scholarly journals Evaluating anthropogenic noise impacts on animals in natural areas

2017 ◽  
Author(s):  
Alexander C. Keyel ◽  
Sarah E. Reed ◽  
Kathryn Nuessly ◽  
Elizeth Cinto-Mejia ◽  
Jesse R. Barber ◽  
...  
Keyword(s):  
Animal Species ◽  
Sound Propagation ◽  
Propagation Model ◽  
Anthropogenic Noise ◽  
Natural Areas ◽  
Noise Sources ◽  
Modeling Tools ◽  
Propagation Models ◽  
Model Predictions ◽  
Noise Impacts

SummaryNoise pollution is detrimental to a diversity of animal species and degrades natural areas, raising concern over the expanding footprint of anthropogenic noise on ecosystems. To guide management of noise sources, modeling tools have been developed to quantify noise levels across landscapes.We demonstrate how to model anthropogenic noise using sound propagation models, including noise from point, line, and polygon sources. In addition, we demonstrate three ways of evaluating spatially-explicit noise impacts, by identifying where noise 1) exceeds a sound level threshold, 2) is audible, or 3) has the potential to mask species communications. Finally, we examine approaches to mitigate these noise impacts on animal species.Noise sources in locations more favorable to sound propagation (e.g., locations with long, unobstructed lines-of-sight) will have a disproportionate impact on the surrounding area. We demonstrate how propagation models can identify sites with smaller acoustic footprints or sites that would benefit from additional noise-control measures.Modeling decisions, such as choice of sound propagation model, sound source information, and the quality of the input data, strongly influence the accuracy of model predictions. These decisions can be guided by comparing model predictions to empirical data when it is available.Synthesis and applications: Here, we demonstrate an approach for modeling and assessing anthropogenic noise sources across a landscape. Our versatile approach allows refining propagation outputs for species-specific questions as well as the quantitative evaluation of management alternatives. While the results are presented in the context of particular species, these approaches can be applied more generally to a wide range of taxa or used for multispecies assessments.

Shipping Noise Predictions: Capabilities and Limitations

2003 ◽  
Vol 37 (4) ◽  
pp. 54-65 ◽  
Author(s):  
Richard M. Heitmeyer ◽  
Stephen C. Wales ◽  
Lisa A. Pflug
Keyword(s):  
Deep Water ◽  
Ambient Noise ◽  
Classical Model ◽  
Propagation Model ◽  
Environmental Data ◽  
Noise Model ◽  
Propagation Models ◽  
Littoral Region ◽  
Model Predictions ◽  
Noise Models

This paper addresses shortcomings in the ability to predict either current levels of the ambient noise generated by shipping or future trends in those levels that might result from changes in the world's shipping fleet. In particular, experimental evidence is presented that predictions of increases in the sound generated by the world's ships based on increases in their speeds and lengths are not justified. This is because, contrary to the classical model of shipping source levels (Ross, 1976), there is a negligible correlation between the source levels of an ensemble of ships and the speeds and lengths of those ships. We also present two examples of noise model predictions that result in large errors. The first shows that two state-of-the-art noise models can yield significantly different noise predictions (5 dB) for the same deep-water, open ocean site. About two dB of this difference is attributed to an approximation inherent in the acoustic propagation model of one of the noise models that is acceptable in some deep-water regions, but not in others. The remaining discrepancy is attributed to differences in the acoustic environmental databases (sound speeds, bathymetries, and geo-acoustic models) between the two noise models. The second example shows that neglecting the local shipping component in a littoral region near a port can result in a noise prediction that is over 15 dB less than a measured value. Taken together, these examples indicate that large errors can result because of inappropriate propagation models or incomplete or inaccurate shipping and environmental data bases. [Work supported by ONR.]

scholarly journals Modeling anthropogenic noise impacts on animals in natural areas

2018 ◽  
Vol 180 ◽  
pp. 76-84 ◽  
Author(s):  
Alexander C. Keyel ◽  
Sarah E. Reed ◽  
Kathryn Nuessly ◽  
Elizeth Cinto-Mejia ◽  
Jesse R. Barber ◽  
...  
Keyword(s):  
Anthropogenic Noise ◽  
Natural Areas ◽  
Noise Impacts

Radio Propagation Models: A Performance Analysis based Impact of Sparse and Dense Deployment of Nodes under Different Propagation Models in Mobile Ad-hoc Networks (MANETs)

2021 ◽  
Author(s):  
Altaf Hussain ◽  
Muhammad Rafiq Khan
Keyword(s):  
Ad Hoc Networks ◽  
Ad Hoc ◽  
Mobile Ad Hoc Network ◽  
Signal Strength ◽  
Propagation Model ◽  
Strong Impact ◽  
Propagation Models ◽  
Mobile Ad Hoc ◽  
Hoc Networks ◽  
The Impact

Abstract Mobile Ad-hoc Network (MANET) is the most emerging and fast expanding technology since the last two decades. One of the major issue and challenging area in MANET is the process of routing due to dynamic topologies and high mobility of mobile nodes. The exchange of information from source to a destination is known as the process of routing. Spectacular amount of attention has been paid by researchers to reliable routing in ad-hoc networks. Efficiency and accuracy of a protocol depends on many parameters in these networks. In addition to other parameters node velocity and propagation models are among them. Calculating signal strength at receiver is the responsibility of a propagation model while mobility of nodes is responsible for topology of the network. A huge amount of loss in performance is occurred due to variation of signal strength at receiver and obstacles between transmissions. Simulation tools are developed to analyze the weakness and strength of protocols along with different parameters that may impact the performance. The choice of a propagation models have an abundant effect on performance on routing protocols in MANET. In this research, it has been analyzed to check the impact of different propagation models on the performance of Optimized Link State Routing (OLSR) in Sparse and Dense scenarios in MANET. The simulation has been carried out in NS-2 by using performance metrics as average Throughput, average packet drop and average latency. The results predicted that propagation models and mobility has a strong impact on the performance of OLSR in considered scenarios.

scholarly journals INVESTIGATION ON NEED FOR SPECIFIC PROPAGATION MODEL FOR SPECIFIC ENVIRONMENT BASED ON DIFFERENT TERRAIN CHARACTERISTICS

2018 ◽  
Vol 19 (2) ◽  
pp. 90-104
Author(s):  
Jide Julius Popoola ◽  
Akinlolu Adediran Ponnle ◽  
Yekeen Olajide Olasoji ◽  
Samson Adenle Oyetunji
Keyword(s):  
Performance Evaluation ◽  
Field Strength ◽  
Measurement Data ◽  
Propagation Model ◽  
Propagation Loss ◽  
Detailed Knowledge ◽  
Propagation Models ◽  
Radio Stations ◽  
Service Environments ◽  
Terrain Characteristics

ABSTRACT: Owing to their speed of excution as well as their limited reliance on detailed knowledge of the terrain characteristics of the service environments, empirical propagation models have enjoyed general acceptability in the wireless communication research community. However, recent industrial observations show that no single propagation model can best fit all the radio service environments, which led to the hypothesis of specific models for specific environments. In order to scientifically verify this hypothesis, the study presented in this paper investigated the performance of the free space propagation loss (FSPL) model in two different radio environments characterised with different types of obstructions. The investigation was conducted through field strength distribution measurement of two broadcasting radio stations transmitting at 96.5 MHz and 102.3 MHz. The field strength measurement data obtained were analysed. The result of the analysis shows gross disparity between the measured path losses and calculated path losses using FSPL model. The disparity thus necessitates the modification of the FSPL model in order to develop each propagation model for each of the two radio stations employed and their environment. The developed models were then evaluated to ascertain their performances relative to the FSPL model. The performance evaluation results show that the predictions of the developed propagation models vary for each of the two environments. Furthermore, the comparative performance evaluation result of the developed models with similar studies in the literature shows that the developed models perform favourably. The overall result from the developed models confirms the hypothesis that each location requires a specific propagation model for proper radio wave design and quality of signal transmission and reception. ABSTRAK: Kelebihan yang ada pada kelajuan perlaksanaannya dan juga kurang pergantungannya pada butiran terperinci ciri-ciri khusus bentuk rupa bumi di persekitaran servisnya, model penyebaran empirik telah diterima umum dalam komuniti kajian komunikasi tanpa wayar. Walau bagaimanapun, pemerhatian industri terkini menunjukkan tidak ada sebarang model penyebaran yang sesuai bagi semua keadaan servis radio, ini menghala kepada hipotesis keperluan model tertentu pada keadaan servis tertentu. Bagi menentusahkan secara saintifik hipotesis ini, kajian yang dibentangkan dalam kertas ini mengkaji tentang prestasi model kehilangan penyebaran pada ruang bebas (FSPL) dalam dua persekitaran radio berlainan melalui beberapa jenis halangan berbeza. Kajian telah dijalankan ke atas dua stesen radio penyiaran pada frekuensi 96.5 MHz dan 102.3 MHz melalui ukuran sebaran ruang keupayaan. Data ukuran ruang keupayaan telah diperoleh dan dianalisa. Keputusan analisis menunjukkan keputusan tidak seragam yang melampau antara ukuran kehilangan laluan dan pada kiraan model FSPL. Ketidaksamaan ini memungkinkan keperluan mengubah model FSPL bagi membangunkan model penyebaran pada setiap dua radio stesen yang digunakan dan persekitarannya. Model yang dibangunkan ini kemudiannya dinilai bagi mengesahkan prestasinya dengan model FSPL. Keputusan penilaian menunjukkan perbezaan pada jangkaan model penyebaran bagi setiap dua keadaan. Tambahan, keputusan perbandingan model yang dibangunkan dalam karya ini adalah serupa seperti kajian lain yang berkaitan. Secara keseluruhannya model yang dibangunkan ini mengesahkan hipotesis bahawa setiap lokasi memerlukan model penyebaran bagi rekaan gelombang radio yang sesuai dan juga kualiti signal penyebaran dan penerimaan.

Flow-dependent modeling of acoustic propagation based on DG-FEM method

2021 ◽  
Author(s):  
Zichen Wang ◽  
Jian Xu ◽  
Xuefeng Zhang ◽  
Can Lu ◽  
Kangkang Jin ◽  
...  
Keyword(s):  
Sound Propagation ◽  
Transmission Loss ◽  
Acoustic Propagation ◽  
Water Area ◽  
Current Speed ◽  
Propagation Model ◽  
Propagation Loss ◽  
Two Dimensional ◽  
Underwater Sound ◽  
Ocean Environment

AbstractThis paper proposes a two-dimensional underwater sound propagation model using the Discontinuous Galerkin Finite Element Method (DG-FEM) to investigate the influence of current on sound propagation. The acoustic field is calculated by the convected wave equation with the current speed parameter. Based on the current speed data from an assimilation model, a two-dimensional coupled acoustic propagation model in the Fram Strait water area is established to observe the variability in propagation loss under different seasonal velocities in the real ocean environment. The transmission loss and signal time structure are examined. The results obtained in different source frequencies are also compared. It appears that the current velocity, time and range variation all have an effect on underwater sound propagation.

scholarly journals Propagation Model in Indoor and Outdoor for the LTE Communications

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Sun-Kuk Noh ◽  
DongYou Choi
Keyword(s):  
Mobile Communication ◽  
Mobile Communications ◽  
Communication Systems ◽  
Large Scale ◽  
Propagation Model ◽  
Time Rate ◽  
Propagation Models ◽  
5G Mobile Communication ◽  
Time Changes ◽  
Indoor And Outdoor

Rapidly rising demand for radio communication and the explosion in the number of mobile communications service subscribers have led to the need for optimization in the development of fifth-generation (5G) mobile communication systems. Previous studies on the development of propagation models considering a propagation environment in the existing microwave band have been mainly focused on analyzing the propagation characteristics with regard to large-scale factors such as path losses, delay propagation, and angle diffusions. In this paper, we investigated the concept of spatial and time changes ratios in the measurement of wave propagations and measured RSRP of Long Term Evolution (LTE) signals at three locations considering the time rate of 1% and 50%. We confirmed the concept of spatial and time changes rate based on the results of analyzing the signal data measured and proposed the propagation models 1 and 2 in microcell downtown. The forecast results using proposed models 1 and 2 were better than the COST231 model in both indoor and outdoor measured places. It was predicted between a time rate of 1% and 50% indoor within 400m and outdoor within 200m. In the future, we will study the propagation model of 5G mobile communication as well as the current 4G communication using artificial intelligence technology.

Sign in / Sign up

Export Citation Format

Share Document