• Journal of Korean Society for Geospatial Information Science
• /
• v.15 no.2 s.40
• /
• pp.77-85
• /
• 2007

According to the survey data during the Japanese Occupation Period, the length of South Korea's coastline is about 11,542 km, including the coastlines of land and islands. It will be very expensive and time-consuming to revise/renew accurately this coastline data through site survey, it will cost great money and time. Also, various development projects such as reclamation works on public waters, constructions of ports/harbors, etc. are frequently changing the coastal areas and coastlines, causing many renewal projects on coastal maps. For such reason, appropriate alternatives for site survey are necessary. This paper demonstrate the utilization of RTK-GPS survey data, qualitative analysis and 3D topographic analysis for extracting the change in five coastal areas (Songjeong, Haeundae, Kwanganri, Songdo and Dadaepo). The local experimental areas subjected for this research were limited to five coastal areas near Busan.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.25 no.3
• /
• pp.191-198
• /
• 2007

According to the survey data during the Japanese Occupation Period, the length of South Korea's coastline is about 11,542km, including the coastlines of mainland and islands. To accurately revise/renew this coastline data through site survey, it will cost great money and time. Also, various development projects such as reclamation works on public waters, constructions of ports/harbors, etc. This paper used aerial photographs, satellite image data and GPS survey data with certain intervals to monitor the change in coastal areas of Songieong, Haeundae, Kwanganri, Songdo and Dadaepo. The local area subjected for this research was limited to areas near Busan. The specific contents of this research include. Launching qualitative/time series analyses on the change of coastal areas using aerial photographs, satellite image data and RTK-GPS surveys.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.5D
• /
• pp.655-662
• /
• 2009

The monitoring for analyzing coastline variations throughout many years is conducted in this study. Haeundae Beach is selected as a test area. We have collected RTK-GPS survey data, airborne LiDAR survey data from Sept. 2008 to 2005. We've done airborne LiDAR survey 2009 to 2006 and we would analyze coastline changes time series through interactive comparison analysis. The mean coastline distance of Haeundae shore is 1,347m (RTK-GPS) by airborne LiDAR survey (2 times). Coastline distance is decreased approximately 4.5% than mean distance in the November survey of 2008. We know right and left sides of the coastline are eroded and the center section shows us the littoral deposit of 3~7m toward sea. It turns out that the sand both sides is transported to the center section by a wave and tide and we know the coastline distance is getting smaller but the coastline width is getting longer like 2~7m.

• Spatial Information Research
• /
• v.15 no.2
• /
• pp.111-121
• /
• 2007

The GPS positioning offer 3D position using code and carrier phase measurements, but the user can obtain the precise accuracy positioning using carrier phase in Real Time Kinematic(RTK). The main problem, which RTK have to overcome, is the necessary to have a reference station(RS) when using RTK should be generally no more than 10km on average, which is significantly different from DGPS, where distances to RS can exceed several hundred kilometers. The accuracy of today's RTK is limited by the distance dependent errors from orbit, ionosphere and troposphere as well as station dependent influences like multipath and antenna phase center variations. For these reasons, the author proposes Network based GPS Carrier Phase Differential Positioning using Multiple RS which is detached from user receiver about 30km. An important part of the proposed system is algorithm and software development, named DAUNet. The main process is corrections computation, corrections interpolation and searching for the integer ambiguity. Corrections computation of satellite by satellite and epoch by epoch at each reference station are calculated by a Functional model and Stochastic model based on a linear combination algorithm and corrections interpolation at user receiver are used by area correction parameters. As results, the users can obtain the cm-level positioning.

• Journal of Korean Society for Geospatial Information Science
• /
• v.10 no.4 s.22
• /
• pp.69-76
• /
• 2002

Nowadays information is very important for Civil Engineering. This information is acquiredmostly via Surveying & Geo-spatial Information System. Also this information is close to the ITS(Intelligent Transformation System), Navigation, Facility Management, and Digital Mapping, etc and applicable to versatile fields from now on. And in surveying fields, GPS satellites are introduced newly and play a great rules. In this study, RTK(Real-Time Kinematic GPS), one of the positioning technology with GPS satellites, is used for the production of Plane Figure of Campus. The results shows that it is possible to extract the information for some part of a flowerbed and road, but not so for the buildings surrounded. Therefore this give occasion to the a lowering of work effectiveness over the total work-flow. So at such a time, it will be expected that the supplementary systems such TS(Total Station), Plane-table, and theodolite, etc have to be used.

• Journal of Astronomy and Space Sciences
• /
• v.21 no.2
• /
• pp.129-140
• /
• 2004

KAO(Korea Astronomy Observatory) GPS group has developed an iRTK system as a near-real time positioning system using GPS carrier phase data. We focused on improving the accuracy of positioning through the updated capability of data processing of KAO's iRTK system using low-cost L1 carrier phase receiver. The accuracy of a positioning was demonstrated by Extended Kalman filter. Experiments were accomplished using from 30m to 20km baselines. Within 10km, the positioning accuracy was improved by approximately 50-70% to the previous study using one minute observable data. However, it took two minutes to obtain 1m level positioning accuracy at 20km point. We expect that the developed iRTK system can be applied to the various fields of GPS in near-real time positioning.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.10a
• /
• pp.565-567
• /
• 2018

The rover acquires its own position information using satellites signals provided by several satellites(at least four or more). For the present, GNSS systems are widely used in various fields. However, there are many factors that cause accuracy errors in positioning between rovers and GNSS satellites. Due to satellite time error, orbit error, ionospheric & convective refraction, multipath, etc., rover can't acquire precise position. Differential GPS(DGPS) and Real-Time Kinematic(RTK) have been developed as compensation techniques to reduce such errors. In this paper, we intend to develop a terminal with RTK technique to acquire precise position information of mobile station.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.1D
• /
• pp.81-88
• /
• 2012

This present research was carried out by dividing two parts; field surveying and data processing, in order to analyze changed patterns of a shoreline. Firstly, the shoreline information measured by the precise GPS positioning during long duration was collected. Secondly, the algorithm for detecting an auto boundary with regards to the changed shoreline with multi-image data was developed. Then, a comparative research was conducted. Haeundae beach which is one of the most famous ones in Korea was selected as a test site. RTK-GPS surveying had been performed overall eight times from September 2005 to September 2009. The filed test by aerial Lidar was conducted twice on December 2006 and March 2009 respectively. As a result estimated from both sensors, there is a slight difference. The average length of shoreline analyzed by RTK-GPS is approximately 1,364.6 m, while one from aerial Lidar is about 1,402.5 m. In this investigation, the specific algorithm for detecting the shoreline detection was developed by Visual C++ MFC (Microsoft Foundation Class). The analysis result estimated by aerial photo and satellite image was 1,391.0 m. The level of reliability was 98.1% for auto boundary detection when it compared with real surveying data.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.04a
• /
• pp.145-150
• /
• 2004

In this paper, development of automation system for real time cadastral surveying and mapping is studied. This system is composed of interface between pc and GPS receiver, input-output-store of positioning information by RTK-GPS surveying. Also coordinates of surveying is displayed on CAD. As a results of this application on the field, transformed coordinates of points are displayed on the map at the real time as surveying. This system is applied to construct coordinate information for a parcel of land, and this could be specially used to realize the information of boundary points in the field.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2006.04a
• /
• pp.513-519
• /
• 2006

South Korea is currently promoting cadastral computerization to modernize the field. Problems of cadastral mismatches are mostly resolved through cadastral mismatch organization projects. Three-dimensional cadastral drafting Is also on its way to wide adoption. In order to safeguard the property ownership rights of people and deliver accurate cadastral information quickly by constructing a three-dimensional cadastral information system, this study intends to provide solutions to survey real-time kinematic GPS (RTK-GPS) in mobile environments and to produce three-dimensional cadastral maps real-time using digital plane tables.