• Journal of Cadastre & Land InformatiX
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• v.51 no.2
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• pp.73-82
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• 2021

According to the government's announcement of the safety management enhancement policy for small and medium-sized private construction sites, the subject of mandatory CCTV installation has been expanded from large construction sites to small and medium-sized construction sites. However, since the existing CCTV at construction sites has been used for simple control for safety management, so research is needed for monitoring of construction sites. Therefore, in this study, three vanishing points were calculated based on a single image taken with a monocular camera, and then a camera matrix containing interior orientation parameters information was determined. And the accuracy was verified by calculating the height of the target object from the height of the reference object. Through height determination experiments using vanishing points based on a monocular camera, it was possible to determine the height of target objects only with a single image without separately surveying of ground control points. As a result of the accuracy evaluation, the root mean square error was ±0.161m. Therefore, it is determined that the progress of construction work at the construction sites can be monitored through the single image taken using the single camera.

• Journal of Korean Society for Geospatial Information Science
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• v.9 no.2 s.18
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• pp.47-54
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• 2001

The aim of this study is to represent the effective method for undertaking cadastral surveying works through analyzing and comparison of the surveying results both Total Station and GPS surveying techniques. in the value of coordinate of land parcels, the surveying results of using Total Station and Real Time Kinematic GPS surveying are compared and anayzed. As a results, each axis X and Y differences are ${\Delta}X=0.02m\;and\;{\Delta}Y=0.02$. Therefore the latter surveying method is available to use for production of numerical casdastral map at a large scale and for field surveying in farmland adjustment area. Furthermore travers surveying is not needed to be done when horizontal position of the boundary of a land parcel is determined by the method of RTK. It is recognized as a effective and efficient method in rapaid, accurate and economical aspects.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.1
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• pp.13-22
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• 2010

In this paper, we propose a management system for positioning and indicating the surveyed control point using RFID and UMPC. This system is composed of digital control point, management system and application. The digital control point transmits information of the surveyed control point and the management system receives the data from the digital control points and manages the scattered digital control points. The system offers three services for managing the surveyed control point. The first service is control point monitoring service for identifying the change of location, locating the missing control point and the second service is control point search service notifying selected control point to user, and the third service is control point land management service for editing the control point information in the land. Therefore, this system makes it easy for administrators to access the control point information of the scattered surveyed control point through the country and enhances the managing efficiency.

• Journal of Ocean Engineering and Technology
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• v.26 no.1
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• pp.47-53
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• 2012

A coastal flood area was predicted using the empirical superposition of the typhoon surge level and typhoon wave height along the Busan coastal area. The historical typhoon damages were reviewed, and the coastal topography was measured using VRS-GPS. A FEMA formula was applied to estimate the coastal flood area in a typhoon case when the measured and predicted data of typhoon waves are not available. The results in the area of Haeundae beach and Gwangalli beach were verified using the flood area data from the case of Typhoon Maemi (2003). If a Hurricane Katrina class typhoon were to pass through the Maemi trajectory, the areathat would be flooded along theBusan coastal area was predicted and compared with the results of the Maemi case. Because of the lack of ocean environment data such as data for the sea level, waves, bathymetry, wind, pressure, etc., it is hard to improve the prediction accuracy for the coastal flood area in the typhoon case, which could be reflected in the policy to mitigate a typhoon's impact. This paper discusses the kinds of ocean environment information that is needed to predict a typhoon's impact with better accuracy.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.2
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• pp.298-303
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• 2010

robots determine the location of the other robot using wireless sensors. Use it to decide how to move his. And go to any location, will make shape of column and line, circle. In this paper, we discuss problem in circle formation enclosing target which moves. It is method about enclosed invader in circle formation based on mutual localization of swarm robot without infrastructure. Therefore, use trilateration that do not need to know the value of the coordinates of reference points. So, Specify enclosed point for the number of robots base on between the relative position of the robot in the coordinate system. And particle filter is proposed to improve the accuracy of the location.

• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.511-527
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• 2016

We propose a rotating stereo frame camera system to acquire indoor images with a low cost. For experiments, we selected a test site and acquired images using the proposed system and control points using a total station. Using these data, we generated various indoor 3D models using commercial photogrammetric software, PhotoScan. We then performed qualitative and quantitative analysis of the generated indoor 3D models to investigate the possibility of the indoor modeling using the proposed system. From the results, it is confirmed that the generated indoor models using the proposed system can be applicable to the services not inquiring high accuracy.

• 한국IT서비스학회:학술대회논문집
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• 2010.05a
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• pp.162-165
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• 2010

우리나라 대형 건설시장의 하나인 터널 시공은 계획 대비 많은 물량과 자재의 소모로 인해 이들 정보의 지속적 관리를 통한 정확한 물량 및 자재 산출 정보 예측에 대한 관심이 꾸준히 요구되고 있는 실정이다. 대부분의 시공현장에서는 굴진의 정확도 검측을 위해 광파기를 사용하고 있다. 광파기는 공사 초기 시부터 유지된 원점으로부터의 정확한 좌표를 사용하고 있어 취득된 정보는 신뢰할 수 있으나, 몇 개의 기준점을 측량하여 굴진방향 및 공사의 진척도를 평가하는 방식이므로, 전체적인 면을 측정하지 못한다는 단점이 있다. 이에 반하여 3차원 스캐너는 제원에 따른 반경 내의 모든 점들을 계측하여 그 정보를 선이 아닌 면으로써 파악하지만 위치에 대한 정확도를 포함할 수 없다. 이러한 문제점을 보완하기 위하여, 광파기와 3차원 스캐너를 동시 활용하는 본 시스템은 현장에서 소모된 자원의 정확한 양을 체크하여 굴진정도를 파악하여 공사의 전반적인 진도를 관리할 수 있다. 또한 여굴의 발생 여부를 직접 확인하고 계획대비 소모된 물량정보를 통해 자재관리를 할 수 있게 된다. 마지막으로 추후 발생할 수 있는 하자에 대한 정확한 근거를 제시하여 균열 및 누수 등에 대한 정확한 원인 파악을 제공할 수 있다는 장점들을 제공한다.

• Korean Journal of Remote Sensing
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• v.36 no.5_4
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• pp.1209-1220
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• 2020

In the case of forest areas, the installation of ground control points (GCPs) and the selection of terrain features, which are one of the unmanned aerial photogrammetry work process, are limited compared to urban areas, and safety problems arise due to non-visible flight due to high forest. To compensate for this problem, the drone equipped with a real time kinematic (RTK) sensor that corrects the position of the drone in real time, and a 3D flight method that fly based on terrain information are being developed. This study suggests to present a method for investigating damage using drones in forest areas. Position accuracy evaluation was performed for three methods: 1) drone mapping through GCP measurement (normal mapping), 2) drone mapping based on topographic data (3D flight mapping), 3) drone mapping using RTK drone (RTK mapping), and all showed an accuracy within 2 cm in the horizontal and within 13 cm in the vertical position. After evaluating the position accuracy, the volume of the landslide area was calculated and the volume values were compared, and all showed similar values. Through this study, the possibility of utilizing 3D flight mapping and RTK mapping in forest areas was confirmed. In the future, it is expected that more effective damage investigations can be conducted if the three methods are appropriately used according to the conditions of area of the disaster.

• Korean Journal of Remote Sensing
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• v.31 no.5
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• pp.461-471
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• 2015

In this study, we generated orthoimages and Digital Elevation Model (DEM) from Unmanned Aerial Vehicle (UAV) to confirm the accuracy of possibility of geospatial information system generation, then compared the DEM with the topographic height values measured from Real Time Kinematic-GPS (RTK-GPS). The DEMs were generated from aerial triangulation method using fixed-wing UAV and rotary-wing UAV, and DEM based on the waterline method also generated. For the accurate generation of mosaic images and DEM, the distorted images occurred by interior and exterior orientation were corrected using camera calibration. In addition, we set up the 30 Ground Control Points (GPCs) in order to correct of the UAVs position error. Therefore, the mosaic images and DEM were obtained with geometric error less than 30 cm. The height of generated DEMs by UAVs were compared with the levelled elevation by RTK-GPS. The value of R-square is closely 1. From this study, we could confirm that accurate DEM of the tidal flat can be generated using UAVs and these detailed spatial information about tidal flat will be widely used for tidal flat management.

• Korean Journal of Remote Sensing
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• v.21 no.4
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• pp.287-302
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• 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.