Effects of multiple scattering, attenuation, and dispersion on fish population density imaging with ocean‐acoustic waveguide remote sensing.

2010 ◽  
Vol 128 (4) ◽  
pp. 2279-2279
Author(s):  
Mark Andrews ◽  
Zheng Gong ◽  
Purnima Ratilal
Keyword(s):  
Remote Sensing ◽  
Population Density ◽  
Multiple Scattering ◽  
Fish Population ◽  
Acoustic Waveguide ◽  
Scattering Attenuation ◽  
Attenuation And Dispersion

Population density imagery of migrating herring shoals by ocean acoustic waveguide remote sensing.

2009 ◽  
Vol 126 (4) ◽  
pp. 2231
Author(s):  
Zheng Gong ◽  
Mark Andrews ◽  
Duong Tran ◽  
Daniel Cocuzzo ◽  
Saumitro Dasgupta ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Population Density ◽  
Acoustic Waveguide

scholarly journals Quantification of Wide-Area Norwegian Spring-Spawning Herring Population Density with Ocean Acoustic Waveguide Remote Sensing (OAWRS)

2021 ◽  
Vol 13 (22) ◽  
pp. 4546
Author(s):  
Daniel Duane ◽  
Olav Rune Godø ◽  
Nicholas C. Makris
Keyword(s):  
Remote Sensing ◽  
Population Density ◽  
Scattering Theory ◽  
Wide Area ◽  
Propagation Path ◽  
Line Transect ◽  
Economic Resource ◽  
Nordic Seas ◽  
Acoustic Waveguide ◽  
Sensing Range

Norwegian spring-spawning herring are a critical economic resource for multiple nations in the North Atlantic and a keystone species of the Nordic Seas ecosystem. Given the wide areas that the herring occupy, it is difficult to accurately measure the population size and spatial distribution. Ocean Acoustic Waveguide Remote Sensing (OAWRS) was used to instantaneously measure the areal population density of Norwegian herring over more than one thousand square kilometers in spawning grounds near Ålesund, Norway. In the vicinity of the Ålesund trench near peak spawning, significant attenuation in signal-to-noise ratio and mean sensing range was observed after nautical sunset that had not been observed in previous OAWRS surveys in the Nordic Seas or in other regions. We show that this range-dependent decay along a given propagation path was caused by attenuation through dense herring shoals forming at sunset and persisting through the evening for transmissions near the swimbladder resonance peak. OAWRS transmissions are corrected for attenuation in a manner consistent with waveguide scattering theory and simultaneous downward directed local line-transect measurements in the region in order to produce instantaneous wide-area population density maps. Corresponding measured reductions in the median sensing range over the azimuth before ambient noise limitation are shown to be theoretically predictable from waveguide scattering theory and observed population densities. Spatial-temporal inhomogeneities in wide-area herring distributions seen synoptically in OAWRS imagery show that standard sparsely spaced line-transect surveys through this region during spawning can lead to large errors in the estimated population due to spatial and temporal undersampling.

Multiple scattering in the remote sensing of natural surfaces

1998 ◽  
Vol 19 (9) ◽  
pp. 1725-1740 ◽  
Author(s):  
W.-H. Li ◽  
R. Weeks ◽  
A. R. Gillespie
Keyword(s):  
Remote Sensing ◽  
Multiple Scattering

scholarly journals The Effect of Attenuation from Fish on Passive Detection of Sound Sources in Ocean Waveguide Environments

2021 ◽  
Vol 13 (21) ◽  
pp. 4369
Author(s):  
Daniel Duane ◽  
Chenyang Zhu ◽  
Felix Piavsky ◽  
Olav Rune Godø ◽  
Nicholas C. Makris
Keyword(s):  
Remote Sensing ◽  
Propagation Path ◽  
Experimental Measurements ◽  
Sound Sources ◽  
Detection Range ◽  
Acoustic Waveguide ◽  
Passive Sensing ◽  
Surface Vessels ◽  
Theoretical Predictions ◽  
Radiated Sound

Attenuation from fish can reduce the intensity of acoustic signals and significantly decrease detection range for long-range passive sensing of manmade vehicles, geophysical phenomena, and vocalizing marine life. The effect of attenuation from herring shoals on the Passive Ocean Acoustic Waveguide Remote Sensing (POAWRS) of surface vessels is investigated here, where concurrent wide-area active Ocean Acoustic Waveguide Remote Sensing (OAWRS) is used to confirm that herring shoals occluding the propagation path are responsible for measured reductions in ship radiated sound and corresponding detection losses. Reductions in the intensity of ship-radiated sound are predicted using a formulation for acoustic attenuation through inhomogeneities in an ocean waveguide that has been previously shown to be consistent with experimental measurements of attenuation from fish in active OAWRS transmissions. The predictions of the waveguide attenuation formulation are in agreement with measured reductions from attenuation, where the position, size, and population density of the fish groups are characterized using OAWRS imagery as well as in situ echosounder measurements of the specific shoals occluding the propagation path. Experimental measurements of attenuation presented here confirm previous theoretical predictions that common heuristic formulations employing free space scattering assumptions can be in significant error. Waveguide scattering and propagation theory is found to be necessary for accurate predictions.

scholarly journals APLIKASI PENGINDERAAN JAUH DAN SISTEM INFORMASI GEOGRAFI UNTUK PEMETAAN DAERAH BERPOTENSI TSUNAMI DI KABUPATEN KUPANG PROVINSI NUSA TENGGARA TIMUR

2018 ◽  
Vol 3 (2) ◽  
pp. 170-178
Author(s):  
Lidia Agustina Rumaal ◽  
Jehunias L. Tanesib ◽  
Jonshon Tarigan
Keyword(s):  
Remote Sensing ◽  
Information System ◽  
Geographic Information System ◽  
Population Density ◽  
Land Cover ◽  
Arrival Time ◽  
Land Cover Map ◽  
The Impact ◽  
Monitoring Area ◽  
Wave Arrival

Abstrak Telah dilakukan pemetaan daerah rawan tsunami berdasarkan estimasi waktu tiba gelombang dan tutupan lahan di Kabupaten Kupang Provinsi Nusa Tenggara Timur menggunakan aplikasi Penginderaan Jauh dan Sistem Informasi Geografi. Penelitian ini bertujuan untuk mengidentifikasi, memetakan daerah rawan tsunami dan tingkat kerawanannya menurut estimasi waktu tiba gelombang dan tutupan lahan sebagai upaya mitigasi dampak bencana tsunami terhadap kepadatan penduduk. Metode penelitian secara umum dibagi dalam empat tahap utama yaitu pembangunan basis data berupa pembuatan peta tutupan lahan, peta gempa dan peta batimetri. Analisis data kerawanan dari peta tutupan lahan dan etimasi waktu tiba gelombang, penyajian hasil data dalam bentuk tingkat kerawanan masing-masing peta dan analisis hasil penelitian berupa tingkat kerawanan secara kualitatif masing-masing daerah titik pantau menurut peta tutupan lahan maupun estimasi waktu tiba gelombang. Selain itu, dampak kerawanan tsunami diklasifikasikan menurut tingkat kepadatan penduduk untuk kebutuhan mitigasi sebagai berikut Kecamatan Kupang Timur, Kupang Barat, Sulamu, Amfoang Timur, Semau, Semau Selatan, Amfoang Utara, Amfoang Barat Daya, Amfoang Barat Laut dan Fatuleu Barat. Kata kunci : Peta rawan tsunami, Penginderaan Jauh, Sistem Informasi Geografi, Estimasi Waktu Tiba Gelombang  Abstract Mapping of hazard tsunami areas based on estimation of arrival time of wave and land cover in Kupang Regency of East Nusa Tenggara Province using remote sensing application and geographic information system has been done. The  aims of this research are to mapping the hazard tsunami area and tsunami vulnerability level in Kupang Regency East Nusa Tenggara according to the estimated arrival time of the wave and land cover as an effort to mitigate the impact of the tsunami disaster on population density. These generally devided into four main phase namely development of database in the form of land cover map , seismic maps and bathymetry maps, data analysis of research results in the form of qualitative vulnerability of each monitoring area according to land cover map and estimated wave arrival time. Presentation of data results in the form of vulnerability level of each map and analysis and results analysis of research the form of vulnerability level of each map and analysis of research results in the form of qualitative vulnerability of each monitoring area according to land cover map and estimated wave arrival time. And then, the impact of tsunami vulnerability is classified according to population density levels for mitigation needs as follows Kupang Timur, Kupang Barat, Sulamu, Amfoang Timur, Semau, Semau Selatan, Amfoang Utara, Amfoang Barat Daya, Amfoang Barat Laut and Fatuleu Barat. Keywords: Tsunami Hazard Map, Remote Sensing, Geographic Information System, Estimated Time of arrival Wave

scholarly journals Mapeamento dos Sistemas Ambientais do Município de Caucaia (CE) utilizando Sistema de Informação Geográfica (SIG): Subsídios para o Planejamento Territorial (Mapping of the Environmental Systems of the Municipality of Caucaia (CE) using Geographic...)

2015 ◽  
Vol 8 (1) ◽  
pp. 025
Author(s):  
Cleyber Nascimento de Medeiros ◽  
Marcos José Nogueira De Souza
Keyword(s):  
Remote Sensing ◽  
Population Density ◽  
Spatial Dynamics ◽  
Human Pressure ◽  
Organizational Conditions ◽  
Territorial Planning ◽  
Environmental Systems ◽  
De Se ◽  
High Population Growth ◽  
The City

Este trabalho objetivou analisar aspectos geoambientais de Caucaia, localizado no Estado do Ceará. O município vem apresentado nos últimos anos um elevado crescimento populacional, suscitando uma forte pressão sobre os recursos naturais, justificando assim a necessidade de se identificar as áreas mais e menos vulneráveis ambientalmente ao adensamento populacional, gerando com isto elementos para o planejamento territorial. Desse modo, procedeu-se a caracterização geoambiental criando os mapas de sistemas ambientais e de vulnerabilidade ambiental. Constatou-se que 21% do território têm alta vulnerabilidade à ocupação, sendo de 58% e 17%, respectivamente, os percentuais para os locais com média e baixa vulnerabilidade. Menciona-se que o planejamento territorial com base na compartimentação geoambiental surge como um importante delineador das condições organizacionais e da funcionalidade dos ambientes, tendo em vista que considera sempre suas características ambientais e sua dinâmica sócio-espacial de maneira integralizada.   A B S T R A C T   This study aimed to analyze geoenvironmental aspects of the city of Caucaia, located in the state of Ceará, Brazil. The municipality has presented in recent years a high population growth, raising a strong human pressure on natural resources, thus justifying the need to identify the most and least environmentally vulnerable areas to population density, generating elements for territorial planning. Thus, we proceeded to environmental characterization creating maps of environmental systems and environmental vulnerability Caucaia, scale 1:50,000, using, for both, the geosystemic theory and the use of remote sensing products, cartographic data and fieldwork. It was verified that 21% of the territory have high vulnerability to occupation, being 58% and 17%, respectively, the percentages for areas with medium and low vulnerability. It is mentioned that the territorial planning based on geoenvironmental compartmentation emerges as important eyeliner of the organizational conditions and functionality of environments, considering their environmental characteristics and socio-spatial dynamics in the integrated form. Keywords: Mapping of environmental systems, Territorial planning, Caucaia.  

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