Stratos Posted October 10, 2018 Share Posted October 10, 2018 Hope this is the place to ask this... Found this in the F-15C Eagle Units in Combat by Steve Davies in Osprey editorial, but cannot understand it fully, last 4 lines. Held the beam maneuver means he was at 90º of the F-15C radar, right? But the part about out of AIM-7 waeapon engagement zone WEZ is what I don't understand. He kep out of range? If beaming, can the F-15 radar still see it? I don't understand anything in russian except Davai Davai! Link to comment Share on other sites More sharing options...
probad Posted October 10, 2018 Share Posted October 10, 2018 (edited) keep in mind that aspect is relative and the wez changes shape depending on aspect. a beaming target not only makes it difficult for the radar to break out, but it also depresses the wez. by managing his aspect to the opponent, a pilot can ride the edge of his opponent's wez to play bait, yet with a slight bearing change, be safely out of danger. Edited October 10, 2018 by probad ✯ МИР ✯ Link to comment Share on other sites More sharing options...
Bimbac Posted October 10, 2018 Share Posted October 10, 2018 You are correct with your first question - the beam maneuver means they flew westwards perpendicular to the F-15's radar beam. That, of course, doesn't mean maintaining a precise 90° angle, but anything between 80° - 100°. It looks to me like those MiGs were under GCI control, so their pilots knew the distance from the F-15s, meaning they kept themselves outside the Sparrow Weapon Engagement Zone. Most probably, the F-15s could see them, but the contacts were intermittent, therefore unreliable - and out of Sparrow's range. Probad's picture gives a perfect explanation. :thumbup: Link to comment Share on other sites More sharing options...
Frederf Posted October 10, 2018 Share Posted October 10, 2018 Doppler radars in the look down mode must do something to filter out Earth returns or they dominate over the returns of air targets. For a given motion of the radar, the Earth return is blue-shfited by some amount. Radars will filter out all returns which have a frequency that Earth returns are expected to have. A target flying with a radial velocity similar to the background Earth, even though it has a large speed lateral, is indistinguishable from a mountainside in terms of the frequency of the return and is filtered out. As for WEZ, presumably the MiGs were inside the kinematic WEZ of the AIM-7 but by beaming denied the fighters tracking info to prevent engagement. After the MiGs were reacquired it turns out they had left the WEZ. And successful beaming of a Doppler radar absolutely will prevent any sort of detection. It looks like empty sky. Link to comment Share on other sites More sharing options...
Bimbac Posted October 11, 2018 Share Posted October 11, 2018 As for WEZ, presumably the MiGs were inside the kinematic WEZ of the AIM-7 but by beaming denied the fighters tracking info to prevent engagement. After the MiGs were reacquired it turns out they had left the WEZ. And successful beaming of a Doppler radar absolutely will prevent any sort of detection. It looks like empty sky. Well, not entirely true - that would apply to the older radars with no look-down, shoot- down capability. Modern radars are not so easy to get fooled by notching - and I'm talking about 1980s technology. Sent via mobile phone using Tapatalk Link to comment Share on other sites More sharing options...
Vilab Posted October 11, 2018 Share Posted October 11, 2018 (edited) Well, not entirely true - that would apply to the older radars with no look-down, shoot- down capability. Modern radars are not so easy to get fooled by notching - and I'm talking about 1980s technology. Sent via mobile phone using Tapatalk it is exactly the other way. an older "pulse" radar would see the notching target, it would just be lost into all the ground clutter ==> most of the time prevents the target from being spotted on the radar display, prevents any kind of lock the "doppler only" radar will filter anything which looks like it has near 0 relative velocity to the ground, so it won't see the notching target ==> the target is not displayed at all current "modern" radar with much higher computer power may be able to see notching targets…. Edited October 11, 2018 by Vilab Link to comment Share on other sites More sharing options...
Bimbac Posted October 11, 2018 Share Posted October 11, 2018 It's a little bit more complicated, because you have to consider the target's composition, shape, materiel and any moving surfaces. A propeller driven plane or a helicopter would be visible even when stationary. Modern radars also have variable Doppler filter threshold so you can change the setting in real time, basically removing the notch, making any reflective contact visible, along with many false returns, of course. The contacts are always visible, they may be just filtered out. Sent via mobile phone using Tapatalk Link to comment Share on other sites More sharing options...
Stratos Posted October 11, 2018 Author Share Posted October 11, 2018 Really interesting answers guys!! I will print the most relevant ones and place them inside the book. I don't understand anything in russian except Davai Davai! Link to comment Share on other sites More sharing options...
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