• Title/Summary/Keyword: GPS측량

Search Result 846, Processing Time 0.024 seconds

A Study on the Development of Field Management System for Underground utility using Self-levelling marker and DGPS. (자동수평마커와 DGPS를 이용한 지하시설물의 현장관리시스템 개발에 관한 연구)

  • Kim, In-Seup
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.27 no.6
    • /
    • pp.733-739
    • /
    • 2009
  • Recently it is being increased rapidly to install magnetic marker and RFID tag on the underground utility lines before backfilling to ensure effective it's management. However, due to changes an attitude and damages of sensors. By pressure and vibration during soil compacting, detecting rate is significantly reduced as well as it allows to use only one line of various pipes since it has an unique frequency. Also it is required too long time to reach to target point with an non-accurate navigational GPS receiver and hard to update existing data base with a manual input of new data in the field. To improve these problems, the researcher developed the field management system that apply with ball typed self-levelling marker which is free from the changes of attitude for sensors during compaction as well as has various radio frequency applicable to many kind of pipes and ensure fast positioning to target point using an incorporated system with PDA based DGPS receiver which allows loading a field GIS software and RFID detector. Further, it provides with viewing all of RFID data on the DGPS receiver screen directly and also input new data to existing data base in the field automatically.

A Study on the Enhancement of DEM Resolution by Radar Interferometry (레이더 간섭기법을 이용한 수치고도모델 해상도 향상에 관한 연구)

  • Kim Chang-Oh;Kim Sang-Wan;Lee Dong-Cheon;Lee Yong-Wook;Kim Jeong Woo
    • Korean Journal of Remote Sensing
    • /
    • v.21 no.4
    • /
    • pp.287-302
    • /
    • 2005
  • Digital Elevation Models (DEMs) were generated by ERS-l/2 and JERS-1 SAR interferometry in Daejon area, Korea. The quality of the DEM's was evaluated by the Ground Control Points (GCPs) in city area where GCPs were determined by GPS surveys, while in the mountain area with no GCPs, a 1:25,000 digital map was used. In order to minimize errors due to the inaccurate satellite orbit information and the phase unwrapping procedure, a Differential InSAR (DInSAR) was implemented in addition to the traditional InSAR analysis for DEM generation. In addition, DEMs from GTOPO30, SRTM-3, and 1:25,000 digital map were used for assessment the resolution of the DEM generated from DInSAR. 5-6 meters of elevation errors were found in the flat area regardless of the usage and the resolution of DEM, as a result of InSAR analyzing with a pair of ERS tandem and 6 pairs of JERS-1 interferograms. In the mountain area, however, DInSAR with DEMs from SRTM-3 and the digital map was found to be very effective to reduce errors due to phase unwrapping procedure. Also errors due to low signal-to-noise ratio of radar images and atmospheric effect were attenuated in the DEMs generated from the stacking of 6 pairs of JERS-1. SAR interferometry with multiple pairs of SAR interferogram with low resolution DEM can be effectively used to enhance the resolution of DEM in terms of data processing time and cost.

A study on the Bessel geoidal height to improve the accuracy of coordinate transformation (좌표변환의 정확도 향상을 위한 Bessel 지오이드고에 관한 연구)

  • Shin, Bong-Ho;Kang, Joon-Mook;Kim, Hong-Jin;Choi, Jong-Hyun
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.2 no.2 s.4
    • /
    • pp.143-151
    • /
    • 1994
  • 3-D coordinates that result form GPS survey are not applied directly in korea because they are based on WGS 84 ellipsoid. Thus they must be transformed into longitude, latitude on the Bessel ellipsoid and orthometric height. Transformation parameters must be determined in order to perform the coordinate transformation. Also, coordinate transformation be preformed on longitude, latitude and ellipsoidal height. First estimation of Bessel geoidal height must be accomplished to acquire Bessel ellipsoidal height This paper suggests accuracy of coordinate transformation according to the estimation method of Bessel geoidal height. Also, This paper suggests that Bessel geoidal height have influence on the coordinates transformation.

  • PDF

해양안전 정보의 효율적 제공방안

  • Seong, Dong-Gwon;An, Jang-Hyeon
    • Information and Communications Magazine
    • /
    • v.34 no.6
    • /
    • pp.73-79
    • /
    • 2017
  • 해마다 증가하고 있는 피서철 해수욕장 안전사고 및 비선박 사고의 감소를 위해 본고에서는 연안해역정밀조사 자료를 활용한 해양안전지도의 제작 및 체감형서비스를 구축하여 서비스하는 방안을 마련하였다. 해양안전에 관련한 각종 자료를 수집, 현장조사, GPS측량, 전문가 및 현지주민의 인터뷰 등을 통해 취득하였다. 서비스에 이용될 기본 배경지도로는 5m급 육상 지형기복도와 국립해양조사원의 수심자료를 사용한 해저지형기복도를 융합하여 제작, 이용하였다. 각종 해양안전관련 정보들은 해양영토(구역), 어촌양식, 항로, 각종사고이력, 시설, 위험요소 등 해양안전과 관련한 총 26종의 다양한 분류체계를 구성하여 구축하였다. 이렇게 수집, 구축된 기본 해양공간정보들을 바탕으로 사용자에게 정보의 전달성을 고려하여 국민이 간접적으로 체감할 수 있는 형태의 사이트(해수욕장 등)별 도면 형태의 해양안전지도를 제작하고, 개방형 대국민 해양공간정보 웹서비스인 '개방해(海)', 해양전문 공공기관용 웹서비스인 '공유해(海)' 대국민 해야안전정보 앱서비스 안전해(海)'와 시스템들을 구축하여 서비스 방안을 구축하였다. 각 서비스에는 해양안전사고 예방을 위한 각종 안전 및 위험정보 콘텐츠들을 수록하였고, 목적에 따라 이용가능한 분석 기능들을 제공하였으며, 위험구역에 노출될 경우 사용자간 위험을 알려주는 알림 기능 등을 제공함으로써 위험에 노출되고 조치하는데 도움을 줄 수 있도록 하였다. 그 결과, 현재 각종 기관에서 해양공간정보의 이용을 확대하고자 연계신청 증가와 더불어, 대국민 서비스 이용자수가 증가하는 실적을 기록하였으며, 향후 보다 광범위한 영역에서 안전사고, 안전대응, 안전관리 등의 분야에서 대책 도구로 활용이 가능할 것으로 기대된다.

우리나라 육상 중역기점 전이

  • Choe, Gwang-Seon;Ok, Su-Seok;Won, Ji-Hun
    • Journal of the Korean Geophysical Society
    • /
    • v.4 no.2
    • /
    • pp.121-131
    • /
    • 2001
  • We have established 88 auxiliary gravity reference stations by using two gravitimeters at the observation offices of the Korean meteorological agency and measured the locations by using GPS. All gravity values have been calculated on the basis of the gravity reference point at Pusan National University, thus, they have been established to bge easily converted to new absolute gravity value later. The increased numbers of the gravity reference stations will minimize errors due to measurements, drift correction etc. and increase the accuracy of the gravity data. The result of this research will be used to verify the gravity data which calculated with the relative gravity meter and to inspect relative gravity meters.

  • PDF

The Precise Positioning with the 3D Coordinate Transformation of GPS Surveying (GPS 측량의 3차원 좌표변환에 의한 정밀위치결정)

  • Park, Woon-Yong;Yeu, Bock-Mo;Lee, Kee-Boo
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.8 no.2 s.16
    • /
    • pp.47-60
    • /
    • 2000
  • On this study, Among the classification methods of land cover using satellite imagery, we compared the classification accuracy of Neural Network Classifier and that of Maximum Likelihood Classifier which has the characteristics of parametric and non-parametric classification method. In the assessment of classification accuracy, we analyzed the classification accuracy about testing area as well as training area that many analysts use generally when assess the classification accuracy. As a result, Neural Network Classifier is superior to Maximum Likelihood Classifier as much as 3% in the classification of training data. When ground reference data is used, we could get poor result from both of classification methods, but we could reach conclusion that the classification result of Neural Network Classifier is superior to the classification result of Maximum Likelihood Classifier as much as 10%.

  • PDF

Development of Remote Control Ship for Acquisition of Underwater Information (수중정보 획득을 위한 무인원격선체 개발)

  • Choi, Byoung-Gil;Cho, Gwang-Hee
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.16 no.3
    • /
    • pp.65-69
    • /
    • 2008
  • This study is aimed to develope a remote control ship for acquisition of various underwater information. Remote control ship equipped with GPS, echosounder, sidescan sonar, subbottom profiler. Remote control ship is an automatic system for acquisition of inland water and coast information. For the development of remote control ship, underwater information acquisition of reservoir, dam, polluted area is expected. Also, multibeam echosounder, image sensor, water analysis sensor, etc. could be equipped in one ship. So robot-ship will be applied for the most part of industry managing water resources and preventing the flood by making bed topographic map and estimating water volumes.

  • PDF

실시간 다중 기준국 GNSS/GPS 반송파 미지정수 결정 기술 연구

  • Park, Jae-Ik;Lee, Eun-Seong;Heo, Mun-Beom
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.37 no.2
    • /
    • pp.157.1-157.1
    • /
    • 2012
  • 1990년대 제안된 RTK(Real-Time Kinematics)는 GNSS/GPS 반송파 위상(carrier phase) 관측값을 이용한 방식으로 cm 수준의 정확도를 실시간으로 산출할 수 있어 측지 측량 등 다양한 분야에서 활용되고 있다. 그러나 한 가지 중요한 단점은 이 방식을 사용하는 기준국과 사용자는 10~20km 이내에 존재해야만 빠르고 신뢰할 수 있는 해를 산출할 수 있다는 점이다. 이는 궤도오차, 대류층 및 전리층 오차에 공간 상관성(spatially correlated) 있기 때문인데, 사용자 주변을 둘러싼 다중 기준국들의 측정치를 조합하여 보상하거나 모델링하여 줄이는 방식인 다중 기준국 네트워크 기반의 RTK 알고리즘이 제안되어 사용되고 있다. 다중 기준국 네트워크 기반의 RTK 프로세스에서 기준국간 미지정수 결정은 전 과정의 핵심 프로세스라고 할 수 있으며, 관련되어 많은 기술들이 제안되고 연구되어 왔다. 특히, 1980년대 말부터 현재까지 후처리 기반으로 꾸준하게 연구되고 있는 Blewitt에 의해 전리층 제거 조합과 Wide-lane 반송파 위상 조합을 활용한 미지정수 검색 방법이 대표적이며 이후에도 Gao, Colombo등 다양한 연구자에 의해 활용되었다. 이 연구에서는 실시간으로 다중 기준국 반송파 미지정수를 결정하는 기술에 대한 연구를 수행하였다. L1, L2 관측값 조합으로 인한 관측값의 잡음 수준이 증가하는 영향을 피하기 위해 L1, L2 반송파 위상 및 의사거리를 그대로 관측값으로 사용하여 사용자 위치 및 속도, 기준국간 이중 차분된 전리층 지연 수직성분, 대류층 wet 지연 수직 성분, 이중 차분된 미지정수를 미지의 상태변수로 확장 칼만필터를 통해 직접적으로 추정하는 방식으로 미지정수의 실수해를 결정하였고, 정수해는 실시간에 적합한 MLAMBDA 기법과 비율테스트를 통한 정수해 검정기법을 통해 결정하였다.

  • PDF

An Analysis of the Coastal Topography and Land Cover Changes in the Haeundae Beach (해운대 해수욕장의 해안지형 및 토지피복 변화 분석)

  • Yang, Ji-Yeon;Choi, Chul-Uong
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.9 no.1
    • /
    • pp.101-115
    • /
    • 2006
  • As coastal erosion is increasing sharply because of sudden changes in the natural environment and increases in artificial development, the problem of coastal erosion become an important issue, socially and economically. To building the data which needed to grasp the situation and find a solution, we need the monitoring system for long-term. In this study, we analyzed the coastal topography and land cover changes in the Haeundae Beach during 60 years. The Haeundae Beach is the most famous beach in the country and coastal erosion are going on. First, we analyzed the change of coastal topography by calculated the coastline and area of the beach using aerial photos during 60 years. We extracted the coastline by digitized on aerial photo and corrected the height of tide level using sounding and GPS survey data. And we computed the area of beach and analyzed the change of area during 60 years. Second, we analyzed the change of land cover using landcover map. We made the detailed landcover map by on-screen digitizing and estimated the soil loss for the area nearby Haeundae Beach. As a result, we could see that the coastline get nearer to land and the area of beach has been reduced in general. We think that interception of sand supply by the development is the artificial cause of coastal erosion. The result of this study would be useful in long-term coastal monitoring and to analyze the cause of coastal environment change. We expect that the result is available on the coastal information system.

  • PDF

The Coordinate Transformation Between Korean Geodetic System and WGS 84 for the Practical Use of GPS (II) (GPS 실용화를 위한 우리나라 측지계와 WGS 84의 좌표변환(II))

  • 박필호;박종욱;강준묵
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.11 no.1
    • /
    • pp.37-45
    • /
    • 1993
  • We research on the coordinate transformation between Korean geodetic system and WGS 1984. We made the wide area an object of our research. This area covers the range of longitude $1^\circ$ 32'and latitude $1^\circ$ 7'and is four times wider than a first stage research published in 1992. For this research, we performed GPS observations at 10 control point (seven astrogeodetic points, three triangulation points) and eight banch marks nearby control points, and then transformed the coordinates of WGS 84 to Korean geodetic system using the 7 parameter method, Molodensky method and MRE method. From this test, we compared the precision of the coordinate transformation by each method and checked which method is more applicable to Korea. We could find that the precision by 7 parameter method is three times better than the other methods and that the coordinate transformation by 7 parameter method is possible with the precision of 0".017, 0".016, 0.329 m in latitude, longitude and height. We could check and correct the height blunder of the control points by the bench marks nearby control point. We also could find the precision of coordinate transformation is more improved by the correction of height blunder.t blunder.

  • PDF