Kenneth J. Voss

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The point spread function (PSF) is an important property for predicting beam propagation and imaging system performance. Measurements of the PSF in three different locations (Pacific Ocean, Tongue of the Ocean, and Sargasso Sea) are presented. These measurements are used to validate extensive laboratory measurements [S. Q. Duntley, "Underwater Lighting by(More)
Remote-sensing reflectance (R(rs)), which is defined as the ratio of water-leaving radiance (L(w)) to downwelling irradiance just above the surface (E(d)(0⁺)), varies with both water constituents (including bottom properties of optically-shallow waters) and angular geometry. L(w) is commonly measured in the field or by satellite sensors at convenient(More)
www.physicstoday.org Light drives the physics, chemistry, and biology of the ocean. Without light in the ocean, life on Earth could not exist, nor would there be fuel for the heat engine that drives the ocean’s currents and the atmosphere’s circulation. Furthermore, light and sound are the two primary means available for probing the ocean. (See the article(More)
A new instrument to measure the point spread function (PSF) in the ocean has provided the opportunity for direct comparison between theoretical predictions and experimental measurement. Theoretical predictions are derived from small angle scattering theory using a simple algebraic fit to the single scattering phase function. The resulting predictions for(More)
The point-spread function (PSF) of a camera can seriously affect the accuracy of radiometric calibration and measurement. We found that the PSF can produce a 3.7% difference between the apparent measured radiance of two plaques of different sizes with the same illumination. This difference can be removed by deconvolution with the measured PSF. To determine(More)
The normalized light scattering polarization matrix has been measured for ocean water using an electrooptic light scattering polarimeter. Measurements were done on samples from the Atlantic and Pacific Oceans and the Gulf of Mexico. The polarization effects in the matrices were found to have, in general, a form which is similar to polarization effects in(More)
Measurements of the spectral scattering and attenuation properties of coccolithophores (Emiliania huxleyi; clone 88E) and their associated coccoliths were made for three growth phases a< well as for acidified cultures. These measurements allow a clean separation and determination of the optical effects of the various components. The beam attenuation cross(More)
We have built a new fisheye camera radiometer to measure the in-water spectral upwelling radiance distribution. This instrument measures the radiance distribution at six wavelengths and obtains a complete suite of measurements (6 spectral data images with associated dark images) in approximately 2 minutes (in clear water). This instrument is much smaller(More)
A new instrument to measure the in situ bidirectional reflectance distribution function (BRDF) of surfaces is described. This instrument measures the BRDF for eight illumination angles from 0 to 65 deg, three colors (475, 570, and 658 nm), and at over 100 selected viewing angles. The viewing zenith angles range from 5 to 65 deg, and the azimuth angles,(More)
Microbial communities often produce copious films of extracellular polymeric secretions (EPS) that may interact with sediments to influence spectral reflectance signatures of shallow marine sediments. We examined EPS associated with microbial mats to determine their potential effects on sediment reflectance properties. Distinct changes in spectral(More)