PESA vs. AESA

**leolover** · 17 Dec 05,, 19:16

ok, please tell me some facts.
what is the way they work, and which sort of radar offers the "better" battlefield-performance?

**The_Burning_Kid** · 17 Dec 05,, 19:20

I don't know about radars that much but from all its hype, I would say the AESA.

**Injecteer** · 20 Dec 05,, 09:26

Originally Posted by leolover

what is the way they work, and which sort of radar offers the "better" battlefield-performance?

they were not tested against each other in a real action. everything else are just speculations.
Also, both PESA and AESA are only the names of technologies used, not the real devices. That means, that a good'ol doppler-radar can be better, than a "hand-made" P/A-ESA gadget

**JBodnar39** · 20 Dec 05,, 11:43

Sniper,

answer this for us

**Injecteer** · 20 Dec 05,, 16:06

lemme guess... the answer would be:

of course the AESA is way better, as the "A" in it's name stands for "America"

**ajaybhutani** · 20 Dec 05,, 19:18

Originally Posted by Injecteer

lemme guess... the answer would be:

of course the AESA is way better, as the "A" in it's name stands for "America"

so whats the p in pesa ??

**Jay** · 20 Dec 05,, 19:27

Originally Posted by ajaybhutani

so whats the p in pesa ??

Defn not Pakistan

May be Poland?

**Bill** · 20 Dec 05,, 19:42

Originally Posted by JBodnar39

Sniper,

answer this for us

Sorry, this is a Jgetti or Highseas type question.

I'll leave it to those much more qualified fellas.

**highsea** · 20 Dec 05,, 21:14

Been there done that...

F-22 vs. Su-37 who would win

F-22 vs. Su-37 who would win

**JG73** · 20 Dec 05,, 21:27

First of all here is some information about todays AESA radars.
http://www.ausairpower.net/aesa-intro.html

As far as I know(???) the PESA radar was just an idea during the early 90ies, the EF2000 for example should have been eqipped with one(was to expensive at this time). The 'P' stands for passiv. That means that the radar should also receive radio/radar waves emitted by another radar. As we all know stealth aircrafts reflect radar waves in every other direction but nearly not back back to the emitting radar. So the idea was to use a 2nd fighters radar to receive the reflected radar waves of the 1st fighters radar. So you can make stealth aircraft visible. The Gripen's PS-05A for example should also be a passiv radar, and also the Captor and the RBE I think, although they have mechanical steered antannas. So if you have at least 3 fighters equipped with these radars you are able to locate the enemie's exact position even if he's 'stealth'.
Here some more information what AESA radars work like on the example of the EF2000's and Rafale's future radar.
http://www.iee.org/oncomms/pn/radar/Roulston.pdf

**BenRoethig** · 21 Dec 05,, 07:46

AESA: Active electronically steered array
PESA: Passive electronically steered array

**highsea** · 21 Dec 05,, 17:01

Originally Posted by JG73

...As far as I know(???) the PESA radar was just an idea during the early 90ies, the EF2000 for example should have been eqipped with one(was to expensive at this time). The 'P' stands for passiv. That means that the radar should also receive radio/radar waves emitted by another radar. As we all know stealth aircrafts reflect radar waves in every other direction but nearly not back back to the emitting radar. So the idea was to use a 2nd fighters radar to receive the reflected radar waves of the 1st fighters radar. So you can make stealth aircraft visible. The Gripen's PS-05A for example should also be a passiv radar, and also the Captor and the RBE I think, although they have mechanical steered antannas. So if you have at least 3 fighters equipped with these radars you are able to locate the enemie's exact position even if he's 'stealth'.

Sorry JG, but you're way off base here. The passive only refers to the way the beam is steered, e.g. ferrite phase shifters vs. MMIC's. Your theory on detection doesn't fly, you are describing a multistatic system, but there is no way to synchronize the signal in your example. Radars will always receive the signal from any other set on the same frequency, but there is no way to process that signal, since the receiver does not know what the timing is. Milliseconds count. (RWR's will do the same thing, of course, which every modern AC is equipped with.)

You should have read the link you referenced...

As the antenna contained only what engineers term passive components, these antennas are also known as passive phased arrays or passive electronically steered arrays.

**leolover** · 22 Dec 05,, 19:40

ok, please correct me if i am wrong:

phased array radars consist of many small emitters/receivers. if different transmitters work, it comes to interference, an this interference focus the beam. so phased arrays can detect and engage more targets more accurate than mechanically steered radars.

a AESA consists of more than 1000 small modules, which are both transmitter and receiver.
so far so good, but then it gets tricky. as i understood every module of an AESA is like a single radar (which can even emitt different frequencies), while in a PESA the energy is produced at an cetral source and then spread to the emitters.

i hope it wasn´t too wrong

**Injecteer** · 23 Dec 05,, 09:53

leolover:
>small emitters/receivers
they are just small antennas (di-poles) which are used for receiving/transmitting.

>if different transmitters work, it comes to interference, an this interference focus the beam.
no. not the interference shapes the beam, but the phase shifts between the elements.

>so phased arrays can detect and engage more targets more accurate than mechanically steered radars.
not necessarily. the main advantage of PAGs is the ability to electronically (w/o moving parts) re-shape and redirect the beam and do it damn FAST

>every module of an AESA is like a single radar (which can even emitt different frequencies)
LOL! can u imagine the size of an on-board computer, which would be able to analyze all the reflections? the Deep Blue would suck in this task

>while in a PESA the energy is produced at an cetral source and then spread to the emitters.
no, both are centrally powered and controlled.
the main diffs (as highsea thinks) are that AESA consumes less power and can be swithced a bit faster, and of course costs A LOT MORE.

I think also, it brings more headache to the service guys, than a PESA gadget does