A study on the effect of scattering properties of marine particles on underwater optical wireless communication channel characteristics
01 Jun 2017-pp 1-7
TL;DR: In this paper, the channel characteristics of an underwater optical wireless communication (UOWC) system are sensitive to angular scattering properties of marine particles (i.e., shape of the phase function), especially in the forward angles (0°-90°).
Abstract: Numerical simulations using a more sophisticated Monte-Carlo technique show that the channel characteristics of an underwater optical wireless communication (UOWC) system are sensitive to angular scattering properties of marine particles (i.e., shape of the phase function), especially in the forward angles (0°–90°). Results of this study include power budget and channel impulse response estimated using different phase functions (Petzold, OTHG, TTHG and SS) and other optical parameters for the cases of harbor waters. Comparison of these results establishes the importance of using an accurate phase function in channel modeling of UOWC systems. Furthermore, comparison with the model based on Beer's law establishes the advantage of considering the finite probability of receiving scattered photons at the receiver end. Our finding reveals that estimation of power loss considering extinction coefficient as in Beer's law severely underestimates the received power, leading to shorter communication range especially in turbid harbor waters.
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01 Apr 1994
TL;DR: In this paper, seven models for computing underwater radiances and irradiances by numerical solution of the radiative transfer equation are compared and applied to the solution of several problems drawn from optical oceanography.
Abstract: Seven models for computing underwater radiances and irradiances by numerical solution of the radiative transfer equation are compared. The models are applied to the solution of several problems drawn from optical oceanography. The problems include highly absorbing and highly scattering waters, scattering by molecules and by particulates, stratified water, atmospheric effects, surface-wave effects, bottom effects, and Raman scattering. The models provide consistent output, with errors (resulting from Monte Carlo statistical fluctuations) in computed irradiances that are seldom larger, and are usually smaller, than the experimental errors made in measuring irradiances when using current oceanographic instrumentation. Computed radiances display somewhat larger errors.
418 citations
TL;DR: The paper is aimed at those who want to undertake studies on UOWC and offers an overview on the current technologies and those potentially available soon, especially on the use of single-photon receivers.
Abstract: Underwater Optical Wireless Communication (UOWC) is not a new idea, but it has recently attracted renewed interest since seawater presents a reduced absorption window for blue-green light. Due to its higher bandwidth, underwater optical wireless communications can support higher data rates at low latency levels compared to acoustic and RF counterparts. The paper is aimed at those who want to undertake studies on UOWC. It offers an overview on the current technologies and those potentially available soon. Particular attention has been given to offering a recent bibliography, especially on the use of single-photon receivers.
140 citations
TL;DR: A method based on a combination of Mie scattering theory and Monte Carlo numerical simulation is used to establish the transmission model of underwater photons and results indicate that the optical coefficients of particles increase with increasing particle size.
Abstract: The complex problem related to the transmission channel of underwater polarized lasers is caused by underwater suspended particles. In order to study the effect of suspended particles on underwater optical communication links and laser polarization characteristics, a method based on a combination of Mie scattering theory and Monte Carlo numerical simulation is used to establish the transmission model of underwater photons. This method is applied to analyze the effect of suspended particles on normalized received energy and channel delay. We also investigate the effects of particle and channel length on the polarization characteristics of four different types of polarized lasers. Theoretical analysis and simulation results indicate that the optical coefficients of particles increase with increasing particle size. Thus, when the transmission channel length is the same, the received normalized energy and light intensity will decrease, and the channel time delay will increase. Meanwhile, a depolarization phenomenon with respect to the laser will be generated with increasing particle size, and particle size has a greater effect on linearly polarized light than circularly polarized light. Therefore, circularly polarized light maintains good polarization characteristics in the underwater laser transmission process.
14 citations
03 Dec 2018
TL;DR: This work proposes a dual-hop UOWC system in which the transmitter-receiver link is assisted by several amplify-and-forward relay nodes, and investigates the impact of key system and particle distribution parameters such as the transmit power, the number of relays, and the spatial position of the attenuation spread on the performance.
Abstract: Underwater optical wireless communication (UOWC) systems are subject to severe performance degradation due to undissolved particles that make the water turbid. The point source diffusion of a substance in water creates a Gaussian-distributed attenuation spread for a given time instance, which makes communication challenging. To overcome this issue, we propose a dual-hop UOWC system in which the transmitter-receiver link is assisted by several amplify-and-forward relay nodes. To characterize the performance gains of this relay system, we study the bit error rate assuming on-off keying modulation. We investigate the impact of key system and particle distribution parameters such as the transmit power, the number of relays, and the spatial position of the attenuation spread on the performance.
10 citations
Cites background from "A study on the effect of scattering..."
...Current literature describes several phase functions such as the Petzold average-particle phase function, Fournier-Forand phase function, one-term Henyey-Greenstein (OTHG) phase function, and Haltrin’s two-term Henyey-Greenstein (TTHG) phase function as applicable to underwater environments [11, 12, 16]....
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01 Jan 2020
TL;DR: In this article, the effects of air-sea interface, bubble and particulate scattering, and medium inhomogeneity on the underwater light field distribution, downwelling irradiance (Ed) was carried out theoretically using Monte Carlo numerical simulation technique.
Abstract: A study of the effects of air–sea interface, bubble and particulate scattering, and medium inhomogeneity on the underwater light field distribution, downwelling irradiance (Ed) was carried out theoretically using Monte Carlo numerical simulation technique. The downwelling irradiance was computed for different scenarios (with and without waves and bubble effects) and compared with the in situ measured values. The wave effect was included according to a model given by Cox and Munk and the effect of bubble was included by estimating the Bidirectional Transmittance Distribution Function (BTDF) of a bubble layer. Furthermore, the effect of the variation of particulate concentration along the vertically downward direction on downwelling irradiance was studied by stratifying the underwater medium, instead of considering homogeneous water column, for the calculation of Ed. The findings showed the importance of considering the air–sea interface (wave and bubble) effects and stratification in estimating the underwater light field distribution and thereby the channel characteristics of an Underwater Wireless Optical Communication (UWOC) system. In particular, the present study can be helpful to researchers and engineers in modelling the effects of air–sea interface, bubble scattering and particulate scattering on the power budget, channel impulse response and signal-to-noise ratio (SNR) of a vertical communication link between aerial and underwater platforms.
4 citations
References
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01 Jan 1940
TL;DR: In this paper, it was shown that the observed intensity of the diffuse light may be explained as scattered radiation if the phase function governing the scattering of starlight by the interstellar matter is strongly forward-throwing.
Abstract: Observations have been obtained to verify the existence of diffuse interstellar radiation. A Fabry photometer, attached to the 40-inch refractor at the Yerkes Observatory, was used to measure the the brightness of regions over a wide range of galactic latitude. The intensities in the photographic region of the spectrum were calibrated by means of the Polar Sequence stars. The mean of four such runs across the Milky Way, on circles of constant latitude $\ell = 40^{\rm{o}}$, shows a maximum brightness of 80 stars of the tenth magnitude per square degree for the diffuse extra-terrestrial radiation. The mean of three runs near $\ell = 140^{\rm{o}}$ shows a maximum of 35 in the same units. It is shown that the observed intensity of the diffuse light may be explained as scattered radiation if the phase function governing the scattering of starlight by the interstellar matter is strongly forward-throwing. The concentration of the diffuse light toward the galactic circle is also in agreement with this property of the phase function. The observations also indicate that the scattering efficiency, or albedo, of the particles is greater than 0.3.
2,498 citations
"A study on the effect of scattering..." refers methods in this paper
...Two Term Henyey-Greenstein phase function The inadequacy of OTHG phase function to estimate scattering at near forward angles (< 20º) and far backward angles (>150º) led to another phase function, given by Haltrin, as weighted sum of two OTHG phase functions [11]....
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...[11] V. I. Haltrin, “One-parameter two-term Henyey-Greenstein phase function for light scattering in seawater,” Appl....
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...[9] L. C. Henyey and J. L. Greenstein, “Diffuse radiation in the galaxy,” The Astrophys....
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...One Term Henyey-Greenstein phase function Originally used for radiative transfer calculations in astrophysics and atmospheric physics, this is an empirical phase function proposed by Henyey and Greenstein [9]....
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...Originally used for radiative transfer calculations in astrophysics and atmospheric physics, this is an empirical phase function proposed by Henyey and Greenstein [9]....
[...]
TL;DR: In this article, it was shown that the observed intensity of the diffuse light may be explained as scattered radiation if the phase function governing the scattering of starlight by the interstellar matter is strongly forward-throwing.
Abstract: Observations have been obtained to verify the existence of diffuse interstellar radiation. A Fabry photometer, attached to the 40-inch refractor at the Yerkes Observatory, was used to measure the the brightness of regions over a wide range of galactic latitude. The intensities in the photographic region of the spectrum were calibrated by means of the Polar Sequence stars. The mean of four such runs across the Milky Way, on circles of constant latitude $\ell = 40^{\rm{o}}$, shows a maximum brightness of 80 stars of the tenth magnitude per square degree for the diffuse extra-terrestrial radiation. The mean of three runs near $\ell = 140^{\rm{o}}$ shows a maximum of 35 in the same units. It is shown that the observed intensity of the diffuse light may be explained as scattered radiation if the phase function governing the scattering of starlight by the interstellar matter is strongly forward-throwing. The concentration of the diffuse light toward the galactic circle is also in agreement with this property of the phase function. The observations also indicate that the scattering efficiency, or albedo, of the particles is greater than 0.3.
2,398 citations
Book•
27 May 1994
TL;DR: In this article, the authors present an invariant imbedding method to solve the RTE problem in the case of underwater light fields, and apply it to the problem of underwater light fields.
Abstract: Fundamentals: Radiometry. Photometry. Optical Properties of Water. Radiative Transfer: Across the Surface. Within the Water. Solutions Methods: Monte Carlo Methods. Invariant Imbedding Methods: Introduction. Invariant Imbedding Methods: Solving the RTE. Eigenmatrix Methods. Inverse Methods. Solutions: Underwater Light Fields. Epilogue. Chapter Problems. References.
2,027 citations
"A study on the effect of scattering..." refers background or methods in this paper
...Precisely, multiple scattering of photons underwater is determined by attenuation length (cz, with link distance z), scattering albedo and scattering phase function [6]....
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...The values of attenuation coefficients and albedo are chosen as per with Petzold’s measurement values [6]....
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01 Oct 1972
TL;DR: In this paper, volume scattering functions for three general types of natural ocean waters have been obtained and are presented and are used for beam transmission in laboratory experiments using sea water, filtered fresh water, and artificial scattering and absorbing agents.
Abstract: Volume scattering functions for three general types of natural ocean waters have been obtained and are presented here. The three types of water are (1) deep clear oceanic water, (2) nearshore ocean water, and (3) very turbid harbor water. Also included are the results of laboratory experiments using sea water, filtered fresh water, and artificial scattering and absorbing agents. The beam transmission was obtained for all waters investigated. A brief description of the instruments used is given.
787 citations
"A study on the effect of scattering..." refers background in this paper
...[7], is derived by taking the average of three phase functions, estimated from the measured VSF values for three water types, clear water, coastal water and harbor water by Petzold in 1972 at a wavelength of 530 nm [8]....
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01 Apr 1994
TL;DR: In this paper, seven models for computing underwater radiances and irradiances by numerical solution of the radiative transfer equation are compared and applied to the solution of several problems drawn from optical oceanography.
Abstract: Seven models for computing underwater radiances and irradiances by numerical solution of the radiative transfer equation are compared. The models are applied to the solution of several problems drawn from optical oceanography. The problems include highly absorbing and highly scattering waters, scattering by molecules and by particulates, stratified water, atmospheric effects, surface-wave effects, bottom effects, and Raman scattering. The models provide consistent output, with errors (resulting from Monte Carlo statistical fluctuations) in computed irradiances that are seldom larger, and are usually smaller, than the experimental errors made in measuring irradiances when using current oceanographic instrumentation. Computed radiances display somewhat larger errors.
418 citations