28-11-2012, 02:24 PM
High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices
High Altitude Electromagnetic.pdf (Size: 189.71 KB / Downloads: 28)
Background
A Commission to Assess the Threat from High Altitude Electromagnetic Pulse
(EMP commission) was established by Congress in FY2001 after several experts
expressed concern that the U.S. critical infrastructure and military were vulnerable
to EMP attack.1 On July 20, 2008, the Commission presented a report to the House
Armed Services Committee (HASC) assessing the effects of an EMP attack on U.S.
critical national infrastructures. The 2008 report contained analysis of results of tests
for modern electronics and telecommunications equipment for public networks
supported by the power grid and by temporary isolated power supplies, including cell
phones, computer servers, and Internet routers and switches. The report also made
recommendations for preparation, protection, and recovery of U.S. critical
infrastructures from EMP attack.
The Commission reported that the ubiquitous dependency of society on the
electrical power system, coupled with the EMP’s particular damage mechanisms,
creates the possibility of long-term, catastrophic consequences for national security.
Comparison was made to hurricane Katrina in 2005, where the protracted power
blackout exhausted the limited fuel supplies for emergency generators. However, in
the case of an EMP attack, a widespread collapse of the electric power grid could
lead to cascading effects on interdependent infrastructures, possibly lasting weeks or
months. The Commission stated, “Should significant parts of the electrical power
infrastructure be lost for any substantial period of time ... many people may
ultimately die for lack of the basic elements necessary to sustain life in dense urban
and suburban communities ... [and] the Federal Government does not today have
sufficiently robust capabilities for reliably assessing and managing EMP threats.
The EMP Commission
The EMP commission was reestablished by P.L. 109-163, the National Defense
Authorization Act for FY2006. The new Commission to Assess the Threat to the
United States from Electromagnetic Pulse Attack (note that the new title no longer
includes the phrase “High Altitude”, and adds the new word “Attack”) continues with
the same membership, and the Secretary of Defense is authorized to appoint a new
member in the event of a vacancy.5 The EMP commission is tasked to monitor,
investigate, and make recommendations about the vulnerability of electric-dependent
systems of the Department of Defense, government agencies, and the private sector.
2008 Report on Critical Infrastructure Vulnerabilities
The 2008 EMP Commission report discussed vulnerabilities and
interdependencies among 10 U.S. critical infrastructures. Findings showed that only
limited EMP vulnerability testing had previously been done for modern electronic
systems that help support these infrastructures. In addition, the Commission
expressed concern that widespread use of automated supervisory and control data
acquisition (SCADA) systems for the critical infrastructure had allowed companies
and agencies to systematically reduce the size of their work forces having the
necessary technical knowledge needed to support manual operations of these
infrastructure control systems, as might be needed during a prolonged emergency.
The Commission concluded, after reviewing national capabilities to manage the
effects of nuclear weapons (and EMP) on modern systems, that “the Country is
rapidly losing the technical competence in this area that it needs in the Government,
National Laboratories, and Industrial Community.”9
Private Sector and State Government Poorly Prepared
Experts on the Commission have asserted that little has been done by the private
sector to protect against the threat from electromagnetic pulse, and that commercial
electronic systems in the United States could be severely damaged by EMP attack.10
Commercial electronic surge arresters commonly used for lightning strikes reportedly
cannot be relied on because most do not clamp fast enough to protect against the
near-instantaneous effects of EMP (see section below on “Electromagnetic Pulse
Overview”).11
In March 2007, a survey of state Adjutants General who oversee National
Guard units throughout the country found that most state-based emergency
responders are not actively preparing against an attack on the United States by
electromagnetic pulse. The survey, entitled “Missile Defense and the Role of the
States”, was conducted jointly by the Anchorage-based Institute of the North and the
Claremont Institute of Claremont, California. Survey questions were sent to
Adjutants General of all 50 states, with more than half responding. Although 96%
of state Adjutants General indicated significant concern over an EMP attack, the
majority had done little or no analysis of the effects of an overhead EMP attack, and
little or no training, or preparation to harden electronic equipment.
Inaction May Increase EMP Threat to the United States
Some analysts discount the likelihood of a large-scale EMP attack against the
United States in the near term, and the extent of possible damage, stating that the
critical infrastructure reportedly would survive, and that military communications
would continue to operate and a high percentage of civilian phone calls would
continue to connect. The argument is that limited testing has shown that modern
commercial equipment may be surprisingly resistant to the effects of electromagnetic
pulse, and that some military systems using commercial equipment are also
retrofitted to be made more EMP resistant before they are fielded.13
However, other analysts maintain that some past testing done by the U.S.
military may have been flawed, or incomplete, leading to faulty conclusions about
the level of resistance of commercial equipment to the effects of EMP. These
analysts also point out that EMP technology has been explored by several other
nations, and as circuitry becomes more miniaturized, modern electronics become
increasingly vulnerable to disruption. They argue that, depending on the targeted
area and power of an EMP attack, it could possibly take years for the United States
to recover fully from the resulting widespread damage to electronics and the power
grid.
Electromagnetic Pulse Overview
Electromagnetic energy, characterized as weapon potentially threatening to
national security, can be created as a pulse traditionally by two methods: overhead
nuclear burst and microwave emission. High-Altitude Electromagnetic Pulse
(HEMP) is a near-instantaneous electromagnetic energy field that is produced in the
atmosphere by the power and radiation of a nuclear explosion, and that is damaging
to electronic equipment over a very wide area, depending on power of the nuclear
device and altitude of the burst. High-Power Microwave (HPM) electromagnetic
energy can be produced as a near-instantaneous pulse created through special
electrical equipment that transforms battery power, or powerful chemical reaction or
explosion, into intense microwaves that are also very damaging to electronics, but
within a much smaller area. In addition, while HEMP weapons are large in scale and
require a nuclear capability along with technology to launch high altitude missiles,
HPM weapons are smaller in scale, and can involve a much lower level of technology
that may be more easily within the capability of some extremist groups. HPM can
cause damage to computers similar to HEMP, although the effects are limited to a
much smaller area.