• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제27권2호
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• pp.177-186
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• 2009

Nowadays, as going to information society based knowledge, the informations are acquired, processed, serviced based digital environment. In surveying field, the trend have been changed from the analog foundation to the digital foundation. Also, aerial photogrammetry is being changed from analog aerial photogrammetry to digital aerial photogrammetry. In this paper, the analysis of accuracy is performed for the comparison of traditional aerial photogrammetry with digital aerial photogrammetry usign UltracamX in AT and Block Adjustment. As the results, Bundle adjustment in digital aerial photogrammetry with GPS/INS have more advantages than traditional independent adjustment in analog aerial photogrammetry. Digital aerial photogrammetry contributes the higher accuracy in AT and block adjustment more than analog aerial photogrammetry.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제27권1호
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• pp.743-750
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• 2009

Since aerial photogrammetry by analog camera began in 1972, recently, high resolution digital camera is actively introduced to improve efficiency of aerial photogrammetry. This study investigated the 3D positioning accuracy of DMC(Digital Mapping Camera) among various high resolution aerial digital cameras to be developed for photogrammetry. For the research, we installed control points in test field around Incheon, and acquired analog and digital aerial photographs. By comparing 3D positioning accuracies of analog and digital photographs, there are few difference between two cameras, and the 3D positioning accuracies of two cameras was somewhat increased in case of aerotriangulation using additional control points based on GPS/IMU EO data.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2015년도 학술발표회
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• pp.383-383
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• 2015

하천의 하상고 측량은 하상변동 분석, 서식처 구조 등을 이해하는데 매우 중요한 정보를 제공한다. 하지만, 현재까지 대부분의 하상고 측량은 일정한 간격의 하천 단면 측량에 의해서 행해져 왔다. 최근 GPS와 다중 빔 측심기를 이용하여 하상의 3차원적 형상을 조밀하게 측량하고 있으나 비용이 많이 들기 때문에 긴 하천 구간을 전부 측량하지는 못하고 특정한 부분에 대해서만 집중하고 있다. 항공 LiDAR의 경우 넓은 지역에 대해 신속하고 고해상도로 지형을 측량할 수 있으나 수중 투과 장비가 고가이며, 일반 적색 레이져 기반 LiDAR는 수중을 측정하지 못하여 하상 측량에 한계가 있다. 이에 대한 대안으로 활용할 수 있는 방법은 광학 기반의 원격 탐사에 의한 수심 측량 방법이다. 이 방법은 얕은 수심의 하천에 대한 활용되었는데, 광학 센서 이미지나 항공사진 등을 이용한다. 본 연구에서는 저고도에서 촬영한 고해상도 디지털 항공사진을 이용하여 모래하천의 수심을 추정하였다. 이 방법은 항공사진의 적색 및 녹색 색상값과 현장에서 정밀한 측위 하에 측량한 수심값 사이의 관계를 이용한다. 이를 통해 보정식을 수립하고 검사 자료를 이용하여 검증한 후 항공사진의 해당 지역에 대해 수심 부분을 마스킹 처리하여 하상고를 구축하였다. 검사 자료에 대한 RMSE는 약 12 cm로 나타났다. 이를 활용하여 대상 구간의 3차원적 지형 형상을 구축하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제28권3호
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• pp.337-345
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• 2010

In general, Digital Photogrammetry is based on independent workstation system, which is costly and has complex process. In this research, a new approach method regarding Digital Photogrammetry procedure is suggested using Web Processing Service, which is a GIS standard proposed by Open Geospatial Consortium. For the experiment, many Generic Processes were defined through WPS profiling procedure which defines standard unit for Photogrammetry, and with the defined process each server and client S/W module was implemented based on WPS standards. In this paper, many users can be expected to share and reuse unit process in WPS server through the web.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제37권6호
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• pp.571-577
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• 2019

Since the introduction of digital cameras in an aerial-photogrammetry field on 2006, the technological paradigm related to the photogrammetry has been shifting from the analog types to digital types. However, current construction standard cost for the aerial-photogrammetry and the digital mapping are being mixed with analog-based concepts and digital-based methods. In the current standard cost, the monthly weather table is closely related to the calculation of the number of flying days in a taking of aerial photograph. The current monthly weather table uses the results calculated from the observation data of total cloud amount from 1999 to 2007. In this study, the monthly weather table was calculated using the total cloud data during ten years from 2009 to 2018. As a result, the newly calculated number of clear days for 29 stations was analyzed as 44 days decreased by 6 days. The maximum number of clear days decreased in Jinju as 23 days, and the highest decreased clearing days was February.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제30권2호
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• pp.173-180
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• 2012

The most recent, 80 mega pixels digital camera appeared through the development of digital technology, and nonmetric digital cameras have been using in various field of photogrammetry. In this study, we experimented lens calibration using aerial photographs and ground control points. The aerial photographs were taken a non-metric digital camera which is CMOS(Complementary Metal Oxide Semiconductor) 21.1 mega pixels sensor and 35mm lens at a helicopter. And the ground control points were selected on the 1:1,000 plotting origin data. As a result, we calculated focal length, PPA(Principal Point of Autocollimation) and symmetric radial distortion coefficients from the lens. Also, RMSE(root mean square error) and maximum residual of the ground control points from the aerial triangulation were compared before and after calibration. And we found that the accuracy of the after calibration was improved very significantly.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.197-200
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• 2007

항공사진 원데이터의 변형을 방지하고 효율적인 관리를 위해서는 자동독취를 통한 수치화 방안이 마련되어야 한다. 항공사진 판독업무에 있어서 기존 판독자만 밀착항공사진과 입체경을 통하여 건축물의 형태와 변화 여부를 판단하던 것을 모니터 상에서 누구나 건물의 변동사항을 볼 수 있도록 효율적인 판독시스템을 구축하여 판독의 신뢰도를 높여야 한다. 판독시스템 구축은 디지털 영상의 다양한 활용과 업무의 효율성 확보 및 대민서비스 향상 차원에서 이루어져야 할 것이다. 또한 현재 외국의 항측사들이 실제로 활용하고 있으며 조만간 국내에서도 도입 예정인 디지털항공카메라는 항공사진의 수치화 단계를 거치치 않고 직접 수치항공영상을 취득 할 수 있으므로 수치화 과정에서 발생하는 많은 오류들을 제거할 수 있음은 물론 판독시스템을 활용한 데이터의 직접처리가 가능해 시간적, 경제적으로 많은 장점들을 가지고 있다. 그러므로 디지털항공카메라의 도입에 대비한 개발현황과 활용도 등에 관한 사전 연구가 수행되어야 한다. 본 연구에서는 사용자가 직접 입체 판독 및 분석을 수행할 수 있는 플랫폼을 구비함으로서 오류를 최소화 할 수 있도록 편광 모니터(Z-Screen)를 사용하여 수행하였다. 또한 환경은 Microsoft Window OS 환경 상에서 구동될 수 있도록 개발함으로서 시스템의 범용적 사용을 위한 기초 환경을 제공하도록 제안하였다.

• 한국공간정보시스템학회:학술대회논문집
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• 한국공간정보시스템학회 2005년도 추계학술대회
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• pp.29-34
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• 2005

Aerial photogrammetry, which is one of the most frequent used technology in mapping and surveying, has been appreciated for its work flow and accuracy to generate 2D and 3D geospatial data. In aerial photograrnrnetry, more than two photographs are taken over the same target area in different position with overlap. Using these photographs and minimum number of ground control points, 3D stereo model is so formed that the ground surface in reality is reconstructed through analogue/analytical plotter or digital photogrammetry system. In case of digital photogrammetry system, 3D geospatial data could be automatically extracted in partial. Recently, in the advent of aerial digital camera such as ADS40 and DMC, digital photogrammetry system will be in the frist place for generating 3D geospatial data. In this paper, we experimentally generated 3D geospatial data using digital photograrnrnetry system in the aspect of work flow.

• Journal of Cadastre & Land InformatiX
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• 제50권1호
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• pp.163-180
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• 2020

In this study, to build a spatial information infrastructure, which is a component of a smart city, a 3D digital twin model in the downtown area was built based on the latest spatial information acquisition technology, the drone. Several analysis models were implemented by utilizing. While the data processing time and quality of the three types of drone photogrammetry software are different, the accuracy of the construction model is ± 0.04 in the N direction and ± 0.03m in the E direction. In the m and Z directions, ± 0.02m was found to be less than 0.1m, which is defined as the allowable range of surveying performance and inspection performance for the boundary point in the area where the registration of the boundary point registration is executed. 1: 500 to 1 of the aerial survey work regulation: The standard deviation, which is the error limit of the photographic reference point of the 600 scale, appeared within 0.14 cm, and it was found that the error limit of the large scale specified in the cadastral and aerial survey was satisfied. In addition, in order to increase the usability of smart city realization using a drone-based 3D urban digital twin model, the model built in this study was used to implement Prospect right analysis, landscape analysis, Right of light analysis, patrol route analysis, and fire suppression simulation training. Compared to the existing aerial photographic survey method, it was judged that the accuracy of the naked eye reading point is more accurate (about 10cm) than the existing aerial photographic survey, and it is possible to reduce the construction cost compared to the existing aerial photographic survey at a construction area of about 30㎢ or less.

• Journal of the Korean Association of Geographic Information Studies
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• 제23권1호
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• pp.41-50
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• 2020

The National Geographic Information Institute of Korea takes digital aerial photograph images every two years to make and modify/renew the digital map. The cameras for aerial photogrammetry to capture these digital aerial photographs are divided into frame types and line types. Computer vision analysis of aerial photograph images was only possible for frame type. Thus, in this study, Line type aerial photograph images was intended to generate geospatial information through computer vision analysis, and forest geospatial information was created as a method for the utilization of aerial picture images. As a result, geospatial information generated by computer vision analysis of line type aerial photograph images showed that RMSE of horizontal and vertical position errors was less than quadruple that of GSD. Forest geospatial information was generated using geospatial information generated by computer vision analysis. It was confirmed that extraction of the crown of tree and calculation of tree height are possible. Through this study, it is expected that utilization of aerial photograph images will be improved.