Previously, it was shown that it is possible to separate the elastic scattering from the chlorophyll fluorescence signal using a polarization discrimination technique. The separation procedure depends however fundamen...
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Previously, it was shown that it is possible to separate the elastic scattering from the chlorophyll fluorescence signal using a polarization discrimination technique. The separation procedure depends however fundamentally on the degree of polarization of the water leaving radiance. In this paper, we study this dependence by simulating the total and polarized reflectance of waterleaving radiances originating from elastic scattering in case 1 and case 2 waters, by superimposing upon these reflectances the contribution of known fluorescence spectra, and by using our procedure to invert the resulting data back into fluorescence spectra. It is shown that the results of this retrieval compare well with the input values of fluorescence spectra for a wide range of underwater light scattering conditions. We show also that height baseline method, which is frequently used for the retrieval of fluorescence, can lead to significant overestimation of fluorescence for coastal zone conditions. The effects of different depths, surface roughness and bottom albedo are also analyzed. It is shown that in most cases fluorescence can be successfully retrieved with acceptable accuracy.
Previously, it was shown that it is possible to separate the elastic scattering from the chlorophyll fluorescence signal using a polarization discrimination technique. The separation procedure depends however fundamen...
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Previously, it was shown that it is possible to separate the elastic scattering from the chlorophyll fluorescence signal using a polarization discrimination technique. The separation procedure depends however fundamentally on the degree of polarization of the water leaving radiance. In this paper, we compare polarization effects and efficiency of the fluorescence retrieval by simulating the total and polarized reflectance of waterleaving radiances originating from elastic scattering in case 1 and case 2 waters using radiative transfer and multiple component Mie scattering programs. This is done by superimposing upon these reflectances the contribution of known fluorescence spectra, and by using our polarization discrimination procedure to invert the resulting data back into fluorescence spectra. It is shown that a Mie scattering code which does not take into account multiple scattering effects can strongly overestimate the degree of polarization for case 1 and case 2 waters as well as reflectances in the green part of the spectra. Making use of these results we propose and evaluate an improvement for the traditional height over baseline fluorescence extraction method which strongly overestimates fluorescence value for case 2 waters. For our approach we use inverse absorption spectra of water and chlorophyll a scaled up and fitted to the reflectance spectra in the red and near IR bands with the subsequent retrieval of the fluorescence spectrum and chlorophyll a concentration. Results and potential of this approach are discussed.
Modulated feedback control introduces periodicity. The global attracting property of the periodic points is established for a simple scalar discrete-time system under -modulated feedback. Attracting regions of the per...
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Feature tracking in large data sets is traditionally an off-line, batch processing operation while virtual reality typically focuses on highly interactive tasks and applications. This paper presents an approach that u...
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Protein structure alignment plays a key role in protein structure prediction and fold family classification. An efficient method for multiple protein structure alignment in a mathematical manner is presented, based on...
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In the context of the recently developed “equation-free” approach to computer-assisted analysis of complex systems, we extract the self-similar solution describing core collapse of a stellar system from numerical ex...
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In the context of the recently developed “equation-free” approach to computer-assisted analysis of complex systems, we extract the self-similar solution describing core collapse of a stellar system from numerical experiments. The technique allows us to sidestep the core “bounce” that occurs in direct N-body simulations due to the small-N correlations that develop in the late stages of collapse, and hence to follow the evolution well into the self-similar regime.
This study is concerned with the uncertainty principles which are related to the Weyl-Heisenberg, the SIM (2) and the Affine groups. A general theorem which associates an uncertainty principle to a pair of self-adjoin...
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The analytic method for the design of recursive digital filters with equiripple response is presented. The design is performed in the digital z-domain. The approach emphasizes discrete nature of the solutions and show...
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The MVDR beamformer is the most extensively used array processing algorithm and involves inverting the sample covariance matrix. In the snapshot deficient scenario, when the number of sensors is greater than or approx...
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