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Mad_Shell

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Everything posted by Mad_Shell

  1. Even low level hovering or slow moving helicopters can be really hard to lock on for radars, despite the moving rotor. Here is an extract from a very recent publication (full publication: https://data.epo.org/publication-server/rest/v1.0/publication-dates/20170208/patents/EP2033011NWB1/document.pdf ) " A hovering helicopter’s body Doppler, however, has merged with clutter and only the return of its rotor assembly extends outside of clutter (due to the rotation of the rotor assembly). Even if the helicopter were moving, different flight geometries could put the helicopter’s body Doppler within the clutter region. If a seeker tries to estimate the range and range-rate of the rotor return, it will find conflicting range-rate measurements since the rotor return constantly changes with time and scintillates (both in amplitude and angle). Thus, the seeker will disregard a majority of the helicopter’s rotor return, and the rotor return samples will not be used to classify the potential target as a helicopter. [0009] There remains a need for a robust technique for detecting and classifying hovering and slow-moving helicopters that is compatible with the existing base of Doppler radars "
  2. Here is the track. But with the whole replay system being bugged, the problems I described never happened a single time when I watched it... bug_Gliding_A20G.trk
  3. While the missile is still burning, its speed suddenly becomes almost constant. I observed that on SA-2, SA-6, SA-10, SA-11 (perhaps more, didn't test them all). A few videos below(too big to drop here, check missiles speeds at the bottom) https://imgur.com/a/vHPZtCJ
  4. if several aircrafts are incoming, SA-2 and SA-3 (and perhaps more, didn't test them all) won't fire at all. It seems they constantly switch target... bug_SA-2.trk bug_SA-2_bis.trk bug_SA-3.trk
  5. From what I've found, the SARH missile requires the ground radar to emit continuous waves to be guided. The RWR will easily interpret those waves as a missile launch and guidance. For TVM the ground radar doesn't need to change its emissions and can remain in search and track mode while guiding the missile, and the RWR will just indicate that you're tracked, nothing more. Anyway I don't want to pollute this thread with this discussion for too long.
  6. Oh I just checked and you're right! I guess ED has to correct the in-game encyclopedia then, it's written that 5V55 missiles do have TVM guidance, while they don't
  7. Yes there are a number of problems with SAMs in general, not just SA-2. The guidance modes are not accurate: IRL SAMs switch between several guidance methods (two points method, three point method, proportionnal navigation, etc...) depending on the terrain, target altitude, speed and maneuvring. For example if a target flying at medium altitude plunge toward the ground to try to defeat the SAM, the method guidance can switch from pure leading to 3 points method so the missile won't crash into the ground. Or if a target begins to make high g evasive maneuvers the guidance will switch from leading to 2 or 3 points methods, so the missile doesn't lose all it's energy too fast. In DCS SAMs always seem to lead targets, which produces some ridiculous situations (https://www.reddit.com/r/hoggit/comments/iuqn1a/how_to_defeat_sams_in_dcs/) Some missiles speeds seem to be incorrect or have strange behaviours: SA-10 max speed: IRL mach 5.5 ; DCS mach 4 SA-6 max speed: IRL mach 2.8 ; DCS mach 1.7 SA-11, SA-6, Tor, perhaps more: missile speed suddenly becomes constant while rocket is still burning (check missile speed in the below video https://cdn.discordapp.com/attachments/543358251694292992/805117090621030430/Digital_Combat_Simulator_Black_Shark_2021.01.30_-_17.13.01.02_Trim.mp4 IRL SA-10 has track-via-missile which allows to not give RWR warning, which isn't modelled in DCS Not related to guidance, but as shrapnel is not modelled, kill distances in DCS are smaller than IRL (kill distance was around 60m for SA-2)
  8. I was looking a bit at some lua files in the game folders, and I perhaps found some questionable stuff in the Eagle Dynamics\DCS World OpenBeta\Scripts\Database\Weapons\warheads.lua For most warheads, expl_mass is equal to the quantity of explosive in the warhead, and not to the total mass of the warhead: warheads["C_5"] = -- S-5KO shaped-charge, fragmented { mass = 1.08, expl_mass = 0.37, -- Warhead 1.08 kg, explosive 0.37 kg + fragments bonus other_factors = { 1.0, 0.5, 0.5 }, concrete_factors = { 1.0, 0.5, 0.1 }, concrete_obj_factor = 0.0, obj_factors = { 1.0, 1.0 }, cumulative_factor= 3.0, cumulative_thickness = 0.1 }; warheads["C_8"] = -- S-8ÊÎÌ shaped-charge, fragmented { mass = 3.0, expl_mass = 0.855, -- Warhead 3 kg, explosive 0.855 kg + fragments bonus other_factors = { 0.5, 0.5, 0.5 }, concrete_factors = { 0.5, 0.5, 0.1 }, concrete_obj_factor = 0.0, obj_factors = { 0.5, 1.0 }, cumulative_factor= 5.0, cumulative_thickness = 0.3 }; warheads["C_8OFP2"] = -- S-8OFP HE { mass = 9.2, expl_mass = 2.7, -- Warhead 9,2 kg, explosive 2.7 kg + fragments bonus other_factors = { 0.5, 1.0, 1.0 }, concrete_factors = { 0.5, 1.0, 0.1 }, concrete_obj_factor = 0.3, obj_factors = { 0.5, 1.0 }, cumulative_factor= 0.0, cumulative_thickness = 0.0 }; but for some other warheads, the expl_mass is equal to the total mass of the warhead example: warheads["C_24"] = -- S-24 HE Warhead 123 kg, explosive 23.5 kg + fragments bonus { mass = 123.0, expl_mass = 123.0, -- Warhead 123 kg, explosive 23.5 kg + fragments bonus other_factors = { 1.0, 1.0, 1.0 }, concrete_factors = { 1.0, 1.0, 0.1 }, concrete_obj_factor = 1.0, obj_factors = { 0.2, 1.0 }, cumulative_factor= 0.0, cumulative_thickness = 0.0 };
  9. You should read again what is written on Stormbirds It is said that the new module was initially meant to be showcased in the 2020 (and not 2021) trailer, but it was pushed back. The awaited module will be teased in the 2021 trailer, absolutely no doubt about that (confirmed again and again by Nineline, Bignewy and GlowingAmraam)
  10. I agree, that's why I said "very possible". But the results seem pretty consistent, the S-300 fired at several targets at different ranges and altitudes, and in the best cases there was still a ~1500 kts gap compared to IRL according to the sources I found. And no way exterior parameters such as temperature, wind, humidity etc can affect speed that much.
  11. SAMs are currently plagued with a lot of issues affecting their performances, especially linked to flawed guidance systems. Missiles guidance systems: Several trajectories are possible to intercept a flying target, and mathematical methods have been developped to find the most efficient ones. IRL, SAMs use methods such as: - (advanced) proportionnal approach - half-straightening approach - three points method - modified versions of some of the above methods also exist for low altitude targets to avoid the SAM to run into the ground. The discussion of those methods is way beyond the scope of this post, but basically missiles will use the most suitable method during their flight to be the most efficient (intercept the target with the most energy possible). Sometime a missile will switch method mid fligth, or even use at the same time a method in the horizontal plane, and another method in the vertical plane! And it allows to avoid having this happening IRL... I don't know exactly what guidance is used in DCS, but it looks like SAMs always try to lead targets, even when they are high G maneuvering at long distance. SAMs bleed all their energy way faster than they would do IRL, because IRL a SAM would not try to lead the target that much for most of the flight. I know implementing exactly the specific methods used by specific SAMs would be a daunting task, and that's not what I ask. Simply some more efficient guidance against high G maneuvering targets would already go a long way in making SAMs not behave in a ridiculous way. It is very possible that some missiles speeds are incorrect too. After some testing the 5V55R missile of the S-300 P SAM system reaches a maximum TAS of around 2500 kts (~ mach 4) in DCS, while several sources indicates a maximum TAS of more than 4000 kts(~ mach 6) IRL. As a result the maximum engagement range also seems slightly lower in DCS compared to IRL (~40 nm vs >50 nm).
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