What's the difference between PESA and AESA?

[VVanks]

Anyone wanna have a go at this?

 

Please be detailed, I can understand more indepth discussions.

 

Passive vs Active.

[Mugatu]

http://en.wikipedia.org/wiki/Active_electronically_scanned_array#The_difference_between_AESA_and_PESA

 

Somes it up.

[Pilotasso]

I am no expert at the electronic aspects of radar but this means that in PESA you can designate multiple targets by swiching the beam between them very fast, (so fast the target supposedly would move only a few inches after each contact, thus re-finding it shouldnt be a problem ) but for AESA, it enables the radar to actualy send several beams at the same time illuminating each target. It can even do that and operate in AG mode silmultaneously. Aditionaly, AESA technology enables the dish to act as a passive signal analyser and even ECM emmiter, you wont need to use dedicated pods under the wings, of course you still need rearward facing emmiters such as that mounted on one of the F-15's vertical fins. Theoreticaly its possible to reverse the beam through the canopy but that would harm the pilot. I have seen graphs showing radar coverage of about 270 degrees. But if you have more AESA arrays such as that in the wings and side panels of the ofthe F-22 (its actualy left out in the first batches for economy reasons) you would achieve nealy 360 degrees of coverage.

 

SOme of the current Generation of fighter would be probably find a hard time operating its radar if the oposition has an AESA array aimed at it.

 

F-22, F-16 Block 60, F-2, Rafale and Mig-35 use AESA.

Su-30MKI and Mig-31 use PESA.

 

Having said that AESA is not always Synonim of superiority. Su-30 and Mig-31 PESA Radar are much more powerfull than that of the Mig-35.

The Captor radar in the Typhoon wich is mechanical array probably beats them all in range except that of the F-22 (APG-77). AESA has its advantages over all other technologies but as I said due to other factors theres exceptions when your comparing radars for different classes of fighters.

 

Curiously the most potent AA radar is the APG-63(V3) mounted on some upgraded F-15's for the simple reason the APG-77 is soft toned down in order to enhance its LPI capabilities, and those F-15's have the RCS the size of a barn and that will give it away before the radar will.