#3185419 - 01/21/11 10:51 PM
Re: S-75M3 Volhov qualification day
[Re: Hpasp]
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Joined: Jan 2011
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PLCC
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That's a fair approach, I suppose. Were there any charts/data relating to miss distance? That would be the primary purpose of modeling the autopilot. A first-order approximation for the overall missile time constant would probably work almost as well, however. On the subject of the missile itself, I have been slowly reading the five associated books. Unfortunately, the Russian set, despite quite a few symbolic equations, contains few numbers or graphs. While reviewing your SA-3 simulator documentation, I found a listed value of 6 Gs as the missile acceleration limit. A brochure I looked at earlier (but remembered only now) has 18 Gs as that quantity. Granted, it's only penciled in (because it is not listed anywhere else, no doubt), but similar marks made in other documents tended to be reasonable. Various missile guidance literature that I've read has always promoted the rule of thumb that missiles must be able to accelerate at a rate at least three times that of a maneuvering target, to successfully prosecute it. Therefore, I am inclined to believe that 18 Gs is correct. Your thoughts? Contrary to the missile publications, the UNK documentation, with complete numerical data provided with most equations, is excellent. I'm really enjoying the volume on guidance algorithms right now. It raises another question, however. Your simulator documentation states that the guidance methods are "three-point" and "lead." My documentation also uses the term "lead," but upon inspection of the equations, it does not appear to be full lead. In fact, it is claimed that the lead angles are limited to 3 degrees , making me wonder if it was worth bothering with the method at all. In the simulator, I wonder, is full lead used? I have not yet fully understood the equations below, so if my assessment is completely incorrect, I accept any due ridicule. Finally, on the console in the simulator the two switch settings are "TT" and "PS," the latter obviously referring to half-lead, as used in the S-75.
Last edited by PLCC; 01/21/11 10:53 PM.
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#3185487 - 01/22/11 12:19 AM
Re: S-75M3 Volhov qualification day
[Re: PLCC]
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NaiseFail
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Finally, on the console in the simulator the two switch settings are "TT" and "PS," the latter obviously referring to half-lead, as used in the S-75.
Wot? I think you mean K, T/T and K.
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#3185675 - 01/22/11 08:11 AM
Re: S-75M3 Volhov qualification day
[Re: PLCC]
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Hpasp
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My documentation also uses the term "lead," but upon inspection of the equations, it does not appear to be full lead. In fact, it is claimed that the lead angles are limited to 3 degrees hahaha, making me wonder if it was worth bothering with the method at all. In the simulator, I wonder, is full lead used?
Full lead cannot be used for several reasons.
At the "75" system, Half lead were utilized, with 4 degrees of limitation. At the "125" system, it is more than half, due to the lower missile speed compared to the target.
Why are you laughing on 3 degrees? It is measured from the UNK, so at 15km target distance, it is 785m.
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#3186201 - 01/23/11 12:43 AM
Re: S-75M3 Volhov qualification day
[Re: Hpasp]
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Joined: Jan 2011
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PLCC
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While reviewing your SA-3 simulator documentation, I found a listed value of 6 Gs as the missile acceleration limit. A brochure I looked at earlier (but remembered only now) has 18 Gs as that quantity.
Do not mix lateral and longitudinal acceleration. Longitudinal 18g is achieved during the launch only. Lateral is 6g. Sorry for the confusion, I was referring to lateral acceleration. It is shocking that it would be that low. The brochure claims, for the S-125M/V-601P combination, the possibility of engaging targets maneuvering up to "4-6" Gs. In my opinion, it would be virtually impossible to hit such a target with a 6 G missile due to the associated lags in the control loop. Additionally, the Russian term in the brochure used to claim 18 Gs is "peregruzka" ("overload"). In the context of missiles, in my experience, this term is used to refer only to lateral acceleration. My documentation also uses the term "lead," but upon inspection of the equations, it does not appear to be full lead. In fact, it is claimed that the lead angles are limited to 3 degrees hahaha, making me wonder if it was worth bothering with the method at all. In the simulator, I wonder, is full lead used?
Full lead cannot be used for several reasons.
At the "75" system, Half lead were utilized, with 4 degrees of limitation. At the "125" system, it is more than half, due to the lower missile speed compared to the target.
Why are you laughing on 3 degrees? It is measured from the UNK, so at 15km target distance, it is 785m. I laughed because 3 degrees for a 700 m/s target wouldn't amount to much of an improvement over no lead at all.
Last edited by PLCC; 01/23/11 12:43 AM.
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#3186246 - 01/23/11 01:32 AM
Re: S-75M3 Volhov qualification day
[Re: PLCC]
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Joined: Oct 1999
Posts: 129
Wolfhound
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Sorry for the confusion, I was referring to lateral acceleration. It is shocking that it would be that low. The brochure claims, for the S-125M/V-601P combination, the possibility of engaging targets maneuvering up to "4-6" Gs. In my opinion, it would be virtually impossible to hit such a target with a 6 G missile due to the associated lags in the control loop.
Additionally, the Russian term in the brochure used to claim 18 Gs is "peregruzka" ("overload"). In the context of missiles, in my experience, this term is used to refer only to lateral acceleration.
I laughed because 3 degrees for a 700 m/s target wouldn't amount to much of an improvement over no lead at all.
PLCC, I'm also surprised that the maximum lateral acceleration for the SA-3 is only 6G. The U.S. Nike Hercules SAM (albeit designed as a long ranged medium to high altitude missile) entered service initially capable of 7G lateral acceleration, this was later increased to 10G. The Nike is much larger than the SA-3 and uses intercept guidance. Reading comments from Vietnam era pilots, I can't understand why a specific set of techniques were required to evade the SA-2 & 3 missiles. With such a lack of agility I would have imagined that a low G reversal of direction (immelmann perpendicular to the missile) would be sufficient to evade it. I have also heard similar to you that a missile requires about 3 times the lateral acceleration performance of the target to be effect and there are also other factors to consider I think, such as the guidance/navigation method used. With 3 point/pure pursuit guidance, the missile at end game may require 5 times the G of the target. Having said all this Hpasp does seem to know his stuff, as well as have access to the necessary technical documents.
*********I have quite a large collection of Flight, Weapon Systems, Tactical & Supplementary Aircraft Manuals for Jets, Helicopters & some Props, spanning the Vietnam era to present. If you're interested in trading Flight Manuals, mainly for modern military aircraft, send me a PM.*********
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#3186266 - 01/23/11 02:05 AM
Re: S-75M3 Volhov qualification day
[Re: PLCC]
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Joined: Oct 1999
Posts: 129
Wolfhound
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Sorry for the confusion, I was referring to lateral acceleration. It is shocking that it would be that low. The brochure claims, for the S-125M/V-601P combination, the possibility of engaging targets maneuvering up to "4-6" Gs. In my opinion, it would be virtually impossible to hit such a target with a 6 G missile due to the associated lags in the control loop.
It would be interesting to read detailed reports of the engagements by these missiles and how many of the targets took evasive action. There is or use to be a saying that "it's the missile you don't see thats going to kill you". If you spot a launch or chasing missile early enough, you could avoid it (However this may not be the case with current generation of missiles). I have a feeling that perhaps many of the tactical aircraft that were shot down by these missiles were surprised/ambushed. There is a case of 3 or 4 tactical aircraft (A-4 Skyhawk's), being shot down by a single SA-2. My understanding is that they were in close formation at detonation and received little to no warning.
*********I have quite a large collection of Flight, Weapon Systems, Tactical & Supplementary Aircraft Manuals for Jets, Helicopters & some Props, spanning the Vietnam era to present. If you're interested in trading Flight Manuals, mainly for modern military aircraft, send me a PM.*********
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#3186588 - 01/23/11 03:05 PM
Re: S-75M3 Volhov qualification day
[Re: NaiseFail]
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Hpasp
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SAMSIM Status update. The S-200VE Vega-E (SA-5B Gammon) simulator is ready. Testing is ongoing. Current task is to write, and translate the 50+ pages of documentation.
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#3186603 - 01/23/11 03:26 PM
Re: S-75M3 Volhov qualification day
[Re: Hpasp]
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Posts: 210
NaiseFail
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SAMSIM Status update. The S-200VE Vega-E (SA-5B Gammon) simulator is ready. Testing is ongoing. Current task is to write, and translate the 50+ pages of documentation. That's great, I've been really looking forward to the SA-5!
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#3186713 - 01/23/11 06:06 PM
Re: S-75M3 Volhov qualification day
[Re: NaiseFail]
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Hpasp
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Documentation so far...
CONTENTS 2 PREFACE 4 REQUIREMENT TO RUN THIS PROGRAM 4 KEYBOARD REFERENCES FOR THE PROGRAM: 5 ENGAGEMENT ZONE 6 S-200VE VEGA-E (SA-5B GANEF) SITE LAYOUT 7 S-50 DAL, WITH THE 5V11 V400 MISSILE (SA-5 GRIFFON) 8 SWITCHING THE SIMULATOR ON 9 SWITCHING THE SIMULATOR OFF 10 METHODS OF TARGET ACQUISITION 10 SENEZH-ME, INTEGRATED AIR DEFENSE SYSTEM (IADS) 11 P-14F OBRONA (TALL KING-B) TARGET ACQUISITION RADAR 12 PARAMETRIC COORDINATE SYSTEM 13 5N62VE RPC (SQUARE PAIR) TARGET ILLUMINATOR RADAR 13 5N62VE RPC (SQUARE PAIR) MODE OF OPERATIONS 14 ШИР. (wide) or УЗК. (narrow) pencil beam 14 МХИ (MHI) Mono-Chromatic Emission 15 ФКМ (FKM) Phase-Code Manipulation 16 ЧМ (FM) Frequency Modulation 16 АС-РПЦ (AS-RPC) 17 Plamja-KV CVM (digital computer) 17 ROTATING THE 5N62VE RPC (SQUARE PAIR) TARGET ILLUMINATOR RADAR 18 Rotate the 5N62VE RPC (Square Pair) target illuminator radar in azimuth and elevation 18 Set the 5N62VE RPC (Square Pair) target illuminator radar bore sight in speed and range 19 TARGET ACQUISITION USING SENEZH-ME, IADS 20 TARGET ACQUISITION USING THE P-14F ACQUISITION RADAR 22 UNDERSTANDING THE DV INDICATOR IN MHI MODE 23 CIRCULAR TARGET SEARCH 24 SECTOR TARGET SEARCH 25 DETERMINING THE TARGET RANGE IN FKM MODE WITH “VERNIER” METHOD 26 FACTORS THAT WOULD LIMIT THE EFFECTIVE TARGET ACQUISITION RANGE 29 RADAR CROSS SECTION OF THE TARGET 29 TANGENTIAL VELOCITY OF THE TARGET 30 EARTH CURVATURE EFFECT 31 NCTR (NON COOPERATIVE TARGET RECOGNITION) 32 5V21 V-860P (SA-5A GAMMON) SURFACE TO AIR MISSILE 33 5V21N V870 (SA-5A GAMMON) SURFACE TO AIR MISSILE 34 5V21V V860PV (SA-5B GAMMON) SURFACE TO AIR MISSILE 34 5V28 V880 (SA-5B GAMMON) SURFACE TO AIR MISSILE 35 5V28N V880N (SA-5B GAMMON) SURFACE TO AIR MISSILE 35 5V28E V880E (SA-5B GAMMON) SURFACE TO AIR MISSILE 36 5V28M V880M (SA-5C GAMMON) SURFACE TO AIR MISSILE 37 5V28 V880 GLL CHOLOD HYPERSONIC TEST BED 37 5G24E GSN CONTINUOUS WAVE SEMI-ACTIVE SEEKER 38 5E23A SRP ONBOARD DIGITAL FLIGHT COMPUTER 39 5P72VE PU LAUNCHER 40 5YU24ME ZM RAIL LOADER 41 5T82M1E TZM MISSILE TRANSPORTER-LOADER 42
Last edited by Hpasp; 01/23/11 06:08 PM.
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#3187074 - 01/24/11 01:39 AM
Re: S-75M3 Volhov qualification day
[Re: Hpasp]
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Joined: Mar 2007
Posts: 210
NaiseFail
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I'm bit afraid, that a 40 step target acquisition process will take its toll between the most hard core fans too... ... not to mention this, when the US NAVY is inbound from the Gulf of Sidra loaded with HARM missiles. 40 steps sounds a bit excessive, but if that's what it takes to operate it then I'm fine with it. Personally, I hate it when things are dumbed down. Even if it means I have to struggle with the system under pressure, I like realistic things. Also, I have a button fetish. :3
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Exodus
by RedOneAlpha. 04/18/24 05:46 PM
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