November 13, 2009:
China has revealed that it has upgraded 200 Russian Kh-31P ARM (anti-radiation missiles) it imported in the 1980s. The Chinese were dissatisfied with the Russian seekers (that detected and homed in on radar transmissions), and developed one of their own. The Chinese seeker detects more radar frequencies (2-18 Ghz) and will hit within 8-10 meters of the radar transmission.
The Kh-31 was originally developed as an anti-ship missile. The Russians quickly realized that, with a different seeker, the missile would also work well as an anti-radiation weapon. The anti-ship version has a range of 50 kilometers, while the ARM version is good for 110 kilometers. The .6 ton missile has an 87 kilogram (191 pound) warhead.
The U.S. equivalent is the .36 ton AGM-88. The latest version of this is the AGM-88E. The first production models of the "E" version will be delivered next year, after more than a decade of development effort. Over 23,000 AGM-88s, of all models, have been produced in the last 27 years.
The current model, 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 nearly $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 the ground radar is turned on or off.
The new 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. This 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. The original 1960s anti- radiation missile (ARM) quickly evolved into what was called HARM (High Speed Anti-Radiation Missile).
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.
China is apparently hoping to steal the new U.S. ARM technology and incorporate it into their Kh-31Ps.