Point defense calculation

[Erik L (OP)]

I'm not seeing it here (if it was ever posted), but what is the formula for calculating PD?

Max tech Fire Control has a maximum tracking speed of 80,000km/s. Max tech missile speed is c. What are the chances of using anything other than missiles at this level?

Max Tech Fire Control

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50% Accuracy at Range: 700,000 km     Tracking Speed: 80000 km/s
Size: 16    HTK: 1    Cost: 8400    Crew: 80
Chance of destruction by electronic damage: 10%
Materials Required: 2100x Duranium  6300x Uridium

Development Cost for Project: 84000RP

Max Tech Missile v1

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Missile Size: 16.5 MSP  (0.825 HS)     Warhead: 67    Armour: 0     Manoeuvre Rating: 10
Speed: 300000 km/s    Endurance: 10 minutes   Range: 189.0m km
Cost Per Missile: 99.8333
Chance to Hit: 1k km/s 3000%   3k km/s 1000%   5k km/s 600%   10k km/s 300%
Materials Required:    16.75x Tritanium   83.0833x Gallicite   Fuel x4375

Development Cost for Project: 9983RP

Max Tech Missile v2

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Missile Size: 16.5 MSP  (0.825 HS)     Warhead: 7    Armour: 0     Manoeuvre Rating: 10
Speed: 300000 km/s    Endurance: 22 minutes   Range: 405.0m km
Cost Per Missile: 84.8333
Chance to Hit: 1k km/s 3000%   3k km/s 1000%   5k km/s 600%   10k km/s 300%
Materials Required:    1.75x Tritanium   83.0833x Gallicite   Fuel x9375

Development Cost for Project: 8483RP
Max Tech missile control

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Active Sensor Strength: 900
Sensor Size: 5    Sensor HTK: 1
Primary Mode:   Resolution: 20    Maximum Range: 540,000,000 km
Chance of destruction by electronic damage: 10%
Cost: 2700    Crew: 25
Materials Required: 675x Duranium  2025x Uridium

Development Cost for Project: 27000RP

As you can see, the maximum size missile for c missiles is 16.5. The control suite probably could be shaved down a bit, so you don't have that extra 100m km of "empty" reach. Though I didn't take into multi-stage missiles.

Okay, I've come up with the following...
MIRV Body

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Missile Size: 24 MSP  (1.2 HS)     Warhead: 0    Armour: 0     Manoeuvre Rating: 10
Speed: 208300 km/s    Endurance: 24 minutes   Range: 300.0m km
Cost Per Missile: 132.5833
Chance to Hit: 1k km/s 2083%   3k km/s 690%   5k km/s 416.6%   10k km/s 208.3%
Materials Required:    5.25x Tritanium   127.3333x Gallicite   Fuel x10000

Development Cost for Project: 13258RP
Submunition (MIRV carries 3)

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Missile Size: 3 MSP  (0.15 HS)     Warhead: 7    Armour: 0     Manoeuvre Rating: 10
Speed: 300000 km/s    Endurance: 17 minutes   Range: 300.0m km
Cost Per Missile: 16.5
Chance to Hit: 1k km/s 3000%   3k km/s 1000%   5k km/s 600%   10k km/s 300%
Materials Required:    1.75x Tritanium   14.75x Gallicite   Fuel x1250

Development Cost for Project: 1650RP
This extends my punch out to 600m km. Yes, the first stage is the easier one to intercept, but what exactly would it take to knock down a flight of those? Max Tech GC have a range of 60,000 km, which is suicidally close in my opinion for these missiles. Max Tech laser (30cm, RoF 5sec) has a range of 2.88m km. Beam FC as we see above only has a range of 700,000 km, or 1/4 the range of my lasers. A PDC variant has a range of 1.05m km. Still around 33% of the range of my lasers.

Looking at other beam weapons...
Microwaves have a max range of 10.08m km.
Plasma carronade have a max range of 1.68m km.
Railguns have a max range of 1.8m km.
Meson have a max range of 10.08m km.
The torpedo has a max range of 1.2m km.
80cm Far Gamma laser has a max range of 20.16m km.

Okay... after that rambling post... the conclusion I've come to, is that there needs to be some sort of assisted targeting system for beams. Some tech line that opens up that allows a ship closer to the target to relay targeting information. I see that vessel as a stealthed scout, sneaking close. Though going active will undoubtedly shorten the lifespan of the ship greatly. Or the new sensor buoys being able to relay targeting information back.

Though missiles still have a HUGE range advantage over anything else.

[Charlie Beeler]

Perhaps something along the lines of a system that gains a cumulative bonus for tracking.

[Erik L (OP)]

Bonus to hit? or a bonus to range?

[Charlie Beeler]

To hit.  Though I was only thinking about PD fire control.  The idea being that the longer you actually track a missile, the better the chance to hit it.  

I have to agree that maximum control range should be equivilant to maximum weapons range.  At least for beam weapons which is what we're talking about.  Missile range being governed by endurance, speed, and on board guidance capability.

Don't I recall this discussion coming up before and Steve telling us that beam control was deliberately limited to a max of 1.4m km because of speed of light?  At least under current accepted partical physics that's probably true. (sorry my partical physics knowledge is severly lacking and may be way off base here).  Perhaps a "break through" with Tran-newtononian research allows for longer range fire control and ability to track and engage C and C+ missiles.

[Erik L (OP)]

I did wander a bit off-track in my original post... But I do think it's a valid point.

The 5-second refire laser (30cm, 25cap, far gamma) has a range of 2.88million km. so that's not anywhere near the speed of light. And if the firecontrol is limited to speed of light, that would give a max range of 1.5 million km in a 5 second burst. Hmmm. is that right? 300,000 x 5. That means max tech lasers are FTL.

Oh. And missiles are limited to 300,000 km/s speed.

[Charlie Beeler]

Oh. And missiles are limited to 300,000 km/s speed. :twisted:


Actually, that was what I was oblequely addressing with my first response.  With beam fire control limited to a max of 80k and missile being able to reach 300k point defense has a poor chance of intercepting incoming.  But, if there is some kind of cumulative bonus to hit based on extended tracking time that problem can be offset to a degree.

The way I'm thinking, the bonus should cap at the elimination of the negative effects of the difference between lower tracking speed and the speed of the incoming missile.  For that matter it doesn't need to be limited to PD.  

It might be a reason to willingly take a slower firing beam weapon, to give fire control time to build a better firing solution.

[Steve Walmsley]

I did wander a bit off-track in my original post... But I do think it's a valid point.

The 5-second refire laser (30cm, 25cap, far gamma) has a range of 2.88million km. so that's not anywhere near the speed of light. And if the firecontrol is limited to speed of light, that would give a max range of 1.5 million km in a 5 second burst. Hmmm. is that right? 300,000 x 5. That means max tech lasers are FTL.

Oh. And missiles are limited to 300,000 km/s speed.

Currently there are no beam fire control systems that work beyond 1.5m kilometers, which is how I have restricted beam weapons to the speed of light (5 secs x 300,000)

Steve

[Steve Walmsley]

Actually, that was what I was oblequely addressing with my first response.  With beam fire control limited to a max of 80k and missile being able to reach 300k point defense has a poor chance of intercepting incoming.  But, if there is some kind of cumulative bonus to hit based on extended tracking time that problem can be offset to a degree.

The way I'm thinking, the bonus should cap at the elimination of the negative effects of the difference between lower tracking speed and the speed of the incoming missile.  For that matter it doesn't need to be limited to PD.  

It might be a reason to willingly take a slower firing beam weapon, to give fire control time to build a better firing solution.

I really like the principle of increasing chance to hit based on tracking time. I will have to give it some thought though as it would have to affect ships as well that you have been tracking for a while.

I think the beam fire control speed ratings need to be increased anyway as they are still the same as they were before the improvements to missiles but if I can come up with a good way to implement your idea then I'll up them a little and use the tracking time modifier to improve them further.

Steve

[Charlie Beeler]

Even though I didn't mention it, I expected that anything that beam fire control targeted could or would benefit from this suggestion.  

It stands to reason though.  A snap shot is usually the least accurate.  Take time to aim and chances to hit improve.  

I've considering the idea for a while.  Main reason I've been hesitant, was that I figured that it might to invasive in an already complex algorithm.  

Just because it might be a good idea, doesn't discount that it has a high order probability to throw a spanner in the works.  

[Erik L (OP)]

Hmmm. Maybe a combat order to aim for x amount of seconds (divisible by 5). Each 5 second increment gives a +x amount to hit.

[Steve Walmsley]

Hmmm. Maybe a combat order to aim for x amount of seconds (divisible by 5). Each 5 second increment gives a +x amount to hit.

I have already added code that tracks how long you have continually had a contact on active sensors. Now i just need to decide how (or if) to make use of it.

At the moment I can't decide whether to make it linear or geometrical. Linear is easier but as you usually don't have much time to engage missiles, anything linear that made a difference to missile engagement is going to make a huge difference to the much longer time you will be tracking ships. With a geometrical approach, something along the lines of the square root of the number of seconds as a percentage would mean 3% for 10 seconds, 7% for 60 seconds, 11% for 120 seconds, 24% for 10 minutes, 60% for one hour, etc. Maxing at 100% at just under three hours. This wouldn't make a huge difference to point blank missile engagements but for long range missiles if you could track them on the way in, it would make a difference. It would be a bigger difference ship to ship though.

Although if this tracking bonus instead became a way to offset a tracking speed penalty, rather than an actual bonus, it would only affect situations where you are suffering a tracking penalty and therefore would generally be much more useful in terms of anti-missile than anti-ship. In that case, it could be done in a more linear way. Perhaps along the lines of Erik's suggestion using 5 second increments. Maybe 2% per 5 seconds. That means a 10% reduction in the tracking penalty for 25 seconds and a 24% reduction in penalty if you track them for a minute. How does that sound?

Steve

[Erik L (OP)]

Hmmm. Maybe a combat order to aim for x amount of seconds (divisible by 5). Each 5 second increment gives a +x amount to hit.

I have already added code that tracks how long you have continually had a contact on active sensors. Now i just need to decide how (or if) to make use of it.

At the moment I can't decide whether to make it linear or geometrical. Linear is easier but as you usually don't have much time to engage missiles, anything linear that made a difference to missile engagement is going to make a huge difference to the much longer time you will be tracking ships. With a geometrical approach, something along the lines of the square root of the number of seconds as a percentage would mean 3% for 10 seconds, 7% for 60 seconds, 11% for 120 seconds, 24% for 10 minutes, 60% for one hour, etc. Maxing at 100% at just under three hours. This wouldn't make a huge difference to point blank missile engagements but for long range missiles if you could track them on the way in, it would make a difference. It would be a bigger difference ship to ship though.

Although if this tracking bonus instead became a way to offset a tracking speed penalty, rather than an actual bonus, it would only affect situations where you are suffering a tracking penalty and therefore would generally be much more useful in terms of anti-missile than anti-ship. In that case, it could be done in a more linear way. Perhaps along the lines of Erik's suggestion using 5 second increments. Maybe 2% per 5 seconds. That means a 10% reduction in the tracking penalty for 25 seconds and a 24% reduction in penalty if you track them for a minute. How does that sound?

Steve

If you offset the tracking speed penalty (by this, I presume you mean the penalty the speed of the missile gives you?) maybe cap it at something based on the sensor rig. If you've got a low-tech sensor, no amount of time past a certain point is going to make it easier to hit. Though you might need a new tech line for this, maybe. Maybe a function of sensor strength. That way, higher tech sensors provide a better long term aiming bonus. Easiest I can see would be to limit the time bonus to the number of seconds equal to the sensor strength.

Weber always had his Manticorans tracking enemies on passives, or actives for long times and that giving them almost a 100% chance to hit. I'd not like to see that great of a bonus, but something to offset those c-missiles at max tech.

As for ships, if the best bonus you can hope for is to negate their speed penalties for you, and if that takes a long time where you are not firing, wouldn't that offset the bonus? Shoot now at a lower chance to hit, or hold fire until you have a better shot. Unless you are meaning firing will continue unabated, but as the combat progresses, the ship gets better at hitting the opponent. That I can see. That would be like tracer fire almost. I think both Charlie and I are thinking you'd not be firing while you are firming up your targeting.

There was another thought I had in here... but it disappeared. If it comes back, I'll add it.

[Steve Walmsley]

If you offset the tracking speed penalty (by this, I presume you mean the penalty the speed of the missile gives you?) maybe cap it at something based on the sensor rig. If you've got a low-tech sensor, no amount of time past a certain point is going to make it easier to hit. Though you might need a new tech line for this, maybe. Maybe a function of sensor strength. That way, higher tech sensors provide a better long term aiming bonus. Easiest I can see would be to limit the time bonus to the number of seconds equal to the sensor strength. Weber always had his Manticorans tracking enemies on passives, or actives for long times and that giving them almost a 100% chance to hit. I'd not like to see that great of a bonus, but something to offset those c-missiles at max tech.

Another good idea. The new tech line for fire control systems would be the maximum benefit you could get from tracking over time.

As for ships, if the best bonus you can hope for is to negate their speed penalties for you, and if that takes a long time where you are not firing, wouldn't that offset the bonus? Shoot now at a lower chance to hit, or hold fire until you have a better shot. Unless you are meaning firing will continue unabated, but as the combat progresses, the ship gets better at hitting the opponent. That I can see. That would be like tracer fire almost. I think both Charlie and I are thinking you'd not be firing while you are firming up your targeting.

I think tracking would firm up during the battle, just like in a big-gun naval battle where the accuracy improved as the battle progressed. Of course, EW effects might improve too but that is for another day

So the combination of ideas gives us an ability for fire control systems to offset a tracking-speed penalty if they can observe the target over time. The ability for the fire control to do that would be limited by a new tech line for fire control system. This will generally aid anti-missile combat more than anti-ship combat because it is much more likely that fire controls will suffer a tracking-speed penalty against missiles than against ships? Actual numbers yet to be determined but does that sum up the general idea?

Steve

[Erik L (OP)]

So the combination of ideas gives us an ability for fire control systems to offset a tracking-speed penalty if they can observe the target over time. The ability for the fire control to do that would be limited by a new tech line for fire control system. This will generally aid anti-missile combat more than anti-ship combat because it is much more likely that fire controls will suffer a tracking-speed penalty against missiles than against ships? Actual numbers yet to be determined but does that sum up the general idea?

Steve

I think that sums it up. Ships are not going to be nearing c in flight, so missiles will always have a advantage.

Off the cuff designs... 8100 ton cruiser with max tech has a speed of 15,432km/s. The installed FC has a tracking speed of 80,000 km/s while the main gun (80cm Far Gamma Laser) has a tracking speed of 20,000km/s. So right there, if our time bonus is just negating the speed advantage, our exisiting FC installations won't gain anything on a ship. On a missile, they will.

On the smaller end of the ship scale, a 1400 ton parasite clocks in at 35,714 km/s. The installed FC of the cruiser will still handle that, especially, if we gear our turrets that way.

On the smallest end, a 280 ton fighter hits 53,571km/s. Still within reach of our FC and turrets.

[Charlie Beeler]

Agreed as well.  Offsetting the speed penalty that usually associated with missiles was my primary concern.