK GPS is more efficient surveying method than total station in hydrographic surveying in river.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.2
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• pp.171-183
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• 2016

Small-scale maps currently used are made by scanning and editing printed maps and its shortcoming is accumulated errors at the time of editing and low accuracy. TM projection method is used but its accuracy varies. In addition, small-scale maps are made without consideration of usability and compatibility with other scale maps. Therefore, it is necessary to suggest projection and coordinates system improvement methods in consideration of usability and compatibility between data. The results of this study reveal that in order to make the optimum small-scale map, projection that fits the purpose of map usage in each scale, coordinate system and neat line composition should be selected in consideration of interrelation and compatibility with other maps. Conic projection should be used to accurately illustrate the entire country, but considering usability and compatibility with other maps, traversing cylindrical projection should be used instead of conic projection. For coordinates system of the small-scale map, Universal Transverse Mercator (UTM-K) based on the World Geodetic System should be used instead of conventional longitude and latitude coordinate system or Transverse Mercator.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.81-86
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• 2003

As the utility value of GPS in surveying field is on the increase after the conversion into the world geodetic system, it is attracting the interest of many people involved in the application of GPS. In this study an algorithm was established settling ambiguity through LAMBDA techniques and the baseline processing program was developed for L1/L2 carrier phase using visual c++ 6.0, which is an object-oriented language. And the developed program proved that it maintained a difference of less than 3mm over the short baseline of 1.5m or shorter when compared with other commercialized programs.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.59-63
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• 2006

본 연구의 목적은 GPS관측에 의한 세계측지계 성과의 산출방안을 연구하는데 그 목적이 있다. GPS 관측 데이터와 상시관측소의 데이터를 활용하여 세계측지계 성과를 산출하기 위한 방안을 연구한다. GPS 관측 데이터의 후처리 결과 상시관측소의 데이터를 사용하지 않았을 경우와 사용하였을 경우의 폐합차를 분석한 결과 모두 정밀1차 기준점 측량작업규정에 만족함을 알 수 있었다. 또한 GPS상시관측소의 데이터를 활용하여 각 측점 지점의 좌표를 산출한 결과, 상시관측소 3개소의 데이터를 사용하였을 경우에 비해 사용하지 않았을 경우의 오차가 가장 크게 나타났으며 1개소 사용, 2개소 사용할 때 점차적으로 오차가 감소하고 있음을 알 수 있었다. 따라서 상시관측소를 고정점으로 사용하되 적어도 3점이상의 점을 사용하여야 함을 알 수 있었다. 본 연구는 제한된 일부 지역을 대상으로 GPS 상시관측소의 관측 데이터를 사용하여 세계측지계의 성과를 산출 한 연구로 향후 광범위한 지역에서의 GPS 상시관측소의 활용에 대한 심도 있는 연구가 진행되어야 할 것이다.