A Study on the Characteristics of Depositional Landform Change in the Geum River Channel Using Unmanned Aerial Vehicle: Focusing on Before and After the Opening Gate of Gongju Weir

2021 ◽  
Vol 28 (4) ◽  
pp. 1-13
Author(s):  
Hye-Yeon Yoon ◽  
Kwang-Sung Yun ◽  
Dong-Ho Jang
Keyword(s):  
Unmanned Aerial Vehicle ◽  
River Channel ◽  
Before And After ◽  
Aerial Vehicle

scholarly journals Performance of an Unmanned Aerial Vehicle (UAV) in Calculating the Flood Peak Discharge of Ephemeral Rivers Combined with the Incipient Motion of Moving Stones in Arid Ungauged Regions

2020 ◽  
Vol 12 (10) ◽  
pp. 1610
Author(s):  
Shengtian Yang ◽  
Chaojun Li ◽  
Hezhen Lou ◽  
Pengfei Wang ◽  
Juan Wang ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Unmanned Aerial Vehicle ◽  
Poor Performance ◽  
River Channel ◽  
Peak Discharge ◽  
Incipient Motion ◽  
Distribution Method ◽  
Flood Peak ◽  
Ephemeral Rivers ◽  
Aerial Vehicle

Ephemeral rivers are vital to ecosystem balance and human activities as essential surface runoff, while convenient and effective ways of calculating the peak discharge of ephemeral rivers are scarce, especially in ungauged areas. In this study, a new method was proposed using an unmanned aerial vehicle (UAV) combined with the incipient motion of stones to calculate the peak discharge of ephemeral rivers in northwestern China, a typical arid ungauged region. Two field surveys were conducted in dry seasons of 2017 and 2018. Both the logarithmic and the exponential velocity distribution methods were examined when estimating critical initial velocities of moving stones. Results reveal that centimeter-level orthoimages derived from UAV data can demonstrate the movement of stones in the ephemeral river channel throughout one year. Validations with peak discharge through downstream culverts confirmed the effectiveness of the method. The exponential velocity distribution method performs better than the logarithmic method regardless of the amount of water through the two channels. The proposed method performs best in the combination of the exponential method and the river channel with evident flooding (>20 m3/s), with the relative accuracy within 10%. In contrast, in the river channel with a little flow (around 1 m3/s), the accuracies are weak because of the limited number of small moving stones found due to the current resolution of UAV data. The poor performance in the river channel with a little flow could further be improved by identifying smaller moving stones, especially using UAV data with better spatial resolution. The presented method is easy and flexible to apply with appropriate accuracy. It also has great potential for extensive applications in obtaining runoff information of ephemeral rivers in ungauged regions, especially with the quick advance of UAV technology.

scholarly journals Unmanned Aerial Vehicle Depth Inversion to Monitor River-Mouth Bar Dynamics

2021 ◽  
Vol 13 (3) ◽  
pp. 412
Author(s):  
Kana Hashimoto ◽  
Takenori Shimozono ◽  
Yoshinao Matsuba ◽  
Takumi Okabe
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Morphological Changes ◽  
Morphological Evolution ◽  
River Mouth ◽  
Weather Conditions ◽  
Estimation Algorithm ◽  
Inversion Method ◽  
Before And After ◽  
Aerial Vehicle ◽  
Mouth Bar

Monitoring the morphological evolution of a river-mouth bar is of both practical and scientific importance. A large amount of sediment is transported from a river to surrounding littoral cells via a deltaic bar after an extreme weather event. However, it is often not feasible to capture drastic morphological changes in the short term with conventional bathymetric surveys. This paper presents a depth-inversion method based on unmanned aerial vehicle technology to estimate two-dimensional bathymetry from video-sensed swell propagation. The estimation algorithm is tested over four cases with varying wave and bathymetric conditions and is validated with transect survey data. The test results suggest that the method can estimate deltaic-bar topography in front of a river mouth with a root-mean-square error of <0.5 m. The applicable range is limited by wave breaking in the inner bar and up to a depth of ~8 m, where swell intensity signals become ambiguous. A comparison of the different cases shows that the method works better under calm weather conditions with dominant swells propagating from non-local sources. Significant morphological changes of a river-mouth bar due to a powerful typhoon are successfully detected by observations right before and after the event.

Study on Fault Diagnosis of Planetary Gearbox in Unmanned Aerial Vehicle Using Multi sensor Data

2020 ◽  
Vol 20 (4) ◽  
pp. 332-342
Author(s):  
Hyung Jun Park ◽  
Seong Hee Cho ◽  
Kyung-Hwan Jang ◽  
Jin-Woon Seol ◽  
Byung-Gi Kwon ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Unmanned Aerial Vehicle ◽  
Sensor Data ◽  
Planetary Gearbox ◽  
Aerial Vehicle

Results of Spatial Structure of Atmosphere Radiation in a Spectral Range (1.5–2) µm Research

2018 ◽  
pp. 7-13
Author(s):  
Anton M. Mishchenko ◽  
Sergei S. Rachkovsky ◽  
Vladimir A. Smolin ◽  
Igor V . Yakimenko
Keyword(s):  
Spatial Structure ◽  
Unmanned Aerial Vehicle ◽  
Wavelength Range ◽  
Spectral Range ◽  
Near Ir ◽  
Optoelectronic Systems ◽  
Aerial Vehicle

Results of experimental studying radiation spatial structure of atmosphere background nonuniformities and of an unmanned aerial vehicle being the detection object are presented. The question on a possibility of its detection using optoelectronic systems against the background of a cloudy field in the near IR wavelength range is also considered.

Positioning the Angle of Attack Sensor on an Unmanned Aerial Vehicle Wing

2016 ◽  
Vol 3 (1) ◽  
pp. 25-33
Author(s):  
Amir Birjandi ◽  
◽  
Valentin Guerry ◽  
Eric Bibeau ◽  
Hamidreza Bolandhemmat ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Angle Of Attack ◽  
Aerial Vehicle

Multi-Disciplinary Design of High-RPM Electric Generator with External Rotor for Unmanned Aerial Vehicle

2016 ◽  
Vol 9 (4) ◽  
pp. 123
Author(s):  
Vyacheslav Vavilov ◽  
Flur Ismagilov ◽  
Irek Khayrullin ◽  
Ruslan Karimov
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Electric Generator ◽  
Aerial Vehicle ◽  
External Rotor
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