• Title/Summary/Keyword: Aerial photographs

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Analysis of sideward footprint of Multi-view imagery by sidelap changing (횡중복도 변화에 따른 다각사진 Sideward Footprint 분석)

  • Seo, Sang-Il;Park, Seon-Dong;Kim, Jong-In;Yoon, Jong-Seong
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2010.04a
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    • pp.53-56
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    • 2010
  • 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. However, multi-looking Aerial Camera for building a 3D spatial information don't use a large-size CCD camera, do uses a medium-size CCD camera, if acquiring forward, backward, left and right imagery of Certain objects, Aerial photographing set overlap and sidelap must be considered. Especially, Sideward-looking camera set up by the sidelap to determine whether a particular object can be acquisition Through our research we analyzed of sideward footprint and aerial photographing efficiency of Multi-view imagery by sidelap changing.

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Generation of High Quality Geospatial Information Using Computer Vision Analysis of Line Type Digital Aerial Photogrammetry Camera Imagery (Line Type 디지털 항공사진측량 카메라 영상의 컴퓨터비전 해석을 통한 고품질 공간정보 생성)

  • LEE, Hyun-Jik
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.1
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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.

Investigation of Shoreline Change by Photogrammetric Method (항공사진측량에 의한 해안선 변화 조사)

  • Lee, Chang-Kyung;Kim, Baeck-Oon;Kim, Nam-Yong
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.2 s.40
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    • pp.15-23
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    • 2007
  • This paper presents a shoreline change analysis on a reclaimed land, using a pair of aerial photographs taken before and after the reclamation. Shorelines that are defined by a tide datum, i.e. Approximately Highest High Water Level, were mapped by both analytical and digital photogrammetric methods. The past shorelines were overlapped with digital cadastral map from which areas of retracted and protruded lands were computed. Magnitude of shoreline changes was estimated by calculating areas between the past and present shorelines. Comparisons in terms of areas showed a fairly good agreement between the two methods. However, particularly in the estuary of complex morphology, shoreline mapping by digital photogrammetric method requires images to be scanned at a resolution higher than 1200 dpi.

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Extraction of Spatial Information of Facility Using Terrestrial and Aerial Photogrammetric Analysis (지상사진과 항공사진 해석에 의한 시설물 공간정보 추출)

  • Sohn, Duk-Jae;Lee, Seung-Hwan
    • Journal of Korean Society for Geospatial Information Science
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    • v.11 no.1 s.24
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    • pp.51-59
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    • 2003
  • This study intended to extract the spatial data and attribute data from the images of terrestrial and aerial photographs and to compile the digital map from the images using various kinds of photogrammetric analysis. The Three Dimensional Frame Model (3DFM) was produced from multiple images of terrestial photographs, and the Three Dimensional Photo Image Model (3DPIM) was made using 3DFM and image patches of terrestrial photo, which is useful for identifying the feature and characteristics of the object. In addition, the spatial data base for the buildings, roads and supplementary facilities in the objective area was updated by the vectorizing procedures with small scale areal photos.

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Time Series Analysis by Coastline Change Using Aerial Photographs (항공사진을 이용한 해안선 변화에 대한 시계열 분석)

  • Kim, Yong-Suk;Hong, Soon-Heon
    • The Journal of the Korea Contents Association
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    • v.7 no.3
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    • pp.160-167
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    • 2007
  • Due to the drastic growth of national economy and the development of overall territory, the shapes of national land and coastal areas are changing from day to day. To detect such changes in lands and coasts efficiently, as well as to establish an appropriate usage plan, it is necessary to secure a monitoring system for coastal areas based on the observation and analysis of the change in coastlines. Currently, looking at the field of producing national coastlines, the lengths of coastlines are inaccurate due to the vague definition of dividing coastline boundaries and insufficient observation data. The level of accuracy and reliability of previous data are also in the very low. This paper used aerial photographs with certain intervals to monitor the change in coastal areas of Songjeong, Haeundae, Kwanganri, Songdo and Dadaepo. The local area subjected for this research was limited to areas near Busan.

Automatic Identification of Fiducial Marks Existing on Aerial Photographs (항공사진에 포함된 사진 지표의 자동 인식)

  • Cho, Seong-Ik;Bang, Ki-In;Kim, Kyung-Ok
    • Journal of Korean Society for Geospatial Information Science
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    • v.10 no.3 s.21
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    • pp.79-87
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    • 2002
  • This paper proposes an approach of automatically identifying the center of fiducial marks using radiometric and geometric characteristics of those marks existing on aerial photographs. Candidate region surrounding a mark, based on radiometric strategy, is determined by producing a bi-level image and by applying morphological operations. Based on geometric strategy, the central location of a mark is determined by applying ${\bigtriangledown}^G$ filtering and symmetry-enhancement filtering, and by finding peak location of symmetry. Evaluation with respect to 66 cases of sub-images containing a fiducial mark showed that the central location of the mark is determined up to around one pixel difference whit it is compared to a manual inspection.

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Variation in Vegetation Area caused by Topographical Change at Jinudo in the Nakdong Estuary (낙동강 하구역 진우도내 지형변동에 따른 식생면적의 변화)

  • Ryu, Sung-Hoon;Lee, In-Cheol;Park, So-Young
    • Journal of Ocean Engineering and Technology
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    • v.23 no.4
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    • pp.19-24
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    • 2009
  • In order to analysis the variation in vegetation area caused by topographical change at Jinudo in the Nakdong estuary, we used aerial photographs of Jinudo from 1998 to 2006. To extract an accuracy shoreline from these aerial photographs, a tide calibration was performed. We also estimated the annual variation in topographic area and vegetation area, and then analyzed the relationship between them by a correlation analysis. The following results were obtained: 1) The calibrated shoreline distance of Jinudo from 1998 to 2006 was estimated to have a range of (-)1,927 cm to (+)4,671 cm. 2) Annual changes in the topographic area and vegetation area in Jinudo have been increasing gradually from 1998, and the correlation coefficient between topographic area and vegetation area is 0.97. 3) The estimated topographic areas were with following order: southern (III), eastern (IV), northern (II) and western (I), while for the vegetation area, the order was southern (III), northern (II), eastern (IV) and western (I). 4) The vegetation area of the southern region (III) of Jinudo had the largest size among the regions, and was calculated to be $4.3{\sim}5.4$ times larger than the eastern region (IV).

Automatic Identification of Fiducial Marks Based on Weak Constraints

  • Cho, Seong-Ik;Kim, Kyoung-Ok
    • Korean Journal of Remote Sensing
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    • v.19 no.1
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    • pp.61-70
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    • 2003
  • This paper proposes an autonomous approach to localize the center of fiducial marks included in aerial photographs without precise geometric information and human interactions. For this localization, we present a conceptual model based on two assumptions representing symmetric characteristics of fiducial area and fiducial mark. The model makes it possible to locate exact center of a fiducial mark by checking the symmetric characteristics of pixel value distribution around the mark. The proposed approach is composed of three steps: (a) determining the symmetric center of fiducial area, (b) finding the center of a fiducial mark with unit pixel accuracy, and finally (c) localizing the exact center up to sub-pixel accuracy. The symmetric center of the mark is calculated tv successively applying three geometric filters: simplified ${\nabla}^2$G (Laplacian of Gaussian) filter, symmetry enhancement filter, and high pass filter. By introducing a self-diagnosis function based on the self-similarity measurement, a way of rejecting unreliable cases of center calculation is proposed, as well. The experiments were done with respect to 284 samples of fiducial marks composed of RMK- and RC-style ones extracted from 51 scanned aerial photographs. It was evaluated in the visual inspection that the proposed approach had resulted the erroneous identification with respect to only one mark. Although the proposed approach is based on weak constraints, being free from the exact geometric model of the fiducial marks, experimental results showed that the proposed approach is sufficiently robust and reliable.