Analysis of Surface Image Velocity Field without Ground Control Points using Drone Navigation Information

Kwonkyu Yu; Junhyeong Lee

doi:10.17820/eri.2022.9.3.154

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2022 Vol.9, Issue 3 Preview Page Next Page

Original Article

Analysis of Surface Image Velocity Field without Ground Control Points using Drone Navigation Information 드론의 비행정보를 이용한 지상표정점 없는 표면유속장 분석

30 September 2022. pp. 154-162

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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.

Keywords

Drone

Ground control point

Spatio-temporal image

Surface image velocimetry

Video

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.

키워드

드론

지상표정점

시공간체적영상분석법

표면영상유속계

동영상

References

Bolognesi, M., Farina, G., Alvisi, S., Franchini, M., Pellegrinelli, A., and Russo, P. 2016. Measurement of surface velocity in open channels using a lightweight remotely piloted aircraft system, Geomatics, Natural Hazards and Risk, Talyor & Francis. 10.1080/19475705.2016.1184717

Fujita, I. 2013. Utilization of far-infrared-ray camera for image-based measurement of river flow and discharge. Nagare 32: 347-352. (in Japanese)

Kinoshita, R. 1967. An analysis of the movement of flood waters by aerial photography concerning characteristics of turbulence and surface flow, Journal of the Japan Society of Photogrammetry 6: 1-17. (in Japanese) 10.4287/jsprs1962.6.1

Kunida, Y., Fujita, I., and Tsubaki, R. 2009. "Analysis of flood using video images from a helicopter and shallow water equation based on unstructured grid system", Annual Journal of Hydraulic Engineering, Japan Society of Civil Engineers 53: 991-996. (in Japanese)

Lee, J.H., Yoon, B.M., and Kim, S.J. 2021. Development of surface velocity measurement techniques without reference points using UAV image. Ecology and Resilient Infrastructures 8: 22-31. (in Korean)

Liu, B. 2021. Development of techniques for measuring velocities of river surfaces using drone images and flight information. Ph.D. theis, Department of Civil Engineering, Dong-eui University. (in Korean)

Notoya, Y., Fujita, I., and Tateguchi, S. 2016. Image stabilization of video images shoot from air vehicles in navigation mode and its application to flood measurements. Journal of Japan Society of Civil Engineers, B1 (Water Resources Engineering) 72. I_877-I_882. (in Japanese) 10.2208/jscejhe.72.I_877

Takehara, K., Fujita, K., Takano, Y., Etoh, G., Aya, S., Tamai, M., Miyamoto, H., and Sakai, N. 2002. An attempt of field measurements of surface flow on a river by using a helicopter aided image velocimetry, Annual Journal of Hydraulic Engineering, Japan Society of Civil Engineers 46: 809-814. (in Japanese) 10.2208/prohe.46.809

Tauro, F., Petroselli, A., and Arcangeletti, E. 2016. Assessment of drone-based surface flow observations, Hydrological Processes 30: 1114-1130. 10.1002/hyp.10698

Yu, K. and Hwang, J.G. 2017. Measurement of surface velocity in open channels using cameras on a drone, Journal of Korean Society of Hazard Mitigation 17: 403-413. (in Korean) 10.9798/KOSHAM.2017.17.2.403

Yu, K. and Liu, B. 2021. Calculation of surface image velocity fields by analyzing spatio-temporal volumes with the fast Fourier transform. Journal of Korea Water Resources Association 54(11): 933-942. (in Korean)

Information

Publisher :Korean Society of Ecology and Infrastructure Engineering
Publisher(Ko) :응용생태공학회
Journal Title :Ecology and Resilient Infrastructure
Journal Title(Ko) :응용생태공학회 논문집
Volume : 9
No :3
Pages :154-162
Received Date : 2022-09-01
Revised Date : 2022-09-15
Accepted Date : 2022-09-16
DOI :https://doi.org/10.17820/eri.2022.9.3.154

Ecology and Resilient Infrastructure ISSN:2288-8527(Online) 응용생태공학회 논문집

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