Portaguard – Hand held Microwave Radar Ground Surveillance System (HMRGSS?)

Found this in, Janes Special forces recognition guide; a hand held device using (doppler) radar to convert movements into sound. Humans produce “zipping” sounds at 300 yards and a car, “rushing” sounds at over 600!

Information is scarce* and the contractor; Wylam Defence Systems-, wont deal with civilian queries, so we can only guess how it works or how to build our own. Hey, that’s the point.

The Portaguard probably works in the X Band of frequencies, 8 to 12 GHz,

A medium-distance, higher-precision range used in professional applications, traffic radars, Military applications, civilian marine applications, weather forecasting. Missile-targeting radars operate in this region. Most Synthetic-aperture radars operate in this frequency range. Nose-mounted aerial radar systems often operate in the X-band and K-band regions.

Notice the word, ‘movement’ in the description; the device only seems able to render moving objects audible.