The challenges of size, weight, power consumption, and the cost of federated sensor systems for defense applications can be mitigated by exploring solutions derived from collaborative activities across government, industry, and academia. But sensor integration is illusive. For example, new vehicles are almost always developed by a single prime contractor; sensors are often identified as Contractor Furnished Material or Government Furnished Equipment and acquired by the “Prime.” This approach leads to federate architectures; sensor upgrades or new additions often show the “Christmas tree” effect, where sensors are more or less “hung” on the platform. This talk will explore novel approaches to integrating sensors needed to provide enhanced or new capabilities. Integrated sensors can support multiple missions performed by a single platform alone or with other manned or unmanned platforms, using common standards emerging from the DoD and Industry.
Future and advanced sensor technologies needed for DoD applications will require more efficient semiconductor materials and devices. Pushing sensor device performance beyond present levels requires a deep understanding of the fundamental limiters. Therefore fundamental research is needed to assure transition of technology from demonstration to system deployment. To address this problem, the Army Research Laboratory (ARL) and Boston University (BU) have come together to create a BU led Consortium for semiconductor Modeling of Materials and Devices (CSM). The Consortium brings together government, academia, and industry in a collaborative fashion to continuously push semiconductor research forward to meet DoD needs. The leveraged attributes of the Consortium include combined broad knowledge base in semiconductor modeling, materials growth and device expertise; sharing of computational resources; project continuity; and extension of the bench. Details regarding the Consortium’s first research topic on understanding vertical transport in Type 2 SL will be discussed.
Timely technology transition with minimal risk requires an understanding of fundamental and technology limitations of material synthesis, device operation and design controllable parameters. However, this knowledge-based approach requires substantial investment of resources in the Science and Technology (ST) stage of development. For low volume niche semiconductor technologies of Department of Defense (DoD) relevance, there is little drive for industry to expend their limited resources towards basic research simply because there is no significant return on investment. As a result, technology transition from ST to product development is often delayed, expensive and carries risks. The Army Research Laboratory (ARL) is addressing this problem by establishing a Center for Semiconductor Modeling of Materials and Devices (CSM) that brings together government, academia, and industry in a collaborative fashion to address research opportunities through its Open Campus initiative. This Center leverages combined core competencies of partner organizations, which include a broad knowledge base in modeling, and its validation; sharing of computational, characterization, materials growth and device processing resources; project continuity; and ‘extension of the bench’ via exchange of researchers between affiliated entities. A critical DoD technology is sensing in the infrared (IR) spectrum, where understanding of materials, devices and methods for sensing and processing IR information must continually improve to maintain superiority in combat. In this paper we focus on the historical evolution of IR technology and emphasize the need for understanding of material properties and device operation to accelerate innovation and shorten the cycle time, thereby ensuring timely transition of technology to product development and manufacturing. There are currently two competing IR technologies being pursued, namely the incumbent II-VI Hg1- xCdxTe technology and the III-V Type 2 Superlattices (SLs) technology. A goal of the CSM is to develop physics based models for Type 2 SLs with the capability to timely understand the knowledge gap between what is built and what is designed.
To increase Soldier readiness and enhance situational understanding in ever-changing and complex environments, there is a need for rapid development and deployment of Army technologies utilizing sensors, photonics, and electronics. Fundamental aspects of these technologies include the research and development of semiconductor materials and devices which are ubiquitous in numerous applications. Since many Army technologies are considered niche, there is a lack of significant industry investment in the fundamental research and understanding of semiconductor technologies relevant to the Army. To address this issue, the US Army Research Laboratory is establishing a Center for Semiconductor Materials and Device Modeling and seeks to leverage expertise and resources across academia, government and industry. Several key research areas—highlighted and addressed in this paper—have been identified by ARL and external partners and will be pursued in a collaborative fashion by this Center. This paper will also address the mechanisms by which the Center is being established and will operate.
The US Army’s future operating concept will rely heavily on sensors, nano-electronics and photonics technologies to rapidly develop situational understanding in challenging and complex environments. Recent technology breakthroughs in integrated 3D multiscale semiconductor modeling (from atoms-to-sensors), combined with ARL’s Open Campus business model for collaborative research provide a unique opportunity to accelerate the adoption of new technology for reduced size, weight, power, and cost of Army equipment. This paper presents recent research efforts on multi-scale modeling at the US Army Research Laboratory (ARL) and proposes the establishment of a modeling consortium or center for semiconductor materials modeling. ARL’s proposed Center for Semiconductor Materials Modeling brings together government, academia, and industry in a collaborative fashion to continuously push semiconductor research forward for the mutual benefit of all Army partners.
The record electronic properties achieved in monolayer graphene and related 2D materials such as molybdenum
disulfide and hexagonal boron nitride show promise for revolutionary high-speed and low-power electronic devices.
Heterogeneous 2D-stacked materials may create enabling technology for future communication and computation
applications to meet soldier requirements. For instance, transparent, flexible and even wearable systems may become
feasible. With soldier and squad level electronic power demands increasing, the Army is committed to developing and
harnessing graphene-like 2D materials for compact low size-weight-and-power-cost (SWAP-C) systems. This paper will
review developments in 2D electronic materials at the Army Research Laboratory over the last five years and discuss
directions for future army applications.
Infrared sensing technology has come a long way since Hershel made the unexpected discovery in 1800 that radiation at wavelengths beyond the visible spectrum were measurable by his rudimentary bolometer instrument. The tremendous advancements in this technology have been propelled heavily through defense research and development, aimed at providing important night vision and target detection capabilities for surveillance, reconnaissance, targeting, and threat warning systems. The maturation of the underlying infrared sensing technology, specifically infrared optics and focal plane arrays, has not only enhanced the system capabilities for these missions, but has also resulted in the proliferation of infrared systems into a more diverse set of air, land, sea, and space-based platforms. Furthermore, infrared sensing has become more affordable through the advent of uncooled and high-operating-temperature focal plane arrays, which has opened up civilian and commercial applications such as thermography, law enforcement, fire and security, weather monitoring, transportation, and spectroscopy.
Mid wave infrared (MWIR) imaging in the 3-5 um spectral band has traditionally been performed by InSb
sensors. InSb technology is presently limited to a near 80K operating temperature and the hunt has been on for a
higher operating temperature (HOT) technology that does as well at 150K as InSb at 80K, but with reduced
power requirements. Amongst these alternative technologies are photovoltaic sensors consisting of heterostructures
of HgCdTe (MCT). In previous work we assessed the device performance of several alternative MWIR
HOT technologies (MCT on Si, MCT on GaAs) as a function of operating temperature. In this work we compare
the NEDT histograms for these alternative technologies with InSb to better understand how their performance can
be improved at higher temperatures. We also present analysis formalism for quantitatively assessing the number
of FPA pixels which reside in the central versus the shoulder portions of the histogram.Begin the Introduction two
lines below the Keywords. The manuscript should not have headers, footers, or page numbers. It should be in a onecolumn
format. References are often noted in the text1 and cited at the end of the paper.
This paper discusses the design and development of a dual field of view, all-refractive infrared optical system
that images the mid-wave infrared (MWIR) light in one field of view and the short wave infrared (SWIR) light
in the narrower second field of view onto the same detector. The narrow field of view images the SWIR
radiation at a slow f/number of 10.0, while the wide field of view images the MWIR radiation at f/1.9. The
field of view is changed via a single lens that changes its axial position within the lens, resulting in an axial
zoom and an overall magnification change of 6X. The change in focal length and f/number at the same time
enables an increased focal length without having to increase the aperture size by the ratio of the focal length
change. The large field of view change is achieved by both the motion of the lens, and the use of the spectral
properties of the materials that change with wavelength. The change in spectral bands is accomplished via the
use of a spectral filter wheel.
Automatic classification of the density of breast parenchyma is shown using a measure that is correlated to the human observer performance, and compared against the BI-RADS density rating. Increasingly popular in the United States, the Breast Imaging Reporting and Data System (BI-RADS) is used to draw attention to the increased screening difficulty associated with greater breast density; however, the BI-RADS rating scheme is subjective and is not intended as an objective measure of breast density. So, while popular, BI-RADS does not define density classes using a standardized measure, which leads to increased variability among observers. The adaptive thresholding technique is a more quantitative approach for assessing the percentage breast density, but considerable reader interaction is required. We calculate an objective density rating that is derived using a measure of local feature salience. Previously, this measure was shown to correlate well with radiologists' localization and discrimination of true positive and true negative regions-of-interest. Using conspicuous spatial frequency features, an objective density rating is obtained and correlated with adaptive thresholding, and the subjectively ascertained BI-RADS density ratings. Using 100 cases, obtained from the University of South Florida's DDSM database, we show that an automated breast density measure can be derived that is correlated with the interactive thresholding method for continuous percentage breast density, but not with the BI-RADS density rating categories for the selected cases. Comparison between interactive thresholding and the new salience percentage density resulted in a Pearson correlation of 76.7%. Using a four-category scale equivalent to the BI-RADS density categories, a Spearman correlation coefficient of 79.8% was found.
We derive a general random-effects model to study the differences in spatial frequency features across class-type (true positive (TP) or true negative (TN) or False Positive (FP)), a sample of 40 mammogram cases, and 9 readers. We derive a measure of feature conspicuity or salience using visually inspired spatial frequency filters and mammogram regions of interest derived from eye-position data. Repeated-measures ANOVA is performed on the salient features obtained from all cases. We hypothesize that statistically significant differences in the average salience measure (D-score) are seen across both class-types and cases. We believe this to be useful for determining the similarity between images in training and testing sets used in CADx algorithm development or for a priori determination of test set difficulty. Further, we hypothesize that our salience measure is useful for distinguishing the spatial frequency bands most relied upon to distinguish true negative and true positive responses. This is useful in discerning the "bottoms-up" cues used to direct the point of gaze during mammogram inspection. These results indicate that our salience measure is useful as an indicator of image similarity and for separating TP & TN regions of interest.
We present a method for locating salient features in mammograms. The perceptual importance or salience of image pixels can be studied using a statistical measure of pixel-based features. The “outliers” or greatest values for this measure can be regarded as salient because in an imaging sense, the outliers tend to contribute to the local feature contrast. Our method finds important image features first by spatially decomposing the image using a process that models the human vision system. Salience maps then are created using the Mahalanobis distance, and a scalar visibility metric then is analyzed. Six mammographers each read three mammograms. Each mammogram had two views. During screening, eye position data were recorded. A K-means algorithm then was applied to identify fixation clusters. Following decomposition, Analysis of Variance (ANOVA) then was performed to examine the effects of observer experience, spatial frequency, and discrimination using the maximum value of the visibility metric. This pilot study shows statistically significant differences in true positive and true negative features, and in both the features and filters used to discriminate true negative results between expert and resident observers. This type of analysis can be useful for finding fixation tendencies that result from the available spatial features during mammogram screening.
Third-Generation, two-color infrared cooled sensors are being developed in order to allow the Army to detect and identify enemy forces at ranges beyond that at which the enemy can detect them. This will ensure that the Army continues to "own" night operations. Developing the technology needed to field these high-performance third-generation cooled imagers poses many challenges to the infrared community. These devices, which are expected to provide high spatial and temporal resolution simultaneously in two-to-three infrared bands, will dramatically increase the ability to find targets in defilade, and will be a major technological breakthrough. Performance has to be close to the theoretical limit, dominated by the limits of photon noise. Cost is also a major factor if sufficient numbers of such sensors are to be fielded. The benefits of this technology are now described, followed by a summary of the challenges faced in meeting the cost and performance objectives.
Uncooled infrared cameras have made dramatic strides recently. Very low cost, lightweight, low power cameras have been built. Also low cost high performance uncooled cameras have been built. A discussion of this technology to make this happen and the resulting new applications will follow.
Fusion of reflected/emitted radiation light sensors can provide significant advantages for target identification and detection. The two bands -- 0.6 - 0.9 or 1 - 2 micrometer reflected light and 8 - 12 micrometer emitted radiation -- offer the greatest contrast since those bands have the lowest correlation, hence the greatest amount of combined information for infrared imaging. Data from fused imaging systems is presented for optical overlay as well as digital pixel fusion. Advantages of the digital fusion process are discussed as well as the advantages of having both bands present for military operations. Finally perception tests results are presented that show how color can significantly enhance target detection. A factor of two reduction in minimum resolvable temperature difference is postulated from perception tests in the chromaticity plane. Although initial results do not yet validate this finding, it is expected with the right fusion algorithms and displays that this important result will be proven shortly.
Small, low cost, low poer infrared imaging sensors are relatively recent innovation, employing the most advanced MEMS processing techniques, integrated circuit design, optical materials, and focal plane array packaging. We will review the rationale behind the development of low cost, small IR cameras, discuss several of the medium performance applications for these sensors via a modeling analysis, discuss the goals and status of our applied research uncooled focal plane array technology programs, and discuss the future of uncooled focal plane arrays.
Air Warrior is a program to define a fully integrated ensemble of equipment to be worn and/or carried by Army aviators. The U.S. Army Night Vision Directorate has conducted a trade study of helmet mounted intensifier and display components having potential utility for Air Warrior. Over two dozen technical design issues were identified (FOV, resolution, mass, symbology viewability, etc.) These were categorized, prioritized and assigned relative weightings amongst each other. Each was also given its own individual scoring metric on a 100 point maximum scale. The scoring system was implemented in a database/model and exercised against over sixty systems differing in number of image intensifier tubes, tube sizes, objective optics, and HMD technologies. The resulting model allows complex systems to be related to one another quantitatively on a common basis. While the benefit of substantial scientific understanding was applied in developing these metrics, the scope of the undertaking and the wide range of issues also required careful use of subjective judgment. Defmitive, quantitative studies have not been concluded on all parameters relevant to Air Warrior, however, the NVESD team believes that the product of this study is as forward thinking and applicable to near-future Army aviation as is possible given the current understanding of the myriad issues involved. The database/model is expected to evolve as the scientific knowledge base grows. This paper discusses model development and sample results of comparison exercises. For more detailed information, readers are referred to the 200 page fmal report which may be requested through Mr. Brian Gillespie at NVESD, Fort Belvoir, Virginia. Keywords: trade study, image intensifier, helmet mounted display, Air Warrior
Today, night vision sensor and display systems used in the pilotage or navigation of military helicopters are either long wave IR thermal sensors (8 - 12 microns) or image intensified, visible and near IR (0.6 - 0.9 microns), sensors. The sensor imagery is displayed using a monochrome phosphor on a Cathode Ray Tube or night vision goggle. Currently, there is no fielded capability to combine the best attributes of the emissive radiation sensed by the thermal sensor and the reflected radiation sensed by the image intensified sensor into a single fused image. However, recent advances in signal processing have permitted the real time image fusion and display of multispectral sensors in either monochrome or synthetic chromatic form. The merits of such signal processing is explored. A part task simulation using a desktop computer, video playback unit, and a biocular head mounted display was conducted. Response time and accuracy measures of test subject responses to visual perception tasks were taken. Subjective ratings were collected to determine levels of pilot acceptance. In general, fusion based formats resulted in better subject performance. The benefits of integrating synthetic color to fused imagery, however, is dependent on the color algorithm used, the visual task performed, and scene content.
The Advanced Helicopter Pilotage (AHP) program is developing a wide field-of-view, night and adverse weather vision system for helicopter navigation and obstacle avoidance. THe AHP hardware consists of a second generation thermal sensor, a high definition image intensified camera, and a helmet mounted display (HMD). The specifications for next generation night vision sensor require through the system performance measures. As such, particular importance is given to the quantification of limiting resolution at operationally relevant illumination levels rather than measures performed under typical laboratory illumination.In this paper, descriptions of the AHP HMD and image intensified camera are given, and the measured modulation transfer function of the HMD is reported. Also covered are the results of noise limited resolution testing of the AHP HMD and image intensified camera. A comparison of MTF and noise limited resolution measures, made under the appropriate illumination, using a Dage HR-2000 is presented.
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