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March 11, 2010

Subterranean operations

As the world's superweapons projects move underground, DARPA has pondered a means of navigating through huge enemy underground bases in the absence of GPS: Sferics-Based Underground Geolocation (S-BUG).

DARPA boffins have noted that one of the few kinds of wireless signal which can penetrate underground is low-frequency radio. Unfortunately such signals are quite hard to generate at the required power levels. A network of lo-freq RF nav stations widespread enough to offer decent accuracy would probably be impossible to deploy.

But the right kind of signals are generated naturally by lightning strikes, which cause the emission of "atmospheric" ("sferic" or "spheric") radio pulses. An underground receiver could perhaps be built capable of detecting sferics from lightning bolts hitting the surface hundreds of miles away. It could be informed of the positions of the strikes over LF comms by a single specialised surface base station, similarly far off, and thus calculate its own position from sferic data coming in from several directions.

Posted by Ghost of a flea at March 11, 2010 09:23 AM