Point defense calculation

[Erik L (OP)]

Hm, I´m not realy buying into the "longer tracking gives a better fire solution" thing entirely.

I started out thinking about such a bonus against fighters and then thought, "Now wait a sec, those fighters will jinx and zig-zag around all the time, throwing your carefully calculated fireing solution off".

The next thought was: "If those fighters can jinx, I sure should be able to program my missiles to do the same, perhaps reducing their range slightly."

So I am now of the opinion, while you will be able to point your ship roughly into the direction of the incoming salvo, this won´t help you a whole lot, if your weapons(mount) is not able to cope with the rather erratic manouvers, the missiles or fighters will make on the run in.

That is a good point. I am also concerned about fire controls getting too much of an advantage against ships and fighters through a tracking time bonus, especially when that element of combat works well at the moment. How about restricting the tracking time bonus just to missiles on the basis that they will generally follow a more predictable path than manned ships or fighters, relying on speed to get them to the target. Observing a ship or fighter over time won't help a great deal in terms of what it might do next but tracking a missile over time will give tracking computers a better idea of when to fire. The thread was begun because of a concern over maximum missile speeds so this would address the primary concern while avoiding any issues with the anti-ship and anti-fighter combat model

Steve

That works for me. You've already got EM (Erratic Maneuvers) simulated on missiles with agility I think.

Or not. Agility only affects the to-hit of the missile. Maybe (and this is going back to making missiles harder to hit) also have Agility affect the missile's being hit. Higher agility missiles jink around more.

[Steve Walmsley]

That is a good point. I am also concerned about fire controls getting too much of an advantage against ships and fighters through a tracking time bonus, especially when that element of combat works well at the moment. How about restricting the tracking time bonus just to missiles on the basis that they will generally follow a more predictable path than manned ships or fighters, relying on speed to get them to the target. Observing a ship or fighter over time won't help a great deal in terms of what it might do next but tracking a missile over time will give tracking computers a better idea of when to fire. The thread was begun because of a concern over maximum missile speeds so this would address the primary concern while avoiding any issues with the anti-ship and anti-fighter combat model

That works for me. You've already got EM (Erratic Maneuvers) simulated on missiles with agility I think.

Or not. Agility only affects the to-hit of the missile. Maybe (and this is going back to making missiles harder to hit) also have Agility affect the missile's being hit. Higher agility missiles jink around more.

High agility missiles aren't harder to hit, they are just better at hitting fast moving targets. Or to use a real world analogy, a short-range air to air missile can make radical turns to chase its target but for most of the way to that target it follows a straight-line path. I could add some code to create jinking missiles but in most (maybe all) cases, higher speed would be preferable as it also makes a missile harder to hit and gets it to the target faster, allowing less time for defensive fire. It could be a lot of work for something that would be hardly ever used and it would complicate the math when the player is trying to visualize to hit chances.

Steve

[jfelten]

Barring FTL sensors, something moving at c (or near c since a physical object couldn't move at c unless using different physics) could not be tracked/targeted.  The best you could do is throw things in its way if you thought it was coming and knew the general direction.  Even a grain of sand would do tremendous damage if hit by something moving c (e=mcc and all that, and c is really big).  Then there is also the time dilation problem for the missile's electronics.  

I'm not sure I follow the tracking speed logic.  If something is moving directly towards you, there is no apparent movement to track.  If it was turning or jinking so as to not come straight in, there would be apparent movement to track, but for something moving near c, the amount of energy need to alter its course would be immense.  Given the angle of approach you can calculate the apparent movement.  

I also don't follow why 5 seconds has anything to do with beam weapons range.  A laser fired will be moving through space at c the same as a missile moving at c.  Its range is infinite.  The question is how much it will spread out and loose energy density over distance.  A rail/gauss gun projectile in space would have infinite range and would not loose hitting power over distance.  Their only disadvantage vs a missile is they are unguided so can't home in on a target.  They would not have less range.

[Father Tim]

Barring FTL sensors, something moving at c (or near c since a physical object couldn't move at c unless using different physics) could not be tracked/targeted.  The best you could do is throw things in its way if you thought it was coming and knew the general direction.  Even a grain of sand would do tremendous damage if hit by something moving c (e=mcc and all that, and c is really big).  Then there is also the time dilation problem for the missile's electronics.

The miracle of modern Trans-Newtonian Elements (aka Aurora science) ignores relativistic physics, thus ships and missiles can be tracked.  Steve tries to keep things belowthe speed of light, but it is possible to tweak a superhigh tech design to 300,000 km/s or above.

I'm not sure I follow the tracking speed logic.  If something is moving directly towards you, there is no apparent movement to track.  If it was turning or jinking so as to not come straight in, there would be apparent movement to track, but for something moving near c, the amount of energy need to alter its course would be immense.  Given the angle of approach you can calculate the apparent movement.

You're approaching the logic backwards.  Steve wanted the ability to track and/or intercept missiles, therefore they jink or turn or whatever, causing targetting difficulties.  And since relativistic physiscs are ignored, Aurora missiles near light speed are as maneuverable (if not mroe so) as subsonic chemical-fueled missiles in atmosphere.

I also don't follow why 5 seconds has anything to do with beam weapons range.  A laser fired will be moving through space at c the same as a missile moving at c.  Its range is infinite.  The question is how much it will spread out and loose energy density over distance.  A rail/gauss gun projectile in space would have infinite range and would not loose hitting power over distance.  Their only disadvantage vs a missile is they are unguided so can't home in on a target.  They would not have less range.

The shortest 'turn' in Aurora is five seconds, therefore a non-missile weapon which requires more than five seconds to hit its target must be tracked over multiple 'combat turns', adding immense programming complexity that can easily be ignored by preventing the situation in the first place.

'Range' in Aurora means "the maximum distance at which the weapon is dangerous" and is determined by the chance to hit the broad side of a space barn rather than the physical distance the projectile will travel.  Every combat game with lasers I've ever played has treated the issue this same way - yes the laser wil go on forever unless it hits something, but the chance of deliberately hitting something is limited to some arbitrary range.

[Hawkeye]

'Range' in Aurora means "the maximum distance at which the weapon is dangerous" and is determined by the chance to hit the broad side of a space barn rather than the physical distance the projectile will travel.  Every combat game with lasers I've ever played has treated the issue this same way - yes the laser wil go on forever unless it hits something, but the chance of deliberately hitting something is limited to some arbitrary range.

I absolutely agree.

There is rage, and then there is effective range.
Your average rifle bullet will easily fly 1.5 to 2 km, your chance to hit anything at that range is so small, we can say it is zero.

Imagine your megalaser with a range of 10 lightseconds fires at a target (a spaceship in this case) 10 lightsecond away and which is capable of an acceleration of 10g. Now, if this ship is unaware of any hostiles around and flies in a staight line, you can hit it, no problem.
If you are in a combat situation, however, this ship will perform random manouvers at those 10g. If I haven´t got my math wrong (nothing unheard of, I have to admit   ), your target can be anywhere within a sphere with r = 10sec x 50m/sec average speed = 500m or a diameter of 1 km.
Looking at the size of the ships in aurora, those ships aren´t exactly deathstars in size, more like modern navy frigats and destroyers or cruisers, so missing by 100m might clip the edge of your target, if you´re very lucky, but it´s much (muuuuuuuch) more likely you totally miss.
And lets not forget, 10g is pretty slow, from what I gather in aurora.
That´s why only homing weapons have a chance to hit at those or longer ranges (at least, that´s how I always thought of it)

[jfelten]

'Range' in Aurora means "the maximum distance at which the weapon is dangerous" and is determined by the chance to hit the broad side of a space barn rather than the physical distance the projectile will travel.  Every combat game with lasers I've ever played has treated the issue this same way - yes the laser wil go on forever unless it hits something, but the chance of deliberately hitting something is limited to some arbitrary range.

I absolutely agree.

There is rage, and then there is effective range.
Your average rifle bullet will easily fly 1.5 to 2 km, your chance to hit anything at that range is so small, we can say it is zero.

Imagine your megalaser with a range of 10 lightseconds fires at a target (a spaceship in this case) 10 lightsecond away and which is capable of an acceleration of 10g. Now, if this ship is unaware of any hostiles around and flies in a staight line, you can hit it, no problem.
If you are in a combat situation, however, this ship will perform random manouvers at those 10g. If I haven´t got my math wrong (nothing unheard of, I have to admit  :) ), your target can be anywhere within a sphere with r = 10sec x 50m/sec average speed = 500m or a diameter of 1 km.
Looking at the size of the ships in aurora, those ships aren´t exactly deathstars in size, more like modern navy frigats and destroyers or cruisers, so missing by 100m might clip the edge of your target, if you´re very lucky, but it´s much (muuuuuuuch) more likely you totally miss.
And lets not forget, 10g is pretty slow, from what I gather in aurora.
That´s why only homing weapons have a chance to hit at those or longer ranges (at least, that´s how I always thought of it)

This is all hand waiving since the game isn't based on anything quantifiable.  Saying a laser has an effective range of 700,000 Km is just as much fantasy as saying it has an effective range of 7 billion Km.  I appreciate that Steve has scaled things for the real universe (well, at least our solar system since we don't have a lot of other examples to consider) but the range of weapons is just made up in the interest of playability.

[Hawkeye]

'Range' in Aurora means "the maximum distance at which the weapon is dangerous" and is determined by the chance to hit the broad side of a space barn rather than the physical distance the projectile will travel.  Every combat game with lasers I've ever played has treated the issue this same way - yes the laser wil go on forever unless it hits something, but the chance of deliberately hitting something is limited to some arbitrary range.

I absolutely agree.

There is rage, and then there is effective range.
Your average rifle bullet will easily fly 1.5 to 2 km, your chance to hit anything at that range is so small, we can say it is zero.

Imagine your megalaser with a range of 10 lightseconds fires at a target (a spaceship in this case) 10 lightsecond away and which is capable of an acceleration of 10g. Now, if this ship is unaware of any hostiles around and flies in a staight line, you can hit it, no problem.
If you are in a combat situation, however, this ship will perform random manouvers at those 10g. If I haven´t got my math wrong (nothing unheard of, I have to admit   ), your target can be anywhere within a sphere with r = 10sec x 50m/sec average speed = 500m or a diameter of 1 km.
Looking at the size of the ships in aurora, those ships aren´t exactly deathstars in size, more like modern navy frigats and destroyers or cruisers, so missing by 100m might clip the edge of your target, if you´re very lucky, but it´s much (muuuuuuuch) more likely you totally miss.
And lets not forget, 10g is pretty slow, from what I gather in aurora.
That´s why only homing weapons have a chance to hit at those or longer ranges (at least, that´s how I always thought of it)

This is all hand waiving since the game isn't based on anything quantifiable.  Saying a laser has an effective range of 700,000 Km is just as much fantasy as saying it has an effective range of 7 billion Km.  I appreciate that Steve has scaled things for the real universe (well, at least our solar system since we don't have a lot of other examples to consider) but the range of weapons is just made up in the interest of playability.

While this is, of course, correct, the term "effective range" is, as far as I know, a clear defined term in the military.
Range is , how far your projectile/beam/whatever flies
Effective Range is, at what range you have a chance to hit anything.

Look at it another way.
Around 1900 A.D. the typical battlship carried 4x12" guns in two turrets.
Those guns had a maximum range of easyly 10km+
The chance to hit anything at that range, however, was pretty much nil (Tsushima comes to mind, where basicly the entire japanese fleet made a 180° turn on a single spot some 8.000m from the russians, who pretty much had crossed their T (the wet dream of any admiral in the gunship aera) and the russians didn´t achieve a single hit)

What I wanted to point out above (in my first post) is: The chance to hit anything with a direct fire weapon at a range larger than 5 lightseconds is so infinitessimal (sp?) small, it´s not realy worth to invest a lot of programming time

[jfelten]

What I wanted to point out above (in my first post) is: The chance to hit anything with a direct fire weapon at a range larger than 5 light-seconds is so infinitesimally small, it´s not really worth to invest a lot of programming time

I'm just saying it is all arbitrary.  By any rational estimate hitting anything the size of a ship moving that fast at 1 light-second (very roughly the distance to the moon) by any technology we can imagine is virtually impossible.  But this is a game and game play usually has to trump physics.  I don't know what the ideal range of beam weapons should be, but IMO they shouldn't be an arbitrary range based on the time keeping system.  Plus we already have the physics problem of near c missiles.  They would hit you at almost the same instant you "saw" them even if launched from extreme distances.  So it isn't like the game is being 100% faithful to known physics as is.

[jfelten]

I'm not sure I follow the tracking speed logic.  If something is moving directly towards you, there is no apparent movement to track.  If it was turning or jinking so as to not come straight in, there would be apparent movement to track, but for something moving near c, the amount of energy need to alter its course would be immense.  Given the angle of approach you can calculate the apparent movement.

You're approaching the logic backwards.  Steve wanted the ability to track and/or intercept missiles, therefore they jink or turn or whatever, causing targetting difficulties.  And since relativistic physiscs are ignored, Aurora missiles near light speed are as maneuverable (if not mroe so) as subsonic chemical-fueled missiles in atmosphere.

Well, no matter how much they jink and turn, they still have to at some point of their flight approach the target in which case tracking their apparent movement is going to be less than their actual velocity.  If a missile is coming towards me at 300,000km/s, my physical weapon barrel (or whatever) does not have to move at 300,000km/s to remain pointed at the missile.  Of course if a missile was actually coming straight at me at 300,000km/s I couldn't see it before it hit barring FTL sensors, so I think the idea of missiles moving at or near c is a bad idea from a suspension of disbelief perspective (again, barring FTL sensors), especially if it is not necessary for game play reasons.

However all this gets sorted out, the main thing I want to campaign for here is a viable "beam" based anti-missile defense so players/NPR's can forgo missiles and still have some chance vs a missile opponent.  Perhaps some sort of low power continuous fire mode for beam weapons firing in PD mode.  They throw out a continuous barrage of anti-missile fire so are not relying on being able to precisely track the incoming missile with a single shot.  Sort of like the current vulcan phalanx system or WWII flak.  Perhaps the game needs dedicated anti-missile systems.  If missiles became the biggest threat, scientists would try to devise a defensive system.  Something balanced enough so there would be no single winning strategy.

[Brian Neumann]

There is already a weapon system that is for point defense.  The Gauss Cannon.  It only does 1 point of damage, has a very limited range, but can get up to 10 shots every 5 seconds.  It can also be mounted in a turret.  With equal tech levels it will take between 2-3 shots to hit an incomming missile.

brian

[Charlie Beeler]

There is already a weapon system that is for point defense.  The Gauss Cannon.  It only does 1 point of damage, has a very limited range, but can get up to 10 shots every 5 seconds.  It can also be mounted in a turret.  With equal tech levels it will take between 2-3 shots to hit an incomming missile.

brian

I'd like to add to this.  

GC's is fast turrets and supported by fast fire controls can play merry havoc on missile salvo's.  It costs quite a bit of research and mass but is possible.  I've found that range is less important for this system, when used for PD, than rate of fire.  

Kurt and I had a discussion on the subject (albet in v3.1) back in Oct/Nov IIRC.  His Russians learned the hard way that GC's not in fast turrets with fast FC are fairly ineffective.

[jfelten]

It is going to take me a lot of time to get enough experience with the combat system to form solid conclusions.  So for now I'll ask you.  In your opinion/experience, given equal investments in research points and resources, can a non-missile fleet mount enough effective PD to survive a missile fleet's missile strike and still have enough direct fire weapons and close with them to have a fair chance of winning a battle?  I can see the non-missile fleet will start at a disadvantage.  The missile fleet gets to hit first.  And unless the missile fleet is defending a fixed location, the beam fleet will have to dedicate enough technology and additional resources to be faster than the missile fleet else they'll never be able to close to engage.  Otherwise the missile fleet would be able to do what damage they can then retreat to reload.  Obviously there are a lot of variables and no such thing as perfect balance, but is it close?

[Brian Neumann]

I just played out a battle between a race from a nebula with mesons and railguns against a missile armed race.  The nebula race had very heavy armor but no shields, total build points was about even between the two fleets.  The missile fleet was slightly faster but was not fast enough to be able to reload and get back before the nebula fleet was almost in range of the planet.  When everything was done the missile fleet was wiped out, after having fired all it's missiles twice.  The nebula fleet was down all of it's main combatants, but thier light ships were basically unhurt and they were what destroyed the missile fleet.

In this scenario the nebula fleet did not have any dedicated anti-missile platforms.  It did have huge numbers of light railguns however, and they actually do a reasonable job as point defence.  This is because for each railgun you get 4 shots, but thier tracking speed is about 1/4th that of the real pd weapons.  Net effect is one railgun is about as effective as 1 laser or meson in a turret with good fire control to back it up.  The reason for the massive number of light railguns, and not heavier railguns is that in thier home nebula the maximum range for their fire control was only about 70,000k.  This meant that a 12cm railgun actually could fire as far as the firecontrol could see in the nebula.

Brian

P.S.  When I say roughyly equal build points, that includes the cost of the missiles.  Missile ships are usually somewhat cheaper than beam armed ships, but the missiles make them slightly more expensive on average.

[jfelten]

I am a bit confused when you say the missile fleet fired all its missiles twice but did not have time to reload?  Do you mean they only got off two salvoes of missiles?  Why so few?  

The nebula race was unable to create a longer range fire control?  

Do you have time to post the ship designs?  

Certainly the cost of the missiles should be included when judging fleet cost.  

Thanks

[Charlie Beeler]

It is going to take me a lot of time to get enough experience with the combat system to form solid conclusions.  So for now I'll ask you.  In your opinion/experience, given equal investments in research points and resources, can a non-missile fleet mount enough effective PD to survive a missile fleet's missile strike and still have enough direct fire weapons and close with them to have a fair chance of winning a battle?  I can see the non-missile fleet will start at a disadvantage.  The missile fleet gets to hit first.  And unless the missile fleet is defending a fixed location, the beam fleet will have to dedicate enough technology and additional resources to be faster than the missile fleet else they'll never be able to close to engage.  Otherwise the missile fleet would be able to do what damage they can then retreat to reload.  Obviously there are a lot of variables and no such thing as perfect balance, but is it close?

That's the question.  The answer is dependent on how you play the missile races and the beam races.

As things stand in v3.2, my short term answer is yes.  But long term probably no.  Even the short term is dependent on how you start the game.

For the short term game the beam race must govern the research with the assumption that missiles exist and must be countered.  To this end tech for PD must be advanced first above propulsion.  (beam tracking speed and turret tracking speed).  Propulsion shouldn't be ignored since ship speed is a major factor in initiative.  Sensors should not be ingnored either, you have to be able to detect the incoming missiles far enough out to with passives so that you can fireup your actives in time.

Personally I have a preference for GC's with ROF of at least 4 in fast turrets with fast fire control set for 10k final defense fire.  Keep a tight (sub 10k) formation and missile salvos have too be quite large to over saturate.  The main counter, other than faster missiles, to this defense is the box launcher.  

Never use GC's for area defense.  If you have the research funds available turret mounted 10cm lasers with capacitor 3(for a 5sec cyclic rate) work well for an area defense layer.

This has worked quite well for me in the early game.  The reason I say this is that propulsion tech can and will outstrip your ability to maintain effective tracking speeds.  For the long game you still need light/fast anti-missiles to counter salvos.

The most effective way, that I've found, to deploy PD turrets is a minimum of one per combat ship.  Light units have singles while the largest hulls, ideally, mount quads with the units in between having dual and triple turrets.  The exception being dedicated escorts having the next size up of the GC turret as well as the area defense turret(s).

Of course if your primary enemy is a beam not missile race you could be in trouble with too much mass dedicated to missile defense.