Air Force Question Thread

[SQ8]

Same as PAF's F-7PG?

We have the Italian radars, right?

We have the Grifo series.
http://www.selexgalileo.com/~/media/Files/S/Selex-Galileo/documents/press-backgrounders/04grifo-family-backgrounder.pdf

 

[ANPP]

f
or anybody who is pretty sure about it.
1. Is there any solid state aesa jammer on board on any fighter jet ?

If you are talking about jamming of AESA radar than, yes.
This "entire spectrum" is in fact very narrow for any useful application. And signal coding is useless if signal/noise ratio is almost zero. You can say AESA a PC/ network more than a radar.
But if it comes gnd based AESA, than no airborne plateform is capable of taking such a large jammer with it (power of GW). And if you are increasing jamming capability of plane than means you are destroying its conventional capabilities like Growler.
You can read many papers in ieee for that solution, but all of them either are not feasible or very less effective by modern tach.

2. can anti radiation missile lock on to aesa radar signals and home on ?

Yes, but pretty tough for missile. As Oscar say only upto LPI mode.

4. can today's bvr missiles (it's mono pulse seeker ) lock on to stealth jet's(will it detect them, if detects will it recognise them as a threat because of extreme low rcs or will it classify it as a bird, clutter or any other false alarm ?

BVR missile can lock-on fighter but again range is issue. Stealth fighter has very low RCS, so missile needs to come enough close to fighter so that threshold of RCS for missile would cross, but it is impossible for missile even with fighter radar by beyond visual range.

 

[bigzgvr4]

what about the NEBo radar that india is building with russia and israel how does that match up in detection and jamming

 

[Donatello]

We have the Grifo series.
http://www.selexgalileo.com/~/media/Files/S/Selex-Galileo/documents/press-backgrounders/04grifo-family-backgrounder.pdf

Which specific one?

Also, if you scroll down, it says Grifo 500 designed for JF-17 platform? Like WTH??

 

[gambit]

3. is anti radiation missiles needs to be guided by any other active method till the anti radiation seeker gets activated ? if yes at what distance ?

Anti-radiation missiles are called that way because that is the ONLY mode of operation they use. The preferred term among many engineers is 'beamrider' because it is bit more visually descriptive.

A missile can have more than one mode of guidance operations.

- Active guidance is where the missile have and employs its own sensor, be it radar or infrared.

- Passive guidance is where the missile relies on external instructions on where is the target and where is it going to be. Understand that an instruction is not the same as a command, even though we uses the two casually. An instruction is more like an FYI whereas a command is like 'DO THIS' or 'TURN HERE'. That is not how internal missile guidance works. Other than a tail chase situation, or pure pursuit guidance, a missile must calculate intercept points that are AHEAD of the target. If you ever done any skeet shooting, you know what I am saying -- lead the target and shoot that empty space. So if you are going to actually command the missile, you must do all that calculations for it.

Under passive guidance are two sub-modes.

Data...The missile can receive literally electronic instructions about the target in this manner: 'You are travelling at 1000 km/hr and the target is approaching you at 30 deg to your right at 500 km/hr at 30 deg descent angle from 1000 meters relative altitude.' The missile then takes this information and calculate its own intercept point. Keep in mind that this is a highly dynamic situation in 3D space so the source of these instructions must keep in constant communication with the missile and that mean those figures are in constant changes.

Radar...The missile receives radar reflections off the target and the source of those transmissions are NOT of its own. The origin can be from a friendly parent like a standoff AWACS or a companion like a flight member, which is most likely the parent launch aircraft.

- Beamrider guidance is the simplest and this is where the missile simply home in the strongest transmitter/source. If the transmission is off angle, the missile will overshoot, senses that there is a loss of signal strength, alters its flight path to the last known direction of that signal strength, then hopefully reacquire. Against ground transmission sources, beamrider mode alone is sufficient because those ground targets are limited to two axes of travel and very slow compare to missile speed. The only thing that would make a ground target beamrider missile more expensive is counter-countermeasures. Two or more ground radar stations can rapidly 'blink' on/off, thereby creating confusion for the missile.

As a side note -- and an important one if you are curious -- wake homing torpedo works on the same concept except the torpedo senses water displacement or 'excitation' on surface and displacement sub-surface. Surface excitation or bubbles create -- noise. And that is sonar reception. Sub-surface displacement disturbs a set of internal gyros and accelerometers designed separately to detect torpedo body deviations from current path. Another set of gyros and accels that navigate and stabilize the torpedo serves as a reference. When the two nulls each other out, the torpedo knows it passed through the wake, then it turns around to the last known location to try to reacquire the wake. The goal for the torpedo is to minimize that time outside the wake. So when it is inside the wake cone if it senses the slightest decrease in disturbance/displacement, it will immediately turn to the opposite direction.

Radar transmissions are always more focused than wake. The result is that the torpedo have a more pronounced zig-zag path to the target than a radar beamrider missile does.

Advanced Acoustic Concepts - News Article

Wake-homing torpedoes are guided by sensors that detect the turbulence of a ship’s wake. The torpedo snakes from side to side within the cone of the wake and follows it to the ship’s stern before detonation.

Nixie is streamed behind a ship on a cable and generates a noise louder than that of the ship, thereby decoying a torpedo away from it.

Anyway...Is it possible to have a missile that have all three modes of guidance operation? Absolutely.

How much money you got? AMRAAM ain't selling on Ebay or Amazon.

4. can today's bvr missiles (it's mono pulse seeker ) lock on to stealth jet's(will it detect them, if detects will it recognise them as a threat because of extreme low rcs or will it classify it as a bird, clutter or any other false alarm ?

If the RCS is low enough, the system will classify as a bird or clutter. Not because it is too low therefore it must be a threat. The reverse is what you are saying and that will create chaos because now every real bird must be classified as a potential threat.

A mono-pulse radar have one transmission source but splits into four antenna transmissions.

The result is four distinct reflections off the target. Comparators inside the radar computer will attempts to inform the operator of any deviation that will take the system greater than the null value the comparator circuit produces. The target must be at the intersection of those four transmissions.

Against an F-117 class body, even if the target is close enough that its RCS rises above the clutter rejection threshold, if the target is maneuvering, it will play havoc on the comparator circuits precisely because the target is shaped to reduce RCS. Remember, there are now four radar views, not one, and certain maneuvers by the target will create reflection strength that are grossly too high or too low for the comparator circuits to compensate.

A mono-pulse radar is no guarantee against an F-117 class body. The only guarantee for now is -- get even closer.

Your other questions have been adequately answered by others.

 

[SQ8]

Which specific one?

Also, if you scroll down, it says Grifo 500 designed for JF-17 platform? Like WTH??

The PG's now use the Grifo-200.. with a 7 series antenna.

There was the Grifo-500 designed for JF-17 but its cost/benefits weren't as high and the KLJ-7 performed better.

 

[Zarbe Momin]

Some body can give me a satisfied answer why pakistan is not going to develop its own air defence missle system. If the task given to NESCOM is not a difficult job.

 

[Last Hope]

Some body can give me a satisfied answer why pakistan is not going to develop its own air defence missle system. If the task given to NESCOM is not a difficult job.

When was the last time you paid your tax?

 

[Dr. Strangelove]

When was the last time you paid your tax?

he is german

 

[Neptune]

How many combat aircraft, rotor fixed, ESW...etc. does PAF have? Thx.

 

[fatman17]

How many combat aircraft, rotor fixed, ESW...etc. does PAF have? Thx.

all these answers are available in PAF section - pls surf

 

[Nucleus]

Can anyone tell why are some of them wearing glasses being pilots?
Thanks!

Full link here so you can zoom in: http://pafwallpapers.com/blog/wp-content/uploads/2012/09/jf-17_thunder_no26_sqn_black_spiders.jpg

 

[SQ8]

Can anyone tell why are some of them wearing glasses being pilots?
Thanks!

Full link here so you can zoom in: http://pafwallpapers.com/blog/wp-content/uploads/2012/09/jf-17_thunder_no26_sqn_black_spiders.jpg

Not everybody's a pilot..
some are the engineers working with the squadron.

 

[S.U.R.B.]

Can anyone tell why are some of them wearing glasses being pilots?
Thanks!

Full link here so you can zoom in: http://pafwallpapers.com/blog/wp-content/uploads/2012/09/jf-17_thunder_no26_sqn_black_spiders.jpg

The are 16 pilots in the image quoted above (as far as i can see).
And none of them are wearing spectacles.

 

[Jango]

The ones with the maps and checklists on their thighs are pilots, also with the strap on chest...rest are not.