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Required surveillance performance accuracy to support 3-mile and 5-mile separation in the National Airspace System

November 1, 2006
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Project Report
Author:
Steven D. Thompson
…
Published in:
MIT Lincoln Laboratory Report ATC-323
Topic:
surveillance
R&D area:
R&D group:

Summary

The Federal Aviation Administration is modernizing the Air Traffic Control system to improve flight efficiency, to increase capacity, to reduce flight delays, and to control operating costs as the demand for air travel continues to grow. Promising new surveillance technologies such as Automatic Dependent Surveillance Broadcast, (ADS-B), multisensor track fusion, and multifunction phased array radar offer the potential for increased efficiency in the National Airspace System (NAS). However, the introduction of these surveillance systems into the NAS is hampered because the FAA Order containing the surveillance requirements to support separation services assumes surveillance is provided by radar technology. The requirements are stated in terms that don't apply to new surveillance technologies. In order to take advantage of new surveillance technologies, the surveillance requirements to support separation services in the NAS must be articulated from a performance perspective that is not technology specific. This will allow the FAA to make the investment and performance trade-off analysis necessary to support the introduction of new surveillance technologies. [not complete]
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Summary

The Federal Aviation Administration is modernizing the Air Traffic Control system to improve flight efficiency, to increase capacity, to reduce flight delays, and to control operating costs as the demand for air travel continues to grow. Promising new surveillance technologies such as Automatic Dependent Surveillance Broadcast, (ADS-B), multisensor track fusion...

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Required surveillance performance accuracy to support 3-mile and 5-mile separation in the National Airspace System

High productivity computing and usable petascale systems

November 1, 2006
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Abstract
Author:
Jeremy Kepner
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Published in:
SC '06: Proceedings of the 2006 ACM/IEEE conference on Supercomputing
Topic:
high performance computing
R&D area:
R&D group:

Summary

High Performance Computing has seen extraordinary growth in peak performance which has been accompanied by a significant increase in the difficulty of using these systems. High Productivity Computing Systems (HPCS) seek to address this gap by producing petascale computers that are usable by a broader range of scientists and engineers. One of the most important HPCS innovations is the concept of a flatter memory hierarchy, which means that data from remote processors can be retrieved and used very efficiently. A flatter memory hierarchy increases performance and is easier to program.
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Summary

High Performance Computing has seen extraordinary growth in peak performance which has been accompanied by a significant increase in the difficulty of using these systems. High Productivity Computing Systems (HPCS) seek to address this gap by producing petascale computers that are usable by a broader range of scientists and engineers...

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High productivity computing and usable petascale systems

Validating and restoring defense in depth using attack graphs

October 23, 2006
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Conference Paper
Author:
Richard P. Lippmann
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Published in:
IEEE Military Communications Conference MILCOM 2006, 23-25 October 2006, pp. 3720-3729.
Topic:
attack graphs
R&D area:
R&D group:

Summary

Defense in depth is a common strategy that uses layers of firewalls to protect Supervisory Control and Data Acquisition (SCADA) subnets and other critical resources on enterprise networks. A tool named NetSPA is presented that analyzes firewall rules and vulnerabilities to construct attack graphs. These show how inside and outside attackers can progress by successively compromising exposed vulnerable hosts with the goal of reaching critical internal targets. NetSPA generates attack graphs and automatically analyzes them to produce a small set of prioritized recommendations to restore defense in depth. Field trials on networks with up to 3,400 hosts demonstrate that firewalls often do not provide defense in depth due to misconfigurations and critical unpatched vulnerabilities on hosts. In all cases, a small number of recommendations was provided to restore defense in depth. Simulations on networks with up to 50,000 hosts demonstrate that this approach scales well to enterprise-size networks.
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Summary

Defense in depth is a common strategy that uses layers of firewalls to protect Supervisory Control and Data Acquisition (SCADA) subnets and other critical resources on enterprise networks. A tool named NetSPA is presented that analyzes firewall rules and vulnerabilities to construct attack graphs. These show how inside and outside...

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Validating and restoring defense in depth using attack graphs

Securing communication of dynamic groups in dynamic network-centric environments

October 23, 2006
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Conference Paper
Author:
Roger I. Khazan
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Published in:
IEEE MILCOM 2006, 23-25 October 2006.
Topic:
cryptography
R&D area:
R&D group:

Summary

We developed a new approach and designed a practical solution for securing communication of dynamic groups in dynamic network-centric environments, such as airborne and terrestrial on-the-move networks. The solution is called Public Key Group Encryption (PKGE). In this paper, we define the problem of group encryption, motivate the need for decentralized group encryption services, and explain our vision for designing such services. We then describe our solution, PKGE, at a high-level, and report on the prototype implementation, performance experiments, and a demonstration with GAIM/Jabber chat.
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Summary

We developed a new approach and designed a practical solution for securing communication of dynamic groups in dynamic network-centric environments, such as airborne and terrestrial on-the-move networks. The solution is called Public Key Group Encryption (PKGE). In this paper, we define the problem of group encryption, motivate the need for...

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Securing communication of dynamic groups in dynamic network-centric environments

SFO marine stratus forecast system documentation

October 17, 2006
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Project Report
Author:
David A. Clark
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Published in:
MIT Lincoln Laboratory Report ATC-319
Topic:
weather
R&D area:
R&D group:

Summary

San Francisco International Airport (SFO) experiences frequent low ceiling conditions during the summer season due to marine stratus clouds. Stratus in the approach zone prevents dual approaches to the airport??s closely spaced parallel runways, effectively reducing arrival capacity by half. The stratus typically behaves on a daily cycle, with dissipation occurring during the hours following sunrise. Often the low ceiling conditions persist throughout the morning hours and interfere with the high rate of air traffic scheduled into SFO from mid-morning to early afternoon. Air traffic managers require accurate forecasts of clearing time to efficiently administer Ground Delay Programs (GDPs) to match the rate of arriving aircraft with expected capacity. The San Francisco Marine Stratus Forecast System was developed as a tool for anticipating the time of stratus clearing. The system relies on field-deployed sensors as well as routinely available regional surface observations and satellite data from the Geostationary Operational Environmental Satellite (GOES-West). Data are collected, processed, and input to a suite of forecast models to predict the time that the approach zone will be sufficiently clear to perform dual approaches. Data observations and model forecasts are delivered to users on an interactive display accessible via the Internet. The system prototype was developed under the sponsorship of the FAA Aviation Weather Research Program (AWRP). MIT Lincoln Laboratory served as technical lead for the project, in collaboration with San Jose State University, the University of Quebec at Montreal, and the Center Weather Service Unit (CWSU) at the Oakland Air Route Traffic Control Center (ARTCC). The National Weather Service (NWS), under the direction of the NWS Forecast Office in Monterey, assumed responsibility for operation and maintenance of the system following technical transfer in 2004. This document was compiled as a resource to support continuing system operation and maintenance.
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Summary

San Francisco International Airport (SFO) experiences frequent low ceiling conditions during the summer season due to marine stratus clouds. Stratus in the approach zone prevents dual approaches to the airport??s closely spaced parallel runways, effectively reducing arrival capacity by half. The stratus typically behaves on a daily cycle, with dissipation...

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SFO marine stratus forecast system documentation

Improving the resolution advisory reversal logic of the traffic alert and collision avoidance system

October 15, 2006
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Conference Paper
Author:
Andrew D. Zeitlin
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Published in:
25th IEEE/AIAA Digital Avionics Systems Conf., 15-18 October 2006, pp. 561-570.
Topic:
collision avoidance
R&D area:
R&D group:

Summary

The Traffic Alert and Collision Avoidance System (TCAS II) is the worldwide standard system for manned aircraft to avoid collisions with airborne transponder-equipped traffic. A safety vulnerability of the collision avoidance logic was reported by European analysts, who also proposed a change to correct it. The safety issue concerns limitations in the ability of TCAS to reverse the sense of a Resolution Advisory (RA) during an encounter. The issue was addressed by a team of experts1 in the Requirements Working Group (RWG) of RTCA Special Committee 147 [1]. This paper discusses the problem, the metrics and methods used in the analysis, and presents results that quantify the effectiveness of the proposed solution. Finally, recommendations are presented for implementing the change.
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Summary

The Traffic Alert and Collision Avoidance System (TCAS II) is the worldwide standard system for manned aircraft to avoid collisions with airborne transponder-equipped traffic. A safety vulnerability of the collision avoidance logic was reported by European analysts, who also proposed a change to correct it. The safety issue concerns limitations...

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Improving the resolution advisory reversal logic of the traffic alert and collision avoidance system

A wafer-scale 3-D circuit integration technology

October 1, 2006
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Journal Article
Author:
James A. Burns
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Published in:
IEEE Trans. Electron Devices, Vol. 53, No. 10, October 2006, pp. 2507-2516.
Topic:
integrated circuit
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R&D group:

Summary

The rationale and development of a wafer-scale three-dimensional (3-D) integrated circuit technology are described. The essential elements of the 3-D technology are integrated circuit fabrication on silicon-on-insulator wafers, precision wafer-wafer alignment using an in-house-developed alignment system, low-temperature wafer-wafer bonding to transfer and stack active circuit layers, and interconnection of the circuit layers with dense-vertical connections with sub-[Omega] 3-D via resistances. The 3-D integration process is described as well as the properties of the four enabling technologies. The wafer-scale 3-D technology imposes constraints on the placement of the first lithographic level in a wafer-stepper process. Control of wafer distortion and wafer bow is required to achieve submicrometer vertical vias. Three-tier digital and analog 3-D circuits were designed and fabricated. The performance characteristics of a 3-D ring oscillator, a 1024 x 1024 visible imager with an 8-um pixel pitch, and a 64 x 64 Geiger-mode laser radar chip are described.
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Summary

The rationale and development of a wafer-scale three-dimensional (3-D) integrated circuit technology are described. The essential elements of the 3-D technology are integrated circuit fabrication on silicon-on-insulator wafers, precision wafer-wafer alignment using an in-house-developed alignment system, low-temperature wafer-wafer bonding to transfer and stack active circuit layers, and interconnection of the...

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A wafer-scale 3-D circuit integration technology

Analysis of nonmodal phonation using minimum entropy deconvolution

September 21, 2006
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Conference Paper
Author:
Nicolas Malyska
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Published in:
Proc. Int. Conf. on Spoken Language Processing, ICSLP INTERSPEECH, 17-21 September 2006, pp. 1702-1705.
Topic:
signal processing
R&D area:
R&D group:

Summary

Nonmodal phonation occurs when glottal pulses exhibit nonuniform pulse-to-pulse characteristics such as irregular spacings, amplitudes, and/or shapes. The analysis of regions of such nonmodality has application to automatic speech, speaker, language, and dialect recognition. In this paper, we examine the usefulness of a technique called minimum-entropy deconvolution, or MED, for the analysis of pulse events in nonmodal speech. Our study presents evidence for both natural and synthetic speech that MED decomposes nonmodal phonation into a series of sharp pulses and a set of mixedphase impulse responses. We show that the estimated impulse responses are quantitatively similar to those in our synthesis model. A hybrid method incorporating aspects of both MED and linear prediction is also introduced. We show preliminary evidence that the hybrid method has benefit over MED alone for composite impulse-response estimation by being more robust to short-time windowing effects as well as a speech aspiration noise component.
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Summary

Nonmodal phonation occurs when glottal pulses exhibit nonuniform pulse-to-pulse characteristics such as irregular spacings, amplitudes, and/or shapes. The analysis of regions of such nonmodality has application to automatic speech, speaker, language, and dialect recognition. In this paper, we examine the usefulness of a technique called minimum-entropy deconvolution, or MED, for...

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Analysis of nonmodal phonation using minimum entropy deconvolution

Lincoln Laboratory high-speed solid-state imager technology

September 17, 2006
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Conference Paper
Author:
Robert K. Reich
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Published in:
SPIE Vol. 6279, 27th Int. Congress on High-Speed Photography and Photonics, 17-22 September 2006, 62791K.
Topic:
optics
R&D area:
R&D group:

Summary

Massachusetts Institute of Technology, Lincoln Laboratory (MIT LL) has been developing both continuous and burst solid-state focal-plane-array technology for a variety of high-speed imaging applications. For continuous imaging, a 128 ¿ 128-pixel charge coupled device (CCD) has been fabricated with multiple output ports for operating rates greater than 10,000 frames per second with readout noise of less than 10 e- rms. An electronic shutter has been integrated into the pixels of the back-illuminated (BI) CCD imagers that give snapshot exposure times of less than 10 ns. For burst imaging, a 5 cm x 5 cm, 512 x 512-element, multi-frame CCD imager that collects four sequential image frames at megahertz rates has been developed for the Los Alamos National Laboratory Dual Axis Radiographic Hydrodynamic Test (DARHT) facility. To operate at fast frame rates with high sensitivity, the imager uses the same electronic shutter technology as the continuously framing 128 x 128 CCD imager. The design concept and test results are described for the burst-frame-rate imager. Also discussed is an evolving solid-state imager technology that has interesting characteristics for creating large-format x-ray detectors with ultra-short exposure times (100 to 300 ps). The detector will consist of CMOS readouts for high speed sampling (tens of picoseconds transistor switching times) that are bump bonded to deep-depletion silicon photodiodes. A 64 x 64-pixel CMOS test chip has been designed, fabricated and characterized to investigate the feasibility of making large-format detectors with short, simultaneous exposure times.
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Summary

Massachusetts Institute of Technology, Lincoln Laboratory (MIT LL) has been developing both continuous and burst solid-state focal-plane-array technology for a variety of high-speed imaging applications. For continuous imaging, a 128 ¿ 128-pixel charge coupled device (CCD) has been fabricated with multiple output ports for operating rates greater than 10,000 frames...

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Lincoln Laboratory high-speed solid-state imager technology

Reducing speech coding distortion for speaker identification

September 17, 2006
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Conference Paper
Author:
Alan V. McCree
Published in:
Int. Conf. on Spoken Language Processing, ICSLP, 17-21 September 2006.
Topic:
speech processing
R&D area:
R&D group:

Summary

In this paper, we investigate the degradation of speaker identification performance due to speech coding algorithms used in digital telephone networks, cellular telephony, and voice over IP. By analyzing the difference between front-end feature vectors derived from coded and uncoded speech in terms of spectral distortion, we are able to quantify this coding degradation. This leads to two novel methods for distortion compensation: codebook and LPC compensation. Both are shown to significantly reduce front-end mismatch, with the second approach providing the most encouraging results. Full experiments using a GMM-UBM speaker ID system confirm the usefulness of both the front-end distortion analysis and the LPC compensation technique.
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Summary

In this paper, we investigate the degradation of speaker identification performance due to speech coding algorithms used in digital telephone networks, cellular telephony, and voice over IP. By analyzing the difference between front-end feature vectors derived from coded and uncoded speech in terms of spectral distortion, we are able to...

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Reducing speech coding distortion for speaker identification
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