Torpedoes and other Unmanned Undersea Vehicles (UUV) are employed by submarines and surface combatants, as well as aircraft, for undersea warfare. These vehicles are autonomous devices whose guidance systems rival the complexity of the most sophisticated air combat missiles. The tactical environment for undersea warfare is a difficult one in terms of target detection,k classification, and pursuit because of the physics of underwater sounds. Both hardware-in-the-loop and all-digital simulations have become vital tools in developing and evaluating undersea weapon and vehicle guidance performance in the undersea environment.

The USAF 46th Test Wing is developing a new hardware-in-the-loop (HITL) facility that will bridge the gap between con-ventional indoor HITL simulation and open-air flight-testing. The 46th Test Wing performs test and evaluation of munitions and command and control systems at Eglin Air Force Base in the panhandle area of Florida. The 46th Test Wing operates numerous ground test facilities including the Guided Weapons Evaluation Facility (GWEF), located at Eglin. The GWEF uses HITL simulation to test munitions' guidance systems by 'flying' them indoors against simulated targets including laser, infrared, radio frequency and millimeter wave. After HITL testing, the munitions are free flight tested on Eglin's land or water ranges. In 1995, Hurricane Opal destroyed several test sites on Santa Rosa Island, a barrier island bordering the Gulf of Mexico and Eglin's land ranges. Instead of simply rebuilding existing sites, the 46th Test Wing decided to reconstitute the island test capabilities to address future test requirements. One component of this effort is the development of a free standing 300-foot tower overlooking the Gulf. A high dynamic three axis flight motion simulator will be mounted atop the open air platform. The Open-Air Hardware-in-the-Loop (OA-HITL) facility will fill a gap in the test process between con-ventional indoor HITL simulation and open-air flight-testing. The OA-HITL will combine benefits of conventional HITL testing with the more realistic conditions of open-air testing. Whereas conventional HITL simulation operates in controlled indoor conditions with simulated targets, the OA-HITL will provide real targets and backgrounds in actual weather condi-tions. However, it will provide more control over the test item than captive carriage or free flight testing. This paper discusses the facility development, capabilities and potential uses, differences between conventional and open-air simulations and challenges to performing open-air simulation.

The Guidance System Evaluation Laboratory (GSEL) at the Johns Hopkins University Applied Physics Laboratory (JHU/APL) has developed a Hardware-in-the-Loop (HWIL) Kinetic Warhead (KW) test capability to support the STANDARD Missile-3 (SM-3) program. The capability is designed to assess KW functionality in the laboratory using complex IR scene stimulus for pre-flight testing and modeling validation. Key components are a 6-DOF body dynamics simulation computer, a Matra BAe IR scene rendering computer, and a BAe Systems resistive heater IR display. This paper examines some of the unique issues encountered in testing a strapdown IR seeker interceptor using a resistive heater display and their resulting impact on the design of 6-DOF simulation software and supporting test computer architecture. We discuss architecture and software implementation issues along with the complimentary use of high-fidelity all-digital and HWIL simulations to provide a broad test capability.

The MSSP program is a tri-service development of a capability for test and evaluation of multi-spectral seeker systems. At the conclusion of the project, each service will be equipped with an MSSP system specifically tailored to meet its specific test and facility requirements.

The Air Force Electronic Warfare Evaluation Simulator Infrared Countermeasures (IRCM) lab currently has the ability to simulate a complete IRCM test environment, including IR missiles in flight, aircraft in flight, and various IR countermeasures including maneuvers, LASERs, flares, and lamp-based jammer systems. The simulations of IR missiles in flight include real missile seeker hardware mounted in a six degree-of-freedom flight simulation table. The simulations of aircraft signatures and IR countermeasures are accomplished by using eight xenon arc lamps, located in 9' X 3' cylindrical housings, in the presentation foreground. A mirror system keeps the high intensity IR sources in the missile field of view. Range closure is simulated in the background by zooming in on the scene and in the foreground by separating and controlling the irises of the arc lamp sources for proper spatial and intensity characteristics. All relative motion and range closure is controlled by missile flyout software and aircraft flight-profile software models.

The Integrated Demonstrations and Applications Laboratory (IDAL) at Wright Patterson AFB is enhancing its Real-time Infrared/Electro-optical Scene Simulator (RISS) capability to include high performance real-time scene rendering and sensor emulation assets. These assets provide a powerful capability which can be used to stimulated a variety of infrared/electro-optical sensor systems. A near term objective of the IDAL team is to support development and risk reduction efforts for the 2-color LIFE Missile Warning System using these assets. This paper will provide an overview of the enhanced IDAL RISS capability and how it is benefiting the LIFE program.

A new Imaging Infrared Countermeasure Hardware-in-the-Loop facility has been designed and built by Matra BAe Dynamics to test imaging sensors in a complex infrared environment. Drawing upon currently available leading edge technologies and UK expertise, the test bed has ben completed in a twelve-month program. The facility comprises a Thermal Picture Synthesizer with up to four further independent channels, each capable of representing a countermeasure (jammer, flare or laser) within the scene. A six stage broadband reflective collimator relays the complex scene to the sensor.

LFK-Lenkflugkorpersysteme GmbH, a subsidiary of EADS Deutschland GmbH is developing and using hardware-in-the- loop simulations for more than two decades consisting of simple computer-in-the-loop simulation up to complex hardware-in-the-loop simulations with point source IR simulation on a Flight Motion Simulator or radar simulation with a missile nose on a 3-axis FMS looking in an anechonic chamber and a fin-aeroland simulator.

DGA/DCE/LRBA (Lab. de Recherches Balistiques et Aerodynamiques), the French MoD missiles and navigation evaluation center has developed several HWIL facilities in order to test the IR-autoguidance-loops of tactical missiles. This IR autoguidance laboratory is composed of several IR image projection systems based on a visible to IR transduction principle. In this paper, we present all the improvements and new acquisitions taking place this coming year in our HWIL facilities.

Naval Research Laboratory (NRL) has been developing high brightness mid-wave IR emitting fibers for HWIL testing. These fibers, based upon rare-earth doped chalcogenide glass, emit from 3.5 - 5 m and are capable of simulating very high temperatures in this band. To date, temperatures of 2400 K have been simulated. The fiber sources operate at room temperature, are environmentally tolerant, and can be formed into fiber bundles with high fill factors and low pixel to pixel cross- talk for IR scene generation. In this paper, we will present the spectral output, temporal response, temperature simulation and output uniformity of the mid-wave IR emitting fibers. The potential for long-wave IR emitting fiber sources will also be presented.

Optical Sciences Corp. has developed a new dynamic infrared scene projector technology called the Micromirror Array Projector System (MAPS). The MAPS is based upon the Texas Instruments Digital Micromirror Device^TM which has been modified to project images that are suitable for testing sensors and seekers operating in the UV, visible, and IR wavebands. The projector may be used in several configurations which are optimized for specific applications. This paper provides an overview of the design and performance of the MAPS projection system, as well as example imagery from prototype projector systems.

We are currently undertaking a design and development phase for the 1024 X 1024 complexity level of infra-red scene projectors based on the emitter resistor array principle. Our approach is based as for previous complexities, on commercially available CMOS with the addition of a custom suspended resistor pixel technology applied monolithically in our own facility. We have adopted the philosophy of continuing to develop the emitter pixel technology, whilst investigating CMOS design concepts, but delaying the detail- design and procurement of the CMOS until a firm commitment to build emerges, so as to allow maximum progress in the CMOS technologies available.

Santa Barbara Infrared's (SBIR) MIRAGE (Multispectral InfraRed Animation Generation Equipment) is a state-of-the- art dynamic infrared scene projector system. Imagery from the first MIRAGE system was presented to the scene simulation community during the SPIE AeroSense 99 Symposium. Since that time, SBIR has delivered ten MIRAGE systems. This paper will provide a brief overview of the MIRAGE system and discuss developments in the emitter materials science effort. Overview data will be shown demonstrating the successful development of a high temperature, high stability emitter structure.

Honeywell has developed a high-speed infrared emitter pixel and implemented the design on two 512 X 512 scene projector array designs. This pixel is a faster version of the original Gen-III Gossamer pixel implemented on previous 512 X 512 arrays. The new pixel has a 10% - 90% rise time under 4 milliseconds, enabling a dramatic increase in scene projection frame rates over currently available arrays. Full array frame rates of 200 Hz are not practical and subarrays can be driven up to 400 Hz. In spite of the increased speed, the array still maintains high brightness using the same CMOS electronics. This design and other array developments will be described.

To date the majority of infrared scene projector development has centered around the creation of devices that provide a large dynamic range with seemingly unlimited scene generation capability using a myriad of ancillary hardware. These devices provide a wide range of simulation capability but do so at the expense of system complexity, size, and at a considerable financial investment. In an attempt to provide an alternative to this expensive type of system, a small low cost alternative was developed to provide moderate levels of infrared scene projection capability to a broader range of potential users and their test environments. A cursory look at the performance of the device and a brief overview of the system are presented within the confines of this paper.

This paper describes the recent addition, characterization, and integration of emerging technologies for dynamic infrared scene projection at the US Army Aviation and Missile Command's Advanced Simulation Center. Infrared scene projection performs a vital role in the daily testing of tactical and theater missile systems within these Hardware- in-the-Loop (HWIL) laboratories. Topics covered within this paper include the addition and characterizations of new Honeywell and Santa Barbara Infrared emitter arrays, the integration and operation of the Honeywell and SBIR emitter array systems into a HWIL test, the development of high speed reduced-size IRSP drive electronics, the development of a NUC/characterization station, added software support, and the status of DMD-based infrared scene projector. Example imagery and test results from several of the projector systems are included within this paper.

The Kinetic Kill Vehicle Hardware-In-the-Loop Simulator, located at Eglin AFB, has developed the capability to perform broadband 2-color testing of guided missile seekers in both ambient and cryogenic environments. The 2-color capability is provided by optically combining two 512 X 512 resistor arrays and projecting through all-reflective optical systems. This capability has raised the following questions: `How would a resistor array, designed to work at ambient conditions, perform when operated in a cryogenic environment?' and `How would a resistor array that was non- uniformity corrected (NUC) at ambient conditions perform when the NUC is applied to the array in a cryogenic environment?' The authors will attempt to address these questions by performing several measurements on a Wideband Infrared Scene Projector (WISP) Phase III resistor array in both ambient and cryogenic conditions. The WISP array performance will be defined in terms of temporal response, spatial non-uniformity, radiometric and thermal resolution, and radiometric and thermal transfer function.

A challenging problem associated with performing hardware- in-the-loop tests of imaging infrared seekers is projecting images that are spatially realistic. The problem is complicated by the fact that the targets may be small and unresolved at acquisition and grow to fill the field of view before intercept. In previous work, mathematical and computer models of the process of observing a pixelized projector with a camera have been developed, metrics of the spatial realism of the projector have been proposed, and model predictions examined.

Infrared projection systems commonly use a collimating optical system to make images of a projection device appear far away from the infrared camera observing the projector. These `collimators' produce distortions in the image seen by the camera. For many applications the distortions are negligible, and the major problem is simply shifting, rotating, and adjusting the magnification, so that the projector image is aligned with the camera. In a recent test performed in the Kinetic Kill Vehicle Hardware-in-the-Loop Simulator facility, it was necessary to correct for distortions as small as 1/10th the size of the camera pixels across the field of view of the camera. This paper describes measurements and analyses performed to determine the optical distortions, and methods used to correct them.

Performance and payload capacity requirements for hardware- in-the-loop motion systems have been growing. This paper describes several new systems that have advanced the state- of-the-art. A Four-Axis, electrically driven system weights 50 tons, has a 20,000-pound payload capacity, and approaches 1-arc second pointing accuracy. Several new hydraulic Five- Axis Flight Motion Simulators (FMS) have larger payload and increased acceleration/bandwidths. An environmentally hardened three-axis open range FMS will be installed atop a 300-foot tower. A new dual-target motion system installed at DERA in the UK is 56 feet wide, 41 feet tall, and has a 12- meter target radius. An electric Five-Axis FMS is under construction for the ballistic missile defense program. This machine will have continuous displacement on the three UUT axes and inner target axis, and achieves high dynamic and pointing accuracy with a 32-kg, 63-cm diameter payload. A new state-space controller has been developed for all Carco simulators.

A Satellite Attitude Dynamics Simulator (SADS) has been developed to facilitate the research and development of spacecraft flight attitude control software at the Naval Postgraduate School in Monterey, CA. The simulator provides a real-time 3 degree of freedom (3DOF) synthetic spacecraft hardware-in-the-loop environment, that includes realistic angular motions, sensor-effector delays, and control torque profiles. Control software, entered into a notebook PC mounted on the equipment platform, is input as high level object oriented code, allowing rapid code development and thorough post-test analysis. Three flight-like reaction wheels and eight cold-gas thrusters that are mounted to the SADS equipment platform provide motion simulation torque. The equipment platform is suspended in air by a spherical segment air bearing. This virtually frictionless suspension allows free rotation of the equipment platform about any rotation axis. Three separate sets of sensors, three single-axis rate gyros, a three-axis magnetometer, and a two-axis sun sensor monitor SADS platform motion. This paper discusses the SADS design, and the practical uses of this simulator for satellite attitude control system software research and development.

The Image Stabilization Testbed (ISTAT) is a high-bandwidth angular motion system for the simulation of missile dynamics with capability beyond that of current flight motion simulators (FMS). This paper describes the development and initial laboratory integration of the ISTAT. The intention is to mount a missile seeker and any associated inertial measurement sensors, and then allow ISTAT to replicate the dynamic boundary conditions at the base of the seeker resulting from both airframe vibrations (flexible body motion) as well as rigid body motion resulting from vehicle control forces or the flight environment. ISTAT will be driven by the output of deterministic simulations and will replicate the time history of the command signals. It can be used in a standalone mode or possibly in conjunction with a conventional large motion lower bandwidth FMS. ISTAT makes use of high bandwidth hydraulic actuation and advanced feedback and feedforward control algorithms to deliver two- and three-axis motion control at frequencies from DC to greater than 500 Hz. The largest motions, achieved at lower frequencies, are about two degrees. The paper describes the motivation, the servohydraulic, mechanical, and electronic subsystems, control software and algorithms, and the software user interface for the testbed. An initial report on the system integration is also provided.

The objective of the HFMS Program is to develop a conceptual design for a `High Frequency Motion Simulator'. This system will complement and extend the simulation capability of existing real time Hardware-in-the-Loop simulation suites.

Hit-to-kill interceptors and other thruster-controlled missiles demand flight motion simulators having sufficiently accurate high frequency dynamic performance to simulate flexible body behavior. A new servoactuator design is described that uses a piezoelectric element to control a novel open-center hydraulic valve. Detailed nonlinear dynamic models are presented for the valve servoamplifier, piezo element, orifice flow, and hydraulic supply decoupling. These are combined with the structural model of a single actuator system. The resulting system model indicates that several such actuators used in combination would provide accurate simulation of missile body vibration signatures up to 1 kHz or beyond.

This paper presents the construction of the overall orientation error model based on the measurable table errors of axis wobble, axes non-orthogonality, axes intersection and axis encoding. With this model, the HWIL simulation engineer may, in the future, be able to calibrate and/or set requirements for the missile and target five-axis motion simulator to reduce the effect of the static orientation error on the simulation.

User desire for flight motion simulator (FMW) dynamic transparency is a major factor in selecting the `optimum' structural design and control strategies for hardware-in- the-loop simulations. There are numerous design strategies that can satisfy a given set of user specifications. However, the resulting FMS performance may not be equivalent in terms of satisfying user objectives. This paper describes software simulation and design optimization tools that are effective in evaluating design trade-offs. Examples of performance trade-offs are provided.

Advanced in inertial guidance testing place increasing demands upon accuracy, resolution, and response of motion- based test table and simulators. These test tables are typically controlled via closed-loop servomechanisms utilizing precision axis position transducers (e.g. Inductosyns, resolvers, optical encoders, etc.) to measure axis motion. A new method of acquiring data from these transducers provides greater resolution, repeatability, and accuracy of axis position measurements, enabling more precise control of the axis.

The Composite Hardbody and Missile Plume (CHAMP) program is a computer simulation used to provide time dependent high- fidelity infrared simulations of airborne vehicles. CHAMP computational algorithms are based on first principles physics that compute hardbody and exhaust plume radiation for arbitrary vehicle operational state, position, orientation, and atmospheric conditions. All computations are performed as a function of time to allow complex vehicle dynamics to be simulated. Image processing functions are included to generate anti-aliased focal p,lane imagery.

This paper provides an overview of the simulation, stimulation, and modeling capabilities that were developed to meet the requirements of the Infrared Sensor Stimulator (IRSS) program. This capability has been installed at the ACETEF since March 2001, putting the IRSS at FOC status.

The development of a modularized millimeter wave (MMW) target and background high resolution scene generator is reported. The scene generator's underlying algorithms are applicable to both digital and real-time hardware-in-the-loop (HWIL) simulations. The scene generator will be configurable for a variety of MMW and multi-mode sensors employing state of the art signal processing techniques. At present, digital simulations for MMW and multi-mode sensor development and testing are custom-designed by the seeker vendor and are verified, validated, and operated by both the vendor and government in simulation-based acquisition. A typical competition may involve several vendors, each requiring high resolution target and background models for proper exercise of seeker algorithms. There is a need and desire by both the government and sensor vendors to eliminate costly re-design and re-development of digital simulations. Additional efficiencies are realized by assuring commonality between digital and HWIL simulation MMW scene generators, eliminating duplication of verification and validation efforts.

There are five features in this approach: (1) The complete nonlinear dynamics of the pursuit-evasion motion is considered in 3D spherical coordinate system. Neither linearization nor small signal assumptions are made. (2) The nonlinear H-infinity guidance design is derived analytically and expressed in a very simple form. (3) Unlike adaptive control concept, implementation of the proposed H_(infinity ) guidance design does not need the information on target acceleration while ensuring acceptable intercept performance for arbitrary targets with the finite acceleration. (4) The derived guidance design exhibits strong robustness against variations in target acceleration. (5) Finally the issues related to the validation of the control law using Hardware In The Loop simulation are presented. The effects of the Flight Motion Simulator static and dynamic accuracies (time delay etc...) are discussed.

This paper discuses recent advances in the development and applications of the Universal Programmable Interface. Development milestones and current performance benchmarks will be presented.

Matra BAe Dynamics/Nallatech have undertaken the task to produce a fully generic Hardware In The Loop facility designed to flexibly test imaging IR systems. The system was required to allow real hardware and their software models to be seamlessly interchanged including a fully reconfigurable interface to whatever hardware was being tested. This required the adoption of a flexible design methodology to allow the traditional boundaries between hardware and software design to 'blur'. This paper describes the methods used to achieve these design aims. It concentrates in the use of the C programming language to define both the hardware (in the form of reconfigurable FPGA devices) and the software to be used in the system giving concrete examples of the benefits and disadvantages of such an approach. It shows that such an approach can lead to the creation of a system which is cheaper to maintain, easier to modify for new requirements and generally more flexible than conventional strict partitioned systems.

Previous work has been presented on the creation of computing architectures called DIME, which addressed the particular computing demands of hardware in the loop systems. These demands include low latency, high data rates and interfacing. While it is essential to have a capable platform for handling and processing of the data streams, the tools must also complement this so that a system's engineer is able to construct their final system. The paper will present the work in the area of integration of system level design tools, such as MATLAB and SIMULINK, with a reconfigurable computing platform. This will demonstrate how algorithms can be implemented and simulated in a familiar rapid application development environment before they are automatically transposed for downloading directly to the computing platform. This complements the established control tools, which handle the configuration and control of the processing systems leading to a tool suite for system development and implementation. As the development tools have evolved the core-processing platform has also been enhanced. These improved platforms are based on dynamically reconfigurable computing, utilizing FPGA technologies, and parallel processing methods that more than double the performance and data bandwidth capabilities. This offers support for the processing of images in Infrared Scene Projectors with 1024 X 1024 resolutions at 400 Hz frame rates. The processing elements will be using the latest generation of FPGAs, which implies that the presented systems will be rated in terms of Tera (10¹²) operations per second.

Real-time SAR processing requires high computational power. At the Laboratorium fur Informationstechnologie a parallel DSP called HiPAR-DSP 16 was developed, which is optimized for image processing algorithms. In this paper we present a compact multi-DSP board utilizing the HiPAR-DSP 16. The board can deliver a performance of up to 15 GOPS, has a volume of 160 X 230 X 20 mm, and consumes less than 20 W. The first version of the board is used for filtering of SAR data to show the capabilities of the system. An estimation showed that our board can process an wk algorithm with a rangeline length of 4096 samples and a PRF of 600 Hz in real-time.

This paper covers the design & development of a system capable of: (1) Generating IR imagery capable of testing an IR imaging based missile system in a full projection HWIL enviroment. (2) Generating IR imagery and all other signals necessary to test an IR imaging based missile processing unit on the bench. (3) Capturing and analyzing missile outputs allowing full test and debug of the UUT. It aims to show that the recent advances in both PC and Field Programmable Gate Array (FPGA) technology has made such a system technically feasible. It also aims to show that the use of standard PC components and Commercial Off the Shelf (COTS) FPGA boards brings significant benefits to the development of such a system. These benefits include low cost, rapid development, access to a wider technology base and robustness against obsolescence. In particular it shows how the use of FPGA products gives the flexibility in function to allow the design to address its two different goals.

The signal processors in pulse Doppler radar can detect the target signal which is spectrally separated from clutter, even if the signal is -60 dB weaker or more than main- lobe clutter, so in missile hardware-in-the-loop it is required that the noise resulted by clutter reconstruction architecture should be -60 dB lower than main-lobe clutter. Because of the restriction, a new method of clutter reconstruction with specific power spectrum is proposed, which include conversion from power spectrum to vector spectrum, randomization of phase, inverse Fourier transform, and then windowing and overlapping the series time domain sequence, which guarantee the expectation value and variance of random sequence continuously. The simulation results demonstrate that by applying the method, the ratio of signal to noise is increased from 30 dB to 60 dB.

Hardware in the loop simulation (HILS) is used in the evaluation of various IR seeker systems. To perform IR HILS testing a number of costly peripheral systems are required. The most important of these are the motion simulation table, the IR scene generator, the IR scene projector, the dynamics simulator and the simulation controller. The cost of IR image projectors prohibits a number of scientists with access to the remaining equipment from preforming HILS testing of IR seekers. Simulating the reticle and calculating the detector signal in real-time allows the evaluator to bypass the IR scene projector and to do signal injection into the unit under test (UUT). The use of a commercial off the shelf personal computer permits the testing of single detector reticle seekers at a fraction of the cost of an IR image projector. This paper will deal with the development of the algorithms required to realize a real-time simulation of a conical scan FM reticle. The simulation makes use of image processing techniques which are computationally intensive. This paper will investigate methods to decrease the simulation time in order to generate real-time signals for the UUT. The implementation of the various techniques as well as the effect on the simulation time will be presented. The disadvantages and problems associated with these methods will also be explored. The algorithms that were developed will be presented along with the fastest simulation times achieved.

This paper describes advances in the development of IR/EO scene generation using the second generation Scene Rendering Subsystem (SRS). The SRS is a graphics rendering engine designed specifically to support real-time hardware-in-the- loop testing of IR/EO sensor systems. The SRS serves as an alternative to visual rendering systems, such as the Silicon Graphics^TM Infinite Reality, when IR/EO sensor fidelity requirements surpass the limits designed into visual rendering hardware. Last year a re-design of the SRS was completed. The new SRS architecture is highly programmable and can be configured to use up to 256 parallel processors. This paper will provide an overview of the second generation SRS architecture and discuss advances in the SRS rendering software that take advantage of the computational power inherent in the new system. The discussion will include a report on the maximum performance achieved by the system, and a description of new rendering modes that support IR/EO scene generation requirements.

The simulation of infrared imagery forms an integral part of the design and evaluation of infrared systems. HWIL simulations require imagery at frame rates of 100Hz and above. The generation of real-time imagery used to be the domain of graphics super-computers and custom rendering hardware. We investigated the use of a new generation of personal computer graphics accelerators to generate real-time infrared imagery, using OpenGL as the graphics library. The hardware was a NVIDIA GeForce-based graphics accelerator running on a standard Pentium III computer. The graphics accelerator is limited to a color resolution of 8 bits per channel. A technique was investigated to artificially increase this resolution in order to increase the fidelity of the simulation. OpenGL was designed to render images in the visual band. The implementation of the simulation in OpenGL requires the mapping of spectrally variant entities such as atmospheric transmittance to single parameter equivalents. Various combinations of sensor spectral response, source radiance and atmospheric transmittance were investigated to determine the situations under which such a mapping is feasible. A combination of rendering images on the graphics card, and processing the resultant images on the personal computer was investigated to increase the rendering speed and the fidelity of the simulation.

The Real-Time CHAMP (RTC) program is a computer simulation used to provide time varying high-fidelity infrared simulations of airborne vehicles and backgrounds in real- time. RTC is currently being utilized to provide real-time infrared imagery to support closed-loop digital and hardware-in-the-loop simulations. RTC computational algorithms take advantage of parametric databases created by its non real-time companion code (CHAMP--Composite Hardbody and Missile Plume) to allow accurate infrared imagery to be generated at real-time frame rates.

The search for optimal infrared scene projection nonuniformity correction procedures reported in earlier papers is continued. in this paper the application of the specialized flood nonuniformity correction algorithm described earlier is extended to the more practical case where the pixel-to-pixel mapping is imperfect.

In this paper we report on effects to correct the spatial radiance nonuniformities in four infrared emitter arrays in the mid-wave infrared. Using a table-top setup in which a 512 X 512 NODDS array was driven by the MRC FIESTA 8500 drive electronics, and the output radiance from the emitter array was captured by a 100% fill-factor InSb focal plane array with fast frame storage capabilities, we were able to improve the emitter radiance nonuniformities by up to a factor of six while collecting the emitter radiances using the sparse grid approach in only 5 minutes. We report on the custom FIESTA operating system we developed, paying particular attention to the real-time nonuniformity correction capabilities since this enabled the emitter nonuniformities to be minimized while the emitter movie was played at frame rates up to 180 Hz. We also report on the custom emitter data processing software we developed which enabled us to determine the radiance from four emitters and write out new, calibrated movies which displayed radiances with only 2% nonuniformity.

The thermal conduction and electronic drive processes that govern the temporal response of resistor array infrared projectors are reviewed. The characteristics and limitations of the voltage overdrive method that can be implemented for sharpening the temporal response are also discussed. Overdrive is shown to be a viable technique provided sufficient drive power and temperature margins are available outside of the normal dynamic range. It is shown also by analysis of overdrive measurements applied to a Honeywell GE snapshot resistor array that practical real-time overdrive processors can be designed to operate consistently with theoretical predictions.

With the increased demand for IR sensor and surveillance systems, there is a growing need for technologies to support their operational readiness. Measurement of sensor characteristics such as sensitivity, MRTD, and dynamic range should be standard in all mission critical systems. The Real-Time Infrared Test Set (RTIR) is a portable system designed to provide in-the-field calibration and testing of IR imaging systems and seekers. RTIR uses the high volume manufacturing processes of the Very Large Scale Integration and the Micro Electromechanical Systems technology to produce a Thermal Pixel Array (TPA). State-of-the-art CMOS processes define all the necessary on-chip digital and analog electronics. When properly driven, this array generates variable temperature, synthetic IR scenes. A nonuniformity measurement of several TPAs is presented.

Although the sparse grid Non-Uniformity Correction (NUC) technique can accurately correct individual emitters on a resistor array, it is not a good solution for all projection applications. Due to busbar robbing, the sparse grid NUC breaks down when a large number of emitters are turned on simultaneously. For this case, a more appropriate NUC data collection method is needed. This method involves measuring the entire resistor array at once with a 1:1 mapping between the projector and NUC sensor. Then busbar effects, measured during the NUC data collection, can be accounted for and corrected. This paper presents details pertaining to the flood NUC technique and results. This NUC system is implemented at the Kinetic Kill Vehicle Hardware In the Loop Simulator (KHILS) at Eglin AFB, Florida.

With the increased demand for IR sensor and surveillance systems, there is a growing need for technologies to support their operational readiness. Measurement of sensor characteristics such as sensitivity, MRTD, and dynamic range should be standard in all mission critical systems. The Real-Time Infrared Test Set (RTIR) is a portable system designed to provide in-the-field calibration and testing of IR imaging systems and seekers. RTIR uses the high volume manufacturing processes of the Very Large Scale Integration (VLSI) and the Micro Electromechanical Systems (MEMS) technology to produce a Thermal Pixel Array (TPA). State-of-the-art CMOS processes define all the necessary on-chip digital and analog electronics. When properly driven, this array generates variable temperature,synthetic IR scenes. A nonuniformity measurement of several TPAs is presented.

This paper will highlight the innovative facility upgrades and modeling techniques that will be utilized to produce hardware-in-the-loop simulations to support both the development and production phases of this Pre-Planned Product Improvement program.

Computer Science and Applications has implemented a fast, automated non-uniformity correction procedure for a 512 X 512 infrared projection array that takes advantage of a relatively inexpensive 256 X 256 infrared camera. The procedure is based on the sparse matrix approach defined in `A simplified method for the hardware implementation of nonuniformity correction on a resistor array infrared scene projector.'

This paper describes the Advanced Simulation Center (ASC) role, recaps the past 2000-2001 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.