New versatile setup for goniometric measurements of spectral radiance

Zhao, Lu; Nielsen, Kristian; Lotsberg, Jon Kåre; Marken, Endre; Stamnes, Jakob J.; Stamnes, Knut

doi:10.1117/1.2205287

Cited by 6 publications

(2 citation statements)

References 15 publications

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“…The VSF measurements were carried out in the laboratory using the LABVSM instrument developed by Zhao et al [2006], which worked according to the following principle. A Xenon lamp (LQX1000, LINOS Photonics GmbH) provided white light, which was guided through a liquid fiber and a collimator.…”

Section: Methodsmentioning

confidence: 99%

Variability of the relationship between the particulate backscattering coefficient and the volume scattering function measured at fixed angles

et al. 2006

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[1] The particulate backscattering coefficient b bp is an inherent optical property that plays a central role in studies of ocean color remote sensing. Because of practical difficulties associated with measurements of the volume scattering function (VSF) over the whole backward hemisphere, b bp is currently derived using fixed-angle backscattering sensors and applying a conversion factor for particulate backscattering, referred to as c p . The underlying assumptions of the fixed-angle approach are as follows: (1) in the green band, c p is fairly constant in the angular range 100°-150°and (2) for a fixed scattering angle, c p is wavelength-independent. In this study we investigated the variability of c p based on spectral measurements of the full VSF, both in situ and for algal culture in the laboratory. The in situ data used in our study were acquired in a coastal environment outside of phytoplankton blooms, whereas the laboratory data were representative for phytoplankton bloom conditions in oceanic waters. At 555 nm, c p was found to vary significantly in the angular range 100°-130°, and at 140°, c p was found to be weakly variable in nonblooming waters only. The spectral variability of c p was studied for the first time, and the spectral slopes of c p , measured in situ, were found to vary within ±6%. Under the assumption that c p (140°) is wavelength-independent, the induced error in the estimates of b bp was found to be lower than 10%. The algal culture showed a much higher spectral variability in c p (±20%), which induced an error in the estimates of b bp up to ±25.8%.Citation: Chami, M., E. Marken, J. J. Stamnes, G. Khomenko, and G. Korotaev (2006), Variability of the relationship between the particulate backscattering coefficient and the volume scattering function measured at fixed angles,

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Section: Methodsmentioning

confidence: 99%

Variability of the relationship between the particulate backscattering coefficient and the volume scattering function measured at fixed angles

et al. 2006

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“…In corresponding literature, several articles dealing with measurements of the scattering phase function can be found. [6][7][8][9][10][11][12][13] Furthermore, a variety of articles dealing with the application of goniometric setups for biological and technical scatterers [14][15][16][17][18][19][20][21] show the importance of precise measurements. Although a lot of work has been done in that field, there are still some unsatisfying issues to be addressed.…”

Section: Introductionmentioning

confidence: 99%

Optimized goniometer for determination of the scattering phase function of suspended particles: simulations and measurements

Foschum

Kienle

2013

J. Biomed. Opt

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We present simulations and measurements with an optimized goniometer for determination of the scattering phase function of suspended particles. We applied the Monte Carlo method, using a radially layered cylindrical geometry and mismatched boundary conditions, in order to investigate the influence of reflections caused by the interfaces of the glass cuvette and the scatterer concentration on the accurate determination of the scattering phase function. Based on these simulations we built an apparatus which allows direct measurement of the phase function from ϑ=7 deg to ϑ=172 deg without any need for correction algorithms. Goniometric measurements on polystyrene and SiO2 spheres proved this concept. Using the validated goniometer, we measured the phase function of yeast cells, demonstrating the improvement of the new system compared to standard goniometers. Furthermore, the scattering phase function of different fat emulsions, like Intralipid, was determined precisely.

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