Bodenseewerk Geratetechnik GmbH (BGT), located at the Lake of Constance, is the prime contractor for the European production of the AIM-9L Sidewinder air-to-air missile. It is active on the field of seeker and missile development and manufacturing, including such missile systems like Sidewinder AIM-9L, RAM, Stinger, TRIGAT and IRIS-T. Along with the different projects, the BGT HIL simulation facility grew continuously. Particularly for the TRIGAT system tests, where an Infra Red Scene Projector (IRSP) from British Aerospace is used, a dedicated subsystem had been built to prevent damaging the IRSP. The general setup of the BGT HIL environment is presented with special emphasis on this proprietary `collision avoidance system'.

This paper addresses the Infrared Sensor Stimulator (IRSS) which will be used to stimulate installed Infrared/Ultraviolet (IR/UV) Electro-Optic sensors undergoing integrated developmental and operational testing. The IRSS program was first briefed at AEROSENSE 1996. This paper updates the capabilities and status of IRSS over the subsequent three years. It provides an overview of the IRSS subsystems and functions with emphasis on facility integration and discussion of the IR modeling, scene generation, and scene projection components.

This paper describes the Advanced Simulation Center (ASC) role, recaps the past year, describes the hardware-in-the- loop (HWIL) components and advancements, and outlines the path-ahead for the ASC in terms of both missile and complete system HWIL simulations and test with a focus on the imaging infrared systems.

The Ballistic Missile Defense Organization (BMDO) sponsored the development of the Kinetic Kill Vehicle Hardware-in-the- Loop Simulator (KHILS) to provide a comprehensive ground test capability for end game performance evaluation of BMDO interceptor concepts. Since its inception in 1986, the KHILS facility has been on the forefront of HWIL test technology development. This development has culminated in closed-loop testing involving large format resistive element projection arrays, 3D scene rendering systems, and real-time high fidelity phenomenology codes. Each of these components has been integrated into a real-time environment that allows KHILS to perform dynamic closed-loop testing of BMDO interceptor systems or subsystems. Ongoing activities include the integration of multiple resistor arrays into both a cold chamber and flight motion simulator environment, increasing the update speed of existing arrays to 180 Hz, development of newer 200 Hz snapshot resistor arrays, design of next generation 1024 X 1024 resistor arrays, development of a 1000 Hz seeker motion stage, integration of a resistor array into an RF chamber, and development of advanced real-time plume flow-field codes. This paper describes these activities and test results of the major facility components.

In recent years computer performance has been improving so rapidly that hardware-in-the-loop simulation by using computer generated images (CGI-HWIL simulation) has come to play the great role in developing and evaluating many kinds of imaging missile systems. Generally speaking, there are two principle methods in CGI-HWIL simulation. One is a method using scene projector for in-band seeker under test, and the other is a method injecting image directly into missile signal processing unit beyond seeker sensor.

For the past three years, the U.S. Army Aviation and Missile Command has been developing a hardware-in-the-loop (HWIL) simulation facility to test common aperture multi-spectral missile seekers. This paper discusses the problems encountered during the development of this facility, the solutions, and the resulting capability of this unique HWIL simulation facility. The Advanced Simulation Center is managed and operated by the Systems Simulation and Development Directorate of the Missile Research, Development, and Engineering Center, Redstone Arsenal, Alabama.

The rapid advance of computer technology and advances in image generation and projection have provided unprecedented growth in the fidelity of hardware-in-the-loop (HITL) simulation. HITL simulation has improved to a level where it can support operational test and evaluation, often providing better insight into system performance than traditional open-air flight tests. This comes at a time of increasing open-air test costs and decreasing test budgets, two factors that are driving the movement for simulation based acquisition. We present two case studies on the application of HITL simulation to the operational test of the AGM-65 Maverick missile system. These studies demonstrate their fidelity of modern HITL simulation, highlight the benefits derived from this testing, and examine the cultural and technical impediments hindering the wider acceptance of simulation based acquisition efforts.

Holographic Interferometry has been successfully employed to characterize the materials and behavior of diverse types of structures under stress. Specialized variations of this technology have also been applied to define dynamic and vibration related structural behavior. Such applications of holographic technique offer some of the most effective methods of modal and dynamic analysis available. Real-time dynamic testing of the structural behavior of aerodynamic control and airfoil structures for advanced aircraft and missile systems has traditionally required advanced instrumentation for data collection in either actual flight test or wind-tunnel simulations. Advanced optical holography techniques are alternate methods which result in full-field behavioral data on the ground in a nondestructive hardware- in-the-loop environment. These methods offer significant insight in both the development and subsequent operational test and modeling of advanced control and airfoil structures and their integration with total vehicle system dynamics. Aerodynamic control structures and components can be analyzed in place with very low amplitude excitation and the resultant data can be used to adjust the accuracy of mathematically derived structural and behavioral models as well actual performance.

The Dynamic InfraRed Scene Projector (DIRSP) meets Army requirements for low-background hardware-in-the-loop testing of imaging infrared sensors. These requirements are met using cryogenic, vacuum technology to cool optical elements and emitter array sources. This paper discusses design and fabrication of two DIRSP subsystems, the Environmental Conditioning Subsystem, and the Mounting Platform Subsystem. These two subsystems enclose and support the Projection Optics Subsystem, and the Infrared Emitter Subsystem.

The utilization of a 672 X 544-resistor array based Mobile Infrared Scene Projector (MIRSP) for hardware-in-the- loop test and evaluation of installed imaging infrared (I²R) sensors is presented. The Army US Test and Evaluation Command is developing MIRSP systems for T&E of I²R sensors installed on both aviation and ground platforms. The initial pathfinder MIRSP, discussed here, will be used as a risk-mitigation tool to help determine and define requirements for the objective MIRSP systems. A description of the pathfinder MIRSP configuration, performance characteristics, and operational modes is provided.

In this paper, our facilities for hardware-in-the-loop simulation (flight simulator, computer, and target generator) are presented. then, the simulation execution approach and method in various development phases are described focusing on the example in which a dual-mode optical sensor is evaluated. Specifically the execution approach in the case only with a sensor (without navigation unit etc.) is described first. Secondly the approach in which a navigation unit is added to a sensor is described. Furthermore, the approach is described when a control unit that includes a servomotor and control surfaces is added to them.

Synthetic scene generation systems require huge computational resources to operate on potentially large data sets of information and to interface to advanced sensor technology via current scene projectors. Nallatech Ltd has been focused in the area of low latency hardware and algorithm development for many years. In collaboration with Matra British Aerospace Dynamics UK, minimum latency systems have already been developed offering latency of only several video lines in 3D target scene generation systems. The rapid progression of FPGAs towards 1 million gate devices together with the ever increasing performance of today's DSPs have allowed Nallatech to formulate an architecture that is particularly suited to HWIL systems.

LADAR (Laser Detection and Ranging) as its name implies uses laser-ranging technology to provide information regarding target and/or background signatures. When fielded in systems, LADAR can provide ranging information to on board algorithms that in turn may utilize the information to analyze target type and range. Real-time closed loop simulation of LADAR seekers in a hardware-in-the-loop (HWIL) facility can be used to provide a nondestructive testing environment to evaluate a system's capability and therefore reduce program risk and cost. However, in LADAR systems many factors can influence the quality of the data obtained, and thus have a significant impact on algorithm performance. It is important therefore to take these factors into consideration when attempting to simulate LADAR data for Digital or HWIL testing. Some of the factors that will be considered in this paper include items such as weak or noisy detectors, multi-return, and weapon body dynamics. Various computer techniques that may be employed to simulate these factors will be analyzed to determine their merit in use for real-time simulations.

A modular cost-effective Infrared Scene Projector (IRSP) system has been designed for testing infrared sensor(s) installed on host aerospace platform(s) in an anechoic chamber environment. The IRSP consists of the following major functional subsystems: Control Electronics Subsystem, Infrared Emitter Subsystem, Projection Optics Subsystem, Mounting Platform Subsystem and Non-Uniformity Correction Subsystem.

This paper describes the test results for the MIRAGE read- in-integrated-circuit (RIIC) designed by Indigo Systems Corporation. This RIIC, when mated with suspended membrane, micro-machined resistive elements, forms a highly advanced emitter array. This emitter array is used by Indigo and Santa Barbara Infrared Incorporated in a jointly developed product for infrared scene generation, called MIRAGE. The MIRAGE RIIC is a 512 X 512 pixel design which incorporates a number of features that extend the state of the art for emitter array RIIC devices. These innovations include an all-digital interface for scene data, snapshot image updates (all pixels show the new frame simultaneously), frame rates up to 200 Hz, operating modes that control the device output, power consumption, and diagnostic configuration. Tests measuring operating speed, RIIC functionality and D/A converter performance were completed. At 2.1 X 2.3 cm, this die is also the largest nonstitched device ever made by Indigo's foundry, American Microsystems Incorporated. As with any IC design, die yield is a critical factor that typically scales with the size and complexity. Die yield, and a statistical breakdown of the failures observed will be discussed.

This paper presents the optical layout that is used to stimulate air-to-ground and ground-to-ground IR seekers featuring: (1) a silicon graphics calculator based IR scene generator; (2) a high flux visible projector; (3) a cooled infrared transducer including a large dimension cell (for high-resolution IR images). Vacuum is realized around the cell in order to optimize its transduction parameters (dynamics, rise time, MTF) from the visible to the IR. The transducer is embedded into an enclosure in which a cooled fluid circulates. The paper describes the development steps of the enclosure and especially the integration of cooled windows in it; and (4) the non-uniformity correction system, which is an electronic device designed around an EEPROM storing video scene parameters (pixel by pixel correction). In addition, the stress is put on a method for correction coefficients generating using IR imagers and image processing. As a conclusion, possible next developments are discussed and some comparison to other IR scene projection systems (cost, performances).

In 1991 the Honeywell Technology Center began the development of large area 2D microemitter arrays for IR scene projection. Since then, 5 different types of 512 X 512 or larger arrays have been fabricated, all in current use. This paper will review the status, properties, and applications of these arrays. Pixel and array improvements which will lead to ultralow power consumption, very high performance, very fast 1024 square arrays are under development. A number of these efforts are described.

As part of the Dynamic Infrared Scene Projector (DIRSP) program a new 672 X 544 format suspended membrane microresistor emitter array has been developed. For risk mitigation purposes, the DIRSP arrays were development in phases. In the first phase, a trade-off-analysis and detailed design effort was performed. The second phase followed with the production of a number of DIRSP Engineering Grade Arrays (DEGAs). The second phase included evaluation of DEGAs to determine the need for any design changes for the third and final phase arrays. The third and final phase produced the science grade arrays for the DIRSP program. The DEGAs were the first resistor arrays fabricated using a three level metal CMOS production process. The uncorrected subjective image quality, before application of Non-Uniformity Correction, is significantly better than any pre-existing resistor array known to the authors. A detailed characterization of the spatial, temporal, spectral and radiometric properties of a sample DEGA array is provided here.

The MIRAGE Dynamic IR Scene Projector is a standard product being developed jointly by Santa Barbara Infrared, Inc. and Indigo Systems Corporation. MIRAGE is a complete IR scene projection system, accepting digital or analog scene data as the input and providing all other electronics, optics and mechanics to project high fidelity dynamic IR scenes to the unit under test. At the heart of the MIRAGE system is the 512 X 512 microemitter array that incorporates many state-of-the-art features previously not available. The Read-In-Integrated-Circuit (RIIC) leverages technology from IR Focal Plane electronics to provide a system with advanced capability with low risk. The RIIC incorporates on chip DACs, snap-shot frame updating, constant current mode, voltage drive emitters and substrate ground plane providing high resolution and low noise performance in a very small package. The first 512 X 512 microemitter assembly has been received and was imaged on 2 APR 99. The complete MIRAGE system is currently in integration with the first deliverable unit scheduled for June 1999.

This paper describes the application of multiple IR projector technologies to hardware-in-the-loop (HWIL) simulations at the US Army Aviation and Missile Command's (AMCOM) Missile Research, Development, and Engineering Center (MRDEC). Several projectors utilizing a variety of emerging technologies are currently being successfully applied within the HWIL facilities of AMCOM's MRDEC. Projector technologies utilized at AMCOM include laser diode array projectors, Honeywell's bright resistive infrared thermal emitter arrays, an IR zoom projector with thermoscenes, and steerable point source projectors. Future plans include a new resistor array projector called the Multispectral Infrared Animation Generation Equipment, which is being manufactured by Santa Barbara Infrared. These projector technologies have been used to support multiple HWIL test entries of various seeker configurations. Seeker configurations tested include: two InSb 256 X 256 FPAs, an InSb 512 X 512 FPA, a PtSi 640 X 480 FPA, a PtSi 256 X 256 FPA, a HgCdTe 256 X 256 FPA, a scanning linear array, and an uncooled 320 X 240 microbolometer FPA. The application, capabilities, and performance of each technology are reviewed in the paper. Example imagery collected from each operational system is also presented.

We describe preliminary characterization results from two newly completed types of 512 X 512 IR scene projection system, covering the cardinal performance features. The two systems have been optimized for different applications, one specializing in high radiometric output and speed, the other in radiometric accuracy and low fixed-pattern noise. The devices show improvements over our previous systems not only in complexity, but also in dynamic output, picture dependency performance and non-uniformity correction. Both systems have been built to operate on flight motion simulator tables.

This paper discusses the performance of the Wideband Infrared Scene Projector (WISP) phase III arrays. Characterization measurements including: spectral output, dynamic range capability, apparent temperature, rise time, and fall time, have been accomplished on the WISP-III array at the Kinetic Kill Vehicle Hardware-in-the Loop Simulator facility and the Guided Weapons Evaluation Facility, Eglin AFB, FL.

The third generation of the Wide-band Infrared Scene Projector (WISP) resistor arrays has been delivered to the Air Force Research Laboratory's Kinetic Kill Vehicle Hardware-in-the-Loop Simulation facility. A critical parameter in determining the extent with which the thermal arrays simulate the real world is the radiometric and thermal resolution. The measurement of the resolution is dependent upon several factors including the input data word resolution, drive electronics resolution, system noise factors, and the measurement sensor. Several measurements were made to quantify the noise components of the WISP array and the measurement sensor to determine the limiting factor for the measurements. Due to the nonlinear transfer function between the command voltage and the projected radiance, measurements were made at several input levels to determine how the resolution varies as a function of command voltage level. Measurements were performed both with and without the spatial non-uniformity correction (NUC) applied to determine the impact of the NUC on the radiometric resolution. Based on the results of these measurements the resolution of the WISP arrays is defined in both radiometric and thermal units.

The Wideband Infrared Scene Projector (WISP) has been undergoing development for the Kinetic-Kill Vehicle Hardware-in-the-Loop Simulator facility at Eglin AFB, Florida. In order to perform realistic tests of an infrared seeker, the radiometric output of the WISP system must produce the same response in the seeker as the real scene. In order to ensure this radiometric realism, calibration procedures must be established and followed. This paper describes calibration procedures that have been used in recent tests. The procedures require knowledge of the camera spectral response in the seeker under test. The camera is set up to operate over the desired range of observable radiances. The camera is then nonuniformity corrected (NUCed) and calibrated with an extended blackbody. The camera drift rates are characterized, and as necessary, the camera is reNUCed and recalibrated. The camera is then set up to observe the WISP system, and calibration measurements are made of the camera/WISP system.

The KHILS Vacuum Cold Chamber (KVACC) provides the capability of testing IR seekers with scenes involving a `cold' background, more closely simulating a high altitude/exoatmospheric engagement. During the past year, a gaseous helium refrigeration system has been installed to simplify the logistics of cooling the chamber. An antechamber has also been installed to serve as a chamber for the sensor under test. A WISP array was installed in the Source Chamber. A thermal control system was developed by connecting the array to a cold surface by way of a thermal choke, then actively controlling the temperature with heating elements. This made it possible to operate the array at user selected, stable substrate temperatures ranging from ambient temperature to below 150 K. This capability makes it possible to select the infrared background level that the array operates at, and to operate with background levels that are adequate for testing the high altitude/exoatmospheric engagements. WISP arrays were designed for room temperature operation, but predicted performance at reduced temperatures appears acceptable. Tests were performed with a Phase I prototype WISP array inside the KVACC Source Chamber. Data on this array's radiometric response at various substrate temperatures are presented. It is demonstrated that the arrays can be operated at substrate temperatures as low as 145 K. Currently two Phase 3 WISP arrays and a dichroic beam combiner are being installed in the Source Chamber for 2- color testing.

Advanced in integrated circuit design and micro-machining of silicon have enabled the fabrication of inexpensive, 2D arrays of resistively heated hot-plates, monolithically integrated with addressing the drive circuitry. Infrared scene simulators using these devices have broad-band spectral radiance which approximates naturally occurring thermal radiation. Characterization of these devices involves near field, far field, temporal and electrical measurements. Devices characterized here are experimental SPAWARSYSCEN, San Diego designs which test concepts for inexpensive fabrication, and a British Aerospace experimental hot-plate design for radiant uniformity improvement. Measurements reported here in the mid-band IR include effective temperature, radiance uniformity, temporal response, radiance distributions over single pixels, and effective fill factor. Also included are near field and far field measurements to characterize an add-on device for effective fill factor and efficiency improvements.

Addressing scene display noise problems in a manner consistent with real-time, hardware-in-the-loop testing requirements is an important issue. Measurements and analysis of different type noise problems in the WISP thermal array, an LCD visible projector and a dynamic laser spot projector have been undertaken. Solutions are offered, some of which are identical for very different kinds of noise. Trade-offs between noise reduction and other display features are discussed. This work originated at Eglin Air Force Base in the Guided Weapons Evaluation Facility.

This paper represents a new real-time infrared scene simulator. Hardware architecture of the simulator contains two PENTIUM 300 MHz CPUs, a hardware Z-BUFFER controller developed by EPLD, and a data transmission controller based on PCI bus, which is presented on basis of the timing analysis of scene simulator process. The software finishes the geometry transform, clipping, and infrared simulator of 3D model of a target to create data for hardware Z-BUFFER controller. The experimental results indicate that software can successfully cooperate with hardware to meet the great demand of application in practice.

The Quick Image Display (QUID) model accurately computes and displays radiance images at animation rates while the target undergoes unrestricted flight or motion. QUID uses a novel formulation for reflective/emissive terms which enables rapid and accurate target image rendering. The fundamental quantity which enters into the determination of reflected radiation is the bi-directional reflectance distribution function (BRDF). QUID's BRDF formulation involves decomposition of the BRDF into a generalized sum of product terms. Each product term is factored into separable spectral and angular functions. The spectral terms can be pre- calculated for the user specified bandpass and for a set of target observer ranges. The only BRDF calculations which must be performed during the simulation involves the observer-target-source angular functions which change with target orientation. Reflected solar radiation can dominate the apparent target signature of aircraft in daytime scenes in the MWIR/SWIR spectral regions. To accurately simulate reflections from curved surfaces either a large number of small flat facets must be used or some type of pseudo curvature technique. Both of these approaches tend to significantly slow down scene rendering. The main thrust of this effort is to find rapid techniques for accurate specular glint rendering on curved surfaces.

One of the challenging areas in real-time infrared scene generation is rendering gaseous and particulate volumes such as missile and aircraft exhaust plumes. New research in particle graphics has shown potential for improving the spatial/temporal fidelity of images produced by present systems. To apply particle graphics in real-time applications, new techniques were developed to leverage the resources in modern computing platforms, particularly the separate pipelines for general-purpose computing and 3D graphics. By taking advantage of these combined resources, the new method has been used to demonstrate real-time frame rates on low-end commercial systems. The rendering software internally computes, stores, and blends pixel intensities in floating point precision so that pixel accuracy is maintained over many decades of flow field emission level. The rendering scheme is scalable, providing a continuum of speed-fidelity tradeoffs across different computing platforms. The rendering approach has also been extended to incorporate moving particles in order to inject dynamic characteristics such as flow and turbulence into the IR imagery, providing a capability not available in current hardware-in-the-loop systems.

This paper is a continuation of a previous effort with an emphasis on the modeling techniques utilized to generate high-resolution IR terrain and sea backgrounds for low altitude scenarios. This paper briefly reiterates the IR scene generation process and unique modeling techniques implemented to build the various target models. This is followed by a detailed discussion on the development of the terrain and sea backgrounds necessary to support low altitude air engagement applications. Finally, a description of the process to render the composite target and background scenes using commercial graphics hardware to satisfy the frame-rate requirements for this program is presented.

A search is commenced directed towards understanding the fundamental elements that underlie the generation of nonuniformity correction information in dynamic infrared scene projection systems.

The contribution of a scene projector array to the nonuniformity of a test article's output image has been calculated. In addition to the inherent nonuniformity of the detector array, the output image nonuniformity is dependent upon the nonuniformity of the projector array and the relative positions of emitter images on the detector array as determined by the sampling ratio. In order to calculate the predicted output nonuniformity, a weighting function was developed that accounts for the different contributions of one emitter to different individual detector elements. It is through this weighting function that parameters such as the sampling ratio, the fill factor of the detector array, the optical blur of the emitters, and the alignment of the emitters with respect to the detectors affect the nonuniformity. A computer program has been written to numerically approximate the weighting function for a user- defined set of parameters. For realistic parameters, a significant contribution to the nonuniformity was found to occur when certain non-integer sampling ratios are used. This nonuniformity is based solely on the relative positions of the emitter images on the detector array and will occur even if the projector array is completely uniform.

Pixel-to-pixel radiance nonuniformity is the prominent noise source from resistive arrays and must be compensated or otherwise mitigated for high-fidelity testing of infrared imaging sensors. Many of the current advances in the capability of resistive array, IR scene projection rest in the improvement of nonuniformity correction (NUC) schemes. Early NUC schemes address the problem of optical crosstalk or spreading and the types of algorithms available that help to mitigate its effect when individual pixel radiometry is performed. However, there has been relatively little work done on scene-based correction to date where the effects such as power drops across the emitter array and thermal crosstalk are important to consider. This paper will examine potential problem areas in scene-based correction and discuss possible algorithms that could be used in a scene- based NUC approach.

The Redstone Technical Test Center (RTTC) has the requirement to project dynamic, infrared (IR) imagery to sensors under test. This imagery must be of sufficient quality and resolution so that, sensors under test will perceive and respond just as they do to real-world scenes. In order to achieve this fidelity from a pixelized infrared resistor emitter array, non-uniformity correction (NUC) is necessary. An important step in performing NUC is to calibrate the IR projection system so as to be capable of projecting a radiometric uniform IR image. The quality of the projected image is significantly enhanced by proper application of this calibration. To properly implement non- uniformity correction, it is necessary to accurately measure the radiometric emission of each element, or display pixel (emitter pixel), in the emitter array. This paper presents mathematical models and image-processing techniques required to successfully calibrate a non-uniform emitter projection system to absolute temperature. RTTC has developed a high- speed, reliable, and flexible means of digitally processing IR images captured from an emitter array. This method of evaluating IR imagery is also useful in performing sensor and overall projection system characterization. The purpose of this paper is to present the methods for correcting the absolute temperature non-uniformity of an IR resistor array.

At the Kinetic-kill vehicle Hardware-in-the-Loop Simulator (KHILS) facility located at Eglin AFB, Florida, a technology has been developed for the projection of scenes to support hardware-in-the-loop testing of infrared seekers. The Wideband Infrared Scene Projector program is based on a 512 X 512 VLSI array of 2 mil pitch resistors. A characteristic associated with these projectors is each resistor emits measurably different in-band radiance when the same voltage is applied. Therefore, since it is desirable to have each resistor emit the same for a commanded radiance, each resistor requires a Non-Uniformity Correction (NUC). Though this NUC task may seem simple to a casual observer, it is, however, quite complicated. A high quality infrared camera and well-designed optical system are prerequisites to measuring each resistor's output accurately for correction. A technique for performing a NUC on a resistor array has been developed and implemented at KHILS that achieves a NUC (standard deviation output/mean output) of less than 1 percent. This paper presents details pertaining to the NUC system, procedures, and results.

We present a description of a new non-uniformity correction system for infra-red resistor arrays which has been designed to produce the maximum uniformity of output from neighbor pixels achievable, with a special emphasis on performance at low (ambient) output radiance levels. The system is based on a precision 1:1 mapping between the sensor and projector pixels, and utilizes an all-on approach for projector pixel illumination. The philosophy for system choices is presented, together with analyses and measurements. The system hardware is outlined, and measurements are presented from the system in use showing that at ambient levels, uniformity of better than 100 mK can be achieved between neighbor pixels. This corresponds to a uniformity deviation of some 0.35%.

The design and preliminary performance characteristics of the projection optical subsystem (POS) of US Army STIRCOM's dynamic infrared scene projector (DIRSP) are presented in this paper. The DIRSP POS, made by Diversified Optical Products of Salem, NH and Mission Research Corporation, serves three purposes. The first is to combine the broadband images of three 544 X 672 pixel resistive emitter arrays using wedge-shaped mirrors to make a 1632 X 672 pixel mosaic image with minimal seams and aberrations. The second is to fold in long-wave infrared (LWIR) light from a blackbody for projecting backgrounds from 240 to 337 K. The third purpose is to collimate the LWIR light from the mosaic image and blackbody with a 5:1 motorized zoom lens. Samples of the mosaic image as seen through the blackbody relay are presented along with the designed characteristics of the zoom lens.

Infrared dynamic scene simulation using projection optics is becoming increasingly common for FLIR's and missile seekers that have narrow to moderate fields of view. This simulation capability enables an imaging system to be tested under a wide variety of simulated scenarios while mitigating some of the cost and complexity of field-testing. OPTICS 1, Inc. has completed a Phase I SBIR and has started Phase II activities to design, fabricate and test an infrared scene projector for wide-angle infrared imaging systems. Specifically, a need was identified to develop dynamic scene simulation capability for extremely wide-angle infrared imagers such as that under development by OPTICS 1 for contract F08630-98-C- 0022 in support of the Programmable Integrated Ordinance Suite program. This sensor images a full hemispheric field of view and therefore presents extreme challenges for scene projection.

Contraves Brashear Systems has designed and fabricated a low-distortion, 2:1 zoom collimator for projection of infrared scenes in the spectral region of 1.5 to 12.0 micrometers to provide dynamic scenes for the Wideband Infrared Scene Projector for testing of missile seekers and other FLIRs. This paper explains the general requirements of the projection collimator optics and describes the system design, assembly, and test. The collimator projects dynamic scenes generated by two 512 X 512 arrays of resistive- emitter elements. The system is composed of four off-axis, powered mirrors, a beamsplitter, spectral filters and array windows. Three of the mirrors and the arrays move to accommodate changing the field-of-view. The worst-case geometric spot size (85% encircled energy) at any field position is less than 0.8 of the angular subtense of an array element for the entire zoom range. Distortion is less than 0.7% and the overlap of the two arrays is better than 0.1 pixels at any field position.

The control of chromatic aberration, especially for appreciably large bandwidths, constitutes one of the most challenging aspects of optical design. In this paper a method for identification of materials whose combinations enable enhanced achromatic performance is addressed. Specifically, an investigation into achromatic design for the mid- to long wave infrared spectral range is studied. Verification of the methodology developed is illustrated by its application to the design of an infrared scene projection optic capable of operation over the 3.0 (mu) to 12.0 (mu) wavelength range.

We describe the status of various aspects of BAe resistor array infra-red scene projector systems for hardware-in-the- loop testing. The aspects covered include subsystem development on current 512 X 512 systems; electronic data handling and driver systems, optical projection collimators, heatsink, cooling and environmental gas control systems. Design aspects are sketched for the progression from existing demonstrator arrays of up to 1024 X 1024 into complete systems.

Large-scale infrared scene projectors, typically have unique opto-mechanical characteristics associated to their application. This paper outlines two large-scale zoom lens assemblies with different environmental and package constraints. Various challenges and their respective solutions are discussed and presented.

Missile warning systems (MWS) present unique problems for hardware-in-the-loop testing compared to other sensors found on modern day military aircraft and ground vehicles. End-to- end testing of an IR MWS like the AN/AAR-44 and other IR MWS requires a scene projector or stimulator capable of large intensity dynamic range, moderate temporal response, and a very large field of regard. These requirements dictate a different type of stimulator than is normally used with more conventional IR imaging systems using IR focal plane arrays and relatively narrow fields of view on the order of 10 - 30 degrees. This paper describes an initial design approach for development of an IR stimulator that satisfies the requirements for hardware and software testing of the AN/AAR-44 and other IR MWS equipment.

This paper will discuss the sensor modeling capabilities of the Universal Programmable Interface and the supporting software and hardware. Sensor modeling capabilities include image blurring due to the sensor's modulation transfer function and pixel effects. A sensor modeling and analysis software tool, based on FLIR92, will be discussed. A technique for modeling other sensor effects will also be presented. This technique, called pixel displacement processing, can model geometric distortion, physical sensor jitter, and other user specified effects. It can also be used to accurately perform latency compensation.

Raytheon Missile Systems Company operates all digital and real-time hardware-in-the-loop simulations in support of infrared guided missile development. These simulations exercise the missile guidance algorithms with inputs reflective of an engagement scenario. When air to air weapon system is achieved it receives pointing cues from the launcher and the infrared seeker slaves to acquire the target image within its field of view. The images are processed by the tracker algorithms to locate salient features in the scene. The resulting target track provides a precise target-relative position update for missile guidance.