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Dual-polarization challenges in weather radar requirements for multifunction phased array radar

October 15, 2013
  |
Conference Paper
Author:
Caleb Fulton
…
Published in:
2013 IEEE Int. Symp. On Phased Array Systems and Technology, 15-18 October 2013.
Topic:
radar
R&D area:
R&D group:

Summary

This paper summarizes the challenges in achieving (and even specifying) the antenna polarization accuracy requirements for the Multifunction Phased Array Radar (MPAR) and the progress that has been made towards meeting these requirements through demonstrations and theoretical investigations.
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Summary

This paper summarizes the challenges in achieving (and even specifying) the antenna polarization accuracy requirements for the Multifunction Phased Array Radar (MPAR) and the progress that has been made towards meeting these requirements through demonstrations and theoretical investigations.

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Dual-polarization challenges in weather radar requirements for multifunction phased array radar

Multi-lithic phased array architecture for airborne sense and avoid radar

October 15, 2013
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Conference Paper
Author:
Sean M. Duffy
…
Published in:
2013 IEEE Int. Symp. On Phased Array Systems and Technology, 15-18 October 2013.
Topic:
radar
R&D area:
R&D group:

Summary

Transmit and receive Ku-band phased array designs are described for testing an airborne sense and avoid radar. The arrays are small with a size of 24 cm x 9 cm and operate from 13 to 17 GHz with electronic scanning from plus of minus 45 degrees in azimuth and plus of minus 30 degrees in elevation. A novel design architecture allows the use of multiple multilayered printed circuit boards and simple air cooling.
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Summary

Transmit and receive Ku-band phased array designs are described for testing an airborne sense and avoid radar. The arrays are small with a size of 24 cm x 9 cm and operate from 13 to 17 GHz with electronic scanning from plus of minus 45 degrees in azimuth and plus...

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Multi-lithic phased array architecture for airborne sense and avoid radar

Ultrawideband time-delay steered UHF dipole linear array antenna

October 15, 2013
  |
Conference Paper
Author:
Alan J. Fenn
…
Published in:
2013 IEEE Int. Symp. On Phased Array Systems and Technology, 15-18 October 2013.
Topic:
antennas
R&D area:
R&D group:

Summary

An ultrawideband fixed time-delay steered UHF dipole array antenna has been developed for coverage in the 300 to 450 MHz frequency range for communications or radar applications. The antenna utilizes a parasitically-tuned dipole array for linear polarization and is mounted over a ground plane. Numerical electromagnetic simulations were used to analyze and optimize the antenna parameters prior to fabrication. Measurements of the prototype antenna in an anechoic chamber demonstrate the antenna's reflection coefficient and radiation gain pattern performance.
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Summary

An ultrawideband fixed time-delay steered UHF dipole array antenna has been developed for coverage in the 300 to 450 MHz frequency range for communications or radar applications. The antenna utilizes a parasitically-tuned dipole array for linear polarization and is mounted over a ground plane. Numerical electromagnetic simulations were used to...

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Ultrawideband time-delay steered UHF dipole linear array antenna

On the development of a tileable LRU for the NextGen surveillance and weather radar capability program

October 15, 2013
  |
Conference Paper
Author:
M. David Conway
…
Published in:
2013 IEEE Int. Symp. On Phased Array Systems and Technology, 15-18 October 2013.
Topic:
integrated circuit
R&D area:
R&D group:

Summary

MIT Lincoln Laboratory is working towards the development of a tileable radar panel to satisfy multimission needs. A combination of custom and commercial off-the-shelf (COTS) Monolithic Microwave Integrated Circuits (MMICs) have been developed and/or employed to achieve the required system functionality. The integrated circuits (ICs) are integrated into a low cost T/R module compatible with commercial printed circuit board (PCB) manufacturing. Sixty-four of the transmit/receive (T/R) modules are integrated onto the aperture PCB in an 8x8 lattice. In addition to the T/R elements, the aperture PCB incorporates transmit and receive beamformers, power and logic distribution, and radiating elements. The aperture PCB is coupled with a backplane PCB to form a panel, the line replaceable unit (LRU) for the multifunction phased array radar (MPAR) initiative. This report summarizes the evaluation of the second iteration LRU aperture PCB and T/R element. Support fixturing was developed and paired with the panel to enable backplane functionality sufficient to support the test objective.
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Summary

MIT Lincoln Laboratory is working towards the development of a tileable radar panel to satisfy multimission needs. A combination of custom and commercial off-the-shelf (COTS) Monolithic Microwave Integrated Circuits (MMICs) have been developed and/or employed to achieve the required system functionality. The integrated circuits (ICs) are integrated into a low...

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On the development of a tileable LRU for the NextGen surveillance and weather radar capability program

Ultrawideband cavity-backed resistively loaded planar dipole array for ground penetrating radar

October 15, 2013
  |
Journal Article
Author:
Alan J. Fenn
…
Published in:
2013 IEEE Int. Symp. On Phased Array Systems and Technology, 15-18 October 2013.
Topic:
antennas
R&D area:
R&D group:

Summary

An ultrawideband (UWB) cavity-backed resistively loaded planar dipole array antenna has been developed for the 100 to 400 MHz frequency range for ground penetrating radar applications. The antenna has been designed with a 3m aperture to perform surveys of a wide swath of ground from a moving vehicle. The performance of the UWB array is quantified by moment method simulations of the electromagnetic field penetration into lossy soil. Integration of the UWB array onto vehicle is discussed.
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Summary

An ultrawideband (UWB) cavity-backed resistively loaded planar dipole array antenna has been developed for the 100 to 400 MHz frequency range for ground penetrating radar applications. The antenna has been designed with a 3m aperture to perform surveys of a wide swath of ground from a moving vehicle. The performance...

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Ultrawideband cavity-backed resistively loaded planar dipole array for ground penetrating radar

Competing Mobile Network Game: embracing antijamming and jamming strategies with reinforcement learning

October 14, 2013
  |
Journal Article
Author:
Youngjune L. Gwon
…
Published in:
2013 IEEE Conf. on Communications and Network Security (CNS), 14-16 October 2013, pp. 28-36.
Topic:
communications
R&D area:
R&D group:

Summary

We introduce Competing Mobile Network Game (CMNG), a stochastic game played by cognitive radio networks that compete for dominating an open spectrum access. Differentiated from existing approaches, we incorporate both communicator and jamming nodes to form a network for friendly coalition, integrate antijamming and jamming subgames into a stochastic framework, and apply Q-learning techniques to solve for an optimal channel access strategy. We empirically evaluate our Q-learning based strategies and find that Minimax-Q learning is more suitable for an aggressive environment than Nash-Q while Friend-or-for Q-learning can provide the best solution under distributed mobile ad hoc networking scenarios in which the centralized control can hardly be available.
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Summary

We introduce Competing Mobile Network Game (CMNG), a stochastic game played by cognitive radio networks that compete for dominating an open spectrum access. Differentiated from existing approaches, we incorporate both communicator and jamming nodes to form a network for friendly coalition, integrate antijamming and jamming subgames into a stochastic framework...

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Competing Mobile Network Game: embracing antijamming and jamming strategies with reinforcement learning

An applications architecture to support FAA wake turbulence mitigation systems development and deployment

October 9, 2013
  |
Project Report
Author:
Vaibhav K. Andleigh
…
Published in:
MIT Lincoln Laboratory Report ATC-412
Topic:
weather
R&D area:
R&D group:

Summary

The Wake Turbulence Program within the Federal Aviation Administration (FAA) is considering a number of new procedures for safely reducing the wake vortex spacing requirements between aircraft. One category of procedures investigates wind-dependent procedures, i.e., procedures that can be applied when wind conditions are expected to transport the wake from a lead aircraft away from the path of a trailing aircraft. MIT Lincoln Laboratory developed a Wind Forecast Algorithm (WFA) to determine when conditions allow these wind-dependent procedures to be available to traffic managers. The baseline WFA is used within the Wake Turbulence Mitigation for Departures (WTMD) system, which establishes spacing procedures for departures on closely spaced parallel runways. A number of new procedures are also under consideration, each of which will require a modification and/or expansion of the baseline WFA. With time, the volume and number of disparate data sources used in the development process has steadily increased to the point where the existing development environment has become cumbersome and inadequate. As a result, through support of the FAA Wake Turbulence Program, MIT Lincoln Laboratory has undergone a complete overhaul of the computer processing and storage architecture used for WFA development. This will serve two main purposes. First, it will greatly expedite the development process, which is highly iterative and requires increasingly large volumes of data. Second, an updated architecture design will allow for an expeditious transition of developmental systems into the operational environment within FAA's NextGen framework. A key focus of this report describes how the new design is sufficiently compatible and flexible to serve within this anticipated FAA framework. The unified application architecture and infrastructure being designed and implemented will support continuing development, playback requirements, and real-time deployments. This architecture is composed of several application components including a wind data extract-transform-loaf (ETL) application, the WFA algorithm, and a display interface to accomodate both the development process and for potential use within the FAA operational environment. The Wind-ETL application component acquires, processes, and archives wind data from a variety of NOAA-based hourly forecasts and airport-vicinity weather measurement equipment. This wind data is ingested by the WFA, which computes and disseminates its availability predictions to the WTMx Display application component, which archives these predictions and also allows for presentation to the airport tower supervisor via the WTMx display user interface decision support tool. This architecture is designed to be flexible to accepting new weather data feeds, scalable to the high bandwidth and processing and storage capabilities required, provide sufficient automation and self-healing capabilities, and portable to allow its introduction into alternate facility sites and its integration into other FAA software systems.
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Summary

The Wake Turbulence Program within the Federal Aviation Administration (FAA) is considering a number of new procedures for safely reducing the wake vortex spacing requirements between aircraft. One category of procedures investigates wind-dependent procedures, i.e., procedures that can be applied when wind conditions are expected to transport the wake from...

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An applications architecture to support FAA wake turbulence mitigation systems development and deployment

Geospatial analysis based on GIS integrated with LADAR

October 7, 2013
  |
Journal Article
Author:
Matthew R Fetterman
…
Published in:
Opt. Express, Vol. 21, No. 20, 7 October 2013, pp. 23579-91.
Topic:
ladar
R&D area:
R&D group:

Summary

In this work, we describe multi-layered analyses of a high-resolution broad-area LADAR data set in support of expeditionary activities. High-level features are extracted from the LADAR data, such as the presence and location of buildings and cars, and then these features are used to populate a GIS (geographic information system) tool. We also apply line-of-sight (LOS) analysis to develop a path-planning module. Finally, visualization is addressed and enhanced with a gesture-based control system that allows the user to navigate through the enhanced data set in a virtual immersive experience. This work has operational applications including military, security, disaster relief, and task-based robotic path planning.
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Summary

In this work, we describe multi-layered analyses of a high-resolution broad-area LADAR data set in support of expeditionary activities. High-level features are extracted from the LADAR data, such as the presence and location of buildings and cars, and then these features are used to populate a GIS (geographic information system)...

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Geospatial analysis based on GIS integrated with LADAR

Materials in superconducting quantum bits

October 1, 2013
  |
Journal Article
Author:
William D. Oliver
…
Published in:
MRS Bulletin, Vol 38, October 2013, pp. 816-825.
Topic:
advanced materials
R&D area:
R&D group:

Summary

Superconducting qubits are electronic circuits comprising lithographically defined Josephson tunnel junctions, inductors, capacitors, and interconnects. When cooled to dillution refrigerator temperatures, these circuits behave as quantum mechanical "artificial atoms," exhibiting quantized states of electronic charge, magnetic flux, or junction phase depending on the design parameters of the constituent circuit elements. Their potential for lithographic scalability, compatibility with microwave control, and operability at nanosecond time scales place superconducting qubits among the leading modalities being considered for quantum information science and technology applications. Over the past decade, the quantum coherence of superconducting qubits has increased more than five orders of magnitude, due primarily to improvements in their design, fabrication, and, importantly, their constituent materials and interfaces. In this article, we review superconducting qubits, articulate the important role of materials research in their development, and provide a prospectus for the future as these devices transition from scientific curiosity to the threshold of technical reality.
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Summary

Superconducting qubits are electronic circuits comprising lithographically defined Josephson tunnel junctions, inductors, capacitors, and interconnects. When cooled to dillution refrigerator temperatures, these circuits behave as quantum mechanical "artificial atoms," exhibiting quantized states of electronic charge, magnetic flux, or junction phase depending on the design parameters of the constituent circuit elements...

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Materials in superconducting quantum bits

Exploring the variable sky with LINEAR. III. classification of periodic light curves

October 1, 2013
  |
Journal Article
Author:
Lovro Palaversa
…
Published in:
Astron. J., Vol. 146, No. 101, October 2013.
Topic:
LINEAR
R&D area:
R&D group:

Summary

We describe the construction of a highly reliable sample of ~7000 optically faint periodic variable stars with light curves obtained by the asteroid survey LINEAR across 10,000 deg^2 of the northern sky. The majority of these variables have not been cataloged yet. The sample flux limit is several magnitudes fainter than most other wide-angle surveys; the photometric errors range from ~0.03 mag at r = 15 to ~0.20 mag at r = 18. Light curves include on average 250 data points, collected over about 25 million objects, we selected ~200,000 most probable candidate variables with r
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Summary

We describe the construction of a highly reliable sample of ~7000 optically faint periodic variable stars with light curves obtained by the asteroid survey LINEAR across 10,000 deg^2 of the northern sky. The majority of these variables have not been cataloged yet. The sample flux limit is several magnitudes fainter...

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Exploring the variable sky with LINEAR. III. classification of periodic light curves
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