Thermal imaging system manufacturers have an extensive product line with many options available for each system. It is impossible to list all the systems nor all the options. Instead, the systems described in this paper are those presented at this conference by the following manufacturers: Agerna, Anther Engineering, Bales Scientific, Cincinnati Electronics, David Sarnoff Research Center, Eastman Kodak, FLIR Systems, Inframnetrics, ISI Group, Mitsubishi Electronics of America, and Santa Barbara Focal Plane. The systems are described in functional form to illustrate the similarities and differences. No attempt is made to rate them. Only the user can rate them when applied to his specific appi icat ion.

The multitude of possible applications of infrared imaging systems will never be explored unless affordable systems become available. The advent of Area Infrared Focal Plane Arrays is making afforthbility a reality. This paper describes an economical IR imaging camera based upon a 64 x 64 InSb Hybrid Focal Plane Array. The results of measurements and comparisons with predictions of NETD and uniformity are investigated.

A high performance IR camera system which features flexible data acquisition and output formats will be discussed. When operated with a standard 128 x 128 second generation focal plane array, frame rates of 1000 Hz are achievable. 256 x 256 InSb focal plane arrays can achieve frame rates of 250 Hz. The acquisition and display electronics provides digitization, timing, non-uniformity correction, and scan conversion. When combined with high-speed digital acquisition, fast transient IR measurements can be made.

An infrared imaging system based on a high resolution platinum silicide detector has been developed. The detector is a 486 x 640 Schottky Barrier photodiode array with a CCD readout multiplexer. The imaging system includes signal processing electronics to correct the fixed pattern noise and implements a histogram projection algorithm for automatic gain and offset adjustment and dynamic range compression. The perfonnance of the pattern noise correction has been demonstrated to reduce the residual pattern noise below the image shot noise over a scene temperature range of more than 50°C. The effect of optical cmss talk in the imager has been examined. The magnitude of the side lobes has been found to be a factor of about 7 x 10' smaller than the central spot.

Infrared imaging systems have increased in number rapidly since the early 1960's; however, system insertion has been almost entirely in military and paramilitaryapplications. In the future, infraredimaging systems wilifind increasedacceptance in commercial applications provided that system costs are reduced. FLIR Systems, Inc. was founded in response to a recognized world wide need for high quality, affordable infrared systems. In this paper we present the salient features of a serial scan forward looking infrared (FUR) system which has been developed to achieve high sensitivity and resolution in systems which are less complex and are inherently less expensive to manufacture, operate and maintain. Specifically our systems utilize an 8 to 12 micron band HgCdTe detector array consisting of two or more rows of detectors in parallel with four to six detector elements in series summed in Time Delay and Integration (TDI). The serial scan approach greatly reduces the complexity and cost of the amplification and scan conversion when compared to parallel scanned systems while a small amount ofparallel scanning reduces the scan rate to a practical level. Design considerations and manufacturing methods are reviewed with emphasis on high performance and system affordability.

This paper reviews the accuracy requirements ofthermal imaging radiometers, for various wavelengths and optical configurations, that must be maintained over the specified ambient temperature range for the instrument. The paper focuses on the Inframetrics 700 Series Radiometers, and briefly reviews the scanner architecture and video signal processing electronics to provide a background for the problem presented. Subsystem component parametric variations, affected by fluctuations in ambient temperature, are enumerated. These variations directly affect the temperature measurement accuracy ofthe system. To exceed the temperature measurement accuracy specification for the instrument, and achieve the highest measurement accuracy possible, Inframetrics individually calibrates each radiometer over the specffied ambient temperature range. This paper describes the Ambient Temperature Calibration (ATC) process. Data collection and test methods used to develop this process are outlined. Initial and ongoing process validation methodology is discussed. Product quality and reliability benefits as a byproduct of this process are also presented.

Staring infrared focal plane arrays (FPAs) utilizing uniform/high quantum efficiency detectors are the enabling technology for systems providing high sensitivity, high speed, and low cost. This paper describes the performance and features of the lmaglR, a commercially available infrared imaging system utilizing staring FPA technology. Budget requirements have driven the infrared community, including the military, to purchase commercially available systems. These systems are required to consist of off-the-shelf hardware and need to interface to commercial display and storage devices. The lmaglR meets and exceeds these requirements by supporting a broad variety of interfaces and by providing a number of storage and processing solutions internal to the system itself.

Pyroelectric Vidicons have been commercially available for approximately nineteen years. In 1975 I.S.I. Group, Inc. began manufacturing a television camera system incorporating the Pyroelectric Vidicon tube. Until this time most systems had been custom fabricated, for special applications. The early camera systems were large, bulky, and difficult to use. These initial camera designs were updated to make them more user oriented and to generally simplify their operation. The original Thermal Imaging systems were comprised of a camera head (incorporating the PEV tube) , a camera control unit (incorporating all the necessary control electronics) , connected by a camera control cable. These systems found many different applications, but had been restricted to areas where 35 watts could be obtained from 110 Volt, 60Hz AC power. Within the past few years a new camera system has been developed. This camera system is completely portable, battery powered, and light weight. This camera system now permits thermal analysis in areas that are remotely located. These camera systems produce images which are displayed on standard television equipment. The PEV detector requires no cooling, either liquid or thermoelectric. These camera systems respond only to thermal energy radiated by an object and no signal is produced by visible light.

This paper will discuss the design rationale and actual applications of a completely programmable, infrared non-destructivetest workstation. The design concepts and goals will be discussed in detail, with emphasis on image generation and processing. The need for proprietary circuitry to provide fast image data transfer and analysis will be explained and depicted in block diagrams. Applications will show the results of generating high resolution thermal images and processing the image data to obtain definitive analysis ofthe exterior and interior ofthe test subject. Applications will also deal with programmable thermal sources for inducing heat into the test subjects for sequential, time lapsed, image analysis.

Mitsubishi produces a product line that should be measured from a "price I performance" standpoint. The high resolution lR-M500 is now affordable in areas historically precluded. The size and weight of the lR-M500 make it operate more like a camcorder than the traditional laboratory equipment of the past. The days of lab coats, gloves, and protective eyewear will soon to be gone forever. Mitsubishi is committed to the U.S. market and plans to continue to announce new products and improved technologies.

The Thermovision 1000 is the next logical extension of AGEMA's high performance infrared scanning systems. The unique scanning module, with its high optical invariant enables the use of a relatively small number of detector elements and a slow scan speed and still exceeds the performance of FLIR's which are currently in service. All of this is achieved with reduced complexity and higher reliability. A unique Fore-Optics design provides a dual FoV with remote operation. The extension of the Thermovision design principles to a state-of-the-art FLIR are discussed in terms of mechanical and optical design, detector application and thermal compensation system.

A Stirling cooled 3 - 5 micron camera system has been developed. The camera employs a monolithic 640 X 480 PtSi-MOS focal plane array. The camera system achieves an NEDT equals 0.10 K at 30 Hz frame rate with f/1.5 optics (300 K background). At a spatial frequency of 0.02 cycles/mRAD the vertical and horizontal Minimum Resolvable Temperature are in the range of MRT equals 0.03 K (f/1.5 optics, 300 K background). The MOS focal plane array achieves a resolution of 480 TV lines per picture height independent of background level and position within the frame.

The Night Vision and Electro-Optics Directorate's FLIR92 model predicts minimum resolvable temperature difference (MRTD) and minimum detectable temperature difference (MDTD) for scanning and staring infrared sensors. FLIR92 retains unchanged for two- dimensional MRTD, and incorporates sampling effects and three-dimensional noise more thoroughly than the simple approximations used in the FLIR90 model. The FLIR92 MRTD predictions are shown to be valid for representative scanning and staring systems.

The Night Vision ACQUIRE model predicts range performance when provided with parameters describing the atmosphere, a 2-D MRT curve which describes the sensor and three additional parameters. Two of the additional parameters (characteristic dimension and target- background contrast) describe the target. The third additional parameter, a cycle criterion (N₅₀) relates to task difficulty. Characteristic dimension and target-background contrast are measured directly in the field. The third parameter N₅₀ is empirically determined from the measured range performance associated with the task. The purpose of this communication is to define terms, protocols and where possible to give recommended values for parameters used with the ACQUIRE model. The methodology and recommended parameter values given here represent Night Vision's best estimates based on years of laboratory and field experience.

Holst and Pickard experimentally determined that MRT responses tend to follow a log-normal distribution. The log normal distribution appeared reasonable because nearly all visual psychological data is plotted on a logarithmic scale. It has the additional advantage that it is bounded to positive values; an important consideration since probability of detection is often plotted in linear coordinates. Review of published data suggests that the log-normal distribution may have universal applicability. Specifically, the log-normal distribution obtained from MRT tests appears to fit the target transfer function and the probability of detection of rectangular targets.

The focal plane examined has a small fill factor; in other words, there is a large dead space between detectors. From the size of the blur spot, one can calculate the fraction of the target energy, from a point source, which is detectable. This fraction is a function of the position of the center of the blur spot. As a result, the detected target intensity varies dramatically as the target moves across the focal plane, even when the target intensity is a constant. Intensity measurements can thus be extremely inaccurate. The effect is studied for several fill factors, from 100% down to 50%,the approximate fill factor for the proposed system. The effect can be compensated for if the precise position of the blur spot on the detector is known. One method, which estimates that position using intensities from adjacent detectors, is shown. This method's value, unfortunately, declines as the fill factor decreases. Furthermore, the method can only work when the detector response as a function of target position is known precisely. The effect of the focal plane design on separation of closely-spaced objects (CSOs) is then derived. Several cases are shown in which multiple targets, separated by substantial fractions of a detector width, are indistinguishable from a single target. The effect of changing the fill factor is also demonstrated. As the fill factor decreases, the effect worsens. Proposed changes to the sensor design include increasing the fill factor and/or defocussing the blur spot. Results are shown for various combinations of these parameters.

This paper investigates changes in target detectability due to alterations in target and clutter contrast structures brought about by sensor aliasing. A human observer model which is sensitive to structural contrast differences has been developed and is used to assess target detectability in aliased imagery generated by the TACOM Thermal Image Model. Results indicate that aliasing can influence target detectability.

Electro-optic staring sensors, which sample a scene with pixels of finite size, generate images that are affected by aliasing and blurring caused by the sampling process. One potential method to reduce the effects of sampling is microscanning. In the microscan process, multiple images of the scene are generated. Between each successive image, the location of the image on the detector array is moved a fraction of a pixel. The set of images produced in the microscan process are then combined to form a single image. We present an analytical model of the microscan process. The model shows that the microscan process can significantly reduce aliasing in the reconstructed image, and that the process does not blur the image beyond the blur caused by the finite pixel aperture. The model also shows that factors such as the blur produced by the imaging optics and the fill factor of the detector array affect the reduction in aliasing produced by microscanning. We present a quantitative description of the effect of microscanning for selected cases of fill factor, optics blur, and number of microscan steps. We also present images produced by computer simulation which qualitatively verify the reduction in aliasing associated with the microscan process.

Imaging IR sensors which are used as target acquisition devices in weapon systems, i.e. FLIRs, have diversified in the 15 years following the development of the Ratches method for predicting static detection and recognition probabilities. Current FLIRs vary from devices which are completely analog in nature, such as the common module FLIR, to those which utilize spatial and temporal sampling to a significant degree, such as scanning or staring FPAs. Due to non-monotonic behavior in the Minimum Resolvable Temperature Difference (MRT) curves typical of most staring systems and uncertainties in the measurement of the MRT, direct use of the Ratches technique for comparing scanning and staring systems has become limited or impossible. Through the use of field test observations and data collection, in conjunction with laboratory measurements of MRT, a revisitation of the analysis procedure is offered which allows for direct and nonambiguous comparisons between scanning and staring FLIR systems. Specifically, cycle criteria appropriate for staring systems are presented along with validating data using multiple scanning and staring systems.

The classical approach for designing sensor systems is to make the blur circle from a point- source object be approximately the same size as a pixel. Problems arise, however, when the blur circle moves around on the focal plane and energy is lost not only in the gaps between pixels but is also spread among multiple pixels. This paper presents some of the details of how a high-fidelity threat-object scene generator, a detailed seeker model, and a signal processing algorithm have been integrated into the Kinetic Energy Weapons Digital Emulation Center (KDEC) six-degree-of-freedom missile simulation. Several different sensor design tradeoffs are examined such as variations in detector size, aperture size and staggered pixel rows. It is shown how spatial sampling of the moving blur circle can have a detrimental effect on the tracking accuracy and final miss distance of guided-missile systems. Point-source and extended (imaged) objects are examined to show the importance of investigating the effects of sensor design on the entire missile system.

In this paper we discuss the development of a new computer tool, InfraRed Design Optimization Code (IRDOC), for the design of infrared sensors. IRDOC consists of a robust model for IR sensors and a powerful optimizing algorithm. The model predicts the signal-to- noise (including clutter) ratio (SNR) with filtering. The model combines important features of spatial-frequency-domain analysis and time-domain analysis. The program inputs a number of system parameters, several constraints, and the allowed ranges for the sensor variables from the user. IRDOC determines the set of variables within their allowed ranges and subject to the constraints, that maximizes the signal-to-noise ratio. A generic example of a point detection sensor and an example of an imaging sensor using scanning sensors are optimized for a variety of background conditions.

The Advanced Sensor Development Laboratory (ASDL) at the Stennis Space Center develops, maintains and calibrates remote sensing instruments for the National Aeronautics & Space Administration. To perform system design trade-offs, analysis, and establish system parameters, ASDL has developed a software package for analytical simulation of sensor systems. This package called 'Analytical Tools for Thermal InfraRed Engineering'--ATTIRE, simulates the various components of a sensor system. The software allows each subsystem of the sensor to be analyzed independently for its performance. These performance parameters are then integrated to obtain system level information such as SNR, NER, NETD etc. This paper describes the uses of the package and the physics that were used to derive the performance parameters. In addition, ATTIRE can be used as a tutorial for understanding the distribution of thermal flux or solar irradiance over selected bandwidths of the spectrum. This spectrally distributed incident flux can then be analyzed as it propagates through the subsystems that constitute the entire sensor. ATTIRE provides a variety of functions ranging from plotting black-body curves for varying bandwidths and computing the integral flux, to performing transfer function analysis of the sensor system. The package runs from a menu- driven interface in a PC-DOS environment. Each sub-system of the sensor is represented by windows and icons. A user-friendly mouse-controlled point-and-click interface allows the user to simulate various aspects of a sensor. The package can simulate a theoretical sensor system. Trade-off studies can be easily done by changing the appropriate parameters and monitoring the effect of the system performance. The package can provide plots of system performance versus any system parameter. A parameter (such as the entrance aperture of the optics) could be varied and its effect on another parameter (e.g., NETD) can be plotted. A third parameter (e.g., the obscuration) could be varied for each plot and several plots obtained on the same graph. The menu for such 'Y vs X plots for different values of Z' currently contains various such options. The package also allows the user to create customized work-sheets of the simulated system and save the analysis for interface with or retrieval to other packages. The emissivity, atmospheric transmission and the optical transmission default as constants over the specified spectral bandwidths. There is an option for making these parameters spectrally variable. If more than one of the above-mentioned three parameters are spectrally variable, then it is possible that the upper and lower wavelength values as well as the resolution of the wavelength array may not be the same for all three arrays. The package performs an interpolation of the data to smooth out the curves and then projects them onto a common wavelength array for all the parameters.

This paper presents a description of a modular simulation architecture which has been implemented on a 386 personal computer running UNIX and X-Windows to model virtually any staring or scanning array system and its associated processing electronics. The modularity of the simulation system permits rapid software-prototyping of a proposed sensor system and provides the designer with a valuable 'what if' tool for evaluating the impact of numerous design alternatives on the performance of the overall system. Such front-end simulations performed during the early stages of a system-level design are effective in reducing costly design iterations and they held to ensure first-run system success. 'AmberSim' provides the capability to quickly construct a model of a scanning or staring sensor system, choose from a library of infrared backgrounds and targets, and produce frames of output displays useful in predicting sensor system performance. Continuing development work will be presented that describes how AmberSim is being ported to today's powerful graphical workstations.

Imaging systems often create undesirable signals such as narcissus, microphonics, shading, etc. It is important to reduce these unwanted signals to an acceptable level during the system design process. To do so, one must develop a model that considers the perceptibility of the unwanted signal to an observer. Consequently, the spatial and temporal characteristics of the eye/brain must be considered. An example is provided that shows a technique to determine the threshold of undesirable signals while considering the spatial and temporal characteristics of the observer.

This paper describes the capabilities, models, and implementation of the SSW sensor model software, and illustrates its utility in processing computer-generated signatures. Sample images illustrate the results of processing computed images with different components of the 55W sensor model. Synthetic scene modeling and signature generation have become important tools used in the development of complex sensor systems for smart weapons. Simulated signatures have proven useful by providing realistic data to support system development, performance prediction, validation, and trade studies for signal processing applications and entire systems. In addition, comparisons between computed signatures and measured data can provide insight into signature phenomenology and modeling. Standard signature prediction codes do not account for effects caused by the sensor. These effects can cause measured signatures to differ significantly from predictions, and may critically affect the performance of applications which use the data. The Strategic Scene Workstation (55W), developed by Nichols Research Corporation for the USAF Wright Laboratory, Armament Directorate, includes a computer model designed to simulate sensor effects in computed signatures. The 55W sensor model simulates spatial effects, noise, and detector characteristics typical if passive sensors used in strategic applications. This function is necessary to custon ze predicted signatures, and has been used effectively to enhance the realism and accuracy of simulated signatures for applications including hardware in the loop simulation at the USAF KHILS facility at Eglin AFB, FL.

Under contract to Rome Lab, Grumman performed studies to determine the magnitude of aircraft infrared (IR) intensities in arctic environments. These studies were then used to establish the requirements of aircraft intensity component measurement facilities. This paper will investigate and assess environment-driven IR intensity components for use in planning future IR measurements under arctic environments. This assessment includes earthshine, solar reflections, solar heating, skyshine, atmospheric attenuation, and background/foreground radiance associated with arctic environments. Results from trade studies are presented, along with a summary of the IR intensities expected under arctic environments. The major findings of this study indicate that by controlling the IR intensity components driven by flight conditions and atmospheric attenuation, measurements of environment-driven IR intensity components need to be performed. This is particularly interesting under arctic environments where the environment-driven IR intensity components have an impact on the overall IR intensity of the airframe.

Minimum Resolvable Temperature Difference (MRTD) has long been the universally accepted standard measure of a thermal imaging sensor's performance. This test is a complete evaluation of man and machine and is the best predictor, short of actual field evaluation, for determining the performance of the man/machine combination. Variables associated with the observer have generally been taken for granted. With the development of more sophisticated sensors for different applications, it is now time to analyze the link between the sensor and observer more closely and how it relates to the MRTD. This paper investigates the impact of the MRTD results due to observer variables such as monocular versus binocular viewing, small amount of head movement and varying viewing distance from the display. The high frequency MRTD appears to be limited by the system's MTF and amount o noise present. The low frequency MRTD appears to be affected by viewing distance and the amount of low frequency noise (non-uniformity) present.

Measurement of the Optical Transfer Function (OTF) of discretely sampled thermal imaging systems, e.g. parallel scanned FLIR systems, on which analysis is done in the cross scan direction, and staring focal plane arrays, it increasingly important as digital image acquisition device technology for the 3 - 5 and 8 - 12 micron (infrared) spectral regions is maturing. The traditional measurement methods used for continuous scan systems may not be valid for discretely sampled systems. This paper presents results of measurements of the OTF using a translating slit to obtain the Line Spread Function (LSF) for discretely sampled systems. Multiple frame acquisition is used for removal of temporal and fixed pattern noise. It is the intent of this laboratory effort to develop a measurement technique to be used when collecting OTF data for discretely sampled systems. The new measurement technique is potentially suitable for all systems, and if successful, will permit characterization of vertical system MTF. If this measurement method is found to be useful, it will be used to generate the OTF data used in the NVEOD FLIR92 model for further development and verification of the model.

Brassboard infrared imagers containing focal plane arrays of more than 80,000 uncooled detectors sensitive to radiation in the 8- to 14-micrometer wavelength region have been fabricated and tested. These imagers, which have demonstrated noise-equivalent temperature difference (NETD) values of 0.10 degree(s)C, do not require cryogenic cooling or mechanical scanning. Two different types of detector, one ferroelectric and the other bolometric, are used for the focal plane arrays. Measurements of NETD, minimum resolvable temperature (MRT) and modulation transfer function (MTF) are reported. Uncooled sensor technology is being incorporated into prototype security sensors and weapon sights that can also be used as handheld surveillance devices.

LEO Thermal imaging is controlled by two parameters: t_o time need to scan the foot print along the track and t_i integration time in thermal band. It is known that whisk broom is adequate when t_o > > t_i (low resolution) and push broom is of interest when t_o is congruent to t_i (high resolution). However moderate size projects are limited to low or intermediate resolution (for 30 m, t_o is about two orders of magnitude greater than t_i) and push broom is not mandatory. The need for high frequency calibration to eliminate 1/f detector noise (especially for (lambda) > 11 micrometers ) makes push broom advantage smaller than expected. Microscanning can be thought of as a way to match t_o and t_i as well as a convenient calibration mechanism. A configuration mixing microscanning and push broom design is shown to be a very efficient compromise. Problems like detector butting, fast calibration, long life time mechanism, and signal processing at chip level are more easily solved within the proposed concept.

There are a good number of IR sensor models available to the electro-optical community. These models predict sensor performance in terms of the system's probability to perform discriminating tasks as a function of target range and geometry, system minimum resolvable temperature and meteorological conditions. However, these models are tedious to use, and require intimate data pertaining to sensor output signal processing and display. Furthermore, these models lack the flexibility in, for example, displaying intermediate results in modifying probability statistics. Although these models are proven analytical tools, their use is somewhat prohibitive when performing every day desk-top calculations. This paper shows how general mathematics software packages available for personal computers, such as MathCad and Mathematica, can be used for rapid and reasonably accurate performance modelling of IR sensors. Examples discussed are estimating apparent target temperature difference, performance modelling using MRT data and transmission modelling.

A central obscuration in a thermal imager will cause performance degradation. This paper presents diagrams showing the normalized aperture diameter as a function of obscuration ratio under a condition for constant NETD and MRTD. Typically, an increase in the relative obscuration from 40% to 60% of the aperture diameter will require a 20 to 30% larger diameter for constant NETD and a 25 to 25% larger diameter for constant MRTD.

Multispectral imagery from a single frame is required for applications in which the target of interest can only be discriminated by its spectral features and the single image sensor is mounted on a moving platform. We describe the imager design and especially the design and fabrication of the optical filter and the resulting imagery.

The proposed approach uses new technology developments, off-the shelf equipment and proven designs which are considered low-to-medium risk. Advanced thermal imaging technology, FPAs and high resolution CCD will be used. Although the optical and stabilization system will be new designs, they are based on present day technology approaches to multi-band, long focal length systems. In summary, the proposed approach to a Light Weight Sensor optical subsystem is fully viable from both the design standpoint as well as the producibility standpoint.

Infrared analysis is re-examined in the light of the current status of imaging infrared technology. The spectral, spatial and temporal characteristics are all considered from the outset, the analysis being structured such that the sub-system characteristics associated with the infrared scene, transmission, detection and optoelectronic spread processes are separated, wherever possible. Each sub-system may therefore be examined on an essentially independent basis. The radiometric, temporal and spatial contributions are all readily apparent within the separated formulae that are derived for the signal, noise and SNR.

Funded by NASA's Office of Commercial Programs, the ATLAS (Airborne Terrestrial Applications Sensor) is a 15-channel multispectral imager for remote sensing applications under development at the Stennis Space Center (MS). This paper describes the overall ATLAS system design, functional sub-systems, and projected sensor performance characteristics (SNR, NETD, etc). In order to satisfy a variety of applications, both wide spectral coverage (0.45 - 12.2 micrometers ), as well as variable spatial resolution (2 - 25 m), are provided. The optics train includes a linescan mirror, Dall-Kirkham telescope, and three spectrometers. The ATLAS sensor package has a 7.5-inch entrance aperture, 2.0 mrad ifov, total field of view of 73 degree(s), and scan rates of 6 - 50 rev/sec. The spectrometer channels are divided as follows: VIS/NIR, 6 channels: 0.45 - 0.90 micrometers ; SWIR/MWIR, 3 channels: 1.55 - 4.20 micrometers ; and TIR, 6 channels: 8.2 - 12.2 micrometers . The ATLAS system combines the functionality of the TIMS (Thermal Infrared Multispectral Scanner) and the CAMS (Calibrated Airborne Multispectral Scanner), currently deployed, calibrated, and maintained by the Advanced Sensor Development Laboratory at Stennis Space Center. The major optical sub- systems, radiometric calibration sources, signal conditioning electronics, and other functions, will be described. ATLAS system specifications will also be presented.

The success of the U.S. Army's Night Vision Program at Fort Belvoir, VA was significantly influenced by the evolution and timely culmination of Visionics technology which was initiated by Mr. John Johnson. In the late 1950's, Visionics technology started with concern for Near Infrared (NIR) and Image Intensifier (II) Night Vision developments. It resulted in the Johnson Criteria which coupled system physical characteristics to visual performance by using resolution of line pairs across the minimum dimension of a target. This led to development of image evaluation procedures and standardized laboratory testing. Later the Visionics team addressed the Far Infrared (FIR) system performance and developed a series of FLIR Performance Models. The Visionic's Static Performance Model computer code was accepted and proliferated widely by the mid-70's. Visionics moved from static viewing to address the problems of search effectiveness. Then came more work on target signatures and the consideration of the effects of fog, rain, snow, artillery barrages, and realistic battlefield conditions on system performance in order to assure the utility of fielded equipments for all theaters of interest. The general use of the various Visionics models and methodology throughout Government and Industry is recognition of the contributions made by Mr. John Johnson and his Visionics staff.

An Equipment for measuring the MTF of sampled imaging systems is described. The system uses several different techniques to obtain an unambiguous result.