ASSESSMENT OF MILLIMETER-WAVE AND TERAHERTZ TECHNOLOGY FOR DETECTION AND IDENTIFICATION OF CONCEALED EXPLOSIVES AND WEAPONS
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NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.
This study was supported by Contract No. DTFA03-99-C-00006 between the National Academy of Sciences and the Transportation Security Administration. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that provided support for the project.
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THE NATIONAL ACADEMIES
Advisers to the Nation on Science, Engineering, and Medicine
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COMMITTEE ON ASSESSMENT OF SECURITY TECHNOLOGIES FOR TRANSPORTATION
JAMES F. O’BRYON, Chair,
The O’Bryon Group
SANDRA L. HYLAND, Vice Chair,
Tokyo Electron Technology Center America
CHERYL A. BITNER,
Pioneer UAV, Inc.
DONALD E. BROWN,
University of Virginia
JOHN B. DALY,1 Consultant,
Arlington, Virginia
COLIN G. DRURY,
State University of New York, Buffalo
PATRICK GRIFFIN,
Sandia National Laboratories
JIRI JANATA,2
Georgia Institute of Technology
HARRY E. MARTZ, JR.,
Lawrence Livermore National Laboratory
RICHARD McGEE,
Army Research Laboratory, Aberdeen Proving Ground (retired)
RICHARD L. ROWE,3
SafeView (retired)
H. BRUCE WALLACE,
MMW Concepts LLC
Staff
GARY FISCHMAN, Study Director (from June 2006)
JAMES KILLIAN, Study Director (until June 2006)
EMILY ANN MEYER, Study Director (from November 2006)
TERI G. THOROWGOOD, Administrative Coordinator
NATIONAL MATERIALS ADVISORY BOARD
KATHARINE G. FRASE, Chair,
IBM
LYLE H. SCHWARTZ, Vice Chair, Consultant,
Chevy Chase, Maryland
JOHN ALLISON,
Ford Motor Company
PAUL BECHER,
Oak Ridge National Laboratory
CHERYL R. BLANCHARD,
Zimmer, Inc.
EVERETT E. BLOOM,
Oak Ridge National Laboratory (retired)
BARBARA D. BOYAN,
Georgia Institute of Technology
L. CATHERINE BRINSON,
Northwestern University
DIANNE CHONG,
The Boeing Company
PAUL CITRON,
Medtronic, Inc. (retired)
FIONA DOYLE,
University of California, Berkeley
SOSSINA M. HAILE,
California Institute of Technology
CAROL A. HANDWERKER,
Purdue University
ELIZABETH HOLM,
Sandia National Laboratories
ANDREW T. HUNT,
nGimat Company
DAVID W. JOHNSON, JR.,
Stevens Institute of Technology
FRANK E. KARASZ,
University of Massachusetts, Amherst
CONILEE G. KIRKPATRICK,
HRL Laboratories
TERRY LOWE,
Los Alamos National Laboratory
KENNETH H. SANDHAGE,
Georgia Institute of Technology
LINDA SCHADLER,
Rensselaer Polytechnic Institute
ROBERT E. SCHAFRIK,
GE Aircraft Engines
JAMES C. SEFERIS,
University of Washington
SHARON L. SMITH,
Lockheed Martin Corporation
Staff
GARY FISCHMAN, Director
MICHAEL MOLONEY, Senior Staff Officer
EMILY ANN MEYER, Staff Officer
TERI THOROWGOOD, Administrative Coordinator
HEATHER LOZOWSKI, Financial Associate
Preface
The Committee on Assessment of Security Technologies for Transportation was appointed by the National Research Council (NRC) in response to a request from the Transportation Security Administration (TSA) for a study of technologies to protect the nation’s air transportation system from attacks by terrorists and others of like mind. The committee judged that the best way to provide a timely response would be to produce a series of short reports on promising technologies, focusing on specific topics of greatest interest to the sponsor. This is the third of four such topical reports, all of which focus on air transportation security.1 The committee believes that the air transportation
environment provides a test case for the deployment of security technologies that could subsequently be used to protect other transportation modes as well.
This report focuses on the currently maturing millimeter-wavelength and terahertz imaging and spectroscopy technologies that offer promise in meeting aviation security requirements through airport screening. The millimeter-wave through the terahertz region is now the subject of aggressive university research driven by the availability of short-pulse generators, which produce a wide spectrum of frequencies through this region. The committee believes that millimeter-wave/terahertz technology has potential for contributing to overall aviation security but that its limitations must be recognized. In light of some common misconceptions, the committee decided that this report should briefly and systematically address expectations, both real and fictional, and help bring into focus cases in which this technology has promise and instances in which it offers no potential benefit as an antiterrorism technology. Additionally, although there are many potential long-range uses for this technology, the committee’s assessment focuses primarily on the near-term uses to interdict imminent threats.
Historically the millimeter band extended from 30 GHz to 300 GHz and the submillimeter band extended from 300GHz to 3 THz. In the current literature the terahertz region has subsumed the submillimeter band and extended it to 10 THz. In this report the term “submillimeter” is used only to be consistent with historical citations.
The committee acknowledges the speakers from government and industry who took the time to share their ideas and experiences in briefings at the committee’s meetings. The committee would like to offer a special thanks to two of its members, Richard McGee and H. Bruce Wallace, who were the major contributors to the writing of this report. Former committee member Thomas S. Hartwick, chair through May 31, 2005, also greatly assisted the work of the current committee through his participation in many of its activities. Finally, the committee acknowledges the contributions to the completion of this report from National Materials Advisory Board director Gary Fischman and NRC staff members James Killian and Teri Thorowgood.
James F. O’Bryon, Chair
Sandra L. Hyland, Vice Chair
Committee on Assessment of Security Technologies for Transportation
Acknowledgment of Reviewers
This report has been reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise, in accordance with procedures approved by the National Research Council’s Report Review Committee. The purpose of this independent review is to provide candid and critical comments that will assist the institution in making its published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process. We wish to thank the following individuals for their review of this report:
Eliot D. Cohen, EBCO Technology Advising, Inc.,
Angela Gittens, HNTB,
Erich N. Grossman, National Institute of Standards and Technology, Boulder,
Eddie Jacobs, U.S. Army, Research Development and Engineering Command,
Samuel H. Moseley, Jr., NASA Goddard Space Flight Center,
Andrew Poggio, Lawrence Livermore National Laboratory, and
James C. Wiltse, Georgia Tech Research Institute.
Although the reviewers listed above have provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations, nor did they see the final draft of the report before its release. The review of this report was overseen by Steve Berry, University of Chicago. Appointed by the National Research Council, he was responsible for making certain that an independent examination of this report was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this report rests solely with the authoring committee and the institution.
Figures and Tables
FIGURES
1-1 |
Generic airport diagram showing various airport spaces and some likely sites for attacks, |
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1-2 |
The three regions of the electromagnetic spectrum considered in this report, |
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2-1 |
Antenna resolution for an imaging system with a 2 meter aperture, |
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2-2 |
Antenna diameter required for an imaging system to achieve the resolution of the human eye, |
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2-3 |
Atmospheric attenuation under various environmental conditions from 10 GHz to 10,000 GHz, |
2-4 |
Transmission measurements through various clothing materials, |
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2-5 |
Measurements made with millimeter-wavelength/terahertz imaging systems of transmission through various building materials, |
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2-6 |
Intercomparison of published explosives phonon bands spectra conducted by Ohio State University, |
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3-1 |
Available solid-state sources, |
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3-2 |
State-of-the-art radio-frequency sources (circa 2003), |
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3-3 |
Power levels available from the various devices produced by Virginia Diodes, |
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3-4 |
Power levels available for sources in the region from 500 GHz to 2,500 GHz, |
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3-5 |
Heterodyne receiver noise temperatures (SIS, HEB, and Schottky) versus frequency in the millimeter-wavelength/terahertz range, |
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3-6 |
Predicted range to identify a concealed weapon using a single scanning spot sensor, |
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4-1 |
SafeView security screening portal, |
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4-2 |
Agilent Technologies millimeter-wave imaging system based on a reflective, confocal millimeter-wave lens, |
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5-1 |
Millimeter-wave image—Pacific Northwest National Laboratory, |
TABLES
In Memoriam
The members of the Committee on Assessment of Security Technologies for Transportation are deeply saddened by the recent loss of one of the committee’s members. John B. Daly had a distinguished career serving the nation in a broad range of positions involving transportation security and technology, and he was the recipient of numerous awards and commendations for his outstanding contributions to the field. He was appointed to this committee in 2005 and continued to serve with distinction until his illness no longer permitted his participation. He was a hardworking professional of the highest integrity. We dedicate this report to his memory as a token of our appreciation for his contributions.