Application of Cellular Communications Models and Designs for Use in Disaster-Aftermath Related Scenarios

2015 ◽  
Vol 7 (3) ◽  
pp. 46-56
Author(s):  
Stephen J. Curran
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Ground Level ◽  
Base Station ◽  
Cellular Communications ◽  
Fixed Position ◽  
Above Ground Level ◽  
High Altitude Platforms ◽  
Major Disaster ◽  
Future Strategy ◽  
Low Altitude

This paper is a pilot study on the concept of an aerial base station as a future strategy for restoring cellular communications in the aftermath of a major disaster. The strategy being studied makes use of low altitude platforms (LAPs) or unmanned aerial vehicles (UAVs) that can hover or orbit in a relatively fixed position and can act as an aerial base station. Unlike High Altitude Platforms (HAP) operating in a layer of the atmosphere above any existing air traffic, the LAPs or UAVs will be able to operate a few hundred to some thousands of meters above ground level. This paper also describes the functionality of the components comprising the aerial base station.

scholarly journals Vertical Measurement of Equivalent Black Carbon Concentration at Low Altitude

2020 ◽  
Vol 10 (15) ◽  
pp. 5142
Author(s):  
Jeonghoon Lee ◽  
Jiseung Park ◽  
Juhyung Kim
Keyword(s):  
Vertical Distribution ◽  
Black Carbon ◽  
Vertical Profile ◽  
Ground Level ◽  
Measurement Noise ◽  
Average Scheme ◽  
Above Ground Level ◽  
Low Altitude ◽  
Averaging Time ◽  
The Vertical Distribution

The vertical profile of equivalent black carbon (eBC) concentrations has been measured together with the temperature up to 130 m above ground level at several locations. A hexacopter was deployed for the measurement of eBC, and the temperature on typical days in winter, spring, summer and early autumn. We observed high eBC concentrations between 10 m and 90 m above ground level, which was related to the vertical distribution of temperature. We examined that the measurement noise could be reduced by using a box-average scheme. Furthermore, the negative values at low eBC concentration could be removed for an averaging time of 30 min or longer.

scholarly journals Use of Unmanned Aerial Vehicles (UAVs) for Updating Farmland Cadastral Data in Areas Subject to Landslides

2018 ◽  
Vol 7 (8) ◽  
pp. 331 ◽  
Author(s):  
Edyta Puniach ◽  
Agnieszka Bieda ◽  
Paweł Ćwiąkała ◽  
Anita Kwartnik-Pruc ◽  
Piotr Parzych
Keyword(s):  
Data Processing ◽  
Unmanned Aerial Vehicles ◽  
Ground Level ◽  
Control Points ◽  
Pixel Size ◽  
Ground Sample ◽  
Above Ground Level ◽  
Aerial Vehicles ◽  
Shooting Distance ◽  
Data Processing Methods

The purpose of this study was to verify the applicability of unmanned aerial vehicles (UAVs) to update cadastral records in areas affected by landslides. Its authors intended to compare the accuracy of coordinates determined using different UAV data processing methods for points which form the framework of a cadastral database, and to find out whether products obtained as a result of such UAV data processing are sufficient to define the extent of changes in the cadastral objects. To achieve this, an experiment was designed to take place at the site of a landslide. The entire photogrammetry mission was planned to cover an area of more than 70 ha. Given the steep grade of the site, the UAV was flown over each line at a different, individually preset altitude, such as to ensure consistent mean shooting distance (height above ground level), and thus, appropriate ground sample distance (GSD; pixel size). The results were analyzed in four variants, differing from each other in terms of the number of control points used and the method of their measurement. This allowed identification of the factors that affect surveying accuracy and the indication of the cadastral data updatable based on an UAV photogrammetric survey.

scholarly journals Spatial Analysis (Measurements at Heights of 10 m and 20 m above Ground Level) of the Concentrations of Particulate Matter (PM10, PM2.5, and PM1.0) and Gaseous Pollutants (H2S) on the University Campus: A Case Study

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 62
Author(s):  
Robert Cichowicz ◽  
Maciej Dobrzański
Keyword(s):  
Spatial Distribution ◽  
Hydrogen Sulfide ◽  
Particulate Matter ◽  
Air Quality ◽  
Spatial Analysis ◽  
Ground Level ◽  
Leeward Side ◽  
High Concentration ◽  
Above Ground Level ◽  
High Concentrations

Spatial analysis of the distribution of particulate matter PM10, PM2.5, PM1.0, and hydrogen sulfide (H2S) gas pollution was performed in the area around a university library building. The reasons for the subject matter were reports related to the perceptible odor characteristic of hydrogen sulfide and a general poor assessment of air quality by employees and students. Due to the area of analysis, it was decided to perform measurements at two heights, 10 m and 20 m above ground level, using measuring equipment attached to a DJI Matrice 600 unmanned aerial vehicle (UAV). The aim of the measurements was air quality assessment and investigate the convergence of the theory of air flow around the building with the spatial distribution of air pollutants. Considerable differences of up to 63% were observed in the concentrations of pollutants measured around the building, especially between opposite sides, depending on the direction of the wind. To explain these differences, the theory of aerodynamics was applied to visualize the probable airflow in the direction of the wind. A strong convergence was observed between the aerodynamic model and the spatial distribution of pollutants. This was evidenced by the high concentrations of dust in the areas of strong turbulence at the edges of the building and on the leeward side. The accumulation of pollutants was also clearly noticeable in these locations. A high concentration of H2S was recorded around the library building on the side of the car park. On the other hand, the air turbulence around the building dispersed the gas pollution, causing the concentration of H2S to drop on the leeward side. It was confirmed that in some analyzed areas the permissible concentration of H2S was exceeded.

scholarly journals Efficient Reactive Obstacle Avoidance Using Spirals for Escape

Drones ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 51
Author(s):  
Fábio Azevedo ◽  
Jaime S. Cardoso ◽  
André Ferreira ◽  
Tiago Fernandes ◽  
Miguel Moreira ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Mobile Robotics ◽  
Point Clouds ◽  
Depth Camera ◽  
Main Task ◽  
Robust Method ◽  
Aerial Vehicles ◽  
Correct Execution ◽  
Low Altitude ◽  
High Degree

The usage of unmanned aerial vehicles (UAV) has increased in recent years and new application scenarios have emerged. Some of them involve tasks that require a high degree of autonomy, leading to increasingly complex systems. In order for a robot to be autonomous, it requires appropriate perception sensors that interpret the environment and enable the correct execution of the main task of mobile robotics: navigation. In the case of UAVs, flying at low altitude greatly increases the probability of encountering obstacles, so they need a fast, simple, and robust method of collision avoidance. This work covers the problem of navigation in unknown scenarios by implementing a simple, yet robust, environment-reactive approach. The implementation is done with both CPU and GPU map representations to allow wider coverage of possible applications. This method searches for obstacles that cross a cylindrical safety volume, and selects an escape point from a spiral for avoiding the obstacle. The algorithm is able to successfully navigate in complex scenarios, using both a high and low-power computer, typically found aboard UAVs, relying only on a depth camera with a limited FOV and range. Depending on the configuration, the algorithm can process point clouds at nearly 40 Hz in Jetson Nano, while checking for threats at 10 kHz. Some preliminary tests were conducted with real-world scenarios, showing both the advantages and limitations of CPU and GPU-based methodologies.

scholarly journals A Climatology of Nocturnal Low-Level Jets at Cabauw

2009 ◽  
Vol 48 (8) ◽  
pp. 1627-1642 ◽  
Author(s):  
P. Baas ◽  
F. C. Bosveld ◽  
H. Klein Baltink ◽  
A. A. M. Holtslag
Keyword(s):  
Wind Speed ◽  
Ground Level ◽  
Geostrophic Wind ◽  
Stable Stratification ◽  
Radiative Cooling ◽  
Inertial Oscillation ◽  
Stable Boundary Layers ◽  
Above Ground Level ◽  
Low Level ◽  
Low Level Jets

Abstract A climatology of nocturnal low-level jets (LLJs) is presented for the topographically flat measurement site at Cabauw, the Netherlands. LLJ characteristics are derived from a 7-yr half-hourly database of wind speed profiles, obtained from the 200-m mast and a wind profiler. Many LLJs at Cabauw originate from an inertial oscillation, which develops after sunset in a layer decoupled from the surface by stable stratification. The data are classified to different types of stable boundary layers by using the geostrophic wind speed and the isothermal net radiative cooling as classification parameters. For each of these classes, LLJ characteristics like frequency of occurrence, height above ground level, and the turning of the wind vector across the boundary layer are determined. It is found that LLJs occur in about 20% of the nights, are typically situated at 140–260 m above ground level, and have a speed of 6–10 m s−1. Development of a substantial LLJ is most likely to occur for moderate geostrophic forcing and a high radiative cooling. A comparison with the 40-yr ECMWF Re-Analysis (ERA-40) is added to illustrate how the results can be used to evaluate the performance of atmospheric models.

HYGIENIC ASSESSMENT OF ELECTROMAGNETIC RADIATION LEVELS OF BASE STATIONS,INSTALLED ON THE ROOFS OF BUILDINGS AND THE TERRITORY OF LAND PLOTS IN TASHKENT

2021 ◽  
Vol 2 (5) ◽  
pp. 5-11
Author(s):  
G. A. Tashpulatova ◽  
◽  
A. N. Krasavin
Keyword(s):  
Public Health ◽  
Electromagnetic Radiation ◽  
Flux Density ◽  
Energy Flux ◽  
Mobile Communications ◽  
Base Station ◽  
Base Stations ◽  
Cellular Communications ◽  
Measurement Results ◽  
Energy Flux Density

This article is about instrumental measurements of the FR EMR energy flux density. The measurement results were analyzed with the division of the data obtained by the purpose of buildings and the height of the antenna equipment placement, a hygienic assessment of the RF EMR levels created by the equipment of base stations of cellular communications, installed on the roofs of residential and public buildings and adjacent territories of Tashkent is given. A proposal is made on the rational placement of radio engineering facilities.Keywords:electromagnetic field; electromagnetic safety; base station for mobile communications; protection of public health; sanitary supervision

scholarly journals Optimal Placement of Low-Altitude Aerial Base Station for Securing Communications

2019 ◽  
Vol 8 (3) ◽  
pp. 869-872 ◽  
Author(s):  
Dong Wang ◽  
Bo Bai ◽  
Guangzheng Zhang ◽  
Zhu Han
Keyword(s):  
Base Station ◽  
Optimal Placement ◽  
Low Altitude

scholarly journals Pruning intensity and amino acids tryptophan and glycine on growth and flowering of Jasminum sambac

2021 ◽  
Vol 27 (1) ◽  
pp. 20-25
Author(s):  
Ziyad Khalf Salih ◽  
Seyedeh Somayyeh Shafiei Masouleh ◽  
Mohamed Abdulla Ahmed ◽  
Marwan Abdulla Sanam
Keyword(s):  
Amino Acids ◽  
Essential Oil ◽  
Foliar Application ◽  
Ground Level ◽  
Growth And Yield ◽  
Reproductive Growth ◽  
Above Ground Level ◽  
Evergreen Shrub ◽  
Jasminum Sambac ◽  
Pruning Intensity

Abstract Jasmine (Jasminum sambac L.) is an evergreen shrub and very fragrant, which has a very importance in the perfume industry and its flowers are used in different religious and ceremonies. Training the shrubs for more yields of flowers and essential oil with horticultural improvement effects of pruning and amino acids may help gardeners to achieve more benefits. This study aimed to investigate the effects of pruning intensity (without pruning, 40, 60 or 75 cm above ground level) and foliar application of amino acids (without amino acids, tryptophan or glycine) on jasmine shrubs for promoting growth and reproductive growth and the content of essential oil. The results showed that plants with light pruning (75 cm) and foliar application of amino acids especially glycine had the best growth and yield, which means that plants were affected by the interactions of pruning level and application of amino acids.

scholarly journals A Dynamic Topology Construction Algorithm for Self-Organizing Wireless Sensor Networks

2021 ◽  
Author(s):  
Waltenegus Dargie
Keyword(s):  
Wireless Sensor Networks ◽  
Environmental Factors ◽  
Unmanned Aerial Vehicles ◽  
Base Station ◽  
Wireless Sensor ◽  
Topology Construction ◽  
Construction Algorithm ◽  
Aerial Vehicles ◽  
Dynamic Topology ◽  
Self Organizing

<div>Self-organizing protocols and algorithms require knowledge of the underlying topology of the network. The topology can be represented by a graph or an adjacency matrix. In most practical cases, establishing the topology prior to a deployment is not possible because the exact placement of nodes and the existence of a reliable link between any two individual nodes cannot guaranteed. Therefore, this task has to be carried out after deployment. If the network is stand-alone and certain aspects are fixed (such as the identity of the base station, the size of the network, etc.), the task is achievable. If, however, the network has to interact with other systems -- such as Unmanned Aerial Vehicles (UAVs) or mobile robots -- whose operation is affected by environmental factors, the task can be difficult to achieve. In this paper we propose a dynamic topology construction algorithm, assuming that the network is a part of a joint deployment and does not have a fixed based station.</div>

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