Migow Posted October 1, 2011 Posted October 1, 2011 hi ,the ka50 rotor is made of composite materials ,so the rotor should have low rcs , then it would be impossible to detect a NOE hovering ka50 at long medium distance?:music_whistling: member of 06 MHR / FENNEC Mi-24P
ericinexile Posted October 1, 2011 Posted October 1, 2011 Low RCS perhaps but with two discs spinning at 600 RPM I can only guess that the dopplar return is still pretty strong to a modern radar. Smokin' Hole My DCS wish list: Su25, Su30, Mi24, AH1, F/A-18C, Afghanistan ...and frankly, the flight sim world should stop at 1995.
EtherealN Posted October 1, 2011 Posted October 1, 2011 then it would be impossible to detect a NOE hovering ka50 at long medium distance?:music_whistling: Wrong. (I'm channeling some GG! :D ) NOE or not has not impact on detecability, what matters is whether the aircraft is terrain masked vis a vis the specific emitter/detector trying to find the helicopter. NOE is a mode of flight, not necessarily "being hidden" per se. Also, composite or not, you still get a very nice doppler return from those rotor blades, good enough to cause a nice bug on most radar scopes this side of the 80's. (Though in DCS:BS/FC2, multiplayer balancing concerns led to the Ka-50 being able to notch doppler radars through standing still. The concern was that Ka-50 pilots would just get slaughtered online otherwise, which is true since most fighter people online don't care about offering protection to their side's strikers. :P) [sIGPIC][/sIGPIC] Daniel "EtherealN" Agorander | Даниэль "эфирныйн" Агорандер Intel i7 2600K @ 4.4GHz, ASUS Sabertooth P67, 8GB Corsair Vengeance @ 1600MHz, ASUS GTX 560Ti DirectCU II 1GB, Samsung 830series 512GB SSD, Corsair AX850w, two BENQ screens and TM HOTAS Warthog DCS: A-10C Warthog FAQ | DCS: P-51D FAQ | Remember to read the Forum Rules | | | Life of a Game Tester
159th_Falcon Posted October 1, 2011 Posted October 1, 2011 Low RCS perhaps but with two discs spinning at 600 RPM I can only guess that the dopplar return is still pretty strong to a modern radar. True, rest assured though, not a single helicopter in world has rotor blades spinning at 600 RPM. For different reasons. Your average helicopter would have an Rotor RPM of 250 to 400 tops. In general, the smaller the helicopter, the smaller diameter the rotor, the faster you COULD let it spin. Though, if the KA50 has an rotor RPM of 300, then the difference between the two rotors would be 600 RPM. About Composite blades and RCS, they always have an leading edge made out of some sort of metal to protect the composite from abrasion type wear from the fast moving air. As well as hard particles that could hit the rotor. (small pieces of rock for example) And as EtherealN mentioned, spinning blades give a nice Doppler return. ~S~ [sIGPIC][/sIGPIC] The keeper of all mathematical knowledge and the oracle of flight modeling.:)
adam12 Posted October 1, 2011 Posted October 1, 2011 He's right that the RCS of blades on doppler is quite small though, regardless, isn't he?
sobek Posted October 1, 2011 Posted October 1, 2011 He's right that the RCS of blades on doppler is quite small though, regardless, isn't he? It's big enough to be detectable from a distance, see the 'Mudhen spoonfeeding a paveway to a Hind' incident. Good, fast, cheap. Choose any two. Come let's eat grandpa! Use punctuation, save lives!
adam12 Posted October 1, 2011 Posted October 1, 2011 From overhead I'd expect the RCS to be much larger, as well as underneath. What about for ground based radars operating at roughly the same height? I'm imagining the physical area of the blade, looking at it edge-on. But, I have no idea if the *size* of a moving object has any affect on the doppler return.
EtherealN Posted October 1, 2011 Posted October 1, 2011 Doppler return is all about speed - that's why it's called "doppler". ;) It has to have two things, basically: sufficient RCS to create an echo of sufficient strength to be detected, and a different doppler return (doppler shift, see "redshift/blueshift" and "doppler effect" on wikipedia) than it's background. Most radars today actually detect a lot more than what you see on the scope. (Of course, they also have false positives during the filtering and so on as well.) Since a helicopter's rotors spin, no matter which direction you observe it from you will always get a strong doppler shift on the reflections coming from the rotor blades. You can't "notch" like a fixed-wing can. [sIGPIC][/sIGPIC] Daniel "EtherealN" Agorander | Даниэль "эфирныйн" Агорандер Intel i7 2600K @ 4.4GHz, ASUS Sabertooth P67, 8GB Corsair Vengeance @ 1600MHz, ASUS GTX 560Ti DirectCU II 1GB, Samsung 830series 512GB SSD, Corsair AX850w, two BENQ screens and TM HOTAS Warthog DCS: A-10C Warthog FAQ | DCS: P-51D FAQ | Remember to read the Forum Rules | | | Life of a Game Tester
GGTharos Posted October 2, 2011 Posted October 2, 2011 Nope. Size has no effect on doppler return OR RCS. See Raptor, AKA F-22 ;) But, I have no idea if the *size* of a moving object has any affect on the doppler return. [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda
GGTharos Posted October 2, 2011 Posted October 2, 2011 (edited) hi ,the ka50 rotor is made of composite materials It is also partly made out of metal. In particular the rotor mast assembly also has metallic parts that do rotate and happen to have all the wrong angles for hiding radar returns. ,so the rotor should have low rcs , then it would be impossible to detect a NOE hovering ka50 at long medium distance?:music_whistling:Incorrect. The rotor has high enough RCS to pick up from 40nm - much like the composite blades of a BlackHawk. Edited October 2, 2011 by GGTharos [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda
Eddie Posted October 2, 2011 Posted October 2, 2011 hi ,the ka50 rotor is made of composite materials You assume composite materials don't reflect radar energy. If only building a stealth aircraft was that simple.
sobek Posted October 2, 2011 Posted October 2, 2011 Since a helicopter's rotors spin, no matter which direction you observe it from you will always get a strong doppler shift on the reflections coming from the rotor blades. You can't "notch" like a fixed-wing can. Well, in case you ping it perfectly orthogonal to it's rotation plane, there would be no doppler shift, although that is a pretty artificial circumstance. Good, fast, cheap. Choose any two. Come let's eat grandpa! Use punctuation, save lives!
EtherealN Posted October 2, 2011 Posted October 2, 2011 Pretty artificial indeed since it assumes no maneuvering and blades that don't flex. Not that you'd probably need a perfectly orthogonal aspect since the flexing of blades will probably not be enough, but there's also the fact that if it moves you'll get discs tilting opposite ways in a coaxial, and in a conventional you instead have the tailrotor. Whether that would be enough... I dunno. I suspect even the people who would have the appropriate data for that haven't bothered checking. :P But yes, in theory, agreed. :) [sIGPIC][/sIGPIC] Daniel "EtherealN" Agorander | Даниэль "эфирныйн" Агорандер Intel i7 2600K @ 4.4GHz, ASUS Sabertooth P67, 8GB Corsair Vengeance @ 1600MHz, ASUS GTX 560Ti DirectCU II 1GB, Samsung 830series 512GB SSD, Corsair AX850w, two BENQ screens and TM HOTAS Warthog DCS: A-10C Warthog FAQ | DCS: P-51D FAQ | Remember to read the Forum Rules | | | Life of a Game Tester
Migow Posted October 3, 2011 Author Posted October 3, 2011 thx for answers :) member of 06 MHR / FENNEC Mi-24P
WildBillKelsoe Posted October 9, 2011 Posted October 9, 2011 hi ,the ka50 rotor is made of composite materials ,so the rotor should have low rcs , then it would be impossible to detect a NOE hovering ka50 at long medium distance?:music_whistling: Residual compressive strength?? RCS?? NOE??? sorry, elaborate more. I love those topics for real!:joystick::smartass: AWAITING ED NEW DAMAGE MODEL IMPLEMENTATION FOR WW2 BIRDS Fat T is above, thin T is below. Long T is faster, Short T is slower. Open triangle is AWACS, closed triangle is your own sensors. Double dash is friendly, Single dash is enemy. Circle is friendly. Strobe is jammer. Strobe to dash is under 35 km. HDD is 7 times range key. Radar to 160 km, IRST to 10 km. Stay low, but never slow.
ajax Posted October 9, 2011 Posted October 9, 2011 RCS = radar cross-section (a measure of radar "visibility") NOE = nap of the earth (type of flying -- close to the earth to lower probability of being detected)
Jaximus Decimus Posted October 9, 2011 Posted October 9, 2011 RCS = Radar Cross Section NOE = Nap of The Earth, 20 ft. AGL or above tallest terrain feature. That's a doctrinal thing, though. Edit: Missed it by THAT much...
WildBillKelsoe Posted October 9, 2011 Posted October 9, 2011 thanks to Ajax and Jaximus Ducimus AWAITING ED NEW DAMAGE MODEL IMPLEMENTATION FOR WW2 BIRDS Fat T is above, thin T is below. Long T is faster, Short T is slower. Open triangle is AWACS, closed triangle is your own sensors. Double dash is friendly, Single dash is enemy. Circle is friendly. Strobe is jammer. Strobe to dash is under 35 km. HDD is 7 times range key. Radar to 160 km, IRST to 10 km. Stay low, but never slow.
tusler Posted October 10, 2011 Posted October 10, 2011 While those guys are looking at the radar return of the blades, I wonder if the Vikhr would give them a good return aswell?:spam_laser: Ask Jesus for Forgiveness before you takeoff :pilotfly:! PC=Win 10 HP 64 bit, Gigabyte Z390, Intel I5-9600k, 32 gig ram, Nvidia 2060 Super 8gig video. TM HOTAS WARTHOG with Saitek Pedals
EtherealN Posted October 10, 2011 Posted October 10, 2011 (edited) While those guys are looking at the radar return of the blades, I wonder if the Vikhr would give them a good return aswell?:spam_laser: Most likely not. I wouldn't be surprised if a radar could technically detect it while close in, but suspect that if it can, this would be at settings where it would detect so much that the entire scope would just be a white sheet of returns. :P (If I remember right - and someone with better knowledge of radar systems would have to chime in - it's been stated that there is a lot of radars that would have no problem detecting F-22's and F-35's. Problem is, at those wavelengths they'd detect so many other things that the plane would just be drowned out in the noise; sort of like how they use doppler to filter out aircraft from ground returns in look-down operation. Before that trick they did get returns from the plane even in look-down, but it was like finding a specific black pixel on a black screen...) Not that the Vikhr is very dangerous for anything airborne that would have a radar to look for it with, though. Not like an F-15, Eurofighter etcetera has to get low and close to see the Ka-50 on the scope. :P Edited October 10, 2011 by EtherealN [sIGPIC][/sIGPIC] Daniel "EtherealN" Agorander | Даниэль "эфирныйн" Агорандер Intel i7 2600K @ 4.4GHz, ASUS Sabertooth P67, 8GB Corsair Vengeance @ 1600MHz, ASUS GTX 560Ti DirectCU II 1GB, Samsung 830series 512GB SSD, Corsair AX850w, two BENQ screens and TM HOTAS Warthog DCS: A-10C Warthog FAQ | DCS: P-51D FAQ | Remember to read the Forum Rules | | | Life of a Game Tester
adam12 Posted October 25, 2011 Posted October 25, 2011 While those guys are looking at the radar return of the blades, I wonder if the Vikhr would give them a good return aswell?:spam_laser: Made me lol :)
adam12 Posted October 25, 2011 Posted October 25, 2011 So an F-35 in a hover near the ground would be pretty damn hard to locate with any kind of radar... (?)
GGTharos Posted October 25, 2011 Posted October 25, 2011 An F-35 with high aspect would be hard to locate with any radar. Hovering has nothing to do with it. [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda
adam12 Posted October 25, 2011 Posted October 25, 2011 Sorry I should have said Harrier. The point being a stationary target with no (exposed) rotating parts.
Eddie Posted October 25, 2011 Posted October 25, 2011 Sorry I should have said Harrier. The point being a stationary target with no (exposed) rotating parts. Possibly, but as it can only hover for 90 seconds at most, and would need to be rather light to do it, it's not what I'd call a realistic option. Besides, depending on the aspect, that massive fan at the front of the Pegasus would give a rather significant radar return on its own.
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