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CHIPS Articles: The U.S. Navy’s New Electromagnetic Pulse (EMP) Program

The U.S. Navy’s New Electromagnetic Pulse (EMP) Program
Resurrecting the Capability in a New World
By Blaise Corbett and James Partak - January-March 2010
Dormant for more than a decade, the U.S. Navy's Electromagnetic Pulse (EMP) Program is being revived through the Naval Sea Systems Command (NAVSEA) Office of the Director for Force Electromagnetic (EM) Effects and Spectrum Management. The program's immediate goals include establishing cognizance about current standards for system acquisition as related to EMP survivability; assisting with developing standards and methodology to test and assess future systems; assessing the current posture of mission critical systems with regard to EMP survivability; and coordinating with other Department of Defense (DoD) services and entities to share EMP resources and information.

High-Altitude Electromagnetic Pulse

Electromagnetic pulse is a radiated electromagnetic field, typically generated and associated with a nuclear detonation. A nuclear device detonated at an altitude in excess of 40 miles generates High-Altitude Elect romagnetic Pulse (HEMP), which is the focus of the U.S. Navy program. This high-altitude nuclear explosion creates high energy photons known as gamma rays. The photons collide with molecules in the upper atmosphere creating free electrons called Compton electrons, which then interact with the Earth's geomagnetic field lines to create a HEMP.

HEMP can be characterized as a radio frequency emission with broad frequency content, high electrical field levels up to 100 kilovolts per meter, and high instantaneous power density levels that can exceed 20 megawatts per meter squared.

HEMP is composed of three components commonly referred to as E1, E2 and E3.

E1, often referred to as the prompt component, is characterized by short pulse duration and a fast rise time. The actual EMP experienced is a function of the weapon yield and design, burst height, latitude of the burst, and relative observer location from the burst point.

E2 is often compared to lightning in terms of duration and frequency content (frequencies contained in the signal), while E3 has the longest duration, lowest frequency content, and lowest field levels.

As such, E1 poses the greatest danger to individual electronic systems, while E3 poses the greatest threat to networked infrastructure, such as long line power and telephone networks. The focus of the military is primarily on electronic system impacts due to E1.

With the collapse of the Soviet Union and no perceived threat, the military's investments in EMP assessment capabilities were significantly reduced.

CBRN Survivability Oversight

The late 20th century saw the emergence of tactical and strategic nuclear capabilities by developing nations whose political agendas and policies are diametrically opposed to the interests of the United States.

In September 2008, the DoD formally established a senior-level Chemical, Biological, Radiological, Nuclear (CBRN) Survivability Oversight Group (CSOG) through the mechanism of the CBRN Survivability Policy, Department of Defense Instruction (DoDI) 3150.09.

The CSOG charter established its mission to ensure that equipment survivability in a nuclear weapons effects environment, including EMP, is addressed specifically by requirements during the acquisition process. Further, the CSOG was charged to establish the process for evaluating legacy system vulnerabilities deployed by the services and to prepare a yearly report to Congress about the progress toward achieving hardening of each service's mission critical systems.

The CBRN Survivability Policy: (1) defines a CBRN mission critical system; (2) calls for the establishment of processes to identify and review a mission critical system in the context of the Joint Capabilities Integration and Development System (JCIDS); (3) establishes processes for ensuring system survivability in a CBRN environment; and (4) identifies lines of responsibility for policy implementation.

EMP Program Mission

The new U.S. Navy EMP Program mission is multifaceted but ultimately comes down to providing senior Navy leadership the information to assess fleet posture with regard to EMP. Currently four core elements comprise the new program: testing and assessment, guidance, surveys and standards.

The U.S. Navy EMP Program supports the functions of the NAVSEA electromagnetic environmental effects (E3) technical warrant holder by providing guidance to Navy acquisition programs relative to military standards, requirements and design practices.

It is vital that the U.S. Navy EMP Program engage program managers early in the acquisition process to provide guidance and education about the effect these requirements have on their respective programs. The EMP Program is standing by to assist program managers with such tasks as developing and/or reviewing capability design documents and system specifications.

The Road Ahead

The road ahead for any new program is fraught with challenges. The most significant challenge for the new U.S. Navy EMP Program is cognizance. Due to the long absence of a robust EMP Program, few people in the U.S. Navy or across the greater DoD community have an intimate knowledge of EMP causes and effects. The prevailing thought appears to be that the probability of occurrence is low, so the issue is not important and can be easily dismissed.

However, the risk of failing to implement a mitigation strategy for EMP is at the highest level, and the consequences of failing to take precautions now can be catastrophic.

Applicable Policy
• DoDI 3150.09. Chemical, Biological, Radiological, and Nuclear (CBRN) Survivability Policy (Change 1). Aug. 17, 2009.
• MIL-STD-1310G. Standard Practice for Shipboard Bonding, Grounding, and Other Techniques for Electromagnetic Compatibility and Safety. June 28, 1996.
• MIL-PRF-24758A. Performance Specification – Conduit Systems, Flexible, Weatherproof. Sept. 24, 2004.
• OPNAVINST 3401.3A. Nuclear Survivability of Navy and Marine Corps Systems. Jan. 5, 1989.
• OPNAVINST 9070.1. Survivability Policy for Surface Ships of the U.S. Navy. Sept. 23, 1988.

Blaise Corbett has been with the Navy since 2002 and has been directly involved in the EMP assessment of naval systems since 2004. Corbett is currently the group leader for the Naval Surface Warfare Center Dahlgren Division EMP assessment group.

James Partak, an engineer originally from Naval Surface Warfare Center White Oak, has more than 39 years of experience in the area of nuclear effects to electronic systems. Now retired from the Navy, Jim supports the EMP assessment group through EG&G, a division of the URS Corp.

TAGS: Spectrum

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