scholarly journals A Pilot Study to Estimate Forage Mass from Unmanned Aerial Vehicles in a Semi-Arid Rangeland

2020 ◽  
Vol 12 (15) ◽  
pp. 2431
Author(s):  
Alexandria M. DiMaggio ◽  
Humberto L. Perotto-Baldivieso ◽  
J. Alfonso Ortega-S. ◽  
Chase Walther ◽  
Karelys N. Labrador-Rodriguez ◽  
...  
Keyword(s):  
High Resolution ◽  
Unmanned Aerial Vehicles ◽  
Sampling Technique ◽  
Ground Level ◽  
South Texas ◽  
Lower Altitude ◽  
Aerial Vehicles ◽  
High Resolution Imagery ◽  
Non Destructive ◽  
Semi Arid

The application of unmanned aerial vehicles (UAVs) in the monitoring and management of rangelands has exponentially increased in recent years due to the miniaturization of sensors, ability to capture imagery with high spatial resolution, lower altitude platforms, and the ease of flying UAVs in remote environments. The aim of this research was to develop a method to estimate forage mass in rangelands using high-resolution imagery derived from the UAV using a South Texas pasture as a pilot site. The specific objectives of this research were to (1) evaluate the feasibility of quantifying forage mass in semi-arid rangelands using a double sampling technique with high-resolution imagery and (2) to compare the effect of altitude on forage mass estimation. Orthoimagery and digital surface models (DSM) with a resolution <1.5 cm were acquired with an UAV at altitudes of 30, 40, and 50 m above ground level (AGL) in Duval County, Texas. Field forage mass data were regressed on volumes obtained from a DSM. Our results show that volumes estimated with UAV data and forage mass as measured in the field have a significant relationship at all flight altitudes with best results at 30-m AGL (r2 = 0.65) and 50-m AGL (r2 = 0.63). Furthermore, the use of UAVs would allow one to collect a large number of samples using a non-destructive method to estimate available forage for grazing animals.

scholarly journals Mapping of land cover with open‐source software and ultra‐high‐resolution imagery acquired with unmanned aerial vehicles

2020 ◽  
Vol 6 (4) ◽  
pp. 487-497 ◽  
Author(s):  
Ned Horning ◽  
Erica Fleishman ◽  
Peter J. Ersts ◽  
Frank A. Fogarty ◽  
Martha Wohlfeil Zillig
Keyword(s):  
High Resolution ◽  
Land Cover ◽  
Unmanned Aerial Vehicles ◽  
Open Source ◽  
Open Source Software ◽  
Aerial Vehicles ◽  
High Resolution Imagery

scholarly journals Using Unmanned Aerial Vehicles (UAV) for mornitoring the construction progress of Ho Chi Minh City urban railway project

2015 ◽  
Vol 18 (2) ◽  
pp. 104-112
Author(s):  
Nhat Huu Nguyen ◽  
Tam Minh Dao ◽  
Trung Van Le ◽  
Chon Trung Le
Keyword(s):  
High Resolution ◽  
Unmanned Aerial Vehicles ◽  
Aerial Images ◽  
3D Objects ◽  
Ground Control Points ◽  
Aerial Vehicles ◽  
High Resolution Imagery ◽  
Gis Data ◽  
High Flexibility ◽  
Railway Construction Project

This paper describes a new approach for monitoring the construction progress of the Urban Railway Construction Project “Metro line1 - Ben Thanh - Suoi Tien” by using Unmanned Aerial Vehicles (UAV) to capture high resolution imagery at different stages of the project. The advantage of the AscTec Falcon 8 systems lies in their high flexibility and efficiency in capturing the surface of an area from a low flight altitude. In addition, further information such as orthoimages, elevation models and 3D objects can easily be processed by Pix4Dmapper software. The Ground Control Points (GCPs) and GIS data were used to compare the achieved accuracy of UAV method. This study shows the feasibility of using an UAV system for acquiring the high resolution aerial images and the new opportunities for managing construction progress over time.

Radiometric Quality Assessment of Video Sequences Acquired from UAV Photogrammetric Systems

2017 ◽  
Author(s):  
Damian Wierzbicki ◽  
Anna Fryskowska
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Video Stream ◽  
Video Data ◽  
Video Sequences ◽  
Wide Field ◽  
Sensing Applications ◽  
Aerial Vehicles ◽  
High Resolution Imagery ◽  
Low Altitude ◽  
Imagery Data

The issue of imagery data collection and its implementation in photogrammetric studies with the use of unmanned aerial vehicles is still valid and provides a wide field of research in the creation of new and expansion of existing solutions. It is particularly important to increase the accuracy of photogrammetric products. These days low altitude unmanned aerial vehicles are being used more and more often in photogrammetric applications. Compact digital cameras had acquired single, high-resolution imagery. Data obtained from low altitudes were often (and still are) used in mapping and 3D modelling. Due to the low costs of flights of UAV systems in comparison with traditional flights, applications of such platforms are also attractive for many remote sensing applications. However, due to the use of non-metric video cameras, one of the main problems when trying to automate the video data processing, is the video sequences’ relatively poor radiometric quality. The article addresses the issue of assessing the quality of the video imagery acquired from a low altitude UAV platform. The Authors presented quality Indicators dedicated to UAV video sequences. The method is based on the analysis of the video stream, obtained in the different weather and lighting conditions. As a result of the research, an objective quality index for video acquired from low altitudes was determined.

scholarly journals Suitability of Unmanned Aerial Vehicles for Cadastral Surveys

2019 ◽  
Vol 19 (1) ◽  
pp. 1-8
Author(s):  
S. Mantey
Keyword(s):  
High Resolution ◽  
Unmanned Aerial Vehicles ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Aerial Vehicles ◽  
High Resolution Images ◽  
The Difference ◽  
Cadastral Surveying ◽  
Difficult Terrain ◽  
Global Navigation Satellite

Cadastral surveys in Ghana often employ well known surveying equipment such as Total Station andGNSSreceivers or a combination of both. These survey techniques are well-established and widely accepted. However, there are limitations in certain areas. In situations where difficult terrain and inaccessible areas and dense vegetation are encountered or when surveyor’s life may be at risk, Unmanned Aerial Vehicles (UAVs) could be used to overcome the limitations of these well-established survey instruments. This research used high resolution images from UAV (DJI Phantom 4) to survey plots within the University of Mines and Technology land area. Coordinates of the boundary points were extracted using Agisoft Photoscan.GNSSreceivers were also used to survey the land and the same boundary point coordinates obtained and compared. This enabled the establishment of accurate ground control points for georeferencing. The coordinates obtained from both UAV andGNSSSurveys were used to prepare cadastral plans and compared. The difference in Northings and Eastings from UAV andGNSSsurveys were +0.380 cmand +0.351 cmrespectively. These differences are well within tolerance of +/-0.9114 m(+/-3 ft) set by the Survey and Mapping Division (SMD) of the Lands Commission for cadastral plans production. This research therefore concludes that high resolution images from UAVs are suitable for cadastral surveying. Keywords: Unmanned Aerial Vehicles, Drones, Global Navigation Satellite Systems, Cadastral Surveys

scholarly journals Operational Framework for Rapid, Very-high Resolution Mapping of Glacial Geomorphology Using Low-cost Unmanned Aerial Vehicles and Structure-from-Motion Approach

2019 ◽  
Vol 11 (1) ◽  
pp. 65 ◽  
Author(s):  
Marek W. Ewertowski ◽  
Aleksandra M. Tomczyk ◽  
David J. A. Evans ◽  
David H. Roberts ◽  
Wojciech Ewertowski
Keyword(s):  
High Resolution ◽  
Unmanned Aerial Vehicles ◽  
Structure From Motion ◽  
Low Cost ◽  
Control Point ◽  
Glacial Geomorphology ◽  
High Resolution Mapping ◽  
Aerial Vehicles ◽  
Resolution Mapping ◽  
Very High

This study presents the operational framework for rapid, very-high resolution mapping of glacial geomorphology, with the use of budget Unmanned Aerial Vehicles and a structure-from-motion approach. The proposed workflow comprises seven stages: (1) Preparation and selection of the appropriate platform; (2) transport; (3) preliminary on-site activities (including optional ground-control-point collection); (4) pre-flight setup and checks; (5) conducting the mission; (6) data processing; and (7) mapping and change detection. The application of the proposed framework has been illustrated by a mapping case study on the glacial foreland of Hørbyebreen, Svalbard, Norway. A consumer-grade quadcopter (DJI Phantom) was used to collect the data, while images were processed using the structure-from-motion approach. The resultant orthomosaic (1.9 cm ground sampling distance—GSD) and digital elevation model (7.9 cm GSD) were used to map the glacial-related landforms in detail. It demonstrated the applicability of the proposed framework to map and potentially monitor detailed changes in a rapidly evolving proglacial environment, using a low-cost approach. Its coverage of multiple aspects ensures that the proposed framework is universal and can be applied in a broader range of settings.

scholarly journals Autonomous Unmanned Aerial Vehicle (UAV) landing in windy conditions with MAP-Elites

2017 ◽  
Vol 32 ◽  
Author(s):  
Sierra A. Adibi ◽  
Scott Forer ◽  
Jeremy Fries ◽  
Logan Yliniemi
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Unmanned Aerial Vehicles ◽  
Ground Level ◽  
Weather Conditions ◽  
High Wind ◽  
Aerial Vehicles ◽  
Dangerous Situation ◽  
Vertical Speed ◽  
Aerial Vehicle

AbstractWith the recent increase in the use of Unmanned Aerial Vehicles (UAVs) comes a surge of inexperienced aviators who may not have the requisite skills to react appropriately if weather conditions quickly change while their aircraft are in flight. This creates a dangerous situation, in which the pilot cannot safely land the vehicle. In this work we examine the use of the MAP-Elites algorithm to search for sets of weights for use in an artificial neural network. This neural network directly controls the thrust and pitching torque of a simulated 3-degree of freedom (2 linear, 1 rotational) fixed-wing UAV, with the goal of obtaining a smooth landing profile. We then examine the use of the same algorithm in high-wind conditions, with gusts up to 30 knots.Our results show that MAP-Elites is an effective method for searching for control policies, and by evolving two separate controllers and switching which controller is active when the UAV is near-ground level, we can produce a wider variety of phenotypic behaviors. The best controllers achieved landing at a vertical speed of <1 m s−1 and at an angle of approach of <1° degree.

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