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1

Mineralogical analysis of iron ore using ultrasonic wave propagation parameters

Morkun Natalia, Fischerauer Gerhard, Tron Vitalii, Gaponenko Alona

Acta Mechanica et Automatica

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2023

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Vol. 17, no. 3

364--371

EN

Availability, relative simplicity and low cost, combined with ever-increasing capabilities, have led to a significant increase in the use of ultrasonic measurements of mining process variables in recent times. The scope of application varies from the study of the characteristics of raw materials and products of its processing to the operational assessment of the current parameters characterising the state of the process equipment. The purpose of this study is to develop methods for obtaining information about the characteristics of mineral raw materials as a result of ultrasonic logging of wells in a rock mass. The proposed approach makes it possible to improve the quality of information support for the management of technological processes of mining and processing of ore and thereby improve the quality of products supplied to the metallurgical stage and reduce overall production costs.

2

A Review on Feasible and Reliable Underwater Wireless Optical Communication System for achieving High Data Rate and Longer Transmission Distance

Joseph Lenin, Anandan Sangeetha

International Journal of Electronics and Telecommunications

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2022

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Vol. 68. No. 4

815--823

EN

Underwater Wireless Optical Communication (UWOC) offers significant research prospective with major challenges in the design and implementation. UWOC is capable of providing high rate of data transmission across large distances. This paper attempts to focus on the intricacies of practical implementations and open research issues of UWOC systems. Critical advances and progresses made in the field, modelling techniques and link design challenges are summarised. The purpose of this review is to give suggestions towards feasible and reliable UWOC design with improved performance. Finally the major points are summarized so that it will assist the future research in UWOC.

3

Remarks on damped Schrodinger equation of Choquard type

Chergui Lassaad

Opuscula Mathematica

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2021

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Vol. 41, no. 4

465--488

EN

This paper is devoted to the Schrodinger-Choquard equation with linear damping. Global existence and scattering are proved depending on the size of the damping coefficient.

4

Measurements of light transfer through drift ice and landfast ice in the northern Baltic Sea

Kari Elina, Jutila Arttu, Friedrichs Anna, Leppäranta Matti, Kratzer Susanne

Oceanologia

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2020

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No. 62 (3)

347--363

EN

The aim of this study was to investigate the light transfer through sea ice with a focus on bio-optical substances both in fast ice and in the drift ice zones in the northern Baltic Sea. The measurements included snow and ice structure, spectral irradiance and photosynthetically active radiation below the sea ice. We also measured the concentrations of the three main bio-optical substances which are chlorophyll-a, suspended particulate matter, and coloured dissolved organic matter (CDOM). These bio-optical substances were determined for melted ice samples and for the underlying sea water. The present study provides the first spectral light transfer data set for drift ice in the Baltic Sea. We found high CDOM absorption values typical to the Baltic Sea waters also within sea ice. Our results showed that the transmittance through bare ice was lower for the coastal fast ice than for the drift ice sites. Bio-optical substances, in particular CDOM, modified the spectral distribution of light penetrating through the ice cover. Differences in crystal structure and the amount of gas inclusions in the ice caused variation in the light transfer. Snow cover on ice was found to be the dominant factor influencing the light field under ice, confirming previous studies. In conclusion, snow cover dominated the amount of light under the ice, but did not modify its spectral composition. CDOM in the ice absorbs strongly in the short wavelengths. As pure water absorbs most in the long wavelengths, the light transfer through ice was highest in the green (549-585 nm).

5

Minimalizacja zjawiska dyspersji kątowej w sieciach komórkowych 5G

Kelner Jan M., Ziółkowski Cezary

Elektronika : konstrukcje, technologie, zastosowania

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2019

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Vol. 60, nr 2

13--20

PL

Współczesne systemy komórkowe bazują na technologii LTE, czyli standardu czwartej generacji (4G). Obecnie trwają pracę nad zakończeniem standardu definiującego systemy piątej generacji (5G), które będą implementowane w najbliższych latach. Nowa generacja systemów dotyczy już nie tylko sieci komórkowych ale również innych systemów łączności bezprzewodowej, od Internetu rzeczy, przez sieci Wi-Fi, po łączność satelitarną. Technologie 5G zrewolucjonizują całą łączność bezprzewodową zapewniając jednocześnie kompatybilność wsteczną. Jednymi z kluczowych technologii 5G są efektywne technologie antenowa, tzn. massive-MIMO oraz elektroniczne sterowanie wiązką. Ich zastosowanie w przyszłych stacjach bazowych makro-komórek pozwoli na przestrzenne zdywersyfikowanie zasobów radiowych. Technologie te pozwalają na generowanie bardzo wąskich wiązek radiowych, dzięki czemu zapewniają przestrzenną filtrację składowych sygnału emitowanych przez antenę nadawczą oraz docierających do anteny odbiorczej w środowiskach wielodrogowych. W artykule przedstawiono problematykę minimalizacji zjawiska dyspersji kątowej w sieciach 5G na bazie badań symulacyjnych. W tym celu wykorzystano wieloeliptyczny model propagacyjny.

EN

Modern cellular systems are based on the LTE technology, i.e., fourth generation (4G) standard. Currently, works on the standard defining fifth generation (5G) systems is underway, which will be implemented in the coming years. The new system-generation applies not only to cellular networks but also to other wireless communication systems, from the Internet of Things, through Wi-Fi networks, to satellite communications. 5G technologies will revolutionize all wireless connectivity while providing backward compatibility. One of the key 5G technologies are efficient antenna technologies, i.e., massive-MIMO and beamforming. Their use in future macro-cell base stations will allow spatial multiplexing of radio resources. These technologies allow the generation of radio narrow-beams, thus providing spatial filtration of the signal components emitted by the transmitting antenna and reaching the receiving antenna in multipath environments. The paper presents issues of minimizing the angular dispersion in 5G networks based on simulation studies. For this purpose, a multielliptical propagation model is used.

6

The Forces Driving Streaming in the Presence of Scatterers Mimicking the Blood Cells and the Contrast Agents

Wójcik Janusz, Secomski Wojciech, Żołek Norbert

Archives of Acoustics

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2019

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Vol. 44, No. 4

659--668

EN

Acoustical Driving Forces (ADF), induced by propagating waves in a homogeneous and inhomogeneous lossy fluid (suspension), are determined and compared depending on the concentration of suspended particles. Using integral equations of the scattering theory, the single particle (inclusion) ADF was calculated as the integral of the flux of the momentum density tensor components over the heterogeneity surface. The possibility of negative ADF was indicated. Originally derived, the total ADF acting on inclusions only, stochastically distributed in ambient fluid, was determined as a function of its concentration. The formula for the relative increase in ADF, resulting from increased concentration was derived. Numerical ADF calculations are presented. In experiments the streaming velocities in a blood-mimicking starch suspension (2 μm radius) in water and Bracco BR14 contrast agent (SF6 gas capsules, 1 μm radius) were measured as the function of different inclusions concentration. The source of the streaming and ADF was a plane 2 mm diameter 20 MHz ultrasonic transducer. Velocity was estimated from the averaged Doppler spectrum obtained from originally developed pulsed Doppler flowmeter. Numerical calculations of the theoretically derived formula showed very good agreement with the experimental results.

7

Analiza wpływu wybranych zaburzeń początkowych na rozrzut wszerz naddźwiękowego pocisku moździerzowego

Merda T.

Problemy Techniki Uzbrojenia

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2018

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R. 47, z. 148

43--60

PL

W pracy przeprowadzono analizę wpływu wybranych zaburzeń początkowych na rozrzut wszerz naddźwiękowego pocisku moździerzowego powstałego w ramach programu RAK AMUNICJA. W pierwszej części pracy wytypowano czynniki mogące mieć wpływ na rozrzut wszerz pocisków moździerzowych. Analizowano wpływ parametrów takich jak: początkowa prędkość poprzeczna pocisku, początkowy kąt odchylenia pocisku, początkowa prędkość kątowa odchylenia pocisku oraz krótkotrwały podmuch wiatru poprzecznego. Następnie oszacowano możliwe wartości zaburzeń tych parametrów i wykonano dla tych wartości obliczenia przy prędkości początkowej v0=500 m/s. Obliczenia prowadzono za pomocą modelu lotu o pięciu stopniach swobody opracowanego dla pocisków moździerzowych. Wyniki obliczeń porównano z rezultatami uzyskanymi analitycznie za pomocą wzoru opisującego wartość podrzutu aerodynamicznego przedstawionego w literaturze. W końcowej części pracy przedstawiono wnioski.

EN

Influence of selected initial disturbances into the lateral dispersion of a supersonic mortar projectile, developed in the frame of RAK MUNITIONS program, is analysed in the paper. In the first part of the paper some factors which may influence the lateral dispersion of mortar projectiles are indicated. Such parameters of the projectile as initial lateral velocity, initial angle of yaw and initial velocity of the yaw angle, and an unexpected lateral gust of wind were analysed. In the next step the possible values of disturbances for these parameters were estimated to perform the calculations for these values at the muzzle velocity of v0=500 m/s. The calculations were performed by using a model of flight with five degrees of freedom which was developed for the mortar projectiles. The results of calculations were compared with the analytical results received with a relation presented in the literature for values of aerodynamic jump. The conclusions are presented in the final part of the paper.

8

Real-time analysis and classification of bioaerosols based on optical scattering properties

Kaliszewski M., Trafny E. A., Włodarski M., Lewandowski R., Stępińska M., Kwaśny M, Kostecki J., Kopczyński K.

Biuletyn Wojskowej Akademii Technicznej

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2017

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Vol. 66, nr 1

27--40

EN

The size and shape of biological particles are important parameters allowing discrimination between various species. We have studied several aerosols of biological origin such as pollens, bacterial spores and vegetative bacteria. All of them presented different morphology. Using optical size and shape analyser we found good correlation between light scattering properties and actual particle features determined by scanning electron and fluorescence microscopy. In this study, we demonstrated that HCA (Hierarchical Cluster Analysis) offers fast and continuous bioaerosol classification based on shape and size data matrices of aerosols. The HCA gives an unequivocal interpretation of particle size vs. asymmetry data. Therefore, it may provide high throughput and reliable screening and classification of bioaerosols using scattering characteristics.

PL

Rozmiar i kształt cząstek biologicznych są ważnymi parametrami pozwalającymi na rozróżnianie pomiędzy różnymi rodzajami cząstek. Przeprowadzone zostały badania aerozoli pochodzenia biologicznego takich jak pyłki roślin, przetrwalniki oraz wegetatywne bakterie. Substancje te wykazywały różne właściwości morfologiczne. W wyniku przeprowadzonych badań przy pomocy optycznego analizatora wielkości i kształtu cząstek znaleziona została wysoka korelacja pomiędzy właściwościami rozpraszania światła a rzeczywistymi właściwościami cząstek określonymi na podstawie SEM (Skaningowego Mikroskopu Elektronowego) oraz mikroskopu fluorescencyjnego. Przedstawione badania pokazują, że HCA (Hierarchical Cluster Analysis) umożliwia szybką, wiarygodną, prowadzoną w sposób ciągły analizę i klasyfikację bioaerozoli w oparciu o ich charakterystyki rozproszeniowe.

9

Bloch wave - ZRP scattering as a key element of solid state physics computation: 1D example

Botman S., Leble S.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2016

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Vol. 20, No 2

197--206

EN

This paper presents calculation of the electron-impurity scattering coefficient of Bloch waves for one dimensional Dirac comb potential. The impurity is also modeled as delta function pseudopotential that allows explicit solution of the Schrodinger equation and scattering problem for Bloch waves.

10

Dispersion estimates for spherical Schrödinger equations: the effect of boundary conditions

Holzleitner M., Kostenko A., Teschl G.

Opuscula Mathematica

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2016

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Vol. 36, no. 6

769--786

EN

We investigate the dependence of the [formula] dispersive estimates for one-dimensional radial Schrödinger operators on boundary conditions at 0. In contrast to the case of additive perturbations, we show that the change of a boundary condition at zero results in the change of the dispersive decay estimates if the angular momentum is positive, l ∈ (0,1/2). However, for nonpositive angular momenta, l ∈ (—1/2,0], the standard [formula] decay remains true for all self-adjoint realizations.

11

Modeling of particle radiation interaction in solid fuel combustion with artificial neural networks

Gronarz T., Habermehl M., Kneer R.

Journal of Power Technologies

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2016

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Vol. 96, nr 3

206--211

EN

In the present investigation, artificial neural networks are applied to model scattering and absorption properties occurring in particle radiation interaction for numerical simulation of pulverized coal combustion. To determine averaged scattering and absorption properties, an averaging procedure over spectral incident radiation profile and particle size distribution is applied. These averaged properties then are approximated by means of an artificial neural network. A study to determine a suitable network architecture is performed.

12

Tissue characterization with ballistic photons: counting scattering and/or absorption centres

Corral F., Strojnik M., Paez G.

Opto-Electronics Review

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2015

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Vol. 23, No. 1

44-52

EN

We describe a new method to separate ballistic from the scattered photons for optical tissue characterization. It is based on the hypothesis that the scattered photons acquire a phase delay. The photons passing through the sample without scattering or absorption preserve their coherence so they may participate in interference. We implement a Mach-Zehnder experimental setup where the ballistic photons pass through the sample with the delay caused uniquely by the sample indices of refraction. We incorporate a movable mirror on the piezoelectric actuator in the sample arm to detect the amplitude of the modulation term. We present the theory that predicts the path-integrated (or total) concentration of the scattering and absorption centres. The proposed technique may characterize samples with transmission attenuation of ballistic photons by a factor of 10-14.

13

Raman scattering utilization for distributed temperature measurement in optical fibres

Cybulski R., Perlicki K., Siergiejczyk M.

Diagnostyka

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2015

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Vol. 16, No. 3

39--46

EN

Concept of fibre spontaneous Raman scattering utilizing for distributed temperature sensing is presented. Chosen approach uses both backscattered Stokes as reference and anti-Stokes as detection signals. The analysis is carried out towards Stokes and anti-Stokes bands temperature dependence. In order to achieve best measurement accuracy influence of maximum modulation frequency on spatial resolution is verified. Analysed technique allows to calculate temperature along the fibre with 5 m space precision and 1°C temperature precision. Simulations involve 200 m standard single mode fibre in temperatures in range < -5°C , 60°C> with 2x1100 m reference fibre maintained in 22°C.

PL

Koncepcja wykorzystania rozpraszania Ramana we włóknie światłowodowym do rozproszonego pomiaru temperatury została przedstawiona. W wykorzystanym podejściu użyto zarówno światła rozpraszania Stokes’a i anty-Stokes’a odpowiednio jako sygnałów odniesienia i czujnikowego. Analiza opiera się na fakcie zależności rozpraszania w pasmach Stokes’a i anty-Stokes’a od temperatury. W celu optymalizacji jakości pomiaru oceniono wpływ maksymalnej częstotliwości modulacji lasera na przestrzenną rozdzielczość pomiaru. W analizowanym przypadku oraz przy przyjętych wartościach parametrów możliwa jest realizacji pomiaru z dokładnością przestrzenną na poziomie 5 m i temperaturową 1 °C. W symulacjach badany jest odcinek 200 m światłowodu czujnikowego G.652 w temperaturach z zakresu < -5°C , 60°C> oraz dwóch odcinków światłowodu odniesienia od długości 1100 m w temperaturze pokojowej 22°C.

14

Wind-induced scattering of permeable unit flooring decks loosely laid on rooftops and balconies of highrise buildings

Uematsu Y., Shimizu Y., Miyake Y., Kanegae Y.

Czasopismo Techniczne. Budownictwo

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2015

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Y. 112, iss. 2-B

191--213

EN

The present paper discusses the mechanism of the wind-induced scattering of permeable unit flooring decks loosely laid on the rooftops and balconies of high-rise buildings. Firstly, the scattering mechanism of decks was investigated, based on a blowing test using a blower and actual decks. Subsequently, a simulation model was constructed for estimating the internal pressures under the decks (pressures acting on the bottom surface of decks) obtained from a wind tunnel experiment – this is based upon the unsteady Bernoulli equation and the time history of external pressures on the rooftop and balconies. Combining the simulated internal pressures and the experimentally obtained external pressures, the time history of net wind pressures acting on the decks were computed. Finally, the threshold wind speed of scattering (scattering wind speed) was obtained by applying the scattering mechanism to the simulated time history of the net wind pressures.

PL

W niniejszej pracy omówiono mechanizm rozwiewania przez wiatr przepuszczalnych podestów tarasowych luźno ułożonych na dachach i balkonach wieżowców. W pierwszym etapie przeanalizowano mechanizm rozwiewania podestów przy użyciu dmuchawy i rzeczywistych podestów. Następnie zbudowano model symulacyjny do szacowania ciśnienia wewnętrznego na podesty (ciśnienie działające na dolną powierzchnię podestów). Model oparto na nieustalonym równaniu Bernoulliego czasowych ciśnienia zewnętrznego działającego na dach i balkony, które zostały otrzymane w ramach eksperymentu przeprowadzonego w tunelu aerodynamicznym. Na podstawie symulowanych ciśnień wewnętrznych i uzyskanych doświadczalnie ciśnień zewnętrznych, obliczono przebieg czasowy całkowitych ciśnień działających na podesty. W ostatnim etapie obliczono progową prędkość wiatru podczas rozwiewania (prędkość rozwiewania) przez zastosowanie mechanizmu rozwiewania do symulowanych przebiegów czasowych ciśnienia wiatru.

15

Badanie chropowatości powierzchni gładkich za pomocą skaterometru kątowego. Cz. 1, Metoda pomiaru : przyrząd pomiarowy

Pawlata A.

Biuletyn Wojskowej Akademii Technicznej

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2015

|

Vol. 64, nr 1

47-58

PL

W artykule opisano podstawowe parametry chropowatości powierzchni. Przedstawiono metodę obliczenia tych parametrów dla powierzchni gładkich na podstawie pomiaru funkcji BSDF charakteryzującej rozproszenie z badanej powierzchni. Opisano zbudowany w IOE WAT zautomatyzowany skaterometr kątowy służący do pomiaru powyższych parametrów.

EN

The basic parameters of surface roughness are described in this article. The method of calculation of these parameters from measurement of BSDF function characterizing scatter from surface is shown. Automated angle scatterometer, built at the Institute of Optoelectronics of the Military University of Technology (IOE MUT), used for measurements of above parameters is described.

16

Badanie chropowatości powierzchni gładkich za pomocą skaterometru kątowego. Cz. 2, Metodyka pomiaru : wyniki pomiarowe wybranych powierzchni

Pawlata A.

Biuletyn Wojskowej Akademii Technicznej

|

2015

|

Vol. 64, nr 1

59-78

PL

W artykule opisano metodykę pomiaru parametrów chropowatości powierzchni za pomocą zbudowanego w IOE WAT zautomatyzowanego skaterometru kątowego. Zaprezentowano wyniki pomiarowe dla trzech wybranych polerowanych powierzchni: z krzemu, z germanu oraz ze stali nierdzewnej. Przedstawiono badania porównawcze wykonane za pomocą scatteroscope SCAT-4. Oszacowano powtarzalność pomiaru i zakres pomiarowy dla skaterometru kątowego.

EN

The experimental procedure for measurements of smooth surface roughness parameters using automated angle scatterometer, built at the Institute of Optoelectronics (IOE), is described. The results of measurements and their analysis for three chosen polished surfaces: silicon, germanium, and stainless steel are presented. The comparative investigations using scatteroscope SCAT-4 are performed. The repeatability and measurement range for built at IOEangle scatterometer is estimated.

17

Coloring of radiation scattered by polymer-dispersed liquid crystals

Maksimyak P., Maksimyak A, Nehrych A

Optica Applicata

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2014

|

Vol. 44, nr 4

545--554

EN

We analyze the effects of coloring of a beam traversing a light-scattering medium. Spectral investigation of the effects of coloring has been carried out using a solution of liquid crystal in a polymer matrix (polymer-dispersed liquid crystals – PDLC). It is shown that the result of coloring of the beam at the output of the medium depends on the magnitudes of the phase delays of the singly forward scattered partial signals. We consider the influence of interference coloring effect on the transmission scattering and spatial-frequency filtering of the radiation which has passed through the PDLC.

18

An extension to the Rayleigh–Gans formula: model of partially absorbing particles

Komar L, Kocifaj M, Kohut I

Optica Applicata

|

2013

|

Vol. 43, nr 2

313--323

EN

The Rayleigh–Gans (R–G) approximation is widely employed in various optical models to simulate the optical response of transparent media. However, the R–G concept can only succeed if the refractive index of scatterers approaches that of surrounding medium. In addition, the sizes of scattering domains are assumed to be small enough. Because of these reasons, the validity of R–G solution is fairly limited. In this paper, a semi-analytical extension to the R–G theory is introduced, resulting in an approximate formula for efficiency factor for scattering Qsca. It is proven numerically that this formula works much better than that for traditional R–G model. The computations have been made on absorbing particles with sizes comparable to or smaller than the wavelength of an incident radiation. The conventional R–G theory is either inapplicable or at least inappropriate for such particles.

19

Global well-posedness and scattering for the focusing nonlinear Schrödinger equation in the nonradial case

Han P.

Opuscula Mathematica

|

2012

|

Vol. 32, no. 3

487-504

EN

The energy-critical, focusing nonlinear Schrödinger equation in the nonradial case reads as follows: [formula]. Under a suitable assumption on the maximal strong solution, using a compactness argument and a virial identity, we establish the global well-posedness and scattering in the nonradial case, which gives a positive answer to one open problem proposed by Kenig and Merle [Invent. Math. 166 (2006), 645-675].

20

Revisiting the role of oceanic phase function in remote sensing reflectance

Freda W., Piskozub J.

Oceanologia

|

2012

|

No. 54 (1)

29-38

EN

The effect of angular structure differences between measured and best-fit analytical phase functions of the equivalent backscattering ratio on calculated reflectance values was studied and shown to be significant. We used a Monte Carlo radiative transfer code to check the effect of choosing different analytical (several Fournier-Forand (1994) and Henyey-Greenstein (1941)) phase functions with backscattering ratios identical to the "classical" average Petzold function. We show that the additional variability of the resulting water leaving radiance is about 7% (4% between the Fournier-Forand functions themselves) for most scenarios. We also show a previously unknown maximum of the discrepancy (up to 10%) for highly scattering waters. We discuss the importance of relative differences in phase function for different angular ranges to this maximum and to the behaviour of the discrepancy as a function of solar zenith angle.