• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.36 no.6
• /
• pp.443-449
• /
• 2018

Acquiring indoor point cloud, using SLAM (Simultaneous Localization and Mapping) based mobile mapping system, is an element progress for development of as-build BIM (Building Information Model) for the maintenance of the building. In this research we proposed a simulation-based target geometry determination for extrinsic calibration of multiple 2D laser scanning mobile system. Four different types of calibration sites were designed: (1) circle type; (2) rectangle type; (3) double circle type; and (4) double rectangle type. Based on the measurement values obtained from each simulated calibration site geometry, least squares solution based extrinsic calibration was derived. As a result, the rectangle type geometry is most suitable for extrinsic calibration of this system. Also, correlation values between extrinsic calibration parameters were high, and calibration results were distinct according to the calibration sites.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.4
• /
• pp.351-357
• /
• 2008

An aerial multi-looking camera system equips itself with five separate cameras which enables acquiring one vertical image and four oblique images at the same time. This provides diverse information about the site compared to aerial photographs vertically. The geometric relationship of oblique cameras and a vertical camera can be modelled by 6 exterior orientation parameters. Once the relationship between the vertical camera and each oblique camera is determined, the exterior orientation parameters of the oblique images can be calculated by the exterior orientation parameters of the vertical image. In order to examine the exterior orientation of both a vertical camera and each oblique cameras in the multi-looking camera relatively, calibration targets were installed in a lab and 14 images were taken from three image stations by tilting and rotating a non-metric digital camera. The interior orientation parameters of the camera and the exterior orientation parameters of the images were estimated. The exterior orientation parameters of the oblique image with respect to the vertical image were calculated relatively by the exterior orientation parameters of the images and error propagation of the orientation angles and the position of the projection center was examined.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.34 no.3
• /
• pp.291-297
• /
• 2016

Direct georeferencing has become widespread in the field of digital aerial photogrammetry; as a result, the boresight calibration has become an essential component of the procedure to calculating exterior orientation parameters of aerial photographs accurately. During this procedure, a reference is used for the height of the geoid model, and the calibration results can appear different depending on the geoid model. The exterior orientation parameters calculated through direct georeferencing during boresight calibration may have varied values according to the corresponding geoid model. With that in mind, the effects of the geoid model on the boresight calibration were analyzed through three different cases. The geoid models used in the experiments were EGM96, EGM08, and KNGeoid14, and, through boresight calibration, the datum shift and boresight angle for each model was computed. After calculating the exterior orientation of each case, the GCP (Ground Control Point) was verified using the DPW (Digital Photogrammetry Workstation). In each case, results in the boresight calibration acquired through the geoid model demonstrated a difference in the Z datum, the exterior orientation heights Z, and the rotation Ω and Φ. After utilizing the DPW in each case and comparing it to the GCP, the difference in accuracy in accordance with the geoid model was found to be within 3cm, and it was concluded that the geoid model did not have a significant impact on boresight calibration.

• Korean Journal of Remote Sensing
• /
• v.33 no.5_3
• /
• pp.787-798
• /
• 2017

In the present study, the interior orientation parameters were computed by using various kinds of methods. Five DSMs (Digital Surface Models) in total were produced by applying interior orientation parameters to the image processing, and the accuracy was evaluated. In order to use interior orientation parameters as independent variables of DSM accuracy, flight parameters and exterior orientation parameters that can affect the accuracy of DSM were set to be the only fixed variables. From the results of the present study, the RMSE of campaign 3-2 was found to be 0.0305 m, which was the most favorable result. Thus, it is advisable to produce DSM by adjusted interior parameters after figuring out the interior orientation parameters using a camera calibration program at laboratory environment.

• Korean Journal of Remote Sensing
• /
• v.19 no.6
• /
• pp.431-445
• /
• 2003

In this paper, we experimentally investigated the precision of 3D positioning using 4S-Van images in photograrmmetric perspective. The 3D calibration target was built over building facade outside and was captured separately by two CCD cameras installed in 4S-Van. After then, we determined the interior orientation parameter for each CCD camera through self-calibration technique. With the interior orientation parameter computed, the bundle adjustment was performed to obtain the exterior orientation parameters simultaneously for two CCD cameras using calibration target image and object coordinates. The reverse lens distortion coefficients were computed and acquired by least squares method so as to introduce lens distortion into epipolar line. It was shown that the reverse lens distortion coefficients could transform image coordinates into lens distorted image coordinates within about 0.5 pixel. The proposed semi-automatic matching scheme incorporated with lens distorted epipolar line was implemented with scene images captured by 4S-Van in moving. The experimental results showed that the precision of 3D positioning from 4S-Van images in photograrmmetric perspective is within 2cm in the range of 20m from the camera.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.2D
• /
• pp.277-285
• /
• 2008

X-ray images are wildly used in medical applications, and these can be more efficiently find scoliosis which is appearing during the growth of human skeleton than others. This research is focused on the calibration of X-ray image and three-dimensional coordinate determination of objects. Three-dimensional coordinate of objects taken by X-ray are determined by two step procedure. Firstly, interior and exterior orientation parameters are determined by camera calibration using Primary Calibration Object (PCO) which has two sides with embedded radiopaque steel ball. Secondly, calibration cage coordinates which is composed of two acrylic sheets that are perpendicular to X-ray source are determined by the parameters. Three-dimensional coordinates of calibration cage determined by photogrammetric technique are compared with that of Coordinate Measuring Machine (CMM). Though the accuracy analysis, X direction which is parallel to X-ray source error values are relatively higher than those of Y and Z directions. But, the accuracies of Y and Z axis are approximately -3 mm to 3 mm. From the research results, it is considered that photogrammetric technique is applied to determine three-dimensional coordinates of patients or assist to make medical devices.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.30 no.2
• /
• pp.181-188
• /
• 2012

The most recent, Digital photogrammetric camera, Airborne LiDAR and GPS/INS same sensors are used to acquire spatial information of various kinds in the field of aerial survey. In addition, Direct Georeferencing technology has been widely utilized with digital photogrammetric camera and GPS/INS. However, the sensor Calibration to be performed according to the combination of various sensors is followed by problems. Most of all, boresight calibration of integrated sensors is a critical element in the mapping process when using direct georeferencing or using the GPS/INS aerotriangulation. The establishment of a national test-bed in Sejong-si for aerial sensor calibration is absolutely necessary to solve this problem. And accurate calibration with used to integration of GPS/INS by aerotriangulation of aerial imagery was necessary for determination of system parameters, evaluation of systematic errors. Also, an investigation of efficient method for Direct georeferencing to determine the exterior orientation parameters and assessment of geometric accuracy of integrated sensors are performed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.27 no.2
• /
• pp.203-211
• /
• 2009

With supply of the domestic digital camera, the relative importance of the digital camera is coming to be high gradually on aerial photogrammetry, the image of digital camera is more applied in image map or digital topographic map production. But, there are cases that do not have position information or attitude information of each photograph in digital camera results. Therefore, we wish to present additional method to get more accurate photograph control point result. In this study, One is called A method, which is the case of entering positioning information of principal point from topographic map as default values that are need to extract tie point automatically using by 56 pieces of photography that are photographed by DMC to the extent to 5 courses and 35 GCP points. The other is called B-method, which is the case of entering exterior orientation parameters that are processed by block adjustment for A-method using by 4 control points in method-1 as default values. We have analyzed about results per control points arrangement for two cases using MATCH-AT that is photograph control point measurement S/W of Germany INPHO company. As a result of analysis, accuracy of B-method was better than that of A-method, and we could get more accurate results if block adjustments are executed including self calibration. Also, it is more effective in expense side that using self calibration for photograph survey in B-method because can reduce GCP numbers.