investigating Non-engaging missile batteries and odd tracking radar angles.

[Tippis]

I've been sifting through various database files to gather stats for our group's wiki on different air defence systems, and I've come across a couple of oddities with the SC Nimitzes.

 

It looks like the the MK95 tracker definitions are facing the wrong way (the angle definitions have the wrong start- and endpoint, or the arc is being calculated in the wrong direction between correct start and end values) or simply aren't hooked up right. Either way, this leaves pretty much all the CVN-7X:s (except the Stennis, of course, since it is using the base-game definitions) have a huge gap in roughly the front 45° arc of defences. Most notably, the forward RIM-7 battery pretty much refuses to fire on an aircraft well within its line of fire, from the 12 o'clock to the 3 o'clock position unless some other on-board system reacts to an incoming threat first.

 

Depending on the range and angle, either of the RIM-116s will detect and fire on a hostile aircraft within their fields of fire, at which point the front-right RIM-7 will wake up and start firing too, but on its own, the forward RIM-7 battery will not engage anything in the forward arc.

 

According to the LUA files, the front-right battery should have a almost completely unobstructed view from 11 to 6 o'clock (in the CVN-71, it's defined as {math.rad(10), math.rad(-170), math.rad(-5), math.rad(80)}, so anything between 10° left to 170° right, between 5° depression to 80° elevation should be a potential target). However, putting an aircraft at, say, 30 right, 10° up, and the battery sits silent. Move it to just over 40°, and the battery will fire, but if you look at the model, what happens is that the rear right RIM-1116 starts firing first, and then the RIM-7 follows. So it is as if the rear battery detects the aircraft and provides the forward battery with something to aim at, rather than the ship's radar systems doing anything useful as far as providing tracking information. Something similar happens if you put an aircraft far enough left to be detected by the left-side RIM-116, or high enough to be within the firing arc of the rear RIM-7. Again, a different battery fires and then the forward battery wakes up and starts doing something.

 

To replicate:

• Place any of the SC Nimitzes, with a fixed direction or heading along the grid.
• Place an aircraft 10km away, dead ahead or no more than 40° right (use the grid to line up 10km positions), 1740m MSL (for a 10° angle at 10km)
• Start the mission and immediately active-pause to keep your position.
• Wait until you run out of fuel or something, the carrier won't fire.

To offer a counter-example

• Move the aircraft to 10km off the starboard.
• Start the mission, immediately active-pause, and press F9 to watch the carrier.
• Watch the RIM-116 fire (futilely), and then see the RIM-7 fire.
• Don't actually explode (because the RIM-116 runs out of energy and the RIM-7 gets confused by your active-paused non-movement)

To exemplify expected behaviour:

• Replace the carrier with a Stennis (or place one in a similar relative position so you can test both at once).
• Start the mission again, and active-pause again.
• Almost explode because the Stennis actually fires, and pretty much immediately.

 

As a slight addendum, in addition to this oddity, I noticed a few other... strange values in the LUA when I was poking around, such as the CVN-72 and -74 having rotational limits set up for the offending front-right battery that would let it fire straight through the deck: its left-angle limit is 40° rather than just the 10° that would let it clear the front of the ramp. Overall, it seems the sensor definitions and the front-right battery definition on all four carriers need to be checked.

nimitz-radar.trk

[NineLine]

SO are you reporting that you are not fired on appropriately when in active pause? A number of things do not respond well to active pause, and shouldnt be used to test in this manner, I'm sorry if I misunderstood.

Thanks

[Tippis]

Active pause is not a factor. Hence the counter-examples.

 

It will fire just fine if you move your plane outside the affected arc (still in active pause) or if you change to a different ship that has the same tracker and missile setup.

 

 So no, I'm reporting that you are not fired on appropriately when in roughly the front 45° arc of defence, as described. I am also reporting that the Lua numbers look very strange, which might be a clue as to what has gone wrong.