The latest version of the U.S.
anti-radiation missile, the AGM-88D, uses GPS so that the missile, which
normally homes in on radar transmissions, can be used to attack targets by
location alone. The AGM-88 moves at high speed (2,200 kilometers an hour, or 36
kilometers a minute) to hit targets 100 kilometers away. This version of the
AGM-88 costs less than $100,000 each. The standard version uses more complex
sensors which can detect and guide the missile to a wide variety of radar
signals. These versions cost about $300,000 each. GPS enables HARM (or the
aircraft carrying it) to locate a radar when it is turned on, store the GPS
location, then go after the target regardless of whether it is turned on or
recent model of the traditional version, the AGM-88E, uses a more expensive
approach to nailing enemy radars that are turned on briefly, and attempts to avoid destruction by quickly
turning off power. The missile, also called the Advanced Anti-Radiation Guided
Missile (AARGM), was developed jointly by U.S. and Italian firms. The original
AGM-88 has been in use since the 1980s, and the original 1960s anti- radiation missile quickly evolved
into what was called HARM (High Speed Anti-Radiation Missile).
version defeats the favorite trick of anti-aircraft units, shutting down their radars when they note a
HARM is on the way. The AGM-88E remembers where the radar is when it was on,
and carries its own high resolution (millimeter wave) radar to make sure it
gets the radar. Finally, the AGM-88E can transmit a picture of the target, just
before it is hit, so the user can be certain of what was taken out. Currently,
there are orders for over 2,000 of these missiles from the U.S. Navy and Marine
Corps, Italy and Germany. Production began last year, on what appears to be an
endless line of HARM variants.