scholarly journals Spatial resolution of unmanned aerial vehicles acquired imagery as a result of different processing conditions

2021 ◽  
Vol 67 (3) ◽  
pp. 148-154
Author(s):  
Jaroslav Kubišta ◽  
Peter Surový
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Spatial Resolution ◽  
Light Condition ◽  
Weather Conditions ◽  
Flight Speed ◽  
Lighting Conditions ◽  
Aerial Vehicles ◽  
Flight Height ◽  
The Impact ◽  
Imagery Data

Abstract Increasing availability of Unmanned aerial vehicles (UAV) and different software for processing of UAV imagery data brings new possibilities for on-demand monitoring of environment, making it accessible to broader spectra of professionals with variable expertise in image processing and analysis. This brings also new questions related to imagery quality standards. One of important characteristics of imagery is its spatial resolution as it directly impacts the results of object recognition and further imagery processing. This study aims at identifying relationship between spatial resolution of UAV acquired imagery and variables of imagery acquiring conditions, especially UAV flight height, flight speed and lighting conditions. All of these characteristics has been proved as significantly influencing spatial resolution quality and all subsequent data based on this imagery. Higher flight height as well as flight speed brings lower spatial resolution, whereas better lighting conditions lead to better spatial resolution of imagery. In this article we conducted a study testing various heights, flight speeds and light conditions and tested the impact of these parameters on Ground Resolved Distance (GRD). We proved that from among the variables, height is the most significant factor, second position is speed and finally the light condition. All of these factors could be relevant for instance in implementation of UAV in forestry sector, where imagery data must be often collected in diverse terrain conditions and/or complex stand (especially vertical) structure, as well as different weather conditions.

scholarly journals Enhanced Particle Swarm Optimization for Path Planning of Unmanned Aerial Vehicles

2020 ◽  
Vol 14 (1) ◽  
pp. 67-78
Author(s):  
Kai Yit Kok ◽  
Parvathy Rajendran
Keyword(s):  
Particle Swarm Optimization ◽  
Path Planning ◽  
Unmanned Aerial Vehicles ◽  
Particle Swarm ◽  
Swarm Optimization ◽  
Aerial Vehicles ◽  
Trial And Error Method ◽  
The Impact ◽  
Enhanced Particle Swarm Optimization ◽  
Error Method

This paper presents an enhanced particle swarm optimization (PSO) for the path planning of unmanned aerial vehicles (UAVs). An evolutionary algorithm such as PSO is costly because every application requires different parameter settings to maximize the performance of the analyzed parameters. People generally use the trial-and-error method or refer to the recommended setting from general problems. The former is time consuming, while the latter is usually not the optimum setting for various specific applications. Hence, this study focuses on analyzing the impact of input parameters on the PSO performance in UAV path planning using various complex terrain maps with adequate repetitions to solve the tuning issue. Results show that inertial weight parameter is insignificant, and a 1.4 acceleration coefficient is optimum for UAV path planning. In addition, the population size between 40 and 60 seems to be the optimum setting based on the case studies.

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 Approaching birds with drones: first experiments and ethical guidelines

2015 ◽  
Vol 11 (2) ◽  
pp. 20140754 ◽  
Author(s):  
Elisabeth Vas ◽  
Amélie Lescroël ◽  
Olivier Duriez ◽  
Guillaume Boguszewski ◽  
David Grémillet
Keyword(s):  
Best Practices ◽  
Unmanned Aerial Vehicles ◽  
Ecological Research ◽  
Ethical Guidelines ◽  
Wetland Area ◽  
Physiological Indicators ◽  
Approach Distance ◽  
Aerial Vehicles ◽  
Approach Speed ◽  
The Impact

Unmanned aerial vehicles, commonly called drones, are being increasingly used in ecological research, in particular to approach sensitive wildlife in inaccessible areas. Impact studies leading to recommendations for best practices are urgently needed. We tested the impact of drone colour, speed and flight angle on the behavioural responses of mallards Anas platyrhynchos in a semi-captive situation, and of wild flamingos ( Phoenicopterus roseus ) and common greenshanks ( Tringa nebularia ) in a wetland area. We performed 204 approach flights with a quadricopter drone, and during 80% of those we could approach unaffected birds to within 4 m. Approach speed, drone colour and repeated flights had no measurable impact on bird behaviour, yet they reacted more to drones approaching vertically. We recommend launching drones farther than 100 m from the birds and adjusting approach distance according to species. Our study is a first step towards a sound use of drones for wildlife research. Further studies should assess the impacts of different drones on other taxa, and monitor physiological indicators of stress in animals exposed to drones according to group sizes and reproductive status.

scholarly journals The Wane of Command: Evidence on Drone Strikes and Control within Terrorist Organizations

2020 ◽  
pp. 1-20
Author(s):  
ANOUK S. RIGTERINK
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Natural Experiment ◽  
Terrorist Attacks ◽  
Terrorist Organizations ◽  
Aerial Vehicles ◽  
Terrorist Groups ◽  
Drone Strikes ◽  
And Control ◽  
The Impact ◽  
Better Than

This paper investigates how counterterrorism targeting terrorist leaders affects terrorist attacks. This effect is theoretically ambiguous and depends on whether terrorist groups are modeled as unitary actors or not. The paper exploits a natural experiment provided by strikes by Unmanned Aerial Vehicles (drones) “hitting” and “missing” terrorist leaders in Pakistan. Results suggest that terrorist groups increase the number of attacks they commit after a drone “hit” on their leader compared with after a “miss.” This increase is statistically significant for 3 out of 6 months after a hit, when it ranges between 47.7% and 70.3%. Additional analysis of heterogenous effects across groups and leaders, and the impact of drone hits on the type of attack, terrorist group infighting, and splintering, suggest that principal-agent problems—(new) terrorist leaders struggling to control and discipline their operatives—account for these results better than alternative theoretical explanations.

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.

Low Speed Aerodynamics of Drogue System Refueling of Unmanned Aerial Vehicles

2014 ◽  
Vol 1016 ◽  
pp. 349-353 ◽  
Author(s):  
Ian R. McAndrew ◽  
Elena Navarro ◽  
Orin Godsey
Keyword(s):  
Wind Tunnel ◽  
Unmanned Aerial Vehicles ◽  
Weather Conditions ◽  
Military Strategy ◽  
Wind Tunnel Experiments ◽  
Low Speed ◽  
Significant Aspect ◽  
Aerial Vehicles ◽  
Low Speeds

Refueling aircraft has become a significant aspect of military strategy for air forces to work at further distances from safe shores. This paper will address the aerodynamics of the drogue refueling system and in particular its characteristics at low speeds, including head and tail winds. Data from wind tunnel experiments are used to show how the docking when refueling is affected by the lower speeds, position behind the supply aircraft and weather conditions. Possibilities of design improvements and implications are related to the task of refueling Unmanned Aerial Vehicles in-flight

Unmanned Aerial Vehicles ‘in service’ of Internal Security of the State

2020 ◽  
Vol 12 (1) ◽  
pp. 195-210
Author(s):  
Renata Włodarczyk
Keyword(s):  
Unmanned Aerial Vehicles ◽  
New Technologies ◽  
Weather Conditions ◽  
The State ◽  
Police Academy ◽  
Internal Security ◽  
Aerial Vehicles ◽  
Native Soil ◽  
Adverse Weather ◽  
Training Courses

The study was created thanks to the author’s preferences to learn increasingly more about new technologies that are able to increase the potential of internal security of the state. Recently, interest in recording areas (difficult to access, dangerous, monitored in adverse weather conditions, monitored due to the implementation of tasks by relevant services), the development of methods enabling the transmission of various materials at a distance, and performing other complicated activities have increased. For this purpose, unmanned aerial vehicles (so-called drones, UAVs) that are versatile in many respects are used. The author noticed the need to disseminate such innovative devices on native soil, especially for using them in multidirectional strengthening of the security sphere. Polish companies producing UAVs for many foreign customers have already marked their presence in this matter. The achievements of the designers are so impressive that it makes us appreciate the development of our technical thought, and above all, the use of drones to ensure security and public order in Poland. A series of training courses is already conducted by the Police Academy in Szczytno, which is a good solution both for teachers and, above all, for the trainees themselves. Such an initiative will undoubtedly translate into increased interest in drones, and especially the incredible usefulness of these devices for uniformed services and other entities.

scholarly journals Modern means of assessing the impact of emergencies on the environmental condition of the ground layer of atmosphere

2021 ◽  
Vol 280 ◽  
pp. 09017
Author(s):  
Anastasiia Turevych ◽  
Svitlana Madzhd ◽  
Larysa Cherniak ◽  
Anatoliy Pavlyuk ◽  
Vincent Ojeh
Keyword(s):  
Air Quality ◽  
Unmanned Aerial Vehicles ◽  
Ecological Monitoring ◽  
Hazardous Substances ◽  
Operational Monitoring ◽  
Aerial Vehicles ◽  
Raising Awareness ◽  
Functional Scheme ◽  
Surrounding Areas ◽  
The Impact

The problem of emergencies will not leave humanity as long as it exists, and therefore it is necessary to at least create conditions under which it is possible to reduce the risks of injuries, diseases and deaths of people who are in the emergency zone. This can be achieved by raising awareness of the nature of the emergency, the hazardous substances that are released in connection with it. Theoretical analysis of various remote means of assessing the impact of emergencies of man-made areas on the ecological state of the atmospheric air of the surrounding areas. It has been found that the use of remote sensing equipment greatly simplifies the procedure of operational monitoring of the environment during emergencies, as well as contributes to the health of professionals. A comparison of different remote means of environmental monitoring of air quality was performed: In particular, stationary automatic stations, mobile automatic stations, probes, and unmanned aerial vehicles (UAVs) were compared. It is proposed to use UAVs as remote means of operational monitoring of air quality. The functional scheme of UAV system implementation for the needs of operative ecological monitoring is offered. The legal features of the use of unmanned aerial vehicles as remote means of monitoring air quality during emergencies are analyzed.

scholarly journals NEW MODEL OF A SOLAR WIND AIRPLANE FOR GEOMATIC OPERATIONS

2015 ◽  
Vol XL-1/W4 ◽  
pp. 137-142
Author(s):  
A. Achachi ◽  
D. Benatia
Keyword(s):  
Solar Wind ◽  
Law Enforcement ◽  
System Design ◽  
Unmanned Aerial Vehicles ◽  
Extended Period ◽  
Flight Crew ◽  
Aerial Vehicles ◽  
The Impact ◽  
Border Surveillance ◽  
New System

The ability for an aircraft to fly during a much extended period of time has become a key issue and a target of research, both in the domain of civilian aviation and unmanned aerial vehicles. This paper describes a new design and evaluating of solar wind aircraft with the objective to assess the impact of a new system design on overall flight crew performance. The required endurance is in the range of some hours in the case of law enforcement, border surveillance, forest fire fighting or power line inspection. However, other applications at high altitudes, such as geomatic operations for delivering geographic information, weather research and forecast, environmental monitoring, would require remaining airborne during days, weeks or even months. The design of GNSS non precision approach procedure for different airports is based on geomatic data.

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