• Journal of Korean Society for Geospatial Information Science
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• v.14 no.3 s.37
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• pp.79-86
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• 2006

Nowadays 3D terrestrial laser scanners record high precision three-dimensional coordinates of numerous points on an object surface in a short period of time. So terrestrial laser scanner is applied to a wide variety of fields including geodesy, and civil engineering, archaeology and architecture, and emergency service and defence, etc. This study deals with the potential application of terrestrial laser scanner in the reconnaissance surveying. The results shows that terrestrial laser scanner is possible to extract the linear features and the positioning accuracy of objects measured by total station surveying is comparative to that by terrestrial laser scanner. Thereafter, it is expected that the potential applications of terrestrial laser scanning will be more increased by combining terrestrial laser scanners with airborne LiDAR (Light Detection And Ranging) and photogrammetric technology.

• Spatial Information Research
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• v.15 no.1
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• pp.53-65
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• 2007

Terrestrial laser scanner provides highly accurate, 3D images and by sweeping a laser beam over a scene or object, the laser scanner is able to record millions of 3D points' coordinates in a short period, so becoming distinguished in various application fields as one of the representative surveying instruments. This study deals with 3D building boundary extraction using Terrestrial Laser Scanner. The results shows that high accuracy 3D coordinates for building boundaries are possibly acquired fast, but terrestrial laser scanner is a ground-based system, so "no roofs", and "no lower part of building" due to trees and electric-poles, etc. It is expected that the combination of total station, terrestrial laser scanner, airborne laser scanner with aerial photogrammetry will contribute to the acquisition of an effective 3D spatial information.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.2
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• pp.79-87
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• 2016

As 3D geospatial information is demanded, terrestrial laser scanners which can obtain 3D model of objects have been applied in various fields such as Building Information Modeling (BIM), structural analysis, and disaster management. To acquire precise data, performance evaluation of a terrestrial laser scanner must be conducted. While existing 3D surveying equipment like a total station has a standard method for performance evaluation, a terrestrial laser scanner evaluation technique for users is not established. This paper categorizes and analyzes error sources which generally occur in terrestrial laser scanning. In addition to the prior researches about categorizing error sources of terrestrial Laser scanning, this paper evaluates the error sources by the actual field tests for the smooth in-situ applications.The error factors in terrestrial laser scanning are categorized into interior error caused by mechanical errors in a terrestrial laser scanner and exterior errors affected by scanning geometry and target property. Each error sources were evaluated by simulation and actual experiments. The 3D coordinates of observed target can be distortedby the biases in distance and rotation measurement in scanning system. In particular, the exterior factors caused significant geometric errors in observed point cloud. The noise points can be generated by steep incidence angle, mixed-pixel and crosstalk. In using terrestrial laser scanner, elaborate scanning plan and proper post processing are required to obtain valid and accurate 3D spatial information.

• Proceedings of the KSRS Conference
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• v.2
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• pp.567-569
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• 2006

Recently, the terrestrial laser scanner is considered as useful measurement equipment for acquiring a three-dimensional data. In this study, a terrestrial laser scanner which has +/- 2.5cm accuracy is examined whether the terrestrial laser scanner is reliable to present the tendency of landslide movement. The test area is covered by protection blocks, and they are being moved by landslide movement. Landslide movement was detected by measuring the movement of protection blocks. Totally three scenes of test area were acquired during 2004 and 2006. The three scenes of the protection blocks were registered in global coordinate system, then the landslide movement was investigated. The landslide movement detected in the three scenes was evaluated by comparing with landslide movement measured by a total station. Although the measurement accuracy of landslide using the terrestrial laser scanner was worse than the total station, the scanning data showed the tendency of landslide movement of the test area.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2009.04a
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• pp.65-73
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• 2009

The terrestrial laser scanner measures the signal delay time of electronic circuit in EDM(Electronic Distance Measurement) Module for distance measurement. To measure signal delay time precisely, transmitting laser beam of terrestrial laser scanner is divided optically. Therefore, 10% of the laser beam power is entered into the electronic circuit and the others go out through lens. But, measure of delay time is severe in the laser scanner system that the laser beam power is changed dynamically by reflectance of a object, because characters like gain of electronic circuit involving APD(Avalanche Photo Diode) and so on are changed by incident laser beam. Therefore, we adapt ND(Neutral Density) filter that has grid pattern to the laser scanner system to keep constant the incident laser beam power. In this paper, we propose the simulation program for efficient design of ND filter pattern. Finally, to affirm simulation program, we conduct the experimental test of simulated ND filter that has linearly transmittance change, and we consider the experiment result.

• Spatial Information Research
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• v.17 no.1
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• pp.39-49
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• 2009

3D terrestrial laser scanners record high precision three-dimensional coordinates of numerous points on an object surface in a short period of time, and is applied to a wide variety of fields including geodesy, and civil engineering, archaeology and architecture, and emergency service and defence, etc. However, most of terrestrial laser scanner utilized in homeland, were imported from foreign country, and also was not authorized formally as the surveying instrument. Therefore, standard test facility to calibrate and perform its evaluation in order to utilize it in a variety of fields is required. This study deals with the test facility of foreign countries for terrestrial laser scanner and suggest the establishment scheme of domestic test facility.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.187-194
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• 2009

This study is to improve position accuracy by selecting proper a servo motor and applying FOC(Field Oriented Control) on developing a 3D terrestrial laser scanner. A 3D terrestrial laser scanner under developing has range of scanning of azimuth 360$^\circ$and elevation 270$^\circ$. It is implemented by precise controlling of a azimuth motor and a elevation motor. In the consequence of study, we have known that position accuracy of the motor can be able to be improved with constant torque of the motor by using FOC(Field Oriented Control). The control technic of the motor is possible to apply a 3D terrestrial laser scanner as well as a robotic total station.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.54-63
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• 2009

Various methods have been employed for acquiring beach surface data, which are used to monitor shoreline changes due to beach erosion. This study explores the possibility of constructing and implementing a surface model of beach using data acquired with a terrestrial laser scanner and RTK-GPS. Digital images and three-dimensional data of beach areas acquired at 20 cm intervals using a laser scanner were used to create a digital surface model covered with digital image. Seven months later, the beach area was surveyed using an RTK-GPS, and another beach model was constructed using the data collected with an accuracy of 1.9 cm. The use of a terrestrial laser scanner is expected to ensure acquisition of good quality results and help deal with seasonal changes in beach areas. Because readings obtained with the RTK-GPS are dependent on the number of sampling points in beach model, difficulties are encountered when fixing the survey points. However, RTK-GPS could be used to implement a three-dimensional model by correcting the hidden parts in images obtained using a terrestrial laser scanner. Therefore, an RTK-GPS and a terrestrial laser scanner can be used in combination to obtain more precise data for the construction of beach model data.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.30-34
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• 2007

Surveyors has desired eagerly surveying technology and equipments which are able to acquire a lot of data easily, quickly and precisely. Laser has the merits that is able to obtain a large number of measurements with high precision in a short time and one of concrete realizations is a terrestrial laser scanner called Terrestrial LiDAR. This paper describes 3D modelling of a old architecture which was conducted using a Z-F laser system and the result of positioning analysis. Use of terrestrial laser scanner is much more efficient than existing photogrammetry in measuring and database constructing for preservation and restoration of cultural assets as well as for deformation monitoring and safety diagnosis of structures.

• Journal of Industrial Technology
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• v.31 no.B
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• pp.9-15
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• 2011

Nowadays, the Surveying field is growing rapidly in terms of technology such as TS(Total Station) surveying, photographic surveying, digital aerial photogrammetry, utilization of GIS(Geographic Information System) using high-resolution satellite imagery, obtaining 3D Coordinate using GPS. But control point surveying, benchmark measuring, and field Surveying are still performed by the engineers in the field. So, 3D yerrestrial laser scanner comes to the fore recently. 3D terrestrial laser scanner can get 3D coordinate about a number of sites of the subject in a short period with high accuracy. This paper compared the accuracy of data from the performance using 3D terrestrial laser scanner with that of TS. It also obtained the geopositioning accuracy result equivalent to the surveying result of TS. With further researches in the future, it is expected to be used not only in LiDAR itself but also in various areas like reconnaissance Surveying and construction by combining with TS or other Surveying equipments.