This PDF file contains the Front Matter for SPIE Volume 7834, including the Title page, Copyright information, Table of Contents, and Conference Committee listing.

A thermal imaging system has been demonstrated, which uses wavefront coding to provide an extended depth of field. Aberrations are introduced into the optical system, which are optimised to be insensitive to defocus; a single image processing algorithm can be successfully applied to images with a range of focus errors. This requires both the design of the wavefront coding surface and the implementation of efficient and effective image processing electronics. The design of the freeform wavefront coding surface goes hand-in-hand with that of the electronics architecture. An optimised decoding algorithm is implemented in the image processing electronics to achieve real-time imaging performance.

Pyroelectric linear arrays can be used to generate profiles of targets. Simulations have shown that generated profiles can be used to classify human and animal targets. A pyroelectric array system was used to collect data and classify targets as either human or non-human in real time. The pyroelectric array system consists of a 128-element Dias 128LTI pyroelectric linear array, an F/0.86 germanium lens, and an 18F4550 pic microcontroller for A/D conversion and communication. The classifier used for object recognition was trained using data collected in petting zoos and tested using data collected at the US-Mexico border in Arizona.

Laser dazzling of electro-optical sensors states a serious problem. Especially when navigational tasks shall be fulfilled a disturbance of the sight is inacceptable. Classical protection measures like e.g. laser safety filters usually lack of the drawback of color distortion and a considerable loss in transmission. Therefore, new protection concepts should be aspired which are independent of the laser wavelength and do not affect the vision. In this paper we discuss a novel concept to protect electro-optical sensors against laser dazzling based on spatial light modulator technology and wavelength multiplexing. In particular, the method is suited as a protection measure against continuous wave laser sources.

SCD's new 17μm pitch VGA VOx μ-Bolometer detector was introduced in April 2010. Due to their overall size, weight and power advantages, 17μm pitch uncooled detectors are currently being considered for next generation systems such as thermal weapon sights (TWS), driver vision enhancers (DVE) and digitally fused goggles (DENVG). In this paper we describe a new video engine developed at SCD to support the new 17μm pitch VGA detector. First, the modular design concept of the hardware for the new video engine is described. This is followed by a description of the software design concept, including features that emphasize the open architecture and the provision for a customer to add on his own algorithms and software. The detector and the engine are on low rate production these days. Full production is planned for Q4/2010.

Thales Cryogenics (TCBV) has an extensive background in developing and delivering long-life cryogenic coolers for military, civil and space programs. This cooler range is based on three main compressor concepts: rotary compressors (RM), linear close tolerance contact seals (UP), and linear flexure bearing (LSF/LPT) compressors. The main differences - next to the different conceptual designs - between these products are their masses and Mean Time To Failure (MTTF) and the availability prediction of a single unit. New developments at Thales Cryogenics enabling compact long lifetime coolers - with an MTTF up to 50.000 hrs - will be outlined. In addition new developments for miniature cooler drive electronics with high temperature stability and power density will be described. These new cooler developments could be of particular interest for space missions where lower costs and mass are identified as important selection criteria. The developed compressors are originally connected to Stirling cold fingers that can directly be interfaced to different sizes of available dewars. Next to linear coolers, Thales Cryogenics has compact rotary coolers in its product portfolio. Though having a higher exported vibration level and a more limited MTTF of around 8.000 to 10.000 hours, their compactness and high efficiency could provide a good alternative for compact cooling of sensors in specific space missions. In this paper an overview of lifetime parameters will be listed versus the impact in the different cooler types. Tests results from both the installed base and the Thales Cryogenics test lab will be presented as well. Next to this differences in operational use for the different types of coolers as well as the outlook for further developments will be discussed.

ABB Bomem is expanding its line of infrared remote sensing products with the addition of a new imaging spectroradiometer. The instrument is modular and support several configurations. One of its configurations is a multipixels sensor optimised for differential acquisition in the VLWIR to support research related to chemical detection. In that configuration, the instrument is equipped with a dual-input telescope to perform optical background subtraction. The resulting signal is the differential between the spectral radiance entering each input port. The other configuration is a general purpose imaging spectroradiometer designed to acquire the spectral signature of rapid events and fast targets in infrared. Overview of the design and results from tests and first field trials will be presented.

In today's naval missions, such as anti-piracy or counter-drugs operations, Electro-Optical (EO) sensors play an increasingly important role. In particular, these sensors are essential for classification and identification of targets. These tasks are traditionally performed by human operators, but because the complexity of today's missions, in combination with reduced manning, automating the information processing of EO sensors is increasingly necessary. This paper discusses the contribution of EO sensor systems to the picture compilation process, and how the deployment of EO sensors can be optimized for current naval missions. In particular, we discuss automation techniques for detection, classification and identification using EO sensors. Based on our findings, we give recommendations for future research.

The three dimensional noise model (3D noise) is a widely used model for characterizing noise in thermal imaging system. In this model, a sequence of images of a uniform background are acquired, and organized in a three dimensional matrix. This matrix is then decomposed into eight orthogonal noise components that can be assessed individually to yield an understanding about the magnitude and source of noise in a given system. Here we show that the estimators used to assess 3D noise are biased statistical estimators, which can lead to systematic errors when measuring system noise using this model. We provide mathematical proof of the estimator bias and demonstrate the effect with Monte-Carlo simulations.

Focal-plane array (FPA) IR systems are affected by fixed-pattern noise (FPN) which is caused by the nonuniformity of the responses of the detectors that compose the array. Due to the slow temporal drift of FPN, several scene-based nonuniformity correction (NUC) techniques have been developed that operate calibration during the acquisition only by means of the collected data. Unfortunately, such algorithms are affected by a collateral damaging problem: ghosting-like artifacts are generated by the edges in the scene and appear as a reverse image in the original position. In this paper, we compare the performance of representative methods for reducing ghosting. Such methods relate to the least mean square (LMS)-based NUC algorithm proposed by D.A. Scribner. In particular, attention is focused on a recently proposed technique which is based on the computation of the temporal statistics of the error signal in the aforementioned LMS-NUC algorithm. In this work, the performances of the deghosting techniques have been investigated by means of IR data corrupted with simulated nonuniformity noise over the detectors of the FPA. Finally, we have made some considerations on the computational aspect which is a challenging task for the employment of such techniques in real-time systems.

This paper introduces a new way to correct the non-uniformity (NU) in uncooled infrared-type images. The main defect of these uncooled images is the lack of a column (resp. line) time-dependent cross-calibration, resulting in a strong column (resp. line) and time dependent noise. This problem can be considered as a 1D flicker of the columns inside each frame. Thus, classic movie deflickering algorithms can be adapted, to equalize the columns (resp. the lines). The proposed method therefore applies to the series formed by the columns of an infrared image a movie deflickering algorithm. The obtained single image method works on static images, and therefore requires no registration, no camera motion compensation, and no closed aperture sensor equalization. Thus, the method has only one camera dependent parameter, and is landscape independent. This simple method will be compared to a state of the art total variation single image correction on raw real and simulated images. The method is real time, requiring only two operations per pixel. It involves no test-pattern calibration and produces no "ghost artifacts".

Improvised explosive devices (IEDs), one of today's major threats that armed forces have to cope with, are particularly menacing during field operations in which the same itinerary is used by troops on a regular basis. The detection of changes observed on an itinerary between different passages of a vehicle can be very revealing. We propose a low-cost solution implementing a GPS receiver, a three-axis magnetic compass as well as a video camera. This device, together with an image processing and computer vision scheme, allow the occupants of a vehicle to focus their attention on any visible changes occurring along their itinerary since a previous passage.

In the context of naval surveillance, shipboard Electro-Optical (EO) sensor systems can contribute to the detection, classification and identification of surface objects. Focusing on the detection process, our previous research offers a method using low-order polynomials for background estimation, which can be used for the automatic detection of objects in a naval environment. The polynomials are fitted to the intensity values in the image after which the deviation between the fitted intensity values and the measured intensity values are used for detection. The research presented in this paper, focuses on the impact of super-resolution algorithms on this detection process. Images enhanced by SR algorithms are expected to be mainly beneficial for classification purposes, regardless whether the classification is automatic or operator driven. This paper analyses the influence of SR algorithms on the detection performance in relation to the increase of computational complexity. The performance of the detection approach is tested on extensive dataset of maritime pictures in the Mediterranean Sea and in the North Sea collected on board of a frigate. We have found that for a good super-resolution image in this environment the sensor should be stabilised while recording and, for fast or near objects or when recording in heavier weather, should have a high frame rate and/or low exposure times.

The IR signature of an aircraft is the result of several major contributions, namely: Hot engine parts of the tail pipe and/or the air intakes; Combustion hot gases (and in some cases hot carbon particles) in the plume; Skin of the airframe, due to the thermal emission resulting from aerodynamic heating and internal heat sources and the reflected ambient radiation from the sun, the sky and the ground. The aim of this paper is to present how the SE-Workbench-EO from OKTAL-SE has been extended in the frame of PRESAGE project (with the financial support of DGA) for computing the IR signature of a jet aircraft taking all these major contributions into account and what kind of results can be obtained both for non real time and real time rendering.

CEA-Leti MINATEC has been involved in infrared focal plane array (IRFPA) development since many years, with performing HgCdTe in-house process from SWIR to LWIR and more recently in focusing its work on new ROIC architectures. The trend is to integrate advanced functions into the CMOS design for the purpose of applications demanding a breakthrough in Noise Equivalent Temperature Difference (NETD) performances (reaching the mK in LWIR band) or a high dynamic range (HDR) with high-gain APDs. In this paper, we present a mid-TV format focal plane array (FPA) operating in LWIR with 25μm pixel pitch, including a new readout IC (ROIC) architecture based on pixel-level charge packets counting. The ROIC has been designed in a standard 0.18μm 6-metal CMOS process, LWIR n/p HgCdTe detectors were fabricated with CEA-Leti in-house process. The FPA operates at 50Hz frame rate in a snapshot integrate-while-read (IWR) mode, allowing a large integration time. While classical pixel architectures are limited by the charge well capacity, this architecture exhibits a large well capacity (near 3Ge-) and the 15-bit pixel level ADC preserves an excellent signal-to-noise ratio (SNR) at full well. These characteristics are essential for LWIR FPAs as broad intra-scene dynamic range imaging requires high sensitivity. The main design challenges for this digital pixel array (SNR, power consumption and layout density) are discussed. The electro-optical results demonstrating a peak NETD value of 2mK and images taken with the FPA are presented. They validate both the pixel-level ADC concept and its circuit implementation. A previously unreleased SNR of 90dB is achieved.

The high level of accumulated expertise by ULIS and CEA/LETI on uncooled microbolometers made from amorphous silicon with 45μm, 35μm and 25μm, enables ULIS to develop VGA and XGA IRFPA formats with 17μm pixel-pitch to fulfill every applications. These detector keeps all the recent innovations developed on the 25μm pixel-pitch ROIC (detector configuration by serial link, low power consumption and wide electrical dynamic range). The specific appeal of these units lies in the high spatial resolution it provides while keeping the small thermal time constant. The reduction of the pixel-pitch turns the TEC-less VGA array into a product well adapted for high resolution and compact systems and the XGA a product well adapted for high resolution imaging systems. High electro-optical performances have been demonstrated with NETD < 50mK. We insist on NETD and wide thermal dynamic range trade-off, and on the high characteristics uniformity, achieved thanks to the mastering of the amorphous silicon technology as well as the ROIC design. This technology node paves the way to high end products as well as low end compact smaller formats like 320 x 240 and 160 x 120 or smaller.

We report high sensitivity carbon nanotube (CNT) based middle wave infrared (MWIR) sensors with a two-dimensional photonic crystal waveguide. MWIR sensors are of great importance in a variety of current military applications including ballistic missile defense, surveillance and target detection. Unlike other existing MWIR sensing materials, CNTs exhibit low noise level and can be used as new nano sensing materials for MWIR detection where cryogenic cooling is not required. However, the quantum efficiency of the CNT based infrared sensor is still limited by the small sensing area and low incoming electric field. Here, a photonic nanostructure is used as a resonant cavity for boosting the electric field intensity at the position of the CNT sensing element. A two-dimensional photonic crystal with periodic holes in a polymer thin film is fabricated and a resonant cavity is formed by removing holes from the array of the photonic crystal. Based on the design of the photonic crystal topologies, we theoretically study the electric field distribution to predict the resonant behavior of the structure. Numerical simulations reveal the field is enhanced and almost fully confined to the defect region of the photonic crystal. To verify the electric field enhancement effect, experiments are also performed to measure the photocurrent response of the sensor with and without the photonic crystal resonant cavity. Experimental results show that the photocurrent increases ~3 times after adding the photonic crystal resonant cavity.

This paper presents an overview of the very recent developments of the MCT infrared detector technology developed by CEA-LETI and Sofradir in France. New applications require high sensitivity, higher operating temperature and dual band detectors. The standard n on p technology in production at Sofradir for 25 years is well mastered with an extremely robust and reliable process. Sofradir's interest in p on n technology opens the perspective of reducing dark current of diodes so detectors could operate in lower flux or higher operating temperature. In parallel, MCT Avalanche Photo Diodes (APD) have demonstrated ideal performances for low flux and high speed application like laser gated imaging during the last few years. This technology also opens new prospects on next generation of imaging detectors for compact, low flux and low power applications. Regarding 3rd Gen IR detectors, the development of dual-band infrared detectors has been the core of intense research and technological improvements for the last ten years. New TV (640 x 512 pixels) format MWIR/LWIR detectors on 20μm pixel pitch, made from Molecular Beam Epitaxy, has been developed with dedicated Read-Out Integrated Circuit (ROIC) for real simultaneous detection and maximum SNR. Technological and products achievements, as well as latest results and performances are presented outlining the availability of p/n, avalanche photodiodes and dual band technologies for new applications at system level.

HgCdTe (Mercury Cadmium Telluride / MCT) staring arrays for infrared detection do show constant improvements regarding their compactness and performances. Among the new detectors, the family of 15 μm pixel pitch detectors is offering a mid-TV format (384 x 288), a TV format (640 x 512) and a HD-TV format (1280 x 1024). Each detector is available in a SWaP configuration (meaning dedicated to applications requiring low Size, Weight and Power) Thanks to recent improvements and new technological breakthrough, the MCT technology allows operating detectors at higher temperature, in order to save power consumption at system level. In parallel, the 15μm pitch permits to reach challenging density and spatial resolution. These Focal Plane Arrays (FPA) are proposed in different tactical dewars, corresponding to various systems solutions.

We report our latest development of HgCdTe electron avalanche photodiode (e-APD) with Cd compositions between 0.3 to 0.41; exponentially increasing gain, synonym of exclusive electron multiplication, was observed in all the devices up to M>600, associated with low noise factors F=1.2; a record high gain of M=7000 was measured in e-APDs with λ_c=4.6μm at 80K, which shows on the stability of the junction; the equivalent input dark current decreases with increasing band-gap and a record low value of 2 aA, was obtained in a λ_c=2.9 μm e-APD at M=24 and spectral response measurements have shown that the gain and quantum efficiency is conserved down to the UV. Dedicated ROICs have been designed for passive and active laser assisted imaging. A passive imaging ROIC for low flux application have been designed for a full frame readout speed of 1.5 kfps and an equivalent input noise lower than 2 electrons. Two active imaging ROICs have already been validated with e-APD arrays. Dual mode passive and active 2D (range gated) e-APDs FPAs have been made using with cut-off wavelengths ranging from 2.9μm to 5.3μm at T=80 K. On the best devices, the operability in gain and noise exceeds 99.6% and relative gain dispersion lower than 10 %, independently of the wavelength at gains M=10-100. First characterizations of multi-mode 3D/2D FPA have shown on a range resolution below 15 cm (1 ns).

CEA-Leti has developed a 320x256 FPA for 3D flash LADAR active imaging. The readout IC (ROIC) performs time-of-flight (TOF) measurement in addition to 2D intensity imaging with a single emitted laser pulse. The FPA consist of a ROIC hybridized to a 30 μm pitch HgCdTe avalanche photodiode (APD) array. The illuminator used for testing this FPA is a 1.57 μm laser producing 8 ns pulses with a maximum energy of 8 mJ per pulse. This paper describes the readout IC pixel architecture and presents ranging performances obtained in laboratory conditions. The first 2D and 3D active images obtained during the first field trial of our prototype LADAR system are presented.

To address the growing needs of the automotive industry for low cost solutions to far infrared imaging, a silicon - silicon germanium (Si/SiGe) quantum well resistive bolometer technology is presented. The Si/SiGe thermistor structure is epitaxially grown and combines a high temperature coefficient of resistance (TCR) with low flicker noise. A TCR of approximately 3%/K for a Ge fraction of 32% is demonstrated. Quantum mechanical calculations show that a minimum SiGe layer thickness of 8 nm is needed to avoid degradation caused by ground state shift due to carrier confinement in the SiGe potential wells. In contrast to most of today's bolometer designs, the optical quarter wave cavity needed to achieve high absorption of radiation is an integral part of the quantum well thermistor structure. Optimization of the full bolometer design is made where the interaction between optical absorption, heat capacity and electrical properties is considered and a design approach targeting the lowest noise equivalent temperature difference is presented. As part of the optimization, it was found that for the best overall solution, optical absorption can be sacrificed in favor for a smaller heat capacity.

Today's readout integrated-circuits (ROICs) require a high level of integration of high performance analog and low power digital logic. TowerJazz offers a commercial 0.18μm CMOS technology platform for mixed-signal, RF, and high performance analog applications which can be used for ROIC applications. The commercial CA18HD dual gate oxide 1.8V/3.3V and CA18HA dual gate oxide 1.8V/5V RF/mixed signal processes, consisting of six layers of metallization, have high density stacked linear MIM capacitors, high-value resistors, triple-well isolation and thick top aluminum metal. The CA18HA process also has scalable drain extended LDMOS devices, up to 40V V_ds, for high-voltage sensor applications, and high-performance bipolars for low noise requirements in ROICs. Also discussed are the available features of the commercial SBC18 SiGe BiCMOS platform with SiGe NPNs operating up to 200/200GHz (f_T/f_MAX frequencies in manufacturing and demonstrated to 270 GHz f_T, for reduced noise and integrated RF capabilities which could be used in ROICs. Implementation of these technologies in a thick film SOI process for integrated RF switch and power management and the availability of high f_T vertical PNPs to enable complementary BiCMOS (CBiCMOS), for RF enabled ROICs, are also described in this paper.

This paper introduces a simple vacuum packaging method which is based on a Chip-to-Wafer process. The MEMS-device is provided with an electroplated solder frame. A Si-lid with the same solder frame is mounted on each die of the wafer using a flip chip process. The same materials for lid and substrate are used in order to reduce the mechanical stress due to the same thermal coefficients of expansion. The resulting cavity between die and lid can be evacuated and hermetically sealed with an eutectic soldering process. The feasibility of the method is demonstrated with an infrared focal plane array (IR-FPA). In this case, the Si-lid acts as an optical window and contains an anti reflective layer for the 8-14 μm wavelength area on both sides. The long-term vacuum stability is supported by a getter film inside the package. This method simplifies the sawing process and has the additional cost benefit that it is possible to package only known good dies.

Reducing production costs would contribute to keep on extending applications of uncooled IRFPA to high volume of low cost camera market where weight, power and cost reduction are of importance. Since the first proof of the pixel level packaging for uncooled IRFPA in 2008, CEA-LETI, MINATEC is still strongly involved in an innovative packaging technology. The main point is that no additional technological steps are necessary to integrate the FPA chip under vacuum as the microbolometer process comprises itself the vacuum integration at the pixel level. Moreover, to keep the vacuum level around each microbolometer a thin film getter is deposited. This paper presents the recent development at CEA-LETI, MINATEC of this innovative packaging technology with getter inside.

The thermal analysis (TA) of the wave propagation in the mid-wave (MWIR) and long-wave (LWIR) infrared bands performed by the direct solutions of the Maxwell electromagnetic (EM) problem with numerical methods is used to propose the design of metamaterials suitable for a new type of thermal vision camouflage, that can be prepared using a nano particle lattice in the IR bands. This lattice, called photonics band gap devices (PBG) or more in general photonic crystal (PhC) works on IR photons providing absorbing, transmission and reflecting bands. All the optical properties are function of the specific nano design tuned in the IR wavelength.

Electro-optical laser systems that use astigmatic semi-conductor laser diodes frequently use beam shaping mechanisms to eliminate the astigmatism and improve the beam uniformity. Conventional beam shaping solutions that use asymmetric diffractive or refractive optical systems are expensive and add additional opto-mechanical complexity. An effective alternative approach to using either the conventional refractive or diffractive methods is to intentionally introduce specific optical aberrations into the transmitted beam. The intentional introduction of optical aberrations is not a universal alternative, but in many cases the introduced aberrations minimize the astigmatic characteristics of the emitted laser diode radiation sufficiently to make further reduction unnecessary. The technique has been used by the authors, in a number of laser designator and LIDAR transceiver designs. This paper describes how this technique has been successfully used to produce lower cost, high performance laser systems. A simple design example is presented together with a description of the modeling techniques employed and measured field test results.

Technology of infrared (IR) photovoltaic (PV) focal plane arrays (FPA) covering spectral range from 1.6 to 14 μm gradually moves from simple quasi-matrix (linear) arrays like as 4×288 pixels to large format high definition arrays 1280×1024 pixels and more. Major infrared detector materials for PV technology are InSb and its alloys and ternary alloys Hg_1-xCd_xTe. Progress in IR PV technology was provided in last decade by serious improvement in material growing techniques. Increasing of PV array format is related always to decreasing of pixel size and spacing between neighbor pixels to minimal size reasonable from point of view of infrared physics. So pitch is small (15-25 μm) in large format arrays. Ambipolar diffusion length of photogenerated charge carriers can exceed pitch many times in high quality absorption layers of PV arrays. It means that each pixel can collect excess charge carriers generated far from n⁺-p junction border. Optimization of resolution, filling factor and cross-talking level of small-pitched PV FPA requires comprehensive estimation of photodiode's (PD) pixel performance depending on pixel and array design, material properties and operating conditions. Objective of the present work was to develop general approach to estimate collection of photogenerated charge carriers in small-pitched arrays.

In several applications, it is important to determine if a target can be easily detected, recognized or identified. It is common practice to measure its thermal signature, represented by the thermal contrast, defined as the target background differencial temperature. In order to obtain the thermal contrast, it is necessary to establish a relationship between the radiance detected by the sensor and the target temperature. Energy emitted by the target will depend not only on its temperature but also on its emissivity. On the other hand, energy received on the sensor will depend, among other factors, on the atmospheric conditions which will affect the path radiance. Hence, target temperature, emissivity and atmospheric conditions are essential parameters in order to give accurate measurements of the thermal contrast. In this work, we propose a comparison between two methods to split temperature and emissivity from radiance measurements, "The Grey Body Emissivity (GBE)" algorithm and the "Bayesian Inference (BI)" method. This comparison has been done with spectral radiance measured with a FTIR spectroradiometer in the MWIR (3-5μm) and LWIR (8-12μm) bands. Measurements were done over a blackbody at different distances (ranging from 6cm to 15m) and temperatures (ranging from 0°C to 140°C), and over metallic plates of different materials and finishing at a fixed temperature of 55°C. Atmospheric conditions were modeled using MODTRAN 4.0 v3r1 computer code.

The paper presents an initial concept of the electro-optical sensor unit for sniper detection purposes. This unit, comprising of thermal and daylight cameras, can operate as a standalone device but its primary application is a multi-sensor sniper and shot detection system. Being a part of a larger system it should contribute to greater overall system efficiency and lower false alarm rate thanks to data and sensor fusion techniques. Additionally, it is expected to provide some pre-shot detection capabilities. Generally acoustic (or radar) systems used for shot detection offer only "after-the-shot" information and they cannot prevent enemy attack, which in case of a skilled sniper opponent usually means trouble. The passive imaging sensors presented in this paper, together with active systems detecting pointed optics, are capable of detecting specific shooter signatures or at least the presence of suspected objects in the vicinity. The proposed sensor unit use thermal camera as a primary sniper and shot detection tool. The basic camera parameters such as focal plane array size and type, focal length and aperture were chosen on the basis of assumed tactical characteristics of the system (mainly detection range) and current technology level. In order to provide costeffective solution the commercially available daylight camera modules and infrared focal plane arrays were tested, including fast cooled infrared array modules capable of 1000 fps image acquisition rate. The daylight camera operates as a support, providing corresponding visual image, easier to comprehend for a human operator. The initial assumptions concerning sensor operation were verified during laboratory and field test and some example shot recording sequences are presented.

Images produced by IR cameras are a specific source of information. The perception and interpretation of such image greatly depends on thermal properties of observed object and surrounding scenery. In practice, the optimal settings of the camera as well as automatic temperature range control do not guarantee the displayed images is optimal from observer's point of view. The solution to this could be the methods and algorithms of digital image processing implemented in the camera. Such solution should provide intelligent, dynamic contrast control applied not only across entire image but also selectively to specific areas in order to maintain optimal visualization of observed scenery. The paper discusses problems dealing with improvement of the visibility of low-contrast objects and presents method of image enhancement. The algorithm is based on adaptive histogram equalization. The image enhancement algorithm was tested on real IR images. The algorithm significantly improves the image quality and the effectiveness of object detection for the majority of thermal images. Due to its adaptive nature it should be effective for any given thermal image. The application of such algorithm is promising alternative to more expensive opto-electronic components like improved optics and detectors.

The recent necessity to protect military bases, convoys and patrols gave serious impact to the development of security systems for perimeter protection. The application of multi-sensor increases functionality and performance of the whole system. Effective ranges of detection depend on the class of the sensor used and the observed scene itself. One of the most important devices used in such systems are IR cameras. Application of IR camera increases the probability of intruder detection regardless of the time of day or weather conditions. It also increases the probability of intruder detection and simultaneously decreased the false alarm rate produced by the system. The paper discusses technical possibilities and limitations to use uncooled IR camera in a multi-sensor system for perimeter protection. The role of IR cameras in the system was discussed as well as technical possibilities to detect human being. The operational distances for perimeter protection are rather high, considering parameters of commercially available thermal cameras. Comparison of exemplary IR cameras, capable to achieve desired ranges was done. The required spatial resolution for detection, recognition and identification was calculated. The simulation of detection ranges was done using NVTherm software. The results of analysis and simulations were finally presented.