BillNyeTheIE

Principia makes big changes to how the physics works, chances are that when you pick up the craft the vessel manager is having to fight Principia because both of them are trying to change where the vehicle is. Generally having multiple mods which change the physics of how craft move active at the same time can cause issues due to all of them trying to do something to the craft simultaneously IDK the actual compatibility of the vessel mover with PersistentThrust or wind mods (I suspect the latter may be more of an issue than the former) but if you do encounter this type of issue they're the first suspects if nothing shoes up on the log. They're all working properly, just that the combined result isn't what you want.

I mean the actual deviation in position designated by the laser, we're looking at the visual issue. It's not an issue with 1.6.x in general but rather 1.6.9.0 as far as I'm aware.

They are meant to be usable by the player, there's just a bug right now that's preventing that. In the next update you should be able to fire them at a radar, IRST or a GPS target. If you want to use the Phoenix for now you can just swap "targetingType = inertial" to "targetingType = radar" for now. The jitter issue is being looked at, right now the deviations seem to be on the order of ~0.1 m at 20 km so it should still be usable for targeting but you do need to be flying steadily. Regarding inertial guidance, like SI said there's a bug in the code that he fixed, they'll work in the next update. Like I said to Rakete you should be able to just swap the Phoenix from "targetingType = inertial" to "targetingType = radar" and the Swordfish from "targetingType = inertial" to "targetingType = heat" and they'll work for now, then swap them back to inertial after the next update goes live. The guidance laws for both the Phoenix and the Swordfish work just fine, it's just that they aren't being sent the targeting information they need.

I haven't played around with inertial guidance yet but I designed the guidance law for that missile and that sounds like an uncommon bug I've encountered with it, could you post the KSP.log file the next time you encounter this issue? Best I can tell is when the stars align in the wrong way, it (or something else) throws a weird bug in Unity which causes the guidance to fail. Have you tried launching the missile after reloading the game at any point? Is it consistently doing that?

Not sure what you mean, are you using the latest BDArmory release? If you mean Modular Missiles, they're behind the regular missiles in terms of features because they're slightly different in terms of code and need code specifically written for them. I explained it in this post

For the first question, I'll refer you to this series which I've posted previously: Long story short though, yes and no, "pronavGain" being set higher results in a more predictive missile, ensuring it's on an intercept course as fast as it can. This is advantageous in that for a predictable target, the energy cost to the missile is reduced, however, for an unpredictable maneuvering target this can be worse as the missile makes very early large adjustments which bleeds off velocity, resulting in an inability to achieve catch. There are no analogous integral and derivative terms for pronav, however there is "aeroSteerDamping" which is a derivative term for the missile, I.E. P = steerMult, D = aeroSteerDamping. In my experience I don't usually need to use it however, good selection of steerMult and maxTorque is typically sufficient. For the second question, as per the documentation on the wiki, there is the "terminalHomingType" field which allows you to select the type of guidance you want as terminal behavior. This defaults to pronav when not specified as aam wasn't achieving very good PK with aamloft. We also do have "hybrid" homing types, which also make use of "terminalHomingType" and allows you to have a boost/cruise phase guidance law and a terminal guidance law. For the third question, it's in the part right click menu, if the missile has "homingType = aamloft" the sliders should show up, with Advanced Tweakables on like you have it you should be able see all of the trajectory parameters. Yeah, apologies for that but currently modular missiles don't have support for some of the new features yet.

1) It's just used by the AI, EXCEPT for RCS missiles 2) It's a speed used in guidance calculations, it should be set to around the cruise speed of the missile, doesn't really have to be that exact. 3) steerMult affects how hard a missile steers, it's analogous to the P in a PID controller. 4) You could, but it'd be kind of difficult to do, you'd need a combination of steerMult, maxAoA and maxTorque to get anything that approaches a max G overload. 5) Missiles start with a 0 torque limit immediately after launch and ramp up to maxTorque at a rate of torqueRampUp torque/s. 6) Yes, just set uncagedLock = false, the missile is limited to 0.35 * maxOffBoresight while on the rail, once off the rail it can use the full maxOffBoresight. There is no current way to specify the on-rail maxOffBoresight independently. 7) uncagedLock = true increases that 0.35 * maxOffBoresight to 0.75 * maxOffBoresight and allows for cueing the missile on targets that are outside of the seeker's FOV prior to launch. 8) Not as of yet, I do plan on eventually working on radar notching being a thing and beaming making chaff more effective but it's not currently a feature of the mod. 9) Apart from loading the game up and firing them? Not really, it's why I allow for in-game adjustments of loft guidance parameters since that can take a while to tune. BDA weapons are generally made with stock aerodynamics and stock engagement ranges in mind, they're also made with gameplay rather than realism as the focus. The main thing that makes the missiles in particular unrealistic is the lack of fuel burn (which is a feature of the mod now) and the ridiculously powerful motors. Also, all the missiles use "aam" guidance rather than "pronav" which leads to it being a lot easier to defeat them, swaping them over to "pronav" and fixing the tuning on them (they'll generally need lower maxTorques and steerMults) will go a long way to improving their "realism".

1. Yes, but I'm not sure I can answer the question properly if you don't give me more of an explanation or an example of what you mean by "does not track". If you mean it doesn't lock when before you launch it, by default if uncagedLock = false, so if you're launching against an air target and the launch vehicle is in the air the max launch angle is 0.35 * maxOffBoresight. If it's true, or the vehicle or the target are landed/splashed then it's 0.75 * maxOffBoresight. If you're still not getting lock, are you close enough? Is the target facing you or flying away from you? If you've got lock and it's not tracking the target after launch, does the target have flares etc.? Flares are fairly effective right now against IR missiles, and the AI uses them pretty effectively. 2. Yes. 3. AAM is lead guidance, I.E. the missile calculates a lead based off of the current position of the target and its velocity and tries to point in that direction. It generally can hit targets, especially with the stock BDA missile configuration files and it's fairly insensitive to tuning, but it's also prone to undershooting and isn't that good against targets that are flying more perpendicular to the missile. ProNav and AugProNav, or proportional navigation and augmented proportional navigation are two commonly used guidance laws for missiles. They're pretty good, however they are much more sensitive to good tuning, I.E. having too high maxTorque, steerMult and/or pronavGain values can result in the missile doing a "twitching" motion as it over-corrects, then tries to correct for the over-correction etc. The explanation for how they work can get quite lengthy, I'd recommend this playlist on YouTube for a more thorough explanation: