""I would enjoy the posters saying with me that for the last 8 years , mostly for the WoT , the only aircrafts who have been fighting and bombing the Talibans fools are the NATO F-16s , F-18s and the French M2000s and Rafales .""

 

You didn 't want it , which is telling me how much anti-French and anti-BW you are . You could have told me "pi** off BW but it is true that the French Mirages and Rafales are doing the job and helping the cause" . But no ...

How do you want me to discuss with people like you ??? You accept nothing even when it comes from Official Sites , you keep shooting at the messenger without checking what the message is and your debating skills are close to none .

 

I am not going to answer the last 3 posts as they are meaningless .

 

Cheers .

First, let me say that they offer some really great capabilities, with more potential still available.  The reason IRSTs become such a contentious topic on message boards is that fanboys have a tendency to misunderstand what they are capable of and make various wild claims about them. 

A good IRST can detect and track a target at extremely long ranges, potentially in excess of 150km.  That same IRST may struggle to detect and track the same target at 50km...  To keep things short, their performance is extremely dependent on environmental factors and the target's aspect.  When you see some company claiming an incredibly long range for an IRST, it isn't necessarily untrue, it is just a best case scenario.  Typical performance will be far less than advertised. 

Another major issue with IRSTs is that like any telescope, they can either have a wide field of view, but relatively low magnification or they can have high magnification and a very small field of view.   In practice that means that at short ranges they can locate and track targets autonomously, but that at longer ranges there is simply too much sky for them to effectively search. (They are doing the equivelant of looking through a soda straw.)  For this reason modern IRSTs, and any other long range optical device such as targeting pods or the TV camera in the Rafale, are almost always designed to be cued where to look by other sensors.  Once told where to find the target, they can often track it at relatively long range, but that isn't the same thing as finding the target in the first place. 

See this article for a little discussion of the Sniper XR targetting pod, which can act as an IRST.  Note the one bit about using the F-16's radar to detect the fighter before switching over to the targetting pod.  A very good RWR, or perhaps a datalink could also provide such cueing. 

h*tp://www.aviationweek.com/aw/generic/story_generic.jsp?channel=awst&id=news/10044top.xml   

Another major limitation that is frequently not understood is that IRSTs have a hard time performing ranging, which is why most rely on a laser range finder.  It isn't impossible to perform ranging without a laser, but you aren't going to get nearly the level of accuracy as you would with a radar.  This makes carrying out long range attacks relying solely on an IRST problematic. It certainly isn't  impossible, but there will be trade-offs, primarily in range and probability of kill.  

Yet another issue is that IRSTs have very poor multi-target performance compared to modern radars, especially AESAs. Tracking a single target is one thing, even 2-3... but if you reach the point where there are a number of targets spread all over the sky it is not going to be able to keep its eye on all of them.  This is a significant issue if you are thinking about an even medium sized air engagement. (Would you be happy knowing where a pair of your opponents are but left wondering where those other two #!$% went?) 

So what is the bottom line?  IRSTs offer some great capabilities.  They really can track targets at very long ranges under the right conditions.  They can perform some useful indentification functions that are very very useful in a low-intensity conflict.  They are passive, can't be jammed, and they aren't affected by radar cross section.  The jamming resistance is important, and one major reason why IRSTs are included on many legacy fighters.  In the event the fighter's radar was jammed, at least it would still have Something... but they were never intended to be a fighter's primary sensor going into an engagement.   

More recently of course there has been a lot of talk about trying to use IRSTs to counter stealth aircraft.  It is pretty impossible to have a meaningful discussion about this because there is simply no information publically available about how susceptable the US's stealth aircraft are to this approach. It is worth noting that all of these aircraft have received major work to reduce their IR signatures.  Look at the engines on the B-2, or F-117, specifically their location.  While you are at it, go back to that link above and see what the targetting pod was actually locking on to when tracking the F-16...    

"XR. Griffiths had some difficulty locating the other fighter in IR white-hot/wide FOV, but finally locked the point-tracker onto