• Title/Summary/Keyword: topographical survey

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Study on the Accuracy Improvement for Survey of Estuary Riverbed (하구하상 측량 정밀도 향상에 관한 연구)

  • 박운용;김천영;김용보
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.21 no.2
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    • pp.137-145
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    • 2003
  • Currently, the availability of 3-D topographical survey by combination of GPS and Echo Sounder has been increased in the various field like as the construction of structure, the dredging and the reclamation in the ocean and river, and observation of topographic change in seabed or riverbed. In this case, the error of depth sounding can divide in form that is happened by combination of GPS and Echo Sounder, and form that is happened in Echo Sounder itself, In this study, in the case happen by Echo Sounder itself, analyzed error by specially about geological features of the seabed and riverbed that is specular surface of sound wave and wished to present solution way. The sounding error about the echo sounder and characteristic of estuary riverbed was found by understanding the relation of average diameter and residual error and we defined correction formula, Y=-0.00474$^{*}$In(X) -0.0045 by the regression analysis. and then we verified applicability of correction formula. As the result, if measure Preliminary investigation or pre-survey the geological features for the survey area at topographical survey of estuary riverbed, we presented the error correction formula that estimate and can correct of error by Echo Sounderer.

The Accuracy Analysis of Design Profile Generation using 3D Digital Terrain Model (3D DTM을 이용한 설계용 프로파일 생성 정확도 분석)

  • Um, Dae-Yong;Lee, Eun-Soo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.6
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    • pp.583-590
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    • 2008
  • In construction work's design process, we must carry out a topographical survey for construction reserved land and to the basis of this, production of profile is indispensable factor for the purpose of every construction work such as road, rail way, canal and etc. From this research, the production of profile about construction reserved land, using topographical information of digital topographical map produced by NGIS project, construct precision 3D terrain model and from this, propose plans for utilizing by producing automatic profile. With the aim of this, extract every layers of main facilities and altitude from digital topographical map and while producing 3D terrain model by using this, we product automatic profile from precision 3D terrain model. And we was carried out to check whether the automatic produced profile's accuracy could be accepted at actual estimation by mutual analysis. It is considered that the result of the research could be suggested as a new techniques concept which can reduce the designing period and expenses and increase the efficiency of affair in the design process for the construction.

A Case Study of Landslides due to Heavy Rainfall (집중호우시 산사태 원인분석에 관한 사례연구)

  • Yoo, Nam-Jae;Park, Byung-Soo
    • Journal of Industrial Technology
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    • v.21 no.A
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    • pp.303-315
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    • 2001
  • This study is a research result of investigating causes of landslides occurred at Uijongbu in Kyonggi Province, Korea. For works of this research, informations and data about landslides occurred at the site, geological and topographical informations were collected to analyze causes of landslides, and mapping landslides was performed by using results of field investigation. Data about rainfall during occurrence of landslides around Uijongbu was also used to find the effect of intense rainfall on occurrence of landslides. Based on informations obtained from field investigation and collected data, the scale and the pattern of landslides were analyzed and influencing factors on landslide such as intensity and duration of rainfall, topography, geologic condition, geotechnical engineering properties of ground, forestry were investigated statistically to find causes of landslides. On the other hands, for geotechnical engineering respects, slope stability analysis was performed for the typical sites chosen from the sites where the landslides occurred, using informations obtained from detailed topographical survey with total stations, field reconnaissance and results from laboratory tests.

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Accuracy Evaluation of Non-prism Total Station for Topographic Surveying (지형측량을 위한 무 프리즘 토털스테이션 정확도 평가)

  • Seo, Dong-Ju
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.5
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    • pp.433-441
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    • 2006
  • With a development of electrical technology in recent, it is possible to measure distance without direct contact to object using laser which launched at instrument and reflect from object. Furthermore, the advent of non prism total station brought the increment of application in many fields including not only road, airport, and harbors but also measurement and monitoring of structural displacement in construction fields. In this study, therefore, to evaluate accuracy of non prism total station, accuracy was analyzed by measuring certain distance which classified by both certain materials and angle of reflection. By this method, the derived values were applied to topographical survey for the efficient applicability. According to a study, result value of non prism total station was satisfBctory regardless of material when the angle of reflection was 90 degrees. RMSE increased when the angle of reflection are gradually increased to acute angle. In result of regression analysis using certain distance which classified by both materials and angles of reflection, there is relationship between distance and angle of reflection, but material has no relevance to the result value. When carrying out general topographical survey, proper application of non prism total station will go far conducting safe and prompt survey at the dangerous site such a road which have lots of traffic flow and rock joint which have high angles of inclination.

Construction of High-Resolution Topographical Map of Macro-tidal Malipo beach through Integration of Terrestrial LiDAR Measurement and MBES Survey at inter-tidal zone (대조차 만리포 해안의 지상 LiDAR와 MBES를 이용한 정밀 지형/수심 측량 및 조간대 접합을 통한 정밀 지형도 작성)

  • Shim, Jae-Seol;Kim, Jin-Ah;Kim, Seon-Jeong;Kim, Sang-Ik
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.1
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    • pp.58-66
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    • 2010
  • In this paper, we have constructed high-resolution topographical map of macro-tidal Malipo beach through integration of terrestrial LiDAR measurement and MBES survey data at inter-tidal zone. To acquire the enough information of inter-tidal zone, we have done terrestrial LiDAR measurement mounted on the roof of vehicle with DGPS through go-stop-scan method at the ebb tide and MBES depth surveying with tide gauge and eye staff measurement for tide correction and MSL calculation at the high tide all together. To integrate two kinds of data, we have unified the vertical coordination standard to Incheon MSL. The mean error of overlapped inter-tidal zone is about 2~6 cm. To verify the accuracy of terrestrial LiDAR, RTK-DGPS measurement have done simultaneously and the difference of Z value RMSE is about 4~7 cm. The resolution of Malipo topographical map is 50 cm and it has constructed to DEM (Digital Elevation Model) based on GIS. Now it has used as an input topography information for the storm-surge inundation prediction models. Also it will be possible to use monitoring of beach process through the long-term periodic measurement and GIS-based 3D spatial analysis calculating the erosion and deposition considering with the artificial beach transition and coastal environmental parameters.

Investigation of Topographic Characteristics of Parcels Using UAV and Machine Learning

  • Lee, Chang Han;Hong, Il Young
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.5
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    • pp.349-356
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    • 2017
  • In this study, we propose a method to investigate topographic characteristics by applying machine learning which is an artificial intelligence analysis method based on the spatial data constructed using UAV and the training data created through spatial analysis. This method provides an alternative to the subjective judgment and accuracy of spatial data, which is a problem of existing topographic characteristics survey for officially assessed land price. The analysis method of this study is expected to improve the problems of topographic characteristics survey method of existing field researchers and contribute to more accurate decision of officially assessed land price by providing more objective land survey method.

Landscape Information Acquisition and Visualization Technique for Rural Landscape Planning (농촌마을 경관계획을 위한 경관자료의 수집과 가시화기법)

  • Han, Seung-Ho;Cho, Tong-Buhm
    • Journal of Korean Society of Rural Planning
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    • v.10 no.2 s.23
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    • pp.35-42
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    • 2004
  • This study aimed at establishing the multi-ranged approach on data acquisition technique for rural landscape planning, which tried categorization, grading and transferring of landscape elements in the more detailed level. For the systematic management of database for the topographic informations in the village level, a kind of the aerial photographing techniques with UAV(Unmanned Aerial Vehicle) was used and its resultant data for the landscape simulation of the rural village, which in turn helped the convenient approach to understanding of its comprehensive spatial structure. The image data from aerial photography was systematically processed through; First, after revision of the distorted one, the image map was adjusted with the topographical and cadastral maps. Second, the farm houses and buildings, and other facilities difficult to find out in the topographical map was digitally read from the adjusted image. The topographical landscape view of rural village was simulated on the base of DEM(Digital Elevation Model) and the 3-dimensional shapes of farm houses and buildings were automatically modelled using the input system developed by the author. In conclusion, the aerial image information adjusted with the edited maps could give more intuitive and detailed villagescape than the ordinary one and through landscape simulation of the rural village, its topography, features of houses/buildings and spatial distribution of land uses were effectively reproduced. And, by the linkage between field survey and photographed/simulated results of the typical landscape elements using hyper-link method, it would be expected to develop as an effective visualization technique of rural landscape.

An Qualitative Analysis on the Beach Deformation of the Sangju Beach with Field Observation (현장관측을 통한 상주해빈 단면변화의 정성적 해석)

  • 함계운;장대정
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.16 no.2
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    • pp.75-82
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    • 2004
  • The changes of sea bottom configuration, which may cause the coastal disasters, have been considered as social problems. It is obvious that the beach deformation is attributable to the sediment transport associated with erosion and acceration. The prediction method and countermeasures for them, however, are not on the level of satisfaction, which indicates that efforts should be made on developing them. In this study, it is found at the groin constructed in Sangju beach on e purpose of beach protection did the aversive function. The reason for this was judged that they accelerated the speed of erosion by increasing the velocity wave-induced current rather than brought storage effect of sediment. Authors found that the storage sediment estimation model by Sonu and Beek(1971) is a useful model at the Sangju beach with the use of topographical survey data from July, 1987 to March, 2003.

The Study of Coastal Change Detection Ortho Aerial Photo and Hydrographic Survey: Parcels Submerged (정사항공사진과 해양조사측량을 이용한 해안선변화 탐지에 관한 연구: 포락지 중심으로)

  • Choi Chul Eung;Kim Youn Soo;Suh Yong Cheol
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.17 no.2
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    • pp.61-69
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    • 2005
  • The coastal erosion and the look of a heap which are mainly occurred in the district along the coast are found for various forms such as the estuary closing, the estuary sand bar the development of the coast sand bar, and the modification of coastline. Recently, due to the coastal development, these transformations have been intensified. The change of coast, which has been made slow progress is required long-term study on a searching examination of the root cause and a suggestion of a counter measure. In this research, ortho aerial photos were produced to analyze volumes of topographical alternations that have been progressed fer the long run, by 10s cycle from 1940s through 1990s, to compute accurate volumes of coastline variation, through a datum point and G.C.P (Ground Control Point). Also in this study, without respect to water level, the coastline variation was analyzed by using comparatively analyzed a Idlest land map, a cadastral map. And to analyze topographical variation volumes, the tidal station's materials was used under consideration f3r tide. Finally, topographical variation volumes are comparatively analyzed through surveying and sounding and a point of fine of aviation photographing was calculated and revised. After this research, by using ortho aerial photos, We can understand efficiency of these in computing volumes of variations of coastline by analyzing quantitatively erosion and look of a heap. Besides, in the future, these will be used for information gathering of the coastline integration control system.

A Study of hollow Landforms of Korea from the point of forming (우리나라의 와지지형에 관한 성인론적 연구 - 현지조사에서 나타난 사례를 중심으로 -)

  • 한국동굴학회
    • Journal of the Speleological Society of Korea
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    • no.66
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    • pp.59-66
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    • 2005
  • The present writer have been engaged in research the Karst topography of Korea from the 1950's. Especially, I have studiedthe hollows indicated on topographical maps(1:5,000, 1:50,000) in library side by side with field survey. As the side by side with field survey. As the result, I came to a conclusion that all the hollows in limestone area are not always dolines. Based on case study, I classified the hollow landforms into 10 groups as follow. 1) Solution hollow 2) Volcanic hollow 3) Desertic hollow 4) Structural hollow 5) Meteoric hollow 6) Limnoic hollow 7) Minal hollow 8) Artificial hollow 9) Bursted hollow 10) Compound hollow I am asking advices of you all.