Ecology and Resilient Infrastructure

Korean Society of Ecology and Infrastructure Engineering (응용생태공학회)
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Analysis of Surface Image Velocity Field without Ground Control Points using Drone Navigation Information

드론의 비행정보를 이용한 지상표정점 없는 표면유속장 분석

  • Yu, Kwonkyu (Department of Civil Engineering, Dong-eui University) ;
  • Lee, Junhyeong (Department of Civil and Environmental Engineering, Myong-ji University)
  • 류권규 (동의대학교 토목공학과) ;
  • 이준형 (명지대학교 토목환경공학과)
  • Received : 2022.09.01
  • Accepted : 2022.09.16
  • Published : 2022.09.30
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Abstract

In this study, a technique for estimating water surface velocity fields in the Universal Transverse Mercator coordinate system using the GPS information of a propagating drone but not ground control points is developed. First, we determine the image direction in which the upper side of an image is directed based on the navigation information of the drone. Subsequently, we assign the start and end frames of the video used and determine the analysis range. Using these two frames, we segment the measurement cross-section into a few subsections at regular intervals. At these subsections, we analyze 30 frame images to create spatio-temporal volumes for calculating the velocity fields. The results of the developed method (propagating drone surface image velocimetry) are compared with those of the existing method (hovering drone surface image velocimetry), and relatively good agreement is indicated between both in terms of the velocity fields.

지상표정점을 이용하지 않고도 동영상에 기록된 위치정보 (GPS 자료)만을 이용하여 드론으로 촬영한 동영상에서 절대위치의 유속을 산정할 수 있는 방법을 개발하였다. 이 방법은 드론 동영상에서 있는 GPS 정보를 이용하여 드론의 이동방향과 영상이 향하는 방향을 결정하고, 각 영상점을 물리적인 전역좌표계 (UTM 좌표계)로 변환하였다. 그 다음 시작프레임과 종료프레임을 지정하여 분석할 동영상의 범위를 결정하였다. 지정된 두 프레임의 정보를 이용하여 측정횡단면을 일정간격의 기준프레임 (측정소단면)으로 나누었다. 그리고, 각 측정소단면에서 1초간 영상 (30 프레임)을 모아서 시공간체적을 구성한 뒤 유속을 분석한다. 이렇게 개발된 방법을 기존의 정지비행드론을 이용한 동영상분석법과 비교한 결과 상당히 양호한 결과를 보였다.

Keywords

Acknowledgement

본 결과물은 환경부의 재원으로 한국환경산업기술원 수생태계 건강성 확보 기술개발사업 (2020003050002)의 지원을 받아 연구되었습니다.

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