Mark August Manzardo

An infrared-scene projector digital model

In infrared-scene projectors, an inherent variability for each emitter element manifests itself as fixed-pattern noise, or nonuniformity. This is unacceptable for valid sensor performance evaluation tasks. This article describes an infrared-scene projector digital model that will be used to simulate infrared-scene projection to assist algorithm development to eliminate this nonuniformity.

Infrared Scene Projector Digital Model Mathematical Description

This paper describes the development of an Infrared Scene Projector Digital Model (IDM). The IDM is a product being developed for the Common High Performance Computing Software Support Initiative (CHSSI) program under the Integrated Modeling and Test Environments (IMT) Computational Technology Area (CTA). The primary purpose of the IDM is to provide a software model of an Infrared Scene Projector (IRSP). Initial utilization of the IDM will focus on developing non-uniformity correction algorithms, which will be implemented to correct the inherent non-uniformity of resistor array based IRSPs. Emphasis here is placed on how IRSP effects are modeled in the IDM.

Infrared Scene Projector Digital Model Development

This paper describes the development of an Infrared Scene Projector Digital Model (IDM). The IDM is a product being developed for the Common High Performance Computing Software Support Initiative (CHSSI) program under the Integrated Modeling and Test Environments (IMT) Computational Technology Area (CTA). The primary purpose of the IDM is to provide a software model of an Infrared Scene Projector (IRSP). Initial utilization of the IDM will focus on developing non-uniformity correction algorithms, which will be implemented to correct the inherent non-uniformity of resistor array based IRSPs. After describing the basic components of an IRSP, emphasis is placed on implementing the IDM. Example processed imagery will be included, as well.

Utilization of a mobile infrared scene projector for hardware-in-the-loop test and evaluation of installed imaging infrared sensors

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.

Infrared scene projector characterization and sparse array nonuniformity correction (NUC)

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.

Image filtering and sampling in dynamic infrared projection systems

Image filtering in sampled dynamic infrared scene projection systems is examined from the point of view of providing an improved insight into the choice of the pixel mapping ratio between the projector and imaging unit-under-test. The 2D vector analysis underlying the transfer of image information in such systems is reviewed and is applied to the dynamic infrared scene projection case. It is shown that the 4:1 (2 X 2:1) pixel mapping ratio previously recommended in a desirable criterion from the spatial fidelity viewpoint, particularly when high spatial frequency information represented by point sources and scene edges is being projected. Cost constraints can, however, prevent the 4:1 mapping ratio from being met, in which case the effects on hardware-in-the-loop simulation validity need to be examined carefully. The vector analysis presented here provides a tool useful for the future examination of such cases.

Automated MRTD using boundary contour system, custom feature extractors, and fuzzy ARTMAP

A prototype automated forward looking infrared (FLIR) minimum resolvable temperature difference (MRTD) evaluation software system was developed and tested. After data capture and preliminary image processing of FLIR 4-bar target imagery, the boundary contour system (BCS) model of the human early vision system was coupled with a custom feature extractor to produce a set of features characteristic of those employed by humans during detection tasks. These feature sets, along with known target visibility, were used to train a fuzzy adaptive resonance theory MAP (ARTMAP) decision algorithm to emulate human observer performance in determining MRTD as a function of target to background contrast and target spatial frequency. During prototype system evaluation, the system was trained on 180 pairs of input imagery and human observer response data (resolvable/not-resolvable), and then tested against another 60 input images without the human judgments. The system predictions of human response to the test images were than compared to actual human response decisions for the images. Prototype success rates in the range of 96% to 100% were achieved in correctly predicting human response MRTD decisions in a low fidelity situation.

Characterization of the dynamic infrared scene projector (DIRSP) engineering grade array (DEGA)

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.

Infrared Scene Projector System Design Description for Installed Infrared Sensor Testing in an Anechoic Chamber Environment

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.

Design and development of a flexible COTS-based nonuniformity data collection interface system

Many test facilities currently have the requirement to project dynamic, infrared (IR) imagery into 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 an infrared micro-resistor based 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 uniform temperature/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 IR emissions of each display element, or display pixel (dixel), in the emitter array. Performing these measurements involves collecting a large volume of data at a high rate. The U.S. Armys Test and Evaluation Command (TECOM) has developed a high-speed, relatively inexpensive and flexible means of digitally capturing IR emissions from an emitter array. This method of digitally capturing IR imagery is also useful in performing sensor and overall system characterization. TECOM has investigated, planned, and developed a non-uniformity data collection system, using primarily Commercial Off-The-Shelf (COTS) hardware and software, capable of digitally capturing the emissions of a long wave IR emitter array at 30 frames per second. The digital images are then processed to characterize individual dixels of the IR scene projection system. This paper presents a description of a test facilitys need, along with a history of the design, development and actual implementation of a non- uniformity data collection system. In addition to the primary purpose of collecting digital imagery for NUC, other system uses for digital imagery collection are discussed.