Octav Posted November 29, 2004 Posted November 29, 2004 A new question for the ones involved in 1.1: is the new radar model including those features: different sized boxes for V, D, AVT, SNP, TP(STROB) modes? One more thing: what about the long-disputed loss of lock in V/D/AVT mode when bankled more than 110 degrees? It was decided (after countless arguments, and prior to 1.02 release) that it affected search modes only, and it appeared as a feature affecting the lock mode also - any changes ? Octav
Shepski Posted November 29, 2004 Posted November 29, 2004 What do you mean by V/D/AVT? Encounter/Pursuit/Auto? The bank angle does not affect lock on in v1.1 when entered in a BVR mode. You can adjust the size of the gun funnel but not the target box.
Alfa Posted November 29, 2004 Posted November 29, 2004 What do you mean by V/D/AVT? Encounter/Pursuit/Auto? Yes thats the abbreviations for those modes(in that order) :) You can adjust the size of the gun funnel but not the target box. I think what Octavian means it that the target box is displayed differently in different radar modes - i.e. not a question of adjustment, but about the nature of the symbology used. JJ
Octav Posted November 30, 2004 Author Posted November 30, 2004 What do you mean by V/D/AVT? Encounter/Pursuit/Auto? Yes thats the abbreviations for those modes(in that order) :) You can adjust the size of the gun funnel but not the target box. I think what Octavian means it that the target box is displayed differently in different radar modes - i.e. not a question of adjustment, but about the nature of the symbology used. Hello Jens, Yes, that's what I mean - the box has different heights, based on the mode - smaller in V mode, about double height in AVT, and triple height (relative to V) in D mode - it's size is the same, measured in km's of distance, but because these 3 modes have different max ranges, the box is scaled-up accordingly. SNP has it's box wider (if I remember correctly, about 1.5 times - I'll have to check the manuals, I'm not at home at the moment, so I have no access to them for a few days), and the TP(STROB) box is a rectangle with a small base and a more than double height. (to prevent confusions, TP(STROB) is the BVR EOS mode) Anyway, I'm glad to hear that there are no more losses of lock in BVR modes, when banking more than 110 degrees. Cheers, Ocavian
Han Posted November 30, 2004 Posted November 30, 2004 The bank angle does not affect lock on in v1.1 when entered in a BVR mode. Wrong ;) It have no affect on medium and high altitudes. On low altitudes it have affect. With Best Regards! Daniel Tuseyev Il-2: Battle of Stalingrad and Rise Of Flight projects manager
Octav Posted November 30, 2004 Author Posted November 30, 2004 The bank angle does not affect lock on in v1.1 when entered in a BVR mode. Wrong ;) It have no affect on medium and high altitudes. On low altitudes it have affect. Why is that? What is the explanation? And it happens in lock mode, or in search mode? P.S. - and what about the different sizes of the target box, depending on the radar mode?
Shepski Posted December 1, 2004 Posted December 1, 2004 Hi Octav, I wouldn't expect to see a change in the size of TD boxes in different modes. As for the bank angle issue... in the current build I have not seen an effect on lock on when at a low altitude... possibley in the next build? ... Han would have to answer that though.
Octav Posted December 1, 2004 Author Posted December 1, 2004 Hi Octav, I wouldn't expect to see a change in the size of TD boxes in different modes. As for the bank angle issue... in the current build I have not seen an effect on lock on when at a low altitude... possibley in the next build? ... Han would have to answer that though. Thanks Mark, Could you try a complete roll in a BVR lock mode, at low altitude (below 100m), and at about 20-30 km to target, so that the issue isn't masked by a switch to TP (EOS) mode? Octav
SwingKid Posted December 1, 2004 Posted December 1, 2004 It have no affect on medium and high altitudes. On low altitudes it have affect. Why is that? What is the explanation? And it happens in lock mode, or in search mode? The sidelobe compensation guard horn antenna is not attached to the scanning reflector in Russian Cassegrain radars, but rather is fixed to the outer antenna housing. It normally points forwards and downwards when the antenna is gyro-stabilized, and is calibrated to reduce sidelobe radio interference reflected from the ground. If the antenna becomes aligned to the fighter in lock mode (as most believe that it does), then rolling the fighter will also rotate the sidelobe guard horn to face away from the ground. The developers believe that in this orientation, the sidelobe intereference is not correctly compensated, and if the interference is strong, as when the fighter is at low altitude, then the it can cause the radar lock to be dropped. At least, that's how I understood the Russian discussion... Pilots that were asked appeared themselves unsure of such engineering details. :? -SK
Shepski Posted December 1, 2004 Posted December 1, 2004 Thanks Mark, Could you try a complete roll in a BVR lock mode, at low altitude (below 100m), and at about 20-30 km to target, so that the issue isn't masked by a switch to TP (EOS) mode? Hi, I wasn't that low. :) I tested this against an F-5E over open water... Han is correct... About 1500m and below, the lock was broken as I rolled inverted... when the target was in range of the EOS, the EOS will continue to hold lock while inverted and when I rolled back upright the radar switched back on holding the lock. The lock would switch back and forth between EOS and radar as I rolled. Cheers
Octav Posted December 1, 2004 Author Posted December 1, 2004 The sidelobe compensation guard horn antenna is not attached to the scanning reflector in Russian Cassegrain radars, but rather is fixed to the outer antenna housing. It normally points forwards and downwards when the antenna is gyro-stabilized, and is calibrated to reduce sidelobe radio interference reflected from the ground. If the antenna becomes aligned to the fighter in lock mode (as most believe that it does), then rolling the fighter will also rotate the sidelobe guard horn to face away from the ground. The developers believe that in this orientation, the sidelobe intereference is not correctly compensated, and if the interference is strong, as when the fighter is at low altitude, then the it can cause the radar lock to be dropped. At least, that's how I understood the Russian discussion... Pilots that were asked appeared themselves unsure of such engineering details. :? -SK Thanks Andrew, now that's an explanation... but how is this "probability" implemented? Any help of somme lobby over there for the implementation, in the next patch, of the target boxes specific to each mode? I believe that now the V mode geometry is used for all modes. Octav EDIT - there seems to be something missing, though... In the close combat modes, I've never heard anything about loosing lock while flying inverted and low. Should it be the fact that the distances involved alre low (below 10 km) and thus the sidelobe is far smaller than the target's signal? If this is the case, then the loss of lock in the BVR modes should happen only beyond certain distances... isn't it?
Octav Posted December 3, 2004 Author Posted December 3, 2004 by the way, looking at the bug fixes list, I've noticed the following thing: Vertical radar angle changed to dH/D*57.3 where dH is predefined by pilot target exceeding (+/ - 15000 m) , D - predefined target distance (10000 -150000m) , you may change D by CTRL+/- or analog axis Target Specified Size /Distance, dH changed like old vertical radar rotation The way of changing dH is good, but D is altered in real life by moving the target designator box on the radar scope - is it possible to implement it the same way? It would save 2 more keys or buttons (apart from being realistic) Octav
SwingKid Posted December 3, 2004 Posted December 3, 2004 The way of changing dH is good, but D is altered in real life by moving the target designator box on the radar scope - is it possible to implement it the same way? Are you sure about this? Let's say the target is straight ahead and at 25 km distance, but dH is set high, and the radar cursor is at 50 km distance. If we move the cursor inwards to 25 km range to try and lock the target, the scan would simultaneously be steered to a higher elevation angle, because of fixed dH. The target would suddenly disappear from the radar screen as we try to lock it at the closer range. It may be realistic, but I'm not sure it's appropriate for a simulator where there is not yet any GCI voice instructing what dH to set the radar. I think the developers made the separate set of controls to make this slewing method optional. -SK
Octav Posted December 3, 2004 Author Posted December 3, 2004 Hello Andrew, Are you sure about this? Let's say the target is straight ahead and at 25 km distance, but dH is set high, and the radar cursor is at 50 km distance. If we move the cursor inwards to 25 km range to try and lock the target, the scan would simultaneously be steered to a higher elevation angle, because of fixed dH. The target would suddenly disappear from the radar screen as we try to lock it at the closer range. I'm very sure - you can find this in the MiG-29 weapons systems usage manual, which was on the net a while ago - I think you have it. Also, it is detailed in the pilot's manual. It is part of the training to adjust dH, if you loose the target while moving the STROB (gate) towards an inner altitude. By the way, the elevation is calculated for the point between scan bars 2 and 3 - so at the upper and lower limits of the scan patterns, elevation is up or down by about 7 degrees, if I remember correctly - so this should be able to lossen up the problem a bit. Let me give you some numbers: Case 1: D mode, dH 2km, STROB moved to 25 km Center elevation angle is 4.6 degrees, upmost part of the scan zone is at 11.6 degrees, lower partt of scan zone is at -2.4 degrees. At the 25 km range, the antenna scans a vertical zone from -1.1 km to 5 km - so aprox 6 km. At the maximum range of the D mode, the antenna scans from -2 to +10 km - so that is 12 km - I think there is a large enough magin of error. Case 2 : AVT mode, dH -1 km, STROB to 50 km Center elevation angle is -1.15 degrees, vertical angular scan zone ranges from +5.85 to -8.1 degrees. Vertical scan zone, in km, at 50 km is from -7.1 to +5.1 km, and at max range for the mode, the antenna scans from -14 to +10 km from the aircraft's altitude. Let's have here a case 2b, as most players I think would use that mode, with dH set to +1, and D set to 33 km: Center elevation 1.75 degrees, full vertical scan zone goes from -5.3 to +8.75 degrees, at the set distance that means from -3 to +5 km, and at max range from -9.2 to +15.2 km. Case 3 : V mode, dH +4km, STROB to 75 km Center elevation angle is 3.1 degrees, angular vertical scan zone from -3.9 to 10.1 degrees, in km at the set distance that means from -5.2 to +13.1 km, and at max range for that mode it will go from -10.3 to +26.2 km. It may be realistic, but I'm not sure it's appropriate for a simulator where there is not yet any GCI voice instructing what dH to set the radar. I think the developers made the separate set of controls to make this slewing method optional. Based on the numbers above, and with a bit of practice, it shouln't present too much probems - maybe we'll get the GCI instructions in the near future, to compensate :). By the way, could you please comment on the issue about the loss of lock while in a roll at low altitudes, which I think shouldn't happen below a certain range - maybe 10-15 km or so? Check my earlier post for details. Cheers, Octavian
SwingKid Posted December 3, 2004 Posted December 3, 2004 By the way, could you please comment on the issue about the loss of lock while in a roll at low altitudes, which I think shouldn't happen below a certain range - maybe 10-15 km or so? Check my earlier post for details. Sorry, I don't know the answer to this. There was a similar question recently asked about losing the gunsight radar lock in the F-15C avionics sticky thread. -SK
Octav Posted December 3, 2004 Author Posted December 3, 2004 Sorry, I don't know the answer to this. There was a similar question recently asked about losing the gunsight radar lock in the F-15C avionics sticky thread. -SK OK - if you manage to find something out please let me know. And maybe the devs would consider modifying the way D is introduced. Octav
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