Dr. William A. Radasky, Ph.D., P.E.
Over the past 6 years a substantial number of articles have been written by this author and others identifying the threat and importance of intentional electromagnetic interference (IEMI) [1-5]. Since the publication of the Interference Technology Annual EMC Guide in 2005, work has continued at an increasing rate with nearly all major EMC conferences dealing with this subject.
Beginning in the spring of 2005, the Zurich EMC Conference had a special session dealing with IEMI and HEMP. In April of 2005 several papers on IEMI were presented at conferences sponsored by the Department of Homeland Security in Boston. In August 2005 there was a tutorial presented on IEMI at the IEEE EMC Conference in Chicago. In early September 2005 the Torino International Conference on Electromagnetics in Advanced Applications was held including an IEMI session. Later in September 2005 there was an EMC Europe Workshop in Rome dealing with the EMC of Wireless Systems, and a special session on IEMI was held. In October 2005 URSI hosted its General Assembly Meeting in New Delhi, and Commission E03 (Intentional EMI) presented several papers of interest. In February and March of 2006 the EMC-Zurich Symposium was held in Singapore and a special session on IEMI was convened. In addition to these conferences, the work of IEC SC 77C continued with the initiation of 3 new projects dealing with IEMI and HEMP.
In order to enable the readers to understand the breadth of the work, most of these activities will be summarized in this article. For those having additional interest, the conference proceedings contain the published papers.
To refresh the reader regarding the terminology employed here, the term IEMI refers to the deliberate attempt to produce electromagnetic radiated and/or conducted disturbances to interfere with the operation of commercial equipment. This could be done for criminal or terrorist purposes, although the purpose of the technical work is to determine the feasibility of such attacks and to determine ways to detect an attack and/or to protect against the types of disturbances that might be generated.
EMC Zurich Symposium (14-18 February 2005 in Zurich, Switzerland)
During this meeting a special session on IEMI and HEMP was convened with 5 papers being presented in the session with an additional paper of interest being noted here:
1) D. Nitsch, A. Bausen, J. Maack, R. Krzikalla, “The Effects of HEMP and UWB Pulses on Complex Computer Systems.”
2) J. Kappenman, W. Radasky, S. Grzybowski, Y. Song, “Simulator Test Results of the Withstand of Distribution Class Insulators to Steep-Front/Short Duration (SFSD) Impulses to Simulate the Early-Time HEMP.”
3) E. Savage, K. Smith, M. Madrid, J. Gilbert, W. Radasky, “Fast Pulse Testing of Power System Control Equipment to Determine their Susceptibility to HEMP Conducted Transients.”
4) A. Kozlov, S. Louzganov, Yu. Parfenov, M. Povareshkin, V. Polischouk, A. Shurupov, L. Zdoukhov, W. Radasky, “Research of Power Line Insulator Flashover due to the Joint Effect of a High Voltage Disturbance and Line Operating Voltage.”
5) J. Kappenman, W. Radasky, J. Gilbert, “Electric Power Grid Vulnerability to Natural and Intentional Geomagnetic Disturbances.”
6) C. Baum, D. Nitsch, “Band Ratio and Frequency-Domain Norms.”
Of special interest is the paper by Kozlov et. al where the behavior of power line insulators under flashover conditions were examined while they were energized with realistic levels of AC power. Figure 1 below indicates a series of three snapshots of a case where the active power was able to destroy the insulator. This is not an expected result, and investigations are underway to understand what conditions are necessary for this to occur.
U.S. Department of Homeland Security Conferences (26-27 April 2005 in Boston, USA)
There were two conferences dealing with security and technology held back to back. The first was the 2005 IEEE Conference on Technologies for Homeland Security and the second was the DHS R&D Partnerships in Homeland Security. For these conferences two papers were accepted dealing with the potential threat of IEMI on transportation and the infrastructure:
1) W. Radasky, “The Threat and Detection of Electromagnetic Weapons at Airports and on Aircraft.”
2) W. Radasky, “The Emerging Threat of Electromagnetic Transients on the Critical Infrastructure.”
One of the important issues arising in this conference was the concern about the electromagnetic survivability of security and detection sensors for Nuclear, Chemical and Biological (NBC) weapons.
IEEE EMC Conference (8-12 August 2005 in Chicago, USA)
During this annual EMC conference, a tutorial was held on Monday, 8 August on Intentional EMI. The following presentations were included in the tutorial:
1) W. Radasky, R. Hoad, “Introduction to IEMI.”
2) R. Hoad, W. Radasky, “The Effects of IEMI on Equipment and Systems.”
3) W. Radasky, R. Hoad, “Mitigation Concepts and Approaches for IEMI.”
4) R. Hoad, W. Radasky, “Standardization Activities in the IEC.”
One of the very interesting data sets presented by Richard Hoad of QinetiQ during the tutorial dealt with the severe upset and damage of personal computers connected to a local area network. Figure 2 illustrates the failure levels due to narrowband EM fields as a function of frequency. It is noted that the cable coupling and aperture regimes are responsible for failures in different frequency ranges.
International Conference on Electromagnetics in Advanced Applications 12-16 September 2005 in Torino, Italy)
At this conference a special session on IEMI was convened by Dr. Carl Baum. Visit SiteUnfortunately this writer was not able to attend, so interested readers should contact Dr. Baum (email@example.com) if detailed information is desired.
EMC Europe Workshop on Wireless Systems (19-21 September 2005 in Rome, Italy)
During this conference a new aspect of IEMI was examined in a special session. The emphasis was on the impacts of wireless systems both to in-band and out-of-band EM threats. This subject has become of increasing interest due to the proliferation of commercial wireless systems. The presented papers included:
1) W. Radasky, M. Bäckström, “Overview of the Threat of Intentional EMI (IEMI) to Civil Wireless Systems.”
2) O.-H. Arnesen, E. Drogager, M. Bäckström, S. Bo-Sande, J. Godo, S. Harkonen, K. G. Lovstrand, M. Moisio, B. Nordstrom, J. Peltonen, O.-M. Oystad, “High Power Microwave Effects on Civilian Wireless Equipment.”
3) T. Nilsson, O. Lunden, M. Bäckström, “HPM Susceptibility Measurements on WLAN and GPS Systems.”
4) J. Delsing, J. Ekman, J. Johansson, “Intentional EMI Considerations for Sensor Networks.”
5) R. Thottappillil, D. Mansson, N. Theethayi, M. Bäckström, T. Nilsson, G. Unden, B. Nordstrom, P. Bohlin, P. A. Lindeberg, U. Hellstrom, P. Lindeberg, G. Bohlin, M. Zitnik, L. Ekenberg, “Response of Civilian Facilities to Intentional Electromagnetic Interference (IEMI) with Emphasis on the Swedish Railway Network.”
6) I. Kohlberg, R. Boling, “Mathematical Structure of Ad-Hoc Wireless Mesh Networks and Their Tolerance Against IEMI Attacks.”
URSI General Assembly (23-29 October 2005 in New Delhi, India)
Commission E03 (Intentional EMI) held a special session during the General Assembly. The presented papers included:
1) W. Radasky, “New Developments in Intentional Electromagnetic Interference (IEMI) and High-Altitude Electromagnetic Pulse (HEMP).”
2) L. Siniy, “Electromagnetic Threats to the Civil Infrastructure.”
3) O.-H. Arnesen, “High Power Microwave Effects on Civil Equipment.”
4) D. J. Serafin, D. Dupouy, “Potential IEMI Threats Against Civilian Air Traffic.”
EMC-Zurich Symposium in Singapore (27 February – 3 March 2006 in Singapore)
I had the privilege to host a special session on IEMI at the first meeting of the EMC-Zurich Symposium held in Asia. The conference was very well attended with many new contributors to the EMC papers. The IEMI session papers were produced by most of the active participants in the field:
1) W. Radasky, “The Threat of Intentional Electromagnetic Interference (IEMI) to Wired and Wireless Systems.”
2) A. M. Zabolotsky, T. R. Gazizov, A. G. Bova, W. A. Radasky, “Dangerous Pulse Excitation of Coupled Lines.”
3) R. Hoad, A. Lambourne, A. Wraight, “HPEM and HEMP Susceptibility Assessments of Computer Equipment.”
4) O.-H. Arnesen, E. Krogager, M. Bäckström, S. Bo-Sande, J. Godo, S. Harkonen, K. Lovstrand, M. Moisio, B. Nordstrom, J. Peltonen, O. Oystad, “IEMI Against Modern Civilian Electronic Technologies.”
5) T. Nilsson, O. Lunden, M. Bäckström, “HPM Susceptibility of WLAN and GPS Systems: An Initial Study.”
6) J. Delsing, J. Ekman, J. Johansson, S. Sundberg, M. Bäckström, T. Nilsson, “Susceptibility of Sensor Networks to Intentional Electromagnetic Interference.”
7) H. Potrykus, I. Kohlberg, “Resistance to Extended IEMI by Physical/Correlated Wireless Random and Non-random Networks.”
While there was a significant amount of important information presented, some exciting new effects data concerning commercial GPS receivers was presented in the Nilsson paper. Figure 3 illustrate the failure levels to an UWB pulse for variations in the orientation of three different test objects. “Level 4 interference” in this chart is defined as a complete “crash” of the system with the need for the operator to restart the system.
IEC SC 77C (EMC: High Power Transient Phenomena)
Over the past year, the IEC completed work on three documents that provide important IEMI information to the users of standards. The three publications deal with the effects of high power electromagnetics in general and IEMI in specific, the categorization of the IEMI environments, and measurement methods for HEMP and IEMI. These publications are listed below:
IEC 61000-1-5, “High power electromagnetic (HPEM) effects on civil equipment and systems,” published as a technical report, November 2004.
IEC 61000-2-13, “High power electromagnetic (HPEM) environments – radiated and conducted,” published as a standard, March 2005.
IEC 61000-4-33, “Measurement methods for high-power transient parameters,” published as a standard, September 2005.
At recent meetings of IEC SC 77C project teams in Cape Town, South Africa in October 2005 and in Singapore in February 2006, three new projects have been initiated. These include the following with the project leaders’ names indicated:
(a) IEC 61000-5-8: HEMP protection methods for the distributed civil infrastructure (W. Radasky, USA)
(b) IEC 61000-5-9: System level susceptibility assessments for HEMP and HPEM (A. Wraight, UK)
(c) IEC 61000-4-35: Intentional electromagnetic interference (IEMI) simulator compendium (F. Sabath, Germany)
The next meeting of the IEC SC 77C project teams will be in Albuquerque, New Mexico on 15 July 2006, immediately following the AMEREM Conference. New participants are invited. Please contact either the Chairman of SC 77C, William Radasky (firstname.lastname@example.org) or the Secretary of SC 77C, Richard Hoad (rhoad@QinetiQ.com).
 W. A. Radasky, “What Is Intentional Electromagnetic Interference (IEMI) and What Can We Do About It?” ITEM Magazine, April 2003.
 W. A. Radasky, “An Update on Intentional Electromagnetic Interference (IEMI),” ITEM Magazine, April 2004.
 W. A. Radasky, “2005 Update on Intentional Electromagnetic Interference (IEMI),” ITEM Magazine, April 2005.
 W. A. Radasky, M. A. Messier, M. W. Wik, “Intentional Electromagnetic Interference (EMI) – Test Data and Implications,” 14th International Zurich Symposium and Technical Exhibition on EMC, February 2001.
 W. A. Radasky, M. W. Wik, “Intentional Electromagnetic Interference (IEMI) – Understanding the Threat and Developing Protection Concepts,” 15th International Zurich Symposium and Technical Exhibition on EMC, February 2003.
William A. Radasky received the B.S. degree with a double major in Electrical Engineering and Engineering Science from the U.S. Air Force Academy in 1968. He also received the M.S. and Ph.D. degrees in Electrical Engineering from the University of New Mexico in 1971 and the University of California, Santa Barbara in 1981, respectively.
He started his career as a research engineer at the Air Force Weapons Laboratory in Albuquerque, New Mexico working on the theory of the electromagnetic pulse (EMP). In 1984 he founded Metatech Corporation in Goleta, California where he is currently President and Managing Engineer. During his 37-year career, he has published over 300 technical papers and reports dealing with electromagnetic interference (EMI) and protection.
Dr. Radasky’ s current interests include studies to understand the threat of Intentional EMI and to develop mitigation and monitoring methods to protect facilities from this new threat. He is Chairman of IEC Subcommittee 77C, which is developing high-power electromagnetic protection and test standards for civil systems. He is also the Chairman of TC-5 (High Power EM) for the IEEE EMC Society. Other IEMI activities include his role as Associate Editor for the IEEE EMC Transactions special issue on IEMI in 2004 and as chair of the IEEE Standards Working Group to provide protection guidelines for publicly accessible computers from the threat of IEMI. In addition he is the Chairman of the IEC Advisory Committee on EMC (ACEC), which is tasked to coordinate all EMC standardization work for the IEC. He is an EMP fellow and a member of the Eta Kappa Nu and Tau Beta Pi honor societies. In October 2004 he was presented the Lord Kelvin Medal in Seoul, South Korea by the International Electrotechnical Commission for exceptional contributions to international standardization.