This PDF file contains the front matter associated with SPIE Proceedings Volume 6615, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

Requirements on accuracy of the atmospheric correction of satellite ocean color data are rather high, and so far attempts to solve this problem as needed have not been quite successful, especially at high latitudes and in coastal waters. New approach to the atmospheric correction problem consists in simultaneous retrieval of the unknown aerosol and ocean reflectances ρ_α(λ_i) and ρ_w(λ_i) from the top-of-the-atmosphere reflectance ρ_t(λ_i) with use of all spectral channels of a satellite sensor in infrared and visible ranges. The approach is based on parameterization of the spectral behavior of ρ_α(λ_i) and ρ_w(λ_i) with help of several basic functions. In this way the problem reduces to determination of several weight coefficients at these basic functions. This allows us to cut drastically the size and number of required lookup tables. The inversion problem is solved by a least square method with inequality constraints. It is shown that the new algorithm results in better agreement with in situ measured ρ_w(λ_i), compared with the standard SeaWiFS algorithm, in Case 2 waters.

Mathematical models and a complex algorithm were elaborated for the remote sensing of the Baltic ecosystem and its primary production within the framework of a large-scale national (Polish) project: "Developing a satellite method for Baltic ecosystem monitoring" (DESAMBEM). This paper analyzes some of the DESAMBEM algorithm's possible applications, focusing on the implementation of the algorithm for investigating the spatial variability of the Baltic ecosystem, and analyzing by way of example primary production distribution maps constructed using the algorithm.

A method to retrieve concentrations of suspended large and small particles in seawater from satellite images is proposed. The method uses as input images of scattering and backscattering coefficients in several satellite channels as well as an image of concentration of chlorophyll. All these three properties are derived using an atmospheric correction algorithm and algorithms to derive inherent optical properties from remote sensing reflectance. The proposed method is based on several approaches developed previously by Twardowski et al, van de Huist, and Evans and Fournier and is based on Mie theory. The proposed method was applied to restore a number of suspended particles and their dynamics in ocean using SeaWIFs satellite optical images.

Potentialities of discriminating water motions and admixture transfer patterns within the surface layer and underlying thickness of the sea from the estimates of spectral-different normalized radiances are demonstrated by the example of the ocean color scanners data for the Black and Baltic Seas. The merits and limitations of the approach are discussed.

The Volume Scattering Function (VSF) is an essential variable in the context of marine radiative transfer modeling and of the inversion of ocean colour remote sensing data. However, an important lack of knowledge on the VSF natural variability affects the present models, in particular for the coastal environment. Measurements of the Volume Scattering Function between 0.6° and 177.3° with an angular resolution of 0.3° were performed in the northern coastal Adriatic Sea onboard an oceanographic platform in October 2004 using a prototype instrument. Observed differences with the commonly used Petzold's functions are significant, in particular for the "open ocean" and "coastal" types in the backward directions. The use of an empirical relationship for the derivation of b_b(λ) from a unique measurement of β(ψ,λ) at ψ=140 for the Hydroscat-6 was validated for this coastal site at that season. Finally, the use of the Kopelevich VSF model together with a measurement of b_p(λ) at λ=555 nm allowed the reconstruction of the VSF to within about 35%.

The volume absorption of solar radiation in water body determines important processes in the upper ocean such as primary bioproduction and heat balance. Assessment of penetration of solar radiation into water body can be performed with satellite data and the previous attempts in this direction were promising. This paper presents a package of the algorithms to compute the components of balance of photosynthetically available radiation (PAR) at sea level (incident, reflected from the rough sea surface, and water-leaving PAR) and to calculate the volume absorption of PAR in the upper layer from satellite ocean color data. Data measured by the SeaWiFS ocean color sensor and the ancillary data needed (such as ozone amount and wind speed) are used. Computations of the underwater irradiance are performed for the 0-25 m upper layer. The errors are estimated by direct comparison between the values of underwater irradiance and volume absorption derived by the algorithms developed and by the exact method. Monthly means of the components of PAR balance as well as the potential daily heating have been estimated in different regions.

New hydro-optical instruments for sub-pixel scale investigation of satellite features and a new technique to invert water properties is described. The new semi-analytic algorithm, based on high resolution spectrally continuous remote sensing reflectance measurements, is proposed for inversion of the optical properties. The algorithm retrieves absorption spectra of phytoplankton pigment and pigment concentration.

Since 1997 the U.S. satellite sensor SeaWiFS is providing an information, that can be helpful to monitor Black Sea waters in routine operational mode. Due to the errors inherent in atmospheric correction procedures, the possibilities to determine the full spectrum of normalized spectral water-leaving radiance are very limited. At the same time the analysis shows that the use of two SeaWiFS channels at 510 and 555 nm allow us to detect many interesting features of temporal and spatial variability of the effects of absorption and scattering of light in the Black Sea.

The mean monthly distributions of chlorophyll a concentration, the particle backscattering and yellow substance absorption coefficients in the Barents, Black, Caspian, and Japan Seas have been computed from data of the SeaWiFS satellite ocean color scanner from 1998 to 2005; the color maps constructed show spatial and temporal variability of photosynthetic phytoplankton, particulate matter and colored organic matter. The modified algorithms developed on the basis of the ship-measured data were used for computations; these regional algorithms provide reasonable agreement between in situ and satellite-based values of bio-optical characteristics in the seas under study. The monthly, seasonal and annual mean values for selected regions were calculated. A brief analysis of the obtained results is given. Some interesting phenomena in the above seas are observed; among them the coccolithophorid blooms in the Black Sea and in the Middle Barents revealed from satellite ocean color data and confirmed then by the field studies. In the Caspian Sea the satellite data displayed sharp increase of chlorophyll concentration and of the particle backscattering attributed to a consequence of invasion of Ctenophore Mnemiopsis.

A new general analytical inversion of the lidar equation with multiple scattering is presented. This inversion of the lidar equation includes all known solutions as particular cases. It works under single and multiple scattering, for any geometry, and for any reference point in the retrieval procedure. This inversion serves as a theoretical base for the newly developed techniques to retrieve the TOP profiles from measured lidar waveforms. The iterative procedures as well as software INVERTER to perform the lidar waveforms inversion are outlined. INVERTER also serves as a tool for verification and refinement of various retrieval techniques. Iterative retrieval algorithms for different lidar systems, their stability and sensitivity to the accuracy of a priory information used are discussed. The examples of the performed retrieval simulations show a reasonable coincidence of the retrieved IOP profiles with the sea truth.

We consider the inverse problems in the retrieval of the water's inherent optical properties (IOP) and the properties of the hydro-physical processes taking place in a water body using the returned signal of an oceanic lidar. An algorithm for the retrieval of the depth distributions of IOPs from a lidar signal was developed using correlations between IOPs in the middle of the visual spectrum. Our algorithm gives simple equations for the attenuation coefficient's depth profile using narrow and wide lidar receiving angles. We also show how to find this profile for an arbitrary lidar receiving angle. Analysis of the algorithm's accuracy demonstrated that the probabilistic nature of the correlations between IOPs produces large errors in the retrieved lOPs. These errors increase with the optical depth of the sensed layer. The suggested adaptive algorithm improves retrieval accuracy by processing the lidar signal itself. It is shown how a two-channel lidar with specific directivity diagrams can be used to well-determine one water optical property, and then find the other TOPs with correlations. We also consider the possibility of detecting hydro-physical processes in water by the example of lidar images of internal waves.

The results of research of application of spectral patterns recognition technique in laser remote sensing of natural waters, conducted by the authors in 2001 - 2006 years, are summarized in this paper. It is shown that application of artificial neural networks allows to perform precision analysis of water Raman scattering and fluorescence bands of humic substances (with possible distortions of those by fluorescence of pollution and other organic contaminants). Based on this, it is possible to solve such problems of laser diagnostics of natural waters as remote determination of temperature, identification and determination of concentration of salts, humic substances, oil pollutions in water, monitoring of hydrological structures.

Airborne lidar survey of the Barents Sea region was carried out from board of the aircraft laboratory AN-26 "Arktika". To conduct the survey the Polarized Airborne Lidar PAL-1M was used. PAL-1M has been designed specially for this aircraft laboratory. Spatial distributions of hydro-optical properties are drawn for the certain areas. The long highscattering layer within the Polar front zone was detected. 2D distribution of the effective scattering coefficient was retrieved and its quasi-periodic structure was obtained.

In earlier work, we have proposed a concept for estimation of ocean optical properties with a mutliple field of view bathymetric lidar. In this paper we consider and implementation of this idea using the Scanning Hydrographic Operational Airborne Lidar Survey (SHOALS) system. The SHOALS design uses two receivers for depth measurement: a shallow-water, APD receiver with and 18 mrad FOV; and a deep-water PMT receiver with a 40 mrad FOV. They simultaneously record the optical power returned from a single pulse of the laser, and consequently provide the desired measurements. Here, we present an algorithm for the estimation of inherent optical properties (IOPs) in the upper ocean layer which is based on "multiple-forward-single-backscattering" model of the returned power, and an analytical solution to the radiative transfer equation (RTE) for finite sounding beam propogation in the small-angle-scattering approximation. Using this algorithm, we have developed an approach for estimation of the backscattering coefficient, the beam attenuation coefficient, the single-scattering albedo, and the VSF asymmetry coefficient, by fitting simulated waveforms to actual data measured by the two receivers. We also present an approach for improvement in estimates of bottom reflectance which compensates for pulse stretching induced by angle of incidence effects.

A theory of imaging of underwater targets with a time gated polarized imaging lidar is briefly presented. This approach is grounded on the analytical theory of polarized light propagation developed by E. Zege and L. Chaikovskaya earlier. An algorithm and software for computer simulation of a performance of ocean imaging lidars with polarization devices are outlined. A vehicle for this model is software simulating the performance of ocean time gated imaging lidars without polarization devices developed by authors earlier. Results of the simulation of images with time-gated CO-POLAR and CROSS-POLAR cameras are presented and discussed.

Shipboard polarized lidar for upper seawater column sounding through sea surface was designed. The lidar was designed to obtain the vertical profiles of hydro-optical properties and to locate of subsurface high-scattering layers and some different inhomogeneities. The source of the linearly polarized light sounding pulses is YAP:Nd Q-switched laser with SHG. Two identical photo-receiving devices are used to register waveforms of the two orthogonal-polarized components of echo-signal power. Field experiments with the use of the device were carried out at the several areas of the Atlantic Ocean. Subsurface high-scattering layers were detected during the field experiments.

This paper is devoted to computer simulation of random realizations of bottom images. Simulations of random images are considered to be a straightforward way to predict bottom visibility under realistic conditions. A simplified version of a bottom imaging model using a fast simulation algorithm has been developed. Simulated results presented here allow the visual evaluation of image quality for different signal/noise ratio (SNR) values. We show how the simulation of random images can be used to predict bottom visibility over a variety of environmental conditions and also determine an optimal observation strategy.

We investigated the feasibility of decreasing the negative influence of roughness on the visibility of underwater objects. The technique is based on the use of information about glitter on the sea surface, which is required for determining the undistorted parts of the underwater object image). The effect of angular resolution of the imaging system on the underwater object image quality is also studied.

An image of a sea bottom observed through a rough sea surface is randomly distorted by the refraction of light at the water-air interface. The negative effect of waves on bottom visibility can be decreased by 'accumulating" image frames. Realistically the possibility of image accumulation is very limited. As a rule an observer has to deal with random images distorted by the rapidly changing sea surface. Thus a question arises: Is it possible to retrieve the "real" image of an object from its distorted image, if an image of the exact water surface distorting the bottom image is made simultaneously? The present paper addresses the correction of a distorted image of a bottom object, when the water surface relief or the spatial distribution of surface slopes is precisely known. Additionally a correction algorithm is given for rapidly processing two-dimensional images, the potential for determining the "instantaneous" spatial distribution of rough sea surface slopes from its instantaneous image is investigated, and finally an analysis is made relating errors in determining sea slopes from a single image to the associated quality of image correction for an object observed through a changing sea surface.

Surf zone measurements and airborne imagery were collected off North Carolina. The data and a surf zone index based on the properties of water clarity, waves, and foam were used to predict imager performance for objects of varying reflectivity and contrast.

Results of laboratory experiments on image transfer through turbid water layer and wavy air-water interface are presented. The laboratory-modeling installation for the study of light field interactions with a wavy water surface is described.

A new more general phase function is derived which models more accurately the refracted and scattered components of the phase function. Modeling accurately the backscatter contribution is absolutely required when evaluating and predicting the performance of oceanographic remote sensing systems and underwater imaging systems, as the veiling glare from the in water scattering particles is the dominant first order source of image degradation. The function is further generalized to account for the effect of shelled organisms with two different indices of refraction for the bulk material and for the outer shell. It explains some of the puzzling discrepancies noticed by many workers who tried to model the oceanic phase functions using a single overall index of refraction. It shows why the index fitting parameter generally used in the phase function for ocean waters is always higher than the bulk index of refraction of the particles measured in the laboratory.

The possibility of the retrieval of the water's inherent optical properties (IOP) from Secchi disk observations is discussed. The paper directly addresses objections to the use of Secchi disks raised by Preisendorfer in 1986. A new version of Secchi depth theory is given, which in contrast to conventional Secchi disk theories includes the effects of light reflection from the sea surface and treats measurements from both the sunny and shaded sides of a vessel. Empirical correlations between different IOP are used to estimate not only the attenuation coefficient, but also the single scattering albedo and the backscattering probability at 550 nm from Secchi depth data. The theory is compared with measurements made in the Black Sea.