항공사진을 이용한 DEM 제작에 관한 연구

박충선 ( Park Chung-sun ),이광률 ( Lee Gwang-ryul ) 한국지형학회 2018 한국지형학회지 Vol.25 No.3

This study estimates possibility and limitation on production of DEM using aerial photo by comparison of DEMs using aerial photo and digital map. Mountain and urban areas show higher elevation in DEM using aerial photo than in DEM using digital map, due to height of vegetation cover and buildings, respectively. However, artificial affects due to bridge, embankment and road construction are responsible for areas with higher elevation in DEM using digital map than in DEM using aerial photo. This difference in elevation between DEMs seems to be caused by rapid change in real elevation that is not reflected in digital map. There is little difference in elevation between DEMs in plain and area with little or no vegetation cover. This study suggests that problems associated with vegetation cover and error by GCP should be fixed, although DEM using aerial photo can quantitatively and 3-dimensionally reconstruct topography with a high resolution.

A Research of Coastline Deformation with an Aerial Photo

Kim, Kam-Lae,Kim, Hak-Joon,Jeon, Ho-Won Korean Society of Surveying 2003 Korean journal of geomatics Vol.3 No.1

The purpose of this study is to make out a history of the coastline deformation with annual aerial photos of the target area and to suggest an efficient method for interpreting the coastline deformation. First, there were difficulties in obtaining annual aerial photos of an identical area as well as collecting periodical datum because of too much change of the real area during more than 27 years. Besides the past aerial photo is inferior to the latest one in quality. So there is nothing but to exclude an accuracy evaluation of the ortho photo. Taken into account the extent of the coastline change for 27 years is more than 10M and the all errors of the ortho image is included in this extent, both an accuracy and an error are ignored. The result of this study show that the coastline in the sea area of Namhangjin maintain advanced forward the ocean and keeps on moving with maintaining fairly wider shape of balance beach. Also The coastline deformation off l㎞ from the estuary is greatly irregular, which means the erosion of the sea in this area is in progress. The latest data being the aerial photo in 1996, it is difficult to find out the current conditions of a coastal erosion. However, considered the construction of a breakwater in Anmok Harbor is going on, the beach erosion becomes more accelerative recently. The aerial photos of the present Namhangjin's situation will make it possible to understand the history of the coastline change more accurately.

과거항공사진을 활용한 도심지에서의 선형구조 추출

김태석,이초희 한국지형학회 2023 한국지형학회지 Vol.30 No.1

The analysis of the lineament is the first task to identify the active fault trace, and DEM constructed from digital topographic map and LiDAR has been mainly used. In urban areas where it is difficult to observe the original topography due to artificial deformation of the surface, lineaments are identified from the restored original topography DEM built from historic aerial photos. Unlike other countries, there has not been much discussion in Korea, about how reliable and robust DEM can be constructed from historic aerial photo in which is conducive to identifying fault-related topography and extracting lineaments in urban areas. In this study, through comparative analysis with digital topographic map-based DEMs, we evaluated how effective historic aerial photo DEMs can be in identifying any fault-related topography in the Hongseong area. Our study demonstrates the DEM built from historic aerial photos is robust and reliable in identifying tectonic lineaments that were not detected in the DEM based on the digital topographic map because any original trace of fault-related topography may have been destructed due to urbanization.

디지털항공사진영상을 이용한 객체기반 토지피복분류

이현직(Lee Hyun Jik),유지호(Lu Ji Ho),김상연(Kim Sang Youn) 대한공간정보학회 2011 대한공간정보학회지 Vol.19 No.1

기존에 제작된 주제도는 중ㆍ저해상도 위성영상 기반으로 제작이 이루어져 위치정확도 및 표현되는 주제 정보의 정밀도가 낮다는 단점이 있다. 최근 촬영되고 있는 디지털항공사진영상은 흑백 및 컬러영역의 밴드와 산림판독이 가능한 근적외선 영역 밴드의 촬영이 가능하며, 고해상도 영상을 획득할 수 있어 정밀한 토지피복분류의 수행이 가능할 것으로 판단된다. 이에 본 논문에서는 디지털항공사진영상을 이용한 객체기반 토지피복분류 가능성 타진과 디지털항공사진영상의 활용성 제시를 위하여 동일한 지역의 GSD 0.12m급 디지털항공사진영상과 GSD 1m급 IKONOS 위성영상으로 객체기반 토지피복분류를 수행하였으며, 정사영상과 기존 중분류 토지피복도의 정성적 분석을 수행하였다. 또한, TTA(Training and Test Area) Mask를 생성하여 분류정확도를 분석하였으며, 영상을 대상으로 스크린디지타이징을 수행하여 분류면적의 비교를 통한 정확도를 분석하였다. 분석결과 디지털항공사진을 이용한 토지피복도 제작이 가능하였으며, 위성영상에 비해 세밀한 분류가 가능하였다. Since existing thematic maps have been made with medium- to low-resolution satellite images, they have several shortcomings including low positional accuracy and low precision of presented thematic information. Digital aerial photo image taken recently can express panchromatic and color bands as well as NIR (Near Infrared) bands which can be used in interpreting forest areas. High resolution images are also available, so it would be possible to conduct precision land cover classification. In this context, this paper implemented object-based land cover classification by using digital aerial photos with 0.12m GSD (Ground Sample Distance) resolution and IKONOS satellite images with 1m GSD resolution, both of which were taken on the same area, and also executed qualitative analysis with ortho images and existing land cover maps to check the possibility of object-based land cover classification using digital aerial photos and to present usability of digital aerial photos. Also, the accuracy of such classification was analyzed by generating TTA(Training and Test Area) masks and also analyzed their accuracy through comparison of classified areas using screen digitizing. The result showed that it was possible to make a land cover map with digital aerial photos, which allows more detailed classification compared to satellite images.

항공사진영상에 의한 3차원 경관모델링 연구

이영진(Lee Young Jin),석진창(Seok Jin Chang),이준혁(Lee Jun Hyuk) 한국지적학회 2006 한국지적학회지 Vol.22 No.1

  본 연구에서는 테스트지역을 대상으로 대축척 입체 항공사진을 이용한 3차원 지형 모델링을 실시하고 입체적인 시뮬레이션을 구현하고자 하였으며, 구축된 3차원 정보 D/B를 활용하여 경관시뮬레이션을 구현하는데 연구목적이 있다.<BR>  테스트지역은 대구광역시 수성구에 위치한 올림픽경기장 부근으로 촬영축척 1/20,000의 항공사진을 이용하여 수치사진측량방법의 공정에 따라 축척 1/5,000 정사영상지도를 생성하였으며, 입체항공사진과 기존의 수치지도를 이용하여 수치표고모델을 생성하였다. 그리고 테스트지역의 건물을 대상으로 GPS측량과 항공영상을 이용하여 건물의 높이값을 결정하였으며, 여기에 수치표고모델을 중첩한 후 3차원건물과 지형의 경관변화에 대한 시뮬레이션을 구현하였다.   In this study, three dimensional simulation of terrain surfaces is performed in built environments. The object of this study is to modelling of landscapes and constitution of three dimensional database by using large scale aerial photographs.<BR>  The test area is located around Olympic Stadium in Susung-gu, Daegu. A 1:5,000 scale of orthophoto image map is generated from 1:20,000 scale of aerial photographs, Digital Elevation Model(DEM) is also extracted from stereo aerial photographs with digital line maps.<BR>  The heights of buildings are determined using GPS control survey and aerial photographs in the test area. And then, the heights are combined to orthophoto image/DEM, three-dimensional changes of landscape views of buildings with terrain are simulated.

광촉매 TiO₂ 층의 비접촉식 공정을 통한 저온 실리콘 산화박막 성장

고천광,이원규,Ko, Cheon Kwang,Lee, Won Gyu 한국공업화학회 2008 공업화학 Vol.19 No.2

자외선 조사에 따른 광촉매 $TiO_2$의 표면에서 발생하는 활성산소종의 기상확산을 이용하여 실리콘기판 위에 산화박막을 성장시켰다. 자외선의 세기, 기판의 온도와 반응기 내의 산소 압력을 공정변수로 한 결과, 일정두께의 실리콘 산화박막의 성장이 자외선의 세기가 증가할수록 빨랐으며, 자외선램프의 세기를 60 W BLB 램프에서 1 kW 고압수은 랩프로 변경할 경우 성장속도가 8배 정도 빨라졌다. 반응기 내의 압력이 증가할수록 실리콘 산화박막의 성장속도는 느렸다. 대부분 산화박막의 성장은 $20{\AA}$에서 포화되었으며, 자외선의 세기가 증가할수록 포화상태까지 도달시간이 빨라졌다. 성장된 산화박막을 열처리를 통하여 전형적인 열산화막의 물성에 도달할 수 있었다. 광활성 산소종의 기상확산은 실리콘 산화박막의 저온 형성에 대한 광촉매 활용이라는 새로운 산화공정 방법으로 사용이 가능함을 확인할 수 있었다. The possibility of silicon oxidation through the aerial-diffusion of active oxygen species has been evaluated. The species originate from the surface of $TiO_2$ exposed by UV. Among process parameters such as UV intensity, substrate temperature and chamber pressure with oxygen, UV intensity was a major parameter to the influence on the oxide growth rate. When 1 kW high pressure Hg lamp was used as a UV source, the growth rate of silicon oxide was 8 times as faster as that of a 60 W BLB lamp. However, as the chamber pressure increased, the growth rate was declined due to the suppression of aerial diffusion of active oxygen species. According to the results, it could be confirmed that the aerial-diffusion of active oxygen species from UV-irradiated photocatalytic surface can be applied to a new method for preparing an ultra-thin silicon oxide at the range of relatively low temperature.

영상 기반 3차원 점군과 FUSION S/W 기반의 임분고 분석 모듈 개발

김경민 ( Kyoung-min Kim ) 한국지리정보학회 2016 한국지리정보학회지 Vol.19 No.4

최근 임상도의 신규 속성으로 임분의 평균 수고인 임분고를 추가하기 시작하였으나 전국 940만개의 포인트를 스테레오 항공사진에서 수동 측정해야 하는 어려움이 예상된다. 아울러, 항공사진에서 수고 측정 시 임연부나 묘지 주변의 수고를 측정하기 쉬워 임분 대표성이 떨어지는 한계를 가지고 있다. 본 연구에서는 고해상도 스테레오 항공사진에서 추출한 영상 기반 3차원 점군과 FUSIONS/W를 활용한 임분고 추정 방법을 제안하고 임분고를 자동 분석할 수 있는 모듈을 개발하였다. 스테레오 항공사진에서 수치표면모델 3차원 점군을 추출한 후 지면점 필터링을 거쳐 수치지면모델을 추출하고 이 두 모델을 차분하여 정규수치표면모델을 제작하였다. 정규수치표면모델에서 표본점별 개체목 수관을 육안판독한 후 수관별 최고점을 추출하여 정규수치표면모델 수고를 산출하였다. 표본점에서의 실측 수고와 정규수치표면모델 수고의 RMSE를 분석한 결과 전체 표본점 평균 수고의 RMSE는 0.96m로 나타났다. 대상지 전체의 개체목 수고를 추출하기 위해 FUSION S/W를 이용하여 항공사진의 정규수치표면모델에서 개체목 수고를 자동 추출하고 이를 임상도의 임분 폴리곤 단위로 평균하여 최종 임분고를 산출하였다. 마지막으로 임분고를 보다 손쉽게 분석할 수 있는 환경을 구현하기 위해 임분고 분석 프로세스를 ArcGIS add-in 모듈 형태로 자동화하였다. Recently mean stand height has been added as new attribute to forest type maps, but it is often too costly and time consuming to manually measure 9,100,000 points from countrywide stereo aerial photos. In addition, tree heights are frequently measured around tombs and forest edges, which are poor representations of the interior tree stand. This work proposes an estimation of mean stand height using an image-based point cloud, which was extracted from stereo aerial photo with FUSION S/W. Then, a digital terrain model was created by filtering the DSM point cloud and subtracting the DTM from DSM, resulting in nDSM, which represents object heights (buildings, trees, etc.). The RMSE was calculated to compare differences in tree heights between those observed and extracted from the nDSM. The resulting RMSE of average total plot height was 0.96 m. Individual tree heights of the whole study site area were extracted using the USDA Forest Service`s FUSION S/W. Finally, mean stand height was produced by averaging individual tree heights in a stand polygon of the forest type map. In order to automate the mean stand height extraction using photogrammetric methods, a module was developed as an ArcGIS add-in toolbox.

고정밀 가상환경 기반 Photo-realistic 영상 획득 군집 드론 임무 계획 시뮬레이션

최의환(Uihwan Choi),양정기(Jeonggi Yang),김인준(Kim In Jun),이수전(Soojeon Lee) 한국항공우주학회 2022 한국항공우주학회 학술발표회 논문집 Vol.2022 No.11

내성천의 하도변화 분석 -영주댐 건설 이전(1970∼2011)-

김용전 ( Yong Jeon Kim ),이찬주 ( Chan Joo Lee ) 한국지형학회 2014 한국지형학회지 Vol.21 No.1

하도 변화는 지형학의 주요 주제로써 외국에서는 다양한 관점 및 시간적 범위에서 연구가 진행되어 왔으나, 우리나라에서는 가용한 자료가 제한된 관계로 상대적으로 연구가 부족한 실정이다. 하지만 산업화 및 국토 개발, 산림 조성 등 하천에 다양한 변화가 초래되어 왔음을 고려할 때 하도 변화에 대한 연구가 수행될 수 있는 여건이 조성되었으므로 가용한 자료를 최대한 사용하여 하도 변화를 분석하고자 하였다. 대상 하천은 내성천으로 최근 4대강 사업 이후로 영주댐이 건설되고 있는 하천이며, 댐 건설로 인해 야기될 수 있는 부정적인 하도의 변화를 우려하여 사회적 이슈가 되고 있으므로 이에 대한 과학적인 조사가 필요한 실정이다. 이러한 배경에서 본 연구에서는 내성천에 대한 장기적 변화를 분석하기 위해 하상재료 조사, 항공사진 분석,측량자료 등을 이용하여 내성천의 변화 양상을 분석하였고, 그 결과 내성천의 하상재료는 과거에 비해 뚜렷한 변화를 보이지 않았으나, 하류인 국가하천 구간에서 저수로의 유로가 축소되고, 식생 피복 면적이 증가하였으며, 최심 하상은 저하되어 단면의 고저차가 증대됨과 동시에 하중도가 많이 생겨 하폭이 감소한 것으로 나타났다. Channel change is one of the main themes of fluvial geomorphology. Foreign previous studies have made under this theme from different temporal views. In contrast, few domestic studies were made due to limitation of data. By using the available data, channel change along the Naesung river was investigated, which might be caused by national development in industry and watershed change during last four decades. Recently, the Naesung river have been a matter of public concern due to anticipated negative channel change after Youngju dam impoundment. Thus, objective and scientific research should be made. On this background, this study was conducted. Change in riverbed material and channel forms planform, longitudinal and cross-sectional morphology were analyzed. Transition in land surface cover along the river was also examined using the aerial photos. Alteration was mainly focused along the downstream reach of the Naesung river. Main channel was generally narrowed with vegetation encroachment. Riverbed was lowered both in the downstream and upstream reaches. Channel width.

항공 LiDAR측량을 이용한 동아대학교 위치정보 분석

이재원,김용석,이동민 東亞大學校 建設技術硏究所 2008 硏究論文集 Vol.31 No.2

This study : An analysis of position accuracy of topography according to using LiDAR data, aerial photo and digital map for a study area was conducted. The study area was selected in Hadan area, Sahagu, Busan aerial LiDAR data and aerial photo in the scales of 1:20,000, which are high tech surveying ways were used. The final digital orthoimage according to orientation process for each image and image resampling was produced. Using it, a checkpoint was chosen, information about the checkpoints selected was extracted, a coordinate of Horizontal Position through the screen digitizing was also extracted. Both the coordinates of LiDAR data and aerial photo using digital map in the scales of 1 : 20,000 announced to the public from NGII(National Geographic Information Institute) were gradually compared and analyzed. Based on the digital map, as a result of being both compared and analyzed, it has shown to us that horizontal position of aerial photo is more accurate than that of aerial LiDAR surveying.