This PDF file contains the front matter associated with SPIE Proceedings Volume 7828, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

MATISSE which acronym means Advanced Modeling of the Earth for Environment and Scenes Simulation is an infrared background scene generator developed by Onera since the mid 1990'. MATISSE main goal is to compute radiance images of natural backgrounds and radiative quantities such as local illumination, spectral transmission, and spectral radiance along lines of sight. The new version MATISSE-v2.0 has been completed during the first quarter of 2010 and the public version is going to be released in few weeks. This latest version uses a multi resolution spatial scheme in order to treat the natural backgrounds with spatial footprint from kilometre sizes (satellite viewing) down to metric sizes. Up to now, this spatial scheme has been used in order to generate infrared images of sea surface. The new sea surface model (water waves and surface optical properties) has been partially validated by using a specific Mediterranean campaign. MATISSE-v2.0 is also accompanied with a new set of GUI (graphical user interface) in order to help the user in defining its computational case. The code is also designed in order to be interfaced with other applications. Our presentation will be devoted to a description of MATISSE-v2.0 new features, with examples of sea surface scenes exemplifying the new code functionalities.

We improve the validation of the sea surface infrared optical properties multiresolution model implemented in MATISSE-v2.0, in the 1D case, by comparison with a reference model using a sub-millimeter discretization of the surface. A set of numerical tests is made for various wind speeds, resolutions and realizations of the sea surface. The tests show a good agreement between the results except for grazing angles, where the influence of inner and mutual multiple reflections and adjacent shadowing has still to be investigated.

Efficient military operations require insight in the capabilities of the available sensor package to reliably assess the operational theatre, as well as insight in the adversary's capabilities to do the same. This paper presents the EOSTAR model suite, an end-to-end approach to assess the performance of electro-optical sensor systems in an operational setting. EOSTAR provides the user with coverage diagrams ("where can I see the threat?") and synthetic sensor images ("how do I perceive the threat?"), and allows assessing similar parameters for threat sensors. The paper discusses the elements of EOSTAR and outlines a few of the possible applications of the model.

The thermal contrast between two surfaces can vary dramatically with the atmospheric conditions. "Neon" is an application to predict the thermal contrast between different surfaces and their backgrounds, and the apparent contrast, given atmospheric conditions, when a target surface and background are viewed through a remotely situated infra-red camera. It is typically used in military assessments of how visible a target will be at a particular range. Recent research work to Neon has concentrated on the conversion of these apparent temperatures to more user-relevant descriptions of the detectability of the target. Accordingly, a development version of Neon now outputs "Detect", "Recognize" and "Identify" guidance. This paper briefly outlines the Neon concepts and then explores the methods behind the calculation of these detectability ranges and probabilities, and their comparison with a simple target acquisition range based only on the apparent contrast of the target and background. It finally explores how variations in the atmosphere impact upon the detectability of a target, and how the atmospheric impact will change with future improvements in sensor technology.

Electro-optical sensors are affected by the atmospheric turbulence, as quantified by the refractive index structure parameter. The present study introduces a method to predict the meteorological-scale variations of this quantity near the surface. The predictions are evaluated against long-term scintillometry measurements. The essential aspects of the meteorological variability of the optical turbulence rate are captured. The method is illustrated to provide a global and predictive assessment of the optical turbulence rate. It can also be used to analyze the corresponding climatological distributions. Existing relationships can further be incorporated to form predictions of the mean optical sensing performance.

We present 1.55 μm short-cavity buried-tunnel-junction VCSELs (Vertical-Cavity Surface-Emitting Lasers) with single mode output powers of 6.7 mW at 20°C and 3 mW at 80°C, respectively. Although the device had been predominantly optimized for high-power applications and a proper heat management, we are also observing a 3dB-cut-off frequency of more than 11 GHz and side mode suppression ratios (SMSRs) beyond 54 dB over the whole temperature range. The tuning range of the devices can be increased from 7 nm based on gain tuning to several tens of nanometers when replacing the top DBR by a micro-electro-mechanical system (MEMS) distributed Bragg reflector (DBR) composed of semiconductor or dielectric material being thermally actuated for changing the cavity length. These devices are perfectly suitable for telecommunication and gas sensing applications and represent outstanding devices for the so called tunable diode laser absorption spectroscopy (TDLAS) technique.

In this paper we report on measurements of atmospheric turbulence effects arising from water air interaction. The aim of this study is to aid in the design of a free-space optical relay system to facilitate longer line-of-sight distances between relay buoys in a large expanse of water. Analysis of turbulence statistics will provide the basis for adaptive optics solutions to improve the relay signal strength affected by scintillation and beam wander. We report on experiments determining the isokinetic angle using an array of broadband incoherent sources of variable angular separation on the order of 0.1 mrad to 2.8 mrad. The experimental setup consists of a 5 inch telescope with high speed CMOS camera observing over a distance of 300 m close at a height of 1.5 m above the water surface. As part of the turbulence characterisation we experimentally estimate the relative image motion of angle-ofarrival fluctuations and perform other time series analysis. Analysis of the image motion requires new techniques due to the extended nature of the source. We explore different centroiding algorithms and surface fitting techniques.

The FATMOSE trial (FAlse-bay ATMOSpheric Experiment) running over a period from November 2009 to July 2010, was a continuation of the cooperation between TNO and IMT on atmospheric propagation and point target detection and identification in a maritime environment. Instruments were installed for measuring scintillation, blurring- and refraction effects over a 15.7 km path over sea. Simultaneously, a set of instruments was installed on a mid-path lighthouse for collecting local meteorological data, including scintillation, sea surface temperature and visibility. The measurements covered summer and winter conditions with a prevailing high wind speed from the South East, bringing in maritime air masses. The weather conditions included variations in the Air-Sea Temperature Difference (ASTD), that may affect the vertical temperature gradient in the atmospheric boundary layer, causing refraction effects in the lightpath. This was measured with a theodolite camera, providing absolute Angles of Arrival (AOA). Blur data were collected with a high resolution camera system with 10 bits dynamic range. Specially designed image analysis software allows determination of the atmospheric blur, while simultaneously providing information on the Scintillation Index (S.I.). This S.I. was also measured by using the Multiband Spectral Radiometer Transmissometer (MSRT). The ratio of the transmission levels of this instrument contains information on the size distribution of the aerosols along the path. In the paper, experimental details on the set-up and the instrumentation are given as well as the methods of analysis. Preliminary results are shown, including a comparison of measured blur and scintillation data with Cn 2 data from the scintillometer, correlation between AOA and ASTD and comparison of transmission data with data from the visibility meter. Blur and scintillation data are compared with predictions from standard turbulence model predictions, using Cn 2. In future studies the data will be used for validation of propagation models such as EOSTAR.

This paper presents a new method for remote sensing of cross-wind by using a naturally illuminated scene as a light source. The method is based on spatial and temporal correlations of the intensity fluctuations measured by a passive imaging device such as a video camera. Adaptable spatial filtering, taking into account variations of the dominant scales of the turbulence (due to changes in meteorological conditions or imaging device performance) is integrated into this method. The major merits of the proposed technique lie in its simple implementation for a wide range of imaging systems and ability to remotely sense the crosswind with naturally occurring targets. Experimental comparison with independent wind measurement using anemometers shows good agreement.

With the advent of high resolution imaging through the atmosphere, turbulence distribution measurement has become a key issue. The possibility to measure C2n profile from Shack-Hartman data, slopes and intensities, acquired on a unique point source has recently been demonstrated numerically.1 This method, called SCOSLIDAR, is exploited here on experimental data. From slopes and intensities of a mid-infrared wavefront sensor, C2n profiles along an oblique line of sight are estimated and compared to local measurements. Time averaged profiles are confronted to a profile deduced from similitude law.

A laser pulse propagating through dense clouds suffers from spatial and temporal distortion caused by multiple scattering of light. Both distortions are function of the optical depth, the particle size of the aerosols and the cloud distance relative to the target and receiver. In order to study the effects of all theses parameters, 3-D Monte-Carlo (MC) simulations were performed. The Monte Carlo developed for this purpose has the unique capability to produce both 2D and 3D images of the scenes. For the 2D images we calculated the MTF using the Fourier transform of the system PSF. For the 3D images gratings with rectangular grooves of various frequencies and height were used and the concept of contrast applied as for the calculation of MTF for 2 D images. We found that 3D temporal distortion effects are significantly reduced when the reconnaissance algorithm is base on the shape of the raising pulse.

It is well known that luminance from photo-chemical reactions of hydroxyl ions in the upper atmosphere (~85 km altitude) produces a significant amount of night time radiation in the short wave infra-red (SWIR) band of wave length 0.9 to 1.7 μm. Numerous studies of these phenomena have demonstrated that the irradiance shows significant temporal and spatial variations in the night sky. Changes in weather patterns, seasons, sun angle, moonlight, etc have the propensity to alter the SWIR air glow irradiance pattern. By performing multiple SWIR measurements a mosaic representation of the celestial hemisphere was constructed and used to investigate these variations over time and space. The experimental setup consisted of two sensors, an InGaAs SWIR detector and a visible astronomical camera, co-located and bore sighted on an AZ-EL gimbal. This gimbal was programmed to view most of the sky using forty five discrete azimuth and elevation locations. The dwell time at each location was 30 seconds with a total cycle time of less than 30 minutes. The visible astronomical camera collected image data simultaneous with the SWIR camera in order to distinguish SWIR patterns from clouds. Data was reduced through batch processing producing polar representations of the sky irradiance as a function of azimuth, elevation, and time. These spatiotemporal variations in the irradiance, both short and long term, can be used to validate and calibrate physical models of atmospheric chemistry and turbulence. In this paper we describe our experimental setup and present some results of our measurements made over several months in a rural marine environment on the Island of Kauai Hawaii.

It is well known that luminance from photo-chemical reactions of hydroxyl ions in the upper atmosphere (~85 km altitude) produces a significant amount of night time radiation in the short wave infra-red (SWIR) band between 0.9 and 1.7 μm wave length. This has been demonstrated as an effective illumination source for night time imaging applications. It addition it has been shown that observation of the spatial and temporal variations of the illumination can be used to characterize atmospheric tidal wave actions in the air glow region. These spatiotemporal variations manifest themselves as traveling wave patterns whose period and velocity are related to the wind velocity at 85 km as well as the turbulence induced by atmospheric vertical instabilities. We are interested in studying these phenomena for a variety of reasons. First they can give an insight into upper atmospheric physics, second we would like to understand the variations in order to determine if air glow can be used as a reliable illumination source for night time terrestrial imaging. To that end we have been collecting data on ground irradiance from air glow over the past six months at a site on the island of Kauai. The purpose of this paper is to discuss some initial analysis of this data.

Related problems are as follows: (i) evolution of the vortical structures which play an important role in turbulence; (ii) laser beam propagation through turbulence; (iii) object-targeting problem. The parametrix method was used. The convergence of the coupled iterative procedure was discussed. We investigated the influence of a point thermal source on the vorticity of a cylindrical vortex. We revised the 3D object-targeting problem.

Compensation of turbulence in atmospheric imaging is usually hampered by the lack of a reference point source. We consider the possibility of phase compensation based on the reference wave scattered by the rough surface of an object under review. Analysis has been made on the basis of numerical simulation. The recently developed method for incoherent imaging through the atmosphere in anisoplanatic turbulent conditions allows simulating both long-exposure and short-exposure images. We analyze the influence of the size of object reflecting reference wave on the efficiency of phase compensation. Image quality enhancement is observed for the object size significantly exceeding the diffractivelimited size with respect to the receiving aperture. Also we consider the features of phase compensation with the reference wavelength different from visible light ones.

In report we review aspects related to the implementation of laser guide star (LGS) in an adaptive optics (AO) system. As soon as lasers were proposed to create guide star for adaptive optics, it was realized that the LGS could not be used to measure tilt. In report the analysis of the possibility of tilt-measurement in the framework of using a LGS are discussed. Results of analytical calculations where assumptions made earlier remove are presented. We suggested the use the algorithm of 'optimal' correction for determination correction the wavefront aberration of the science object by means of the measured wavefront LGS. The analytical and numerical calculations are presented. For numerical calculation we used set the various model of turbulence profile. The significant increases in efficiency of phase correction based on this algorithm are achieved.

The development of a system intended as a demonstrator for improving the tracking of distant point-like sources through the correction of the atmospheric optical distortions is here reported. The demonstrator consists of a motorized mirror, which can pursuit a moving light source, united to an adaptive optics setup to improve the performances and the precision of the tracing of the object trajectory. The adaptive optics setup consists of a closed loop between a quad cell sensor and a tip-tilt mirror for the atmospheric jitter compensation and of another closed loop between a Shack-Hartmann sensor and a membrane deformable mirror for the compensation of higher order aberrations. Atmospheric measurements of an incoherent source will be also presented. In the case of our interest, where the atmospheric disturbances cannot be addressed only to a turbulent layer near the pupil (near field approximation), the scintillation becomes an important part of the noise. Its effects will be analyzed here, with particular attention to the influence on the wavefront sensor.

Free-space optical (FSO) communication systems have currently a restricted range, because of atmospheric effects which reduce their application range. The goal of the SCALPEL project is to study the feasibility of long range FSO systems (goal: 20 km), i.e. to estimate how dedicated devices could enhance the range of FSO communication systems, for example by changing the link's wavelength for a better atmospheric transmission and weaker turbulence effects, and/or by using an innovative adaptive optics device to compensate, at least partially, turbulence perturbations. In this paper, we study how the atmosphere constrains the system design in terms of transmission and turbulence. We show that the system cannot work unless it has a full-wave adaptive optics correction, and that a wavelength around 4 μm presents several advantages toward the usual wavelength, i.e. 1.55 μm. A first design of the system is then presented, including the source and the sensor.

Cramér-Rao lower bound (CRB) theory can be used to calculate algorithm-independent lower bounds to the variances of parameter estimates. It is well known that the CRBs are achievable by algorithms only when the parameters can be estimated with sufficiently-high signal-to-noise ratios (SNRs). Otherwise, the CRBs are still lower bounds, but there can be a large gap between the CRBs and the variances that can be achieved by algorithms. We present results from our initial investigations into the SNR dependence of the achievability of the CRBs by multi-frame blind deconvolution (MFBD) algorithms for high-resolution imaging in the presence of atmospheric turbulence and sensor noise. With the use of sample statistics, we give examples showing that the minimum SNR value for which the CRBs can be achieved by our MFBD algorithm typically ranges between one and five, depending upon the strength of the prior knowledge used in the algorithm and the SNRs in the measured data.

Motion-Compensated Averaging (MCA) with blind deconvolution has proven successful in mitigating turbulence effects like image dancing and blurring. In this paper an image quality control according to the "Lucky Imaging" principle is combined with the MCA-procedure, weighting good frames more heavily than bad ones, skipping a given percentage of extremely degraded frames entirely. To account for local isoplanatism, when image dancing will effect local displacements between consecutive frames rather than global shifts only, a locally operating MCA variant with block matching, proposed in earlier work, is employed. In order to reduce loss of detail due to normal averaging, various combinations of temporal mode, median and mean are tested as reference image. The respective restoration results by means of a weighted blind deconvolution algorithm are presented and evaluated.

A recently introduced approach to restore images distorted by atmospheric turbulence without a direct knowledge about the wavefront is being discussed in this paper. This technique is based on the use of a deformable mirror controlled by a Stochastic Parallel Gradient Descent (SPGD) algorithm applied to an image quality measurement. This procedure is now being tested for the correction of extended sources as well as laser beams. Because the technique does not rely on wavefront sensors, the problems related to scintillations are noticeably reduced. Preliminary results are presented.

A high precision Shack-Hartmann wavefront (WF) sensor has been developed on the basis of a low-aperture off-axis diffraction lens array. The device is capable of measuring WF slopes at array sub-apertures of size 640x640 μm with an error not exceeding 4.80 arcsec (0.15 pixel), which corresponds to the standard deviation equal to 0.017λ at the reconstructed WF with wavelength λ . Also the modification of this sensor for adaptive system of solar telescope using extended scenes as tracking objects, such as sunspot, pores, solar granulation and limb, is presented. The software package developed for the proposed WF sensors includes three algorithms of local WF slopes estimation (modified centroids, normalized cross-correlation and fast Fourier-demodulation), as well as three methods of WF reconstruction (modal Zernike polynomials expansion, deformable mirror response functions expansion and phase unwrapping), that can be selected during operation with accordance to the application.