I was under the impression that Iraq had this, but I could be wrong.



Exact capabilities of jamming equipment against the ... opponent equipment is secret; either way, the exact capabilities will dictate tactics. It doesn't matter if the system is degraded or disabled if 'degraded' means you can stick a HARM or SLAM or some other stand-off weapon in it. It was, however, part of the pod's stated capability (I think it was the 184).



Depends on the type of jammer and its power; there are of course backup capabilities as well. But most importantly, the Dvina does not use a homing missile. This allows it some backup capabilities that a homing missile would not normally have ... although arguably, one might say that a Patriot/S300 can use the TVM system to function in a similar manner in the case of heavy jamming.

I think it depends on the guidance strategy being employed. A pure pursuit missile or similar (three point guidance) may require 5 times the target 'g' level to prosecute an intercept, however a missile flying an intercept geometry and also using a form of proportional navigation, may only require 3 times the targets 'g'.

Also reading Vietnam accounts of missile evasion, pilots would often pull a minimum of 6g to evade an SA-2 and these missiles (only capable of around 7g) would still past pretty close by.

The rule of thumb is five. It is a rule of thumb; the actual numbers will depend on the given situation. Typical PN constant is 5.



You maximize the miss distance by pulling the most g you can. It's that simple. This isn't a game where you try to 'nail the optimal pull'.

The required 'g' is no more than x2 for PN, although an acheived x3 is often selected to make the guidance 'brisker' and lower energy use by earlier manoeuvring. Under many circumstances required 'g' is far lower, x1.5 should be ample to maintain aiming error constant (and thus miss distance reducing monotonically with range).

I agree that it depends, particularly on attack geometry. However it does make me wonder about quotes of 20g SAMs being able to hit targets manoeuvring at up to 7g, but I guess this falls into the 'it depends' category, where the 'it depends' criteria are favourable.





I understand that, but what is confusing is why the missiles often passed very close to the evading jet, despite a well executed manoeuvre?

BTW, where did you get those AIM-9L/M graphs from and do you have any more similar information and performance charts?
Cheers

Yep Possibly either the jet or missile were quite slow, or it was an in-plane maneuver. That's all speculation though.





'Very close' doesn't mean much. Did someone get out and measure with a tape? If not, then the testimony is not very reliable. Additionally, 'well executed maneuver' is again subjective - the type of maneuver and geometry needs to be known, etc.



It was a study of missile aerodynamics modification - the second performance line is the same missile with fins more like the 120's and a pointed radar radome instead of the IR radome. The paper is not free though.

Sometimes the accounts use estimates such as 'within a wingspan' etc. Also I think in one of Randy Cunningham's accounts, he mentioned that the missiles fuse must have failed because it was well within lethal range. I just read these accounts the other day, so I'll post some of them later.





Do you have the name of the paper?

The value N used in PN tracking is a gain factor for the autopilot, not a multiplier for the 'g' requirement. In fact as the N value increases the peak 'g' required for a centre of mass impact reduces.

The primary effect of a very high N is to eliminate aim-off error at launch (ie off-axis capability of a dogfight missile) - As most of the earlier SAM systems launch the missile along the target LOS (or the 'initial' estimate of required lead) a lower gain will have a similar effect over most of the distance.

A secondary effect of high N is to noticeably increase 'g' and turn requirement in the early phase of flight - the benefit is less tendency to a tail-chase intercept geometry and reduced terminal manoeuvring requirement - noise in the measured LOS rate tends to result in larger course excursions for the same sensor quality, although the correction is more rapid.

N doesn't alter the required lead angle to reach an intercept point at constant velocities, or the turning ability of either target or missile.

With a roughly 100m allowable miss distance, the effect of lower N, or alternative guidance strategies (eg command guidance, beam-riding etc) is a lower probability (and tighter geometry requirements) of a direct hit, but still high probability of passing inside the fusing radius...

This is obviously more likely to be survivable, than a direct hit, but you cannot guarantee forcing a miss unless residual missile 'g' is significantly lower than the target - with optimal geometry you can force a near pass with target 'g' near 0.5 missile 'g', but not only might this be insufficient against a succeeding shot from the same salvo, but any missile passing 'close' has the possibility of fusing.

guys... loock at this vietnam line brack II !

loock at number of missile launche! date one 65 missile launch but only 3 b52 it shot down!






idont know why lauched a lot of missile like that chart ! i think vietnamian sam crew was very nerves

"In a jamming environment the TVM technique is still usable because the system can measure range difference and as it has the angular measurement of the target it can determine the difference in path length without loss of range resolution. It has the same range resolution as a non-jamming target"

In normal words, if you successfully deny all information of your distance from a Patriot/S-300P SAM, it simply triangulate you (Fire Control Radar - SAM Missile TVM head - Jamming Target).
As jamming is not affecting the lead point calculation at all, Patriot/S-300P systems has no TT guidance methods implemented, they fly UPR or lofted UPR depending on target range.



AN/ALQ-184 is a BAD choice against S-300P.
I would rather choose AN/ALE-50 / -55, or Stealth, after all metric target acquisition radars were eliminated by standoff weapons.


I still think that sending in F-117A above Belgrade alone, without any support (CAP/ECM/Weasel) was over optimistic, or suicidal.