낙동강 하구 신자도 해빈 퇴적물의 시·공간적인 변화

김백운,김부근,이상룡 한국해양환경·에너지학회 2012 한국해양환경공학회 학술대회논문집 Vol.2012 No.5

사진측정법을 이용한 해빈단면의 추정

김백운,박용안,오임상,김부근,최경식,Kim, Baeck-Oon,Park, Yong-Ahn,Oh, Im-Sang,Khim, Boo-Keun,Choi, Kyung-Sik 한국해양학회 1998 바다 Vol.3 No.4

본 연구는 비측량용 사진기를 이용한 근거리 사진측정법을 적용하여 해빈단면을 추정하는 방법을 제시한다. 수평면 위에 고정된 비디오로부터 획득한 경사비디오영상을 해석하는 방법을 기초로 다음 두 가지 관점을 고려하여 경사사진 해석에 적합한 방정식을 유도하였다. (1) 사진기가 광축에 대하여 회전되는 것을 허용하였다. (2) 정확도를 향상시키기 위하여 렌즈왜곡을 비롯한 사진 계통상의 오차를 보정하는 단순한 오차모형을 도입하였다. 수정된 방정식을 검증하기 위하여 1998년 2월에 동해시 해빈에서 사진촬영과 정밀한 수준측량을 수행하였다. 그 결과 근거리 사진측정을 통한 해빈단면 추정값과 실제 측량값 사이의 수직거리에 대한 RMS 오차는 10 cm 이내였다. This study presents a close-range photogrammetry that is applicable to beach profile estimation using a non-metric camera. Based on the analysis of oblique video image in which the video camera was installed on a horizontal plane and the field of view was fixed, a new equation to analyze a photograph was developed considering the following aspects: (1) camera is allowed to be rotated about its optical axis and (2) a simple error model is adopted to correct lens distortion and other systematic errors associated with the non-metric camera, which improves accuracy of non-metric imageries. To test the modified technique, photographs of the beach were taken near the Donghae City in February, 1998. In addition, beach profiles were surveyed with conventional dumpy level and surveying staff. RMS error between the estimated and measured beach profiles is less than 10 cm in elevation.

동해안 군사시설보호구역 주변 향호 연안역을 대상으로 무인항공사진측량에 관한 예비 연구

김백운,윤공현,장태수,박장준,김성필 한국해양과학기술원 2017 Ocean and Polar Research Vol.39 No.2

To evaluate the accuracy of UAV photogrammetry for Hyangho coast, eastern coast of Korea, we conducted a field experiment wherein UAV photogrammetry test was repeated three times. Since the Haygho coast is located within a military reservation zone, it was necessary to obtain permission to gain access to the beach and to have sensitive aerial photographs showing military facilities inspected and cropped. The standard deviation of the UAV shooting position between the three tests was less than 1 m, but repeatability of footprint on the ground was low due to wind-driven variability of the UAV pose. Selfcalibrating bundle adjustment(SCBA) of implementing non-metric camera calibration was failed in one test. In two tests, the vertical error was twice as large as the pixel size except for those areas that were subject to security inspection and cropping. Given the problems that can arise with regard to the repeatability of the shooting area as well as the possibility of failure with regard to SCBA, we strongly recommend that UAV photogrammetry in coastal areas needs to be repeated at least twice.

서해 배타적경제수역(EEZ)내 해사채취구역의 지형변화

김백운,이상호,양재삼 한국지구과학회 2005 한국지구과학회지 Vol.26 No.8

Two data sets of repeated hydrographic surveys with a single beam echo-sounder were obtained to investigate morphological changes on a sand mining site within EEZ near the Eocheong Islands, West Sea of Korea. Their accuracies of depth measurement, estimated from the crossover analysis, correspond to the Oder 2 of IHO standards. Bathymetric maps show a feature of 300 m wide and 10 m deep hollow, whose evolution can be seen in difference grids of the two bathymetric maps. However, data of higher accuracy and resolution enable precise quantification of extracted sand volume. Since this morphological change could affect sedimentary environment as well as benthic ecology, environmental impact assessment based on scientific research data is required for management and sustainable development of limited sand resource. 서해배타적경제수역내해사채취구역에서해저지형변화를규명하기위하여 2회에걸쳐단일빔음향측심기를이용한측심자료를획득하였다. 교차점분석에의한측심자료의정확도는 IHO 표준의 2등급에해당하였다. 지형도는폭300 m, 깊이 10 m 의구덩이형태를나타내었으며, 이러한지형의변화과정이두지형도수심차의분포에서표현되었 다. 그러나해사채취량을정량화하기위해서는더욱정확하고정밀한자료가요구된다. 이러한지형변화는퇴적환경및저서생태환경에영향을미칠수있으므로한정된모래자원을관리하고지속가능한개발을위해서는과학적인조사자료에근거한환경영향평가가요구된다.

낙동강 하구 신자도 해빈 퇴적물의 시·공간적인 변화

김백운,김부근,이상룡 대한조선학회 2012 대한조선학회 학술대회자료집 Vol.2012 No.5

낙동강 하구 해안선변화 연구를 위한 모자이크 항공사진의 구축

김백운,김부근,이상룡 한국해양과학기술원 2005 Ocean and Polar Research Vol.27 No.4

This paper presents a method for obtaining mosaic aerial photographs that are useful for a long-term shoreline change study in the Nakdong estuary. Although this method involves digital photogrammetry software off the shelf, its usage can be simplified to accomodate the shoreline change study. Ground control points, which are common in aerial photographs, were measured from digital maps. Block triangulation was highly affected by land-based GCPs. Extension of tie points near the shoreline to vertical control points gave more reliable results for the block triangulation. A constant Digital Elevation Model (DEM), close to mean sea level, was employed to produce ortho-rectified photographs, from which mosaic photographs were made. Accuracy of photographs were found to be acceptable for the analysis of long-term shoreline change, and the promising construction of a shoreline change database in the Nakdong estuary.

Image Processing for Video Images of buoy motion

김백운,조홍연 한국해양과학기술원 2005 Ocean science journal Vol.40 No.4

In this paper, image processing technique that reduces video images of buoy motion to yield time series of image coordinates of buoy objects will be investigated. The buoy motion images are noisy due to time-varying brightness as well as non-uniform background illumination. The occurrence of boats, wakes, and wind-induced white caps interferes significantly in recognition of buoy objects. Thus, semi-automated procedures consisting of object recognition and image measurement aspects will be conducted. These offer more satisfactory results than a manual process. Spectral analysis shows that the image coordinates of buoy objects represent wave motion well, indicating its usefulness in the analysis of wave characteristics.

The Use of Elevation Adjusted Ground Control Points for Aerial Triangulation in Coastal Areas

김백운,윤공현,이창경 대한토목학회 2014 KSCE JOURNAL OF CIVIL ENGINEERING Vol.18 No.6

A method to improve the quality of aerial triangulation for photographs in coastal areas is proposed. Uneven distribution of groundcontrol points and tie points due to the presence of sea water causes the aerial triangulation to produce a systematic error, which isrepresented by elevation difference of ground control points between stereo model surface and real topography. Compensation of theelevation difference is given to the ground control points with which the following triangulation corrects exterior orientationparameters so as to match stereo model surface to real topography. An experimental study using historical photographs for beachenvironment, GPS surveys of ground control points and independent check points demonstrates that the proposed method givesRMSE of the elevation difference less than 0.1 m.

낙동강 하구역 진우도 해빈의 춘추계 표층퇴적물 조직변수의 변화

김부근(Khim, Boo-Keun),김백운(Kim, Baeck-Oon),이상룡(Lee, Sang-Ryong) 한국해안해양공학회 2009 한국해안해양공학회 논문집 Vol.21 No.6

진우도 해빈에서 2005년 11월과 2006년 5월의 2회에 걸쳐서 표층퇴적물을 채취하여 퇴적물의 조직변수를 분석하였다. 2005년 11월에 비하여 2006년 5월에는 진우도 서쪽 해빈의 최빈값은 3.0?(i.e., 0.125 mm)로 변화가 거의 없었으나, 동쪽 해빈에서는 최빈값3.0?(i.e., 0.125 mm)의 함량이 대폭 감소하고 2.5?(i.e., 0.177 mm)가 절대적으로 우세한 조립화 경향이 발생하였다. 마찬가지로 표층퇴적물 평균 입도는 서쪽 해빈에서는 두 조사의 차이가 거의 미약하지만, 동쪽 해빈의 평균입도는 증가되어 조립화된 특징을 반영한다. 이러한 조립화는 2006년 5월에 진우도의 동쪽 해빈의 표층퇴적물에서 상대적으로 양의 값으로 변화된 왜도 경향과 일치한다. 결과적으로 2005년 겨울을 지나면서 진우도의 표층퇴적물은 서쪽 해빈은 큰 변화를 보이지 않는 반면에 동쪽 해빈은 3.0?(i.e., 0.125 mm)의 세립 사질퇴적물이 제거되는 현저한 조립화 경향이 나타난 것이다. 이와 같은 변화는 낙동강 하구역에 하계동안 증가된 강수량과 낙동강 방출량 그리고 동계동안 우세한 파랑 그리고 조석의 영향 등이 복합적으로 작용하여 진우도 서쪽 해빈과 동쪽 해빈의 표층퇴적물에 영향을 주는 수리학적 조건과 퇴적물의 공급/제거가 다르기 때문이다. Textural parameters were calculated from the surface sediments collected from Jinu-do beach in Nov. 2005 and May 2006. In Nov. 2005 and May, 2006, the grain size distribution of surface sediments shows that the mode of 3.0?(i.e., 0.125 mm) dominated the west beach of Jinu-do, but in the east beach the mode of 3.0?(i.e., 0.125 mm) decreased and the mode of 2.5?(i.e., 0.177 mm) was apparently distinct, resulting in the more coarsening trend. Mean grain size of surface sediments also indicates little difference in the west beach between two investigations, but the increasing difference between mean grain sizes in the east beach, showing more coarsening pattern. Such seasonal pattern corresponds to the positive skewness in the east beach in May, 2006. As a result, after the winter in 2005, the surface sediments in the west beach of Jinu-do experienced a little variation, whereas the apparent coarsening of surface sediments occurred in the east beach by removal of 3.0?(i.e., 0.125 mm) fine-grained sand particles. The observed seasonal change may be attributed to the different hydrographic condition and sediment delivery/removal on the surface sediments between the west beach and the east beach of Jinu-do through the increased precipitation and more freshwater discharge from the Nakdong River during the summer and the intensified wave and tide during the winter in the Nakdong River estuary.

안면도의 면적 변화와 연안침식지역 해안선의 속성 분포

김백운(Kim, Baeck-Oon) 한국해안해양공학회 2010 한국해안해양공학회 논문집 Vol.22 No.3

1910년대에 제작된 지형도와 2003년에 구축된 해안선 조사측량 DB를 비교하여 안면도의 해안선 길이 및 면적 변화와 해안선의 속성 분포를 산정하였다. 안면도의 해안선은 수많은 간척사업으로 단순화되어 58%정도 감소하였으나, 면적은 36%정도 증가하였다. 2003년에 자갈 해안선의 분포가 가장 우세하였다. 방조제 해안선의 길이도 전체 해안선의 33%에 달하였다. 자갈 해안선은 안면도 동측 해안에, 모래 해안선은 안면도 서측 해안에 주로 분포하는 것으로 나타났다. 이러한 해안선 속성을 연안침식지역에 적용하기 위해서는 정확한 과거의 해안선이 요구되는 바, 1910년대에 제작된 지형도는 이러한 목적에는 적합하지 않은 것으로 판단되었다. Changes in coastline length and land area as well as coastline attribute distribution in Anmyondo were quantified by comparing topographic map produced in 1910's with coastline survey database compiled in 2003. Numerous reclamation has simplified complicated coastline, which resulted in reducing coastline length by 58% but increasing land area by 36%. In 2003, gravel coastline was mostly dominated. Coastline of tidal barrier also reached up to 33% of overall coastline. Gravel coastline occurred dominantly at the eastern side of Anmyondo, whereas sand coastline at the western side. An application of coastline attribute to coastal erosion zone required accurate coastline data, but it was conceived that the topographic map produced in 1910's was not useful for this purpose.