The non-solar related EMP threat seems to be a very hot topic right now. We still think that this is mostly hype, much like others we’ve seen in the past. It’s always best to know what you’re dealing with so before you run out and buy a truckload of copper mesh here’s some condensed information about the threat. The quotes below are discussing non-nuclear emp devices and are clipped from a Global Security article HERE , HERE and HERE. The red highlighting is added by me. Per the articles referenced (and others that I’ve read) a man-made EMP “event” would most likely affect a much smaller area than many may realize…… In other words, folks living in rural areas away from the large coasts and large border towns may really have no need to worry about this if they’ve got a way to generate their own electricity for a while since their electric power provider may be in a target zone. Please give it a read and decide for yourself if this is something that can directly impact you.
What is an E-bomb?
E-bomb is short for `Electromagnetic Bomb’. The definition is very broad, but essentially covers all bombs or warheads designed to damage targets with a very intense pulse of electromagnetic energy. The principal distinction is the wavelength of the energy produced by the weapon. Low frequency E-bombs approximate the effects of a close lightning strike, microwave or HPM E-bombs flood the target with a directional field of intense microwave illumination. The the latter is not unlike a microwave oven, but it is extremely short in duration and involves much higher power levels.
What effects are produced by an E-bomb?
An E-bomb which is well matched to it intended target set can cause electrical damage over a footprint which might be as large as hundreds of metres in diameter.
Victim devices may suffer secondary damage from their power supply. Victim devices may also be `wounded’ and experience failure minutes, hours, days or weeks later, from electrical overstress. If the weapon does not generate enough power to produce permanent damage, it can cause computers to crash, hang or reboot, thus yielding a temporary disruptive effect.
How does an E-bomb couple energy into its target?
Low frequency or broadband E-bombs will produce `spikes’ or electrical surges in electrical grid wiring and telephone or communications wiring. These propagate until they encounter an attached piece of equipment like a computer, which is exposed to an electrical overload and damaged.
Microwave or HPM E-bombs produce electrical standing waves in electrical grid wiring and telephone or communications wiring – the microwave energy then couples into the target device via the cable connector and may cause internal damage. This is termed `backdoor coupling’. Another way in which microwave weapons can effect `backdoor coupling’ is via cooling and ventilation grilles, which might act as a `slot antenna’ permitting energy to penetrate into an otherwise shielded case. Radio frequency equipment can also be damaged via `frontdoor coupling’ effects where the microwave energy penetrates through the victim equipment’s antenna.
Electromagnetic Pulse (EMP) and High Powered Microwave (HMP) Weapons offer a significant capability against electronic equipment susceptible to damage by transient power surges. This weapon generates a very short, intense energy pulse producing a transient surge of thousands of volts that kills semiconductor devices. The conventional EMP and HMP weapons can disable non-shielded electronic devices including practically any modern electronic device within the effective range of the weapon.
The effectiveness of an EMP device is determined by the power generated and the characteristic of the pulse. The shorter pulse wave forms, such as microwaves, are far more effective against electronic equipment and more difficult to harden against. Current efforts focus on converting the energy from an explosive munitions to supply the electromagnetic pulse. This method produces significant levels of directionally focused electromagnetic energy.
As with a conventional munition, a microwave munition is a “single shot” munition that has a similar blast and fragmentation radius. However, while the explosion produces a blast, the primary mission is to generate the energy that powers the microwave device. Thus, for a microwave munition, the primary kill mechanism is the microwave energy, which greatly increases the radius and the footprint by, in some cases, several orders of magnitude. For example, a 2000-pound microwave munition will have a minimum radius of approximately 200 meters, or footprint of approximately 126,000 square meters.
An important factor in assessing the lethal coverage of an electromagnetic weapon is atmospheric propagation. While the relationship between electromagnetic field strength and distance from the weapon is one of an inverse square law in free space, the decay in lethal effect with increasing distance within the atmosphere will be greater due (to) physical absorption effects. This is particularly so at higher frequencies, and significant absorption peaks due water vapour and oxygen exist at frequencies above 20 GHz. These will therefore contain the effect of HPM weapons to shorter radii than are ideally achievable in the K and L frequency bands.
See also: Thoughts on EMP and GeoMagnetic Stormsby