Time filter

Source Type

Huntsville, AL, United States

The Missile Defense Agency is the section of the United States government's Department of Defense responsible for developing a layered defense against ballistic missiles. The agency has its origins in the Strategic Defense Initiative, which was established in 1983 and was headed by Lt. General James Alan Abrahamson. It was renamed the Ballistic Missile Defense Organization in 1993, and then renamed the Missile Defense Agency in 2002. See National Missile Defense for the history of DoD missile defense programs. Wikipedia.

Gunapala S.D.,Jet Propulsion Laboratory | Bandara S.V.,Jet Propulsion Laboratory | Liu J.K.,Jet Propulsion Laboratory | Mumolo J.M.,Jet Propulsion Laboratory | And 9 more authors.
IEEE Journal of Quantum Electronics | Year: 2010

Quantum well infrared photodetectors (QWIPs) are well known for their stability, high pixel-pixel uniformity and high pixel operability which are quintessential parameters for large area imaging arrays. In this paper we report the first demonstration of the megapixel-simultaneously-readable and pixel-co-registered dual-band QWIP focal plane array (FPA). The dual-band QWIP device was developed by stacking two multi-quantum-well stacks tuned to absorb two different infrared wavelengths. The full width at half maximum (FWHM) of the midwave infrared (MWIR) band extends from 4.4-5.1 μm and FWHM of the long-wave infrared (LWIR) band extends from 7.8-8.8 μm. Dual-band QWIP detector arrays were hybridized with direct injection 30 μm pixel pitch megapixel dual-band simultaneously readable CMOS read out integrated circuits using the indium bump hybridization technique. The initial dual-band megapixel QWIP FPAs were cooled to 68 K operating temperature. The preliminary data taken from the first megapixel QWIP FPA has shown system NEΔT of 27 and 40 mK for MWIR and LWIR bands, respectively. © 2010 IEEE. Source

Huang B.,University of Tennessee at Knoxville | Shu X.,University of Tennessee at Knoxville | Vukosavljevic D.,Missile Defense Agency (MDA)
Journal of Materials in Civil Engineering | Year: 2011

This paper presents the results from a laboratory study in which hot-mix asphalt (HMA) mixtures with No. 4 sieve screened reclaimed asphalt pavement (RAP) were characterized for their cracking resistance through laboratory performance testing. A typical surface mixture commonly used in the state of Tennessee was evaluated at 0, 10, 20, and 30% RAP contents. Two types of aggregate (limestone and gravel) and three types of asphalt binders (PG 64-22, PG 70-22, and PG 76-22) were used in this study. Mixture cracking resistance was evaluated through Superpave indirect tension (IDT), beam fatigue, and semicircular bending (SCB) tests. The results from this study indicated that the inclusion of RAP generally increased stiffness and indirect tensile strength; however, it generally compromised cracking resistance for the mixtures studied. Mixture properties changed significantly at 30% RAP content as compared to those with 10 and 20% RAP. Field projects validated the findings from the laboratory study. © 2011 American Society of Civil Engineers. Source

Buford Jr. J.A.,Missile Defense Agency (MDA) | Murrer Jr. R.L.,Millennium Engineering And Integration Company
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

This PDF file contains the front matter associated with SPIE Proceedings Volume 7663, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing. © 2010 Copyright SPIE - The International Society for Optical Engineering. Source

Donnell K.M.,Missouri University of Science and Technology | McClanahan A.,Missouri University of Science and Technology | McClanahan A.,Missile Defense Agency (MDA) | Zoughi R.,Missouri University of Science and Technology
IEEE Transactions on Instrumentation and Measurement | Year: 2014

Detection of surface-breaking cracks in metals is an important issue in many industries (e.g., transportation, aerospace, nuclear). Commonly, eddy current and ultrasonic techniques are used for this purpose. In recent years, a significant amount of work has also been conducted using microwave methods. Consequently, to better understand the interaction between a microwave probe (i.e., open-ended rectangular waveguide or coax) and a crack, a number of electromagnetic models have been developed. For an open-ended coaxial probe, when a crack coincides with the center conductor region of the probe, all previously developed models significantly underestimate the results obtained from measurements. This paper examines the primary reason for this discrepancy, which turns out to be due to a geometrical perturbation in the probe center conductor geometry and its subsequent interaction with a crack. © 1963-2012 IEEE. Source

Land S.K.,Missile Defense Agency (MDA)
IEEE Potentials | Year: 2014

Susan K. Land shares her leadership experiences and the role of women in the field of computer science. According to her, women and girls who have an aptitude for science must be encouraged that it is a career where they will be in high demand and never lack for opportunities. The message should be that technology careers allow individuals, regardless of gender, to express their intellect and allow for them to be evaluated on their performance. It should be emphasized that jobs in technical fields are in high demand and will provide for lifelong learning, excitement, and satisfaction and that these jobs never become routine or boring. Sharing her experience, she says that it was during this job that she found the IEEE Computer Society and their package of software and systems engineering standards. These standards provided her with accepted guidance to support team training in the basics such as requirements management, configuration management, and quality assurance. Source

Discover hidden collaborations