Posted on 05/01/2009 8:13:15 AM PDT by sukhoi-30mki
Wide-Angle Radar For Gripen NG
Posted by Bill Sweetman at 5/1/2009 1:00 AM CDT
Back around Aero-India, certain of Gripen's competitors (you know who you are) were circulating the rumor that the NG version was in trouble because it didn't have a radar. The demonstrator will fly with a Thales active electronically scanned array (AESA) but the French government and Dassault - now seeing the NG as a competitor in India and Brazil - had blocked the export of a production radar.
By that time, though, it was pretty clear that Saab was talking to Selex - which, back when it was Ferranti, was a partner on the Gripen radar - about its own AESA technology. Saab had also been very clear that the Thales AESA was purely there for test purposes.
Now that the Saab-Selex deal is official, Saab has posted a brochure on the planned radar - showing that it uses the "swashplate" design mooted by Selex some years ago. I discussed it here in connection with Eurofighter.
Saab
With a 200 degree field of regard in azimuth and elevation, the swashplate AESA is strong in off-boresight performance, an area where the fixed AESA is weak - because the latter loses performance off-boresight and can't scan more than 120 degrees at all. And it does it all with one mechanical bearing, which is much less highly loaded than the gimbals of a mechanically scanned radar.
In BVR missile engagements, the wide-angle scan allows you to launch a missile and continue to track the target while weaving to make the adversary's shot more difficult. In WVR, it works well with a datalink-equipped high-off-boresight missile. It's also possible to see how it would work in an all-weather or through-weather attack on a moving ground target, allowing the fighter to keep tracking the target (updating a guided bomb in flight) by performing a "pylon turn" around the target's location.
A mechanically scanned electronically scanned array - brilliant!
Actuall, this does make a lot of sense when you consider that when the antenna is rotated properly you can get a radar beam to track an object past 3 o’clock. However, you’re temporarily blind at the 9 o’clock, so track while scan won’t see anything in that quadrant.
Sexy.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.