This PDF file contains the front matter associated with SPIE Proceedings Volume 8015, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

Several organizations in the government and industry are actively developing IR emitter array nonuniformity correction (NUC) algorithms. While significant effort has been expended and progress has been made, there are no standard and comprehensive metrics for describing post NUC emitter nonuniformity. Subsequently, the nonuniformity data reported by one organization may not be comparable with data from another. Further, the sigma/mean uniformity values typically reported do not shed light on fixed pattern noise such as row and column offsets. As a result, NUC reporting often does not give a customer adequate insight into the value of emitter nonuniformity correction. This paper offers standard metrics for measuring and reporting IR emitter array nonuniformity. The metrics established here allow data from one measuring organization to be directly compared with that of another. Further, more practical aspects of nonuniformity correction are addressed which shed light on issues such as fixed pattern noise (FPN), emission gradients and other undesirable artifacts. Data analysis techniques described in this paper demonstrate the new metrics and their descriptive role in the NUC process. The NUC parameters established here characterize the ability of IR emitter arrays to accurately represent terrestrial scenes as well as hot objects and gases. This paper also explores areas in the emitter dynamic range that provide special challenges for generating a NUC table and their influence in the selection of nonuniformity correction radiance levels.

We report on development and characterization of square registered infrared imaging bundles fabricated from As₂S₃fiber for HWIL applications. Bundle properties and cross-talk measurements are presented.

We report a significant increase in electroluminescence from GaSb based mid-wave infrared inter band cascade (IC) LED device through coupling with localized surface plasmon layer. Thin Au Plasmon layer of 20 nm thickness is deposited on top anode electrode by e-beam evaporation technique. Surface Plasmon enhancement effects result is 100% increase in light output for 50 μm square mesa device. We fabricated an IC LED device with nine cascade active/injection layers with InAs/Ga1-xInxSb/InAs quantum well (QW) active region.

OPTRA has developed a two-band midwave infrared (MWIR) scene projector based on digital micromirror device (DMD) technology; the projector is intended for training various IR tracking systems that exploit the relative intensities of two separate MWIR spectral bands. Next generation tracking systems have increasing dynamic range requirements (on the order of 12-bits) which current DMD-based projector test equipment is not capable of meeting. While sufficient grayscale digitization can be achieved with drive electronics, commensurate contrast is not currently available. In this paper we present a detailed analysis of the contrast of our MWIR DMD-based scene projector. A series of factors which affect the overall contrast are modeled and design approaches to address the worst offenders are presented. In addition, we present methods for meeting the grayscale digitization requirements through the drive electronics.

This newly developed prototype Multispectral Polarized Scene Projector (MPSP), configured for the short wave infrared (SWIR) regime, can be used for the test & evaluation (T&E) of spectro-polarimetric imaging sensors. The MPSP system generates both static and video images (up to 200 Hz) with 512×512 spatial resolution with active spatial, spectral, and polarization modulation with controlled bandwidth. It projects input SWIR radiant intensity scenes from stored memory with user selectable wavelength (850-1650 nm) and bandwidth (12-100 nm), as well as polarization states (six different states) controllable on a pixel by pixel basis. The system consists of one spectrally tunable liquid crystal filter with variable bandpass, and multiple liquid crystal on silicon (LCoS) spatial light modulators (SLMs) for intensity control and polarization modulation. In addition to the spectro-polarimetric sensor test, the instrument also simulates polarized multispectral images of military scenes/targets for hardware-in-the loop (HIL) testing.

The CVORG group at the University of Delaware is responsible for designing and developing a test platform for the operation and characterization of a 512×512 array of infrared LED emitters. This platform consists mainly of an integrated circuit responsible for driving current to the LEDs, a package to which the driver and LEDs can be mounted, and a cryogenic dewar used to run tests at 77K. The fabrication of the driver read-in integrated circuit, or RIIC, was completed using a 0.5μm CMOS process from OnSemiconductor. Because of the size of the array, stitching techniques were used to create the 3.3cm×3.3cm chip. The cryogenic package is a custom 6-layer printed circuit board (PCB) plated in a soft wire-bondable gold. Finally, modifications were made to the cryogenic dewar to allow us to properly interface with the RIIC.

Performing a good non-uniformity correction is a key part of achieving optimal performance from an infrared scene projector, and the best NUC is performed in the band of interest for the sensor being tested. While cooled, large format MWIR cameras are readily available and have been successfully used to perform NUC, similar cooled, large format LWIR cameras are not as common and are prohibitively expensive. Large format uncooled cameras are far more available and affordable, but present a range of challenges in practical use for performing NUC on an IRSP. Some of these challenges were discussed in a previous paper. In this discussion, we report results from a continuing development program to use a microbolometer camera to perform LWIR NUC on an IRSP. Camera instability and temporal response and thermal resolution were the main problems, and have been solved by the implementation of several compensation strategies as well as hardware used to stabilize the camera. In addition, other processes have been developed to allow iterative improvement as well as supporting changes of the post-NUC lookup table without requiring re-collection of the pre-NUC data with the new LUT in use.

Leveraging the Naval Surface Warfare Center, Indian Head Division's historical experience in weapon simulation, Naval Sea Systems Command commissioned development of a remote-controlled, digitally programmable Sensor Test Target as part of a modern, outdoor hardware-in-the-loop test system for ordnance-related guidance, navigation and control systems. The overall Target system design invokes a sciences-based, "design of automated experiments" approach meant to close the logistical distance between sensor engineering and developmental T&E in outdoor conditions over useful real world distances. This enables operating modes that employ broad spectrum electromagnetic energy in many a desired combination, variably generated using a Jet Engine Simulator, a multispectral infrared emitter array, optically enhanced incandescent Flare Simulators, Emitter/Detector mounts, and an RF corner reflector kit. As assembled, the recently tested Sensor Test Target prototype being presented can capably provide a full array of useful RF and infrared target source simulations for RDT&E use with developmental and existing sensors. Certain Target technologies are patent pending, with potential spinoffs in aviation, metallurgy and biofuels processing, while others are variations on well-established technology. The Sensor Test Target System is planned for extended installation at Allegany Ballistics Laboratory (Rocket Center, WV).

A number of techniques have been utilized to evaluate the performance of Aircraft Survivability Equipment (ASE) against threat Man-Portable Air Defense Systems (MANPADS). These techniques include flying actual threat MANPADS against stationary ASE with simulated aircraft signatures, testing installed ASE systems against simulated threat signatures, and laboratory hardware-in-the-loop (HWIL) testing with simulated aircraft and simulated missile signatures. All of these tests lack the realism of evaluating installed ASE against in-flight MANPADS on a terminal homing intercept path toward the actual ASE equipped aircraft. This limitation is due primarily to the current inability to perform non-destructive MANPADS/Aircraft flight testing. The U.S. Army Aviation and Missile Research and Development and Engineering Center (AMRDEC) is working to overcome this limitation with the development of a recoverable surrogate MANPADS missile system capable of engaging aircraft equipped with ASE while guaranteeing collision avoidance with the test aircraft. Under its Missile Airframe Simulation Testbed - MANPADS (MAST-M) program, the AMRDEC is developing a surrogate missile system which will utilize actual threat MANPADS seeker/guidance sections to control the flight of a surrogate missile which will perform a collision avoidance and recovery maneuver prior to intercept to insure non-destructive test and evaluation of the ASE and reuse of the MANPADS seeker/guidance section. The remainder of this paper provides an overview of this development program and intended use.

An approach to streamline the Hardware-In-the-Loop (HWIL) simulation development process is under development. This Common HWIL technique will attempt to provide a more flexible, scalable system. The overall goal of the Common HWIL system will be to reduce communication latencies, minimize redundant development, operational labor and equipment expense. This paper will present current status and test results.

The Low-Background Infrared (LBIR) facility at NIST has performed on-site calibration and initial off-site deployments of a new infrared transfer radiometer with an integrated cryogenic Fourier transform spectrometer (Cryo- FTS). This mobile radiometer can be deployed to customer sites for broadband and spectral calibrations of space chambers and low-background hardware-in-the-loop testbeds. The Missile Defense Transfer Radiometer (MDXR) has many of the capabilities of a complete IR calibration facility and replaces our existing filter-based transfer radiometer (BXR) as the NIST standard detector deployed to customer facilities. The MDXR features numerous improvements over the BXR, including: a cryogenic Fourier transform spectrometer, an on-board absolute cryogenic radiometer (ACR) and an internal blackbody reference source with an integrated collimator. The Cryo-FTS can be used to measure high resolution spectra from 3 to 28 micrometers, using a Si:As blocked-impurity-band (BIB) detector. The on-board ACR can be used for self-calibration of the MDXR BIB as well as for absolute measurements of external infrared sources. A set of filter wheels and a rotating polarizer within the MDXR allow for filter-based and polarization-sensitive measurements. The optical design of the MDXR makes both radiance and irradiance measurements possible and enables calibration of both divergent and collimated sources. Results of on-site calibration of the MDXR using its internal blackbody source and an external reference source will be discussed, as well as the performance of the new radiometer in its initial deployments to customer sites.

Arnold Engineering Development Center (AEDC) is involved in the development of technologies that enable hardwarein- the-loop (HWIL) testing with high-fidelity complex scene projection to validate sensor mission performance. Radiometric calibration with National Institute of Science and Technology (NIST) radiometers has improved radiometric and temporal fidelity testing in this cold background environment. This paper provides an overview of pertinent technologies being investigated and implemented at AEDC to support a variety of program needs such as HWIIL testing and space situational awareness (SSA).

Frequency stepping is an established technique for increasing the range resolution of pulsed Linear Frequency Modulation (LFM, or chirp) radar waveforms [1]. When a monostatic radar system employs this waveform for increased range resolution measurements on an object with motion relative to the radar platform, simple changes in the received waveform arise, requiring fine motion compensation on a per-pulse basis. These motion effects include phase, frequency and frequency slope offsets which vary according to the transmitted pulse frequency and frequency rate, and the object range and range rate. All three offsets are easily compensated by complementary offsets in Direct Digital Synthesizer outputs used to form frequency conversion LO signals in the radar receiver. Radars employing stepped frequency LFM waveforms may be tested in a Hardware-in-the-Loop (HWIL) facility in simulations involving scenes or objects with radar-relative motion. Under these conditions, the motion effects on the radar receiver input signals must be accurately computed, synthesized and must modify the transmit signal prior to its return to the receiver. Engineers at the U.S. Army AMRDEC Advanced Simulation Center have developed signal processing techniques for accurate simulation of fine range motion effects to support HWIL testing of pulsed LFM radar systems. This paper provides an analysis of the signal processing involved for a simple model of an HWIL RF signal generation chain. Some results are presented from successful application of the motion simulation methods in an HWIL test setting.

An object oriented simulation framework, called KARMA, was developed over the last decade at Defence Research and Development Canada - Valcartier (DRDC Valcartier) to study infrared countermeasures (IRCM) methods and tactics. It provides a range of infrared (IR) guided weapon engagement services from constructive to HWIL simulations. To support the increasing level of detail of its seeker models, DRDC Valcartier recently developed an IR scene generation (IRSG) capacity for the KARMA framework. The approach relies on Open-Source based rendering of scenes composed of 3D models, using commercial off-the-shelf (COTS) graphics processing units (GPU) of standard PCs. The objective is to produce a high frame rate and medium fidelity representation of the IR scene, allowing to properly reproduce the spectral, spatial, and temporal characteristics of the aircraft's and flare's signature. In particular, the OpenSceneGraph library is used to manage the 3D models, and to send high-level rendering commands. The atmospheric module allows for accurate, run-time computation of the radiative components using a spectrally correlated wide-band mode. Advanced effects, such as surface reflections and zoom anti-aliasing, are computed by the GPU through the use of shaders. Also, in addition to the IR scene generation module, a signature modeling and analysis tool (SMAT) was developed to assist the modeler in building and validating signature models that are independent of a particular sensor type. Details of the IR scene generation module and the associated modeling tool will be presented.

Continuing interest exists in the development of cost-effective synthetic environments for testing Laser Detection and Ranging (ladar) sensors. In this paper we describe a PC-based system for real-time ladar scene simulation of ships and small boats in a dynamic maritime environment. In particular, we describe the techniques employed to generate range imagery accompanied by passive radiance imagery. Our ladar scene generation system is an evolutionary extension of the VIRSuite infrared scene simulation program and includes all previous features such as ocean wave simulation, the physically-realistic representation of boat and ship dynamics, wake generation and simulation of whitecaps, spray, wake trails and foam. A terrain simulation extension is also under development. In this paper we outline the development, capabilities and limitations of the VIRSuite extensions.

The ability to simulate authentic engagements using real-world hardware is an increasingly important tool. For rendering maritime environments, scene generators must be capable of rendering radiometrically accurate scenes with correct temporal and spatial characteristics. When the simulation is used as input to real-world hardware or human observers, the scene generator must operate in real-time. This paper introduces a novel, real-time scene generation capability for rendering radiometrically accurate scenes of backgrounds and targets in maritime environments. The new model is an optimized and parallelized version of the US Navy CRUISE_Missiles rendering engine. It was designed to accept environmental descriptions and engagement geometry data from external sources, render a scene, transform the radiometric scene using the electro-optical response functions of a sensor under test, and output the resulting signal to real-world hardware. This paper reviews components of the scene rendering algorithm, and details the modifications required to run this code in real-time. A description of the simulation architecture and interfaces to external hardware and models is presented. Performance assessments of the frame rate and radiometric accuracy of the new code are summarized. This work was completed in FY10 under Office of Secretary of Defense (OSD) Central Test and Evaluation Investment Program (CTEIP) funding and will undergo a validation process in FY11.

The US Army Aviation and Missile Research, Development and Engineering Center (AMRDEC) and the Redstone Test Center (RTC) has formed the Scene Generation Development Center (SGDC) to support the Department of Defense (DoD) open source EO/IR Scene Generation initiative for real-time hardware-in-the-loop and all-digital simulation. Various branches of the DoD have invested significant resources in the development of advanced scene and target signature generation codes. The SGDC goal is to maintain unlimited government rights and controlled access to government open source scene generation and signature codes. In addition, the SGDC provides development support to a multi-service community of test and evaluation (T&E) users, developers, and integrators in a collaborative environment. The SGDC has leveraged the DoD Defense Information Systems Agency (DISA) ProjectForge (https://Project.Forge.mil) which provides a collaborative development and distribution environment for the DoD community. The SGDC will develop and maintain several codes for tactical and strategic simulation, such as the Joint Signature Image Generator (JSIG), the Multi-spectral Advanced Volumetric Real-time Imaging Compositor (MAVRIC), and Office of the Secretary of Defense (OSD) Test and Evaluation Science and Technology (T&E/S&T) thermal modeling and atmospherics packages, such as EOView, CHARM, and STAR. Other utility packages included are the ContinuumCore for real-time messaging and data management and IGStudio for run-time visualization and scenario generation.

AMRDEC has developed the Multi-spectral Advanced Volumetric Real-time Imaging Compositor (MAVRIC) prototype for distributed real-time hardware-in-the-loop (HWIL) scene generation. MAVRIC is a dynamic object-based energy conserved scene compositor that can seamlessly convolve distributed scene elements into temporally aligned physicsbased scenes for enhancing existing AMRDEC scene generation codes. The volumetric compositing process accepts input independent of depth order. This real-time compositor framework is built around AMRDEC's ContinuumCore API which provides the common messaging interface leveraging the Neutral Messaging Language (NML) for local, shared memory, reflective memory, network, and remote direct memory access (RDMA) communications and the Joint Signature Image Generator (JSIG) that provides energy conserved scene component interface at each render node. This structure allows for a highly scalable real-time environment capable of rendering individual objects at high fidelity while being considerate of real-time hardware-in-the-loop concerns, such as latency. As such, this system can be scaled to handle highly complex detailed scenes such as urban environments. This architecture provides the basis for common scene generation as it provides disparate scene elements to be calculated by various phenomenology codes and integrated seamlessly into a unified composited environment. This advanced capability is the gateway to higher fidelity scene generation such as ray-tracing. The high speed interconnects using PCI Express and InfiniBand were examined to support distributed scene generation whereby the scene graph, associated phenomenology, and the scene elements can be dynamically distributed across multiple high performance computing assets to maximize system performance.

This study focuses on the performance analysis of a hydraulic based Flight Motion Simulator (FMS). Since the motion of each axis of the FMS is controlled independently from other axes by an individual motion controller, a nonlinear model of one axis of an FMS was developed in order to analyse and specify a new control system for the FMS. The paper presents a performance analysis of different control structures of an FMS motion controller, and the advantages and disadvantages of each control structure. In addition, the paper details the requirement specification of a new FMS motion controller in order to achieve the FMS's optimum dynamic performance despite inherent nonlinearities, such as stiction and nonlinear orifice flow rate.

Traditionally, control systems are designed in a single computer with discrete analog and digital signals to the power amplifiers or other components. Emerging real-time bus technologies open the possibility to modularize such a control system and simplify the system design. It offers more flexibility and better maintainability. The system control can be distributed between state-of-the-art servo drives, digital IO, sensors and the control computer. All the components are connected via a real-time network which communicates the data deterministically. An implementation with this new approach is shown and explained with a large scale 10 degrees-of-freedom motion simulator.

A typical hardware-in-the-loop (HWIL) lab normally integrates a wide array of digital equipment, each driven by its own internal oscillator. While the various equipment designers may strive to utilize high-precision oscillators in their products, if no synchronization scheme is employed, then time-base drift between the various HWIL components is inevitable. If real-time communications between components is required, such as between the motion simulator controller and the simulation (host) computer, this time-base drift, exacerbated by timing jitter in the communication channel and each component's internal processing loop, can degrade the simulation fidelity. By designing the motion simulator controller to synchronize to an externally provided, facility-wide, standards-based site timing reference such as the Global Positioning System (GPS), the relative time-base drift can be completely eliminated. This paper discusses the advantages of this approach for improving HWIL simulation performance.