Aurora 4x
C# Aurora => Development Discussions => Topic started by: Steve Walmsley on March 26, 2019, 02:37:27 PM
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In VB6 Aurora, a ship always has its max same thermal signature even when not moving. The fleet can be set to a lower speed if desired, which reduces the signature, but that isn't directly related to movement. Part of the rationale was that a ship would need to have engines warmed up to dodge incoming fire.
However, it doesn't seem realistic that a stationary ship and one moving at full speed should have the same thermal signature so I am going to change that for C# Aurora. The 'dodge argument' doesn't really hold given the instant acceleration rates of TN ships. I'm just debating between two options:
1) If the ship has no movement orders, it has zero thermal signature. Otherwise, the signature is (current speed / max speed) * max thermal signature. This is the simplest to implement and easiest to understand. The current movement orders condition would apply regardless of whether the order at that point involved movement, so a freighter in transit and one loading cargo are both 'moving'.
2) A ship without orders has some baseline thermal output, probably based on 1% to 5% of size in hull space, so using 5% a 10,000 ton ship would have a thermal signature of 10 (200 HS x 5%). I could make a distinction for commercial but probably easier to leave as is on the basis that some commercial functions (mining, terraforming, harvesters) would generate heat and even freighters would have less thermal shielding than similar size warships. This removes the idea of being invisible to thermal sensors when motionless, but it is still a low signature compared to VB6.
This has some implications for scouting, as there could be large stationary alien warships that you will only detect if they move or activate sensors, or if you activate sensors.
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Number 2
Fits with real thermodynamics better.
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I would also go with option 2 ... sounds like the better way to go for me..
if it works, it may open a possibility for C# 1.1 - higher base output but the possibility to reduce it with a new research tech...
but for 1.0 I think 2) as you mentioned it would be great :)
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I'm assuming Option 2 also includes the "otherwise, the signature is (current speed / max speed) * max thermal signature" part? That we're only debating how to handle non-moving ships?
I would prefer the second. I would also prefer that unloading/refueling/etc. ships also have a reduced thermal signature, since due to my reliance on cycling orders my freighters & colony ships will always have a 'Move to (at max speed)' order queued.
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I vote for #1. Easier to understand is better, and with the changes to active sensors it would encourage using those to search for hidden vessels.
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No 2, it means a thermal sensor will always be able to detect SOMETHING, you're not totally blind - but also seems largely consistent with actual physics
Also, good shout - this has always bothered me!
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I'm all for 2.
Doesn't sound like those ships would be all that much easier to detect than the occasional DSTS or other small base, that's fine.
But oh wait, does this mean orbital platforms will have a heat signature too now? That's even better.
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No 2, it means a thermal sensor will always be able to detect SOMETHING, you're not totally blind - but also seems largely consistent with actual physics
Also, good shout - this has always bothered me!
This is a tough one. As I agree with the quote I also understand the mechanism Steve is trying to implement. Question: wouldn't be then better have a way to switch off the ship? This could have a button same to the active sensor. To get on again you could suffer a jump shock alike penalty which depends on training crew etc. This should impact only thermal and EM as I don't like mothballing features to be back again.
Otherwise, I vote number 1: it sounds better than the 2nd just because the latter doesn't actually move things forward but just make them more complicated.
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I also vote for #1. I don't think the passive heat helps in any way. If anything, it would be more interesting if the change was not instant but it cooled gradually. That would presumably be a lot harder to code.
Then again, something like:
current_temp += (calc_temp() - current_temp) / 100.0;
Or this for computing with time.
diff = calc_temp() - current_temp;
diff * pow(0.99, time);
current_temp = calc_temp() - diff;
This would make a residual heat be present until it disappears with rounding errors and would prevent just stoping to disapper suddenly and shake heat-seeking missiles...
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I'm all for 2.
Doesn't sound like those ships would be all that much easier to detect than the occasional DSTS or other small base, that's fine.
But oh wait, does this mean orbital platforms will have a heat signature too now? That's even better.
Yes re orbital platforms.
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I'm assuming Option 2 also includes the "otherwise, the signature is (current speed / max speed) * max thermal signature" part? That we're only debating how to handle non-moving ships?
I would prefer the second. I would also prefer that unloading/refueling/etc. ships also have a reduced thermal signature, since due to my reliance on cycling orders my freighters & colony ships will always have a 'Move to (at max speed)' order queued.
Yes, that is for non-moving, although I would code it so that very slow-moving ships would not drop below their 'base thermal signature'.
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I also vote for #1. I don't think the passive heat helps in any way. If anything, it would be more interesting if the change was not instant but it cooled gradually. That would presumably be a lot harder to code.
Then again, something like:
current_temp += (calc_temp() - current_temp) / 100.0;
This would make a residual heat be present until it disappears with rounding errors and would prevent just stoping to disapper suddenly and shake heat-seeking missiles...
Yes, I considered residual heat but decided it would be a pain to code :) and only make a difference on very rare occasions.
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No 2, it means a thermal sensor will always be able to detect SOMETHING, you're not totally blind - but also seems largely consistent with actual physics
Also, good shout - this has always bothered me!
This is a tough one. As I agree with the quote I also understand the mechanism Steve is trying to implement. Question: wouldn't be then better have a way to switch off the ship? This could have a button same to the active sensor. To get on again you could suffer a jump shock alike penalty which depends on training crew etc. This should impact only thermal and EM as I don't like mothballing features to be back again.
You can already 'switch off' the ship by using the 'Picket 1 km/s' order. This is to avoid having to do that every time you end your orders.
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Number 2
Fits with real thermodynamics better.
I kind of disagree. I just can't see the few degrees kelvin being detectable from thousands of kilometers. It also punishes large ships for no particular reason, as having one big ship or 10 small ones should be simillar for detection, when the heat is spread out (larger hull), not concentrated around engines...
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I like 2. Not from any realism argument - I've made my speech before that I think mechanics should be based on gameplay instead of realism. Rather, it's because 1 would enable you to hide perfectly from passive sensors, and I like that 2 allows for the possibility of sub warfare style fights, where both sides are trying to remain stealthy while finding the other first.
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Number 2
Fits with real thermodynamics better.
I kind of disagree. I just can't see the few degrees kelvin being detectable from thousands of kilometers. It also punishes large ships for no particular reason, as having one big ship or 10 small ones should be simillar for detection, when the heat is spread out (larger hull), not concentrated around engines. . .
Inferred telescopes can measure temps from just about anywhere in the observable universe. The problem is they only see tiny portions of the sky. Aurora sensors are different so I can't speculate on them.
(EDIT)
Also they are limited to speed of light, which means they would have to wait for 4. 4 years to see a ships thermal signature in Alpha Centauri. Well I am typing I believe they also have low resolution.
(EDIT 2)
Man I didn't read that right, I am sorry i believe you may be right on the detection of degrees around 0
kelvin. But real spaceships produce lots of heat and it is very hard to get anywhere close too those temps, in a crewed ship operating with electronics and other machines. So they sould be radiating heat all the time unless dead in space.
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Option 2 for sure
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I'm for option 2.
Additional tech could potentially allow warships when 'switched off' to completely negate their baseline thermal output. Maybe something similar to absorption shields could soak up the baseline thermal output to a point before releasing it, either one pulse or perhaps once that point is reached it starts releasing a percentage of the saved up thermal, untill the amount being released matches the baseline output, then at that point it releases the full thermal output plus the same fraction of the saved thermal untill its all gone.
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I much more like the second option, instantly disappearing would likely enable weird tactics with thermal seeker missiles.
Actually, while a cooldown might be too much, giving a delay might be necessary to ensure ships keep slow to reduce their signature, and not just drop speed for 5s to cause missiles to loose lock.
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Late to the party but put me in the Option 2 camp.
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Goes for two.
But perhaps having a mothball option down to o emissions, mothballing is essential power downthe ship and opening up to the vacume to preserve it, isn't ?
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Surely options 2. For gameplay reasons.
Large warships being able to stay at 0 thermal emission, effectively completely invisible to passive sensors, would be a REALLY bad thing for gameplay in my opinion. Completely change the flow of the game in some situations.
It would mean that your ONLY choice for scouting a system is going is with active sensors switched on, because passive do not guarantee you have useful information. You can literally park a huge fleet of warships 10km from a planet, and be 100% sure the enemy will never see them unless they use active sensors.
This would give a huge advantage to whomever "occupies" the system first. I come in, scout with actives, I'm relatively sure I'm alone, park my ships with speed zero. This results in me being effectively hidden now.
If someone else comes in the system later, they are at a complete disadvantage. If they move around, I can see their thermal emissions. And they can't see me unless they turn on actives. Which would make them visible from a LONG distance away thanks to my passive EM sensors.
Basically, I have every advantage in being able to decide whether to engage or not, while they are forced to turn actives on or be completely blind, and risk me being able to launch a devastating surprise attack.
This would be a big change in gameplay, and not one I would like.
I would put the thermal emission of ships not moving at 5% or so of maximum. Maybe add a tech research line to lower that somewhat, but certainly never to 0
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If there's a technology to lower the minimum thermal emission when stationary, I'd rather we start at something like 10 or even 15 percents and then end at 5. The values are going to be ridiculously tiny and hard to spot and effectively 0 if we go any lower than 5%, won't they ? DSTS might be able to spot a 40k tons ship's 40 stationary thermal signature easy and from far away, but I don't think I ever had a warship with 1000 or 2000 in thermal sensor sensitivity.
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Option 2 to keep a logical detection system and technobable
A wreck can be seen anywhere in a system, even without thermal or EM sensor, just like a planet.
Let's say it can be detected by standard navigational systems included in every ship to avoid crashing on an asteroid.
But what is the difference between a wreck and a powered down ship ? (or a mothballed one)
An aurora ship navigates in an aether, which make it invisible on standard sensors (not thermal nor EM), but when destroyed it goes off the aether, and become detectable easily.
I like the idea of a ship not powered down having a minimum thermal signature due to its size or power. (thermal is only based on engines, why not including other generator? I'm sure most power generator system in aurora must also generate heat, it is the same for every human being aboard.
Just an additional question : will aurora C# have an improved "hide and seek" system ?
When there is only one grouped fleet, you can hide on the other side of a planet, you can try to power down some of your systems to increase stealth, at least for some time, at the cost of being unable to restart them immediately when needed, etc...
In honor harrington, a ship can hide itself easily by cutting its wedge. It is unable to move, has no protection from wedge, and needs soem time to start them, but he can hide. In other books some stealthy ships have a heatsink, with a limited capacity to absorb the generated heat and become invisible as long as it can avoid to radiate heat.
But does Aurora needs these features ?
Will an AI be able to use them? Is it possible to use it when you play versus yourself without schizophrenia ?
I think it won't be easy to implement.
My 2 cents
Hubgbf
Edit : aether is now a canon notion for C#, and not a technobable used by Kurt in his last campaign like I wrote in the first verison of the post.
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It seems to me like this boils down to a single question: What is "stationary?"
If "stationary" means just turning off the engines and coming to a stop, but leaving other systems (weapons, sensors and so on) running, then option 2 would be the obvious choice, since all of those systems would generate heat.
If "stationary" means turning off all non-critical systems that generate heat, leaving only the absolutely necessary systems (like life support) and systems that don't generate heat running, then option 1 would make more sense.
Personally, I think option 2 would be preferable; if the ship can start moving and shooting immediately (minus the crew's reaction time), that means that non-critical systems are left on (since it would take time to activate those kinds of systems), and if they were left on, they'd be generating heat.
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Option 2 looks good to me. Possibly multiple the base heat for those ships in refit to reflect they are being worked on? Also what about minimum passive EM as well?
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No 2, it means a thermal sensor will always be able to detect SOMETHING, you're not totally blind - but also seems largely consistent with actual physics
Also, good shout - this has always bothered me!
This is a tough one. As I agree with the quote I also understand the mechanism Steve is trying to implement. Question: wouldn't be then better have a way to switch off the ship? This could have a button same to the active sensor. To get on again you could suffer a jump shock alike penalty which depends on training crew etc. This should impact only thermal and EM as I don't like mothballing features to be back again.
Otherwise, I vote number 1: it sounds better than the 2nd just because the latter doesn't actually move things forward but just make them more complicated.
This points out a potential exploit that should be taken into account. Let's say I've got a missile with a thermal seeker chasing me. Should I be able to make it lose lock by simply cutting my engines? Admittedly it's hard to know whether or not an enemy seeker has thermal capability, but still....
BTW, I always thought that thermal output was proportional to speed in the first place. When approaching a potentially inhabited planet during scouting I used to have an involved process where I would gradually slow down as I got closer. It sounds like this was all for naught - that my thermal output was the same no matter what (which sounds counter-intuitive to me).
John
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BTW, I always thought that thermal output was proportional to speed in the first place. When approaching a potentially inhabited planet during scouting I used to have an involved process where I would gradually slow down as I got closer. It sounds like this was all for naught - that my thermal output was the same no matter what (which sounds counter-intuitive to me).
Slowing down does matter in VB6. As you slow down your thermal output drops. The problem in VB6 is that a ship with max speed is assumed to have full thermal, even when it isn't moving (has no orders). Everything is based on current speed, not current orders. In VB6, you can set a ship to 1 km/s using the picket order and drop its thermal output to virtually nothing.
The difference for C# would be that anything without orders would be assumed to have zero speed (effectively the same as setting the 1 km/s order in VB6) and anything with orders would use the current speed (as per VB6).
The concerns over option 1) and the ability to shut down to avoid thermal seekers already exist in VB6.
Option 2) seems a better option and is the more popular, so I will implement that. The question is what proportion to use. I think perhaps 5% of size and maybe even a little more.
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sorry if I'm remembering this wrongly, but doesn't missile interception chances depend on ship speed? Yeah the ship's not technically moving but I'm assuming it's flying around dodging missiles.
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sorry if I'm remembering this wrongly, but doesn't missile interception chances depend on ship speed? Yeah the ship's not technically moving but I'm assuming it's flying around dodging missiles.
Yes, in VB6. So the downside of setting low speed is easy to hit.
The assumption in C# would be the ship would accelerate to dodge missiles. Missiles are much easier to detect in C# so this isn't too much of a stretch. I might need to add something to show a thermal signature when the ship dodged, but it would be a rare situation where that was meaningful (as the ship would need to be detected already in order to have to dodge the missiles).
In effect, the C# change would remove the micromanagement in VB6 of slowing to 1 km/s after movement and then speeding up in response to missile attack. This would happen automatically instead. Plus with option 2 the VB6 ability to almost vanish from thermal sensors would be removed.
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I vote two, with the caveat of having some technological means to (temporarily?) reduce that signature.
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The assumption in C# would be the ship would accelerate to dodge missiles. Missiles are much easier to detect in C# so this isn't too much of a stretch. I might need to add something to show a thermal signature when the ship dodged, but it would be a rare situation where that was meaningful (as the ship would need to be detected already in order to have to dodge the missiles).
I know we are deep into tiny details now, but where I can see it make a difference is intel gathering on the class.
And yes option #2 is better.
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My vote goes for Option 2 too.
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The assumption in C# would be the ship would accelerate to dodge missiles. Missiles are much easier to detect in C# so this isn't too much of a stretch. I might need to add something to show a thermal signature when the ship dodged, but it would be a rare situation where that was meaningful (as the ship would need to be detected already in order to have to dodge the missiles).
I know we are deep into tiny details now, but where I can see it make a difference is intel gathering on the class.
And yes option #2 is better.
Yeah, if they're dodging missiles you're gathering information on speed/engine power or whatever i guess
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Can we assume that cloaking will reduce the base thermal output?
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Option 2.
I would start with 10 or 15% of ship size. In the future a tech could be added to allow that to be reduced. A tech in the same category as cloaking that gets it down to 5% would be worthwhile.
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Ships shouldn't get to dodge missiles and have low thermal emissions. It could create a situation where thermal sensors on missiles or mines have trouble detecting a vessel that is still "moving" to dodge. I can see a situation where an enemy jumps into an area and finds many mines, or I use missiles with thermal sensors for some reason. I could fire other missiles and force them to either not dodge or to come into view of the thermal sensors, but if the evasion is emissions-free there's no point. Or a missile with a thermal sensor could be passing nearby, but I'm unsure what detection range it has. If I can sit still and reduce my thermal signature, the best choice is definitely to sit still: I get all the benefits of reduced detection, but if the missile does notice me I can still evade it without activating further ones.
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Having a tech to reduce the base thermal signature seems like it would overcomplicate things to me. Not everything needs a tech line.
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Maybe base the base thermal emissions on # of armor columns instead of # of hull spaces? Would still increase with size, just not linearly.
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BTW, I always thought that thermal output was proportional to speed in the first place. When approaching a potentially inhabited planet during scouting I used to have an involved process where I would gradually slow down as I got closer. It sounds like this was all for naught - that my thermal output was the same no matter what (which sounds counter-intuitive to me).
Slowing down does matter in VB6. As you slow down your thermal output drops. The problem in VB6 is that a ship with max speed is assumed to have full thermal, even when it isn't moving (has no orders). Everything is based on current speed, not current orders. In VB6, you can set a ship to 1 km/s using the picket order and drop its thermal output to virtually nothing.
The difference for C# would be that anything without orders would be assumed to have zero speed (effectively the same as setting the 1 km/s order in VB6) and anything with orders would use the current speed (as per VB6).
Ahhh - now I remember. My recollection is the "picket speed" command was to make it easier to for people to perform your option 1 by hand.
John
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Vote for 2, as it will be less disbelieve and less micromanagement.
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I vote for 2
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What if certain ship systems had a passive thermal signature? Specifically, things like missile launchers that are loaded and ready to fire and power plants, specifically.
The former which, with some hand wavium, is another thing reigning in missile supremacy in specific roles, and the latter to a minor extent that full fire rate gunboats will be hot, where low fire rate reduced capacitor alpha strike boats would be slightly harder to detect, but may be largely helpless once it gets a salvo off. This also means certain ships are really hard to find when stationary, for example, small fighter ship with a basic sensor package onboard. As the ship only has engines and sensors, it can be invisible to passives as it doesn't have any "passively hot" equipment.
Perhaps we could allow a "stand down" stance to ships, that has weapons offline, which both sets thermals to 0 entirely, and also is noticeable on actives, so other race ships can identify that you've got weapons cold for diplomatic reasons, or enemy ships can see it as a wide opening to strike. "Weapons offline" would probably need a significant duration to toggle, of course, say several ingame hours, perhaps slightly delayed based on task force readiness. For obvious reasons, the ship would need to be expressing a "weapons active" signature while attempting the switch, in either direction.
Perhaps the "weapons online" mode could also have a specific affect on military engines, such that not being offline would make the ship slightly faster, less fuel efficient. That one's a bit of a stretch though.
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Option 2 sounds good as long as it's indeed a floor (I'm always sceptical of mechanics that scream to be played around).
The above sounds interesting, but may be a little too involved. Optional shutdown of nonvital systems, eliminating or reducing the minimum signature while giving one a warm-up period until one can use sensors/weapons/propulsion at full efficiency could be interesting.
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I was about to post the same as Iceball3, but I realized I am late to the party.
You can make the equation simply Heat Sig = Base + Engines and save you a line of code to get the greater of the two.
The you can later add features as you wish with += Powergens/capacitors, += LaunchingTubes (lasts for whole reload. . . a big negative for single shot pods as they can't quickly cool to hide), -= heatsinks, etc. .
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Option 2, hands down. In essence.
While burning engines would produce a big heat spike, the routine operation of a spacecraft's systems generates heat.
Each vessel should produce a base amount of heat, for starters.
- If you want more complexity, a portion of that should come from the hull, and then each individual system should pile on that.
- If you want more, certain systems other than the engines (like weapons) could produce secondary heat spikes.
- If you want more, each ship could have a heat radiation rate according to the number and quality of radiator components installed. They would control how fast heat comes down to base level after a spike, and after the ship stops burning its engines.
Beyond that, there could be certain components which decrease the base heat signature, like specialized power infrastructure and certain hull coatings. If you want more complexity, you could have heatsink components, which would temporarily absorb large amounts of vessel heat (and therefore reduce the base level) for circumstantial tactical advantage.
Lots of potential here.
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I would just really like to suggest using square root of the size of the ship for thermal signature purposes. Eg: Thermal = roof(sqrt(HS)) would result in:
Size Sqrt Current
250t 3 0.25 (=0 ??)
1 000t 5 1
10 000t 15 10
25 000t 23 25
50 000t 32 50
100 000t 45 100
I love to play with smaller number of larger warships and there are many detriments to this in Aurora already. This one however seems to be particularly crippling in some scenarios. The square root approach gives a nicer baseline signature for fighters to be detected but does not end up lighting larger ships like a x-mass tree on passive sensors. This both allows larger warships to be used with some amount of stealth as well as prevents fighters abusing being undetectable (less then 1 thermal signature).
I also have to ask... From your Changes post, it seems there is an exploit. Notably if the ship IS moving at very slow speed, the speed formula is used allowing to go below the minimal intended thermal signature. Is this just a bad wording in the post or is this also an error in the coding?
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I would just really like to suggest using square root of the size of the ship for thermal signature purposes. Eg: Thermal = roof(sqrt(HS)) would result in:
Size Sqrt Current
250t 3 0.25 (=0 ??)
1 000t 5 1
10 000t 15 10
25 000t 23 25
50 000t 32 50
100 000t 45 100
I love to play with smaller number of larger warships and there are many detriments to this in Aurora already. This one however seems to be particularly crippling in some scenarios. The square root approach gives a nicer baseline signature for fighters to be detected but does not end up lighting larger ships like a x-mass tree on passive sensors. This both allows larger warships to be used with some amount of stealth as well as prevents fighters abusing being undetectable (less then 1 thermal signature).
I also have to ask... From your Changes post, it seems there is an exploit. Notably if the ship IS moving at very slow speed, the speed formula is used allowing to go below the minimal intended thermal signature. Is this just a bad wording in the post or is this also an error in the coding?
With the new passive sensor rules, the square root of the signature is already used for detection:
http://aurora2.pentarch.org/index.php?topic=8495.msg103085#msg103085
The minimum is the base signature, even when the ship is moving. It is coded that way but I didn't mention it in the post. I'll update it.
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With the new passive sensor rules, the square root of the signature is already used for detection.
I failed to consider that. Thanks for the clarification :)
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Wouldn't the ship still be radiating heat regardless of whether its engine were on or not? Gotta keep the lights on somehow.
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Wouldn't the ship still be radiating heat regardless of whether its engine were on or not? Gotta keep the lights on somehow.
Yes, that is what I implemented.
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Wouldn't the ship still be radiating heat regardless of whether its engine were on or not? Gotta keep the lights on somehow.
Really depends on the heat being generated internally versus the thickness of the 'insulation layers' before reaching the exterior surface.
If you have something like a well insulated interior layer, followed by the hull plating and then several layers of armour that is intended to absorb and mitigate thermal energy amongst everything else , then the likely hold of any 'thermal leakage' from idle life support operations is probably close to zero. If there was ample thermal leakage that any 3rd party could detect heat emitting from entirely contained interior sources then the operational upkeep simply to keep the crew alive would incredibly expensive compared to just designing the various foundation layers acting as insulation more efficiently so that heat generated internally is contained between the interior and hull before being dispersed back into the interior in some fashion.
Whilst it would still be a gross simplification of what is being represented, making thermal output when idle tied to hull tonnage against layers of armour present as a basic representation would at least make a bit more sense then the idea of space craft designed so inefficiently that every ship is just bleeding out any noticeable heat into space as part of basic life support operations.
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Wouldn't the ship still be radiating heat regardless of whether its engine were on or not? Gotta keep the lights on somehow.
Really depends on the heat being generated internally versus the thickness of the 'insulation layers' before reaching the exterior surface.
If you have something like a well insulated interior layer, followed by the hull plating and then several layers of armour that is intended to absorb and mitigate thermal energy amongst everything else , then the likely hold of any 'thermal leakage' from idle life support operations is probably close to zero. If there was ample thermal leakage that any 3rd party could detect heat emitting from entirely contained interior sources then the operational upkeep simply to keep the crew alive would incredibly expensive compared to just designing the various foundation layers acting as insulation more efficiently. . . . it's space travel after all. Not high altitude plane travel. ;)
Well in space there is nothing for the heat to transfer to outside the ship so any heat you absorb into any material must at some point be released, unless you have some sci-fi system for converting heat back into some other form of energy that is stable and can be stored and used again.
Although it should be entirely possible to stop heat from radiating out into space for a certain time, but at some point you will have to vent it all out. You could then use such a system to be very stealthy to heat sensors for a certain time period, could be an interesting game mechanic instead of the technology that just reduce the heat signature of a ship. In general I don't find this technology to be that worthwhile because you can always reduce a ships speed to reduce their heat signature... going slow is generally not much of a problem while conductive covert operations.
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Wouldn't the ship still be radiating heat regardless of whether its engine were on or not? Gotta keep the lights on somehow.
Really depends on the heat being generated internally versus the thickness of the 'insulation layers' before reaching the exterior surface.
If you have something like a well insulated interior layer, followed by the hull plating and then several layers of armour that is intended to absorb and mitigate thermal energy amongst everything else , then the likely hold of any 'thermal leakage' from idle life support operations is probably close to zero. If there was ample thermal leakage that any 3rd party could detect heat emitting from entirely contained interior sources then the operational upkeep simply to keep the crew alive would incredibly expensive compared to just designing the various foundation layers acting as insulation more efficiently. . . . it's space travel after all. Not high altitude plane travel. ;)
Well in space there is nothing for the heat to transfer to outside the ship so any heat you absorb into any material must at some point be released, unless you have some sci-fi system for converting heat back into some other form of energy that is stable and can be stored and used again.
Although it should be entirely possible to stop heat from radiating out into space for a certain time, but at some point you will have to vent it all out. You could then use such a system to be very stealthy to heat sensors for a certain time period, could be an interesting game mechanic instead of the technology that just reduce the heat signature of a ship. In general I don't find this technology to be that worthwhile because you can always reduce a ships speed to reduce their heat signature. . . going slow is generally not much of a problem while conductive covert operations.
Indeed, kind of amended a afterthought based on this point to my previous post.
I would imagine with the relatively low amount of thermal output needed just to sustain a crew and basic power generation (Assuming ships are using a less intensive form of power generation for undemanding critical systems, and only utilise the main generators for active operations), a efficient design should be able to re-purpose at least a decent amount of its thermal output back into supporting the internal upkeep of the crew.
A general idea might be compare hull tonnage to armour layers (Lets assume the gradual build-up under idle situations is gradually passed through the hull and directed so it spreads across the entire surface of the exterior armour rather than just gets spat out at one singular point) then exaggerate the end result by a % of time the ship is over its intended deployment time.
So the ship design would be drafted up to efficiently handle basic idle life support conditions for xxx number of months, within that period of time the thermal output determined directly through the relationship of tonnage versus armour. So given enough size given away to armour layers you can keep output to zero during idle conditions. However once a ships deployment time exceeds the designs intended duration the ships thermal output both when idle and when under active operation escalates with each passing month.
When a ship then returns to a shipyard for maintenance, I suppose the shipyard could also have a process where when performing maintenance on a ship it can take that stored energy from the ships operation that hasn't been bled out and actually use it in some way. . . . essentially ships could be used as small scale batteries. Not enough to sustain itself obviously, but with all the military and civilian traffic it's likely to see in a single day probably enough to actually be a relatively efficient approach and lore wise provide additional justification for the basic design efforts over just bleeding everything straight into space and ramping up power generation demands.
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let's start with some basic assumptions :
- In space, thermic exchange are made by IR radiation. It is ruled by the Stefan-Boltzmann's law, sigma*€*T^4
- Due to solar radiation, an object is naturally heated.
- By insulation, you can slow thermic exchange, but you cannot stop them. You can concentrate heat on a thermal sink for some amount of time if you want.
- Everything generates heat : human bodies, cooking, recycling Co2, etc...
In conclusion
Even without internal thermic generation, an object in space has a thermic signature.
Without an internal heat sink, you will heat up to a temperature which allow you to radiate enough heat to compensate for the generated heat. And the relation is not a ^2, but a ^4.
Heat generated has a component scaled to the crew (body heat, survival gear, cooking, and so on)
Efficiency and reactor tech have an impact as the more efficient a powerplant or engine is, the less heat it generates per Kw/h.
On a technobable point of view, the reduced thermal tech is some sort of thermal sink coupled with radiator which can store then radiate heat on a directional path, to avoid detection.
But if you consider a base thermal signature, IMHO it must be scaled to the crew and not the size of the ship, as you can cut nearly everything on a ship but life support.
A fun addition will be to have for a limited time the possibility to set a thermal reduction order for ships : the crew get into spacesuit, breath stored oxygen, and eat protein bar. It will reduce efficiency, but will lower the thermal signature, at least for some days...
My 2 cents.
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Efficiency and reactor tech have an impact as the more efficient a powerplant or engine is, the less heat it generates per Kw/h.
This is mistaken.
An engine/power plant has a specific power production rating. A ship has a total energy draw. Because energy conversion is not perfect, you lose energy due to inefficiencies in the system, and energy consumed by a ship's system produces waste heat as well, if not necessarily a lot of it.
A power planet rated for 100 MW is going to create 100 MW of exploitable energy presuming 100% efficiency. This would let you then power 100 MW of machinery and equipment on board the spaceship, which must eventually be shed at the same rate to maintain the same temperature. However, if you have a 40% efficiency of energy conversion you can only power 40 MW of machinery and equipment, but you are still producing 100 MW of energy.
Even if 60 MW of that energy is waste heat that cannot be converted, you are still producing and consuming 100 MW of energy.
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Alternative technobabble: The simplest and cheapest TN engines run hot and thermal tech reduces the core temperature and/or recovers exhaust heat to preheat fuel but this requires more complex and expensive hardware.
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Hmmm...
What if the stealth module allowed ships equipped with it to picket in dead space without a thermal signature? As long as the ship remains stationary. This would be in addition to it's active sensor effective detected size effect it already has.
Might make it more generally useful, and allow empires to specifically hide ships of size in space depending on how well stealth technology is researched, and incur less mission space occupancy based on the efficiency of the stealth modules as before.