By lex, on February 25th, 2007
An occasional reader sent along an interesting link **:
Pakistan’s recent November 2006 purchase of 500 AIM-120C AMRAAM missiles is creating counterpressure on the subcontinent, and reportedly has India looking for 120km BVRAAMs (Beyond Visual Range Air-Air Missiles). Missiles with this notional head-on range would far outstrip the 60km of the AIM-120C, and even the 60-90km (36-54 miles) reported for the Russian AA-12/R-77 ‘AMRAAMski’ that India already deploys. Indeed, this figure would be closer to the ramjet-powered Meteor under development via MBDA.
Need to tread cautiously here: If I had been keeping up with missile technology the way I used to, I wouldn’t be able to comment on these capabilities at all since I’d be running classification risks. On the other hand, since I haven’t been keeping up, I’m not particularly qualified to speak on them. How liberating!
I do think a single-minded focus on range is misguided, however – while all things being equal it’s better to have a long-range missile than one of shorter range, all things are very rarely equal. Seeing a target at a hundred miles is one challenge. Knowing who or what that target is and whether or not he ought to be shot is another challenge altogether. That comes down to training and command and control.
Also, radar azimuth discrimination is determined by radar beam width, which – on a conventionally scanned antenna anyway – is inversely proportional to aperture size. Aperture size is functionally equivalent to antenna width and, although some games can be played on the margins in antenna design and signal processing, this is a physical constraint with relatively little slack. The long and short of it is that a radar small enough to fit into the nose of a supersonic fighter will have a relatively large beam width, and – as beam width is measured in degrees – the implications of that beam width grow geometrically with range. At a hundred miles a powerful radar will tell you that there is “a guy” out there, about how far away he is and how fast he is moving. But there might instead be three or four guys out there right alongside him that you won’t know about because they all look like one target to the radar in beam width.
With that in mind, consider the active missile itself – obviously its antenna is smaller even than the one in the fighter. This means that it will need lots of inflight guidance updates from the launch platform if employed at very long ranges. This in turn means that, in order to get missile guidance quality data from the launch platform to the in-flight missile, fighter radar scan volumes will probably have to be collapsed. The result of which is that great gobs of air mass must go unsanitized, increasing the risks of untargeted bandits slipping in literally “under the radar” even as those that are targeted at range are free to employ countermeasures.
Finally, the move towards greater stealth minimizes the effectiveness of very long range air-to-air missiles while rendering as liabilities the powerful targeting radars necessary to employ them. Stealth versus stealth warfare will be akin to two guys fighting in a blackened out garage with pistols and flashlights – In an environment like that, who will want to be the first guy to turn his flashlight on?
RAMJET-powered air-to-air missiles are probably more than a marketing ploy, but probably less than the end of the world.
Note: Commenters who know what they’re talking about need to be vewwwy cawful on this one…
** 07-27-2018 Original link gone; replacement found – Ed.