scholarly journals Method for Estimating Optimal Position of S-Band Relay Station through Path Loss Analysis in an Outdoor Environment

2020 ◽  
Vol 10 (17) ◽  
pp. 6089
Author(s):  
Doyoung Jang ◽  
Sungsik Wang ◽  
Chun Won Kim ◽  
Yong Bae Park ◽  
Hosung Choo
Keyword(s):  
Complex Terrain ◽  
Estimation Method ◽  
Path Loss ◽  
Outdoor Environment ◽  
Relay Station ◽  
Optimal Position ◽  
Loss Analysis ◽  
Optimum Position ◽  
Outdoor Environments ◽  
Main Station

This article investigates a novel estimation method to optimize the position of a relay station of the S-band telemetry system in outdoor environments. To determine an optimal relay station position, complex terrain surface and buildings near the Naro Space Center are included in the EM (Electromagnetic) simulation. The optimal relay station position is then determined using the estimation method by comparing the path losses from the rocket to the main station and some candidate positions of the relay station. To better understand the path loss, the ray analysis is also conducted, and the result demonstrates that once the rocket altitude to be covered by the relay station is determined, it is possible to find the optimum position of the relay station.

scholarly journals Analysis of Heuristic Uniform Theory of Diffraction Coefficients for Electromagnetic Scattering Prediction

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Diego Tami ◽  
Cássio G. Rego ◽  
Dinael Guevara ◽  
Andrés Navarro ◽  
Fernando J. S. Moreira ◽  
...  
Keyword(s):  
Mobile Networks ◽  
Electromagnetic Scattering ◽  
Reference Model ◽  
Path Loss ◽  
Absolute Error ◽  
Propagation Model ◽  
Outdoor Environment ◽  
Model Based ◽  
Uniform Theory Of Diffraction ◽  
Outdoor Environments

We discuss three sets of heuristic coefficients used in uniform theory of diffraction (UTD) to characterize the electromagnetic scattering in realistic urban scenarios and canonical examples of diffraction by lossy conducting wedges using the three sets of heuristic coefficients and the Malyuzhinets solution as reference model. We compare not only the results of the canonical models but also their implementation in real outdoor scenarios. To predict the coverage of mobile networks, we used propagation models for outdoor environments by using a 3D ray-tracing model based on a brute-force algorithm for ray launching and a propagation model based on image theory. To evaluate each set of coefficients, we analyzed the mean and standard deviation of the absolute error between estimates and measured data in Ottawa, Canada; Valencia, Spain; and Cali, Colombia. Finally, we discuss the path loss prediction for each set of heuristic UTD coefficients in outdoor environment, as well as the comparison with the canonical results.

Path Loss Model in Crowded Outdoor Environments Considering Multiple Human Body Shadowing of Multipath at 4.7GHz and 26.4GHz

2019 ◽  
Vol E102.B (8) ◽  
pp. 1676-1688 ◽  
Author(s):  
Mitsuki NAKAMURA ◽  
Motoharu SASAKI ◽  
Wataru YAMADA ◽  
Naoki KITA ◽  
Takeshi ONIZAWA ◽  
...  
Keyword(s):  
Human Body ◽  
Path Loss ◽  
Loss Model ◽  
Path Loss Model ◽  
Outdoor Environments

scholarly journals Determination of emergency roads to emergency accommodation using loss analysis results

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Sajad Ganjehi ◽  
Khadijeh Norouzi Khatiri
Keyword(s):  
Estimation Method ◽  
Emergency Evacuation ◽  
Influential Factors ◽  
Urban Crisis ◽  
Time Duration ◽  
Loss Analysis ◽  
Expert Choice ◽  
Data Layers ◽  
Temporary Accommodation

AbstractTeh present study aims to identify proper places to build temporary accommodation for people and accessible roads using damage analysis results during a probable earthquake. Teh HAZUS damage estimation method, which is one of teh most common ones currently used in teh world, was used in dis study. Teh influential factors in locating teh temporary accommodation in Shiraz were studied by using damage results, AHP model, and Expert Choice software. Then, map for temporary accommodation was prepared. By integrating layers, teh ultimate map of optimal locating for temporary accommodation was presented. Subsequently, all teh parameters influencing teh safety of emergency evacuation and relief network were identified and teh impact rate of each one was determined based on experts’ opinions through AHP. Based on teh importance of each index, roads were weighed and coded. Then, teh optimal safe road for relief and emergency evacuation was proposed. Teh results suggested dat relief roads are different based on different indices and teh optimal road was obtained through overlapping teh data layers according to teh importance of each parameter. dis optimal road could provide maximum services in teh minimum time duration and subsequently create capacity building in urban crisis management.

The Green Building Environment of the Gymnasium

2018 ◽  
Vol 878 ◽  
pp. 202-209 ◽  
Author(s):  
Feng Qian ◽  
Li Yang
Keyword(s):  
Natural Ventilation ◽  
Residential Buildings ◽  
Green Building ◽  
Residential Area ◽  
Simulation Software ◽  
Living Environment ◽  
Outdoor Environment ◽  
Residential Areas ◽  
Outdoor Environments ◽  
Area Planning

The natural ventilation of residential areas has placed more and more emphasis on residential area planning, according to the relationship between natural ventilation environments and the layout of architecture, we can reduce the energy consumption and the adverse effect of wind outdoors, improve the living environment and quality of life, making harmony between human and the nature. In this paper, we use Air-Pak to simulate the wind environment of residential areas. Through analyzing and simulating the air field which forms when the wind blows around the residential buildings by Air-Pak, we explain the advantage of the combination of computer simulation software and residential area planning. And we give some advice to the layout of the outdoor environment early in the residential planning area by the simulation of outdoor environments of buildings.

scholarly journals MEASUREMENTSBASEDEVALUATION OF PATHLOSSEXPONENTS IN URBAN OUTDOORENVIRONMENTS

2021 ◽  
Vol 9 (03) ◽  
pp. 72-79
Author(s):  
Akohoule Alex ◽  
◽  
Bamba Aliou ◽  
Kamagate Aladji ◽  
Konate Adama ◽  
...  
Keyword(s):  
Mobile Networks ◽  
Average Power ◽  
Path Loss ◽  
Wireless Channel ◽  
Propagation Model ◽  
Strong Impact ◽  
Efficient Design ◽  
Path Loss Exponent ◽  
Outdoor Environments ◽  
The Impact

In wireless networks, propagation models are used to assess the received power signal and estimate the propagation channel. These models depend on the pathloss exponent (PLE) which is one of the main parameters to characterize the propagation environment. Indeed, in the wireless channel, the path loss exponent has a strong impact on the quality of the links and must therefore be estimated with precision for an efficient design and operation of the wireless network. This paper addresses the issue of path loss exponents estimation for mobile networks in four outdoor environments. This study is based on measurements carried out in four outdoor environments at the frequency of 2600 MHz within a bandwidth of 70 MHz. It evaluates the path loss exponent, and the impact of obstacles present in the environments. The parameters of the propagation model determined from the measurements show that the average power of the received signal decreases logarithmically with the distance. We obtained path loss exponents values of 4.8, 3.53, 3.6 and 3.99 for the site 1, site 2, site 3 and site 4, respectively. Clearly the density of the obstacles has an impact on the path loss exponents and our study shows that the received signal decrease faster as the transmitter and receiver separation in the dense environments.

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