09-18-2020, 07:05 AM | #1 |
Join Date: Aug 2004
Location: Hamilton, Ont. CANADA
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[Spaceships] Query: Can dirt shielding reduce an IR Signature?
It started as a tagline in a post, but as I considered it took on the dimensions of a real question. When the Pyramid #3/34: Alternate GURPS article "Alternate Spaceships" introduced the concept of Spaceships as Buildings (page 9) I wondered if putting heat producing systems in the basement levels would reduce their IR signature from outside. How would I determine and calculate this? (Remember sensor readings on a building would not serve the same purposes as those on a spaceship.)
Dalton “Well, is there a reactor down there or not?” Spence
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09-18-2020, 07:34 AM | #2 |
Join Date: Dec 2006
Location: Meifumado
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Re: [Spaceships] Query: Can dirt shielding reduce an IR Signature?
Earth is an insulator, so you'd need somewhere to vent your heat if you don't want to cook your inhabitants. That's either out to the surface, probably with air or water cooling systems, or maybe into the surrounding bedrock, which would require more extensive heat exchange piping.
The other problem is that on Earth-like planets, the rock gets warmer as you go deeper, so how effective your cooling is depends a lot on the planet and local geological conditions.
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09-18-2020, 07:56 AM | #3 |
Join Date: Oct 2007
Location: Kentucky, USA
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Re: [Spaceships] Query: Can dirt shielding reduce an IR Signature?
Presumably for some sort of bunker?
The thick layer of dirt would be a good insulator and diffuse the heat signature over a larger area, but the heat still has to go somewhere so IR sensors would be a bit spot of slightly warmer dirt rather than a sharp point of heat. Maybe a "Planetary Cooling System" that reduces IR signature by 1 per system, presuming there's enough space around the building for the buried radiators, +1 effective SM per -1 to IR signature. I have no numbers to back this up, just eyeballing it.
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09-18-2020, 08:02 AM | #4 | ||
Join Date: Aug 2004
Location: Hamilton, Ont. CANADA
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Re: [Spaceships] Query: Can dirt shielding reduce an IR Signature?
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Dalton “Interesting topic, IR Stealth for Underground Structures” Spence
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09-18-2020, 11:26 AM | #5 | |||
Join Date: Dec 2006
Location: Meifumado
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Re: [Spaceships] Query: Can dirt shielding reduce an IR Signature?
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09-18-2020, 11:57 AM | #6 | |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: [Spaceships] Query: Can dirt shielding reduce an IR Signature?
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09-18-2020, 12:49 PM | #7 | |
Join Date: Dec 2007
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Re: [Spaceships] Query: Can dirt shielding reduce an IR Signature?
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09-18-2020, 12:51 PM | #8 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: [Spaceships] Query: Can dirt shielding reduce an IR Signature?
For what it's worth, using infrared sensors to detect houses that are being used for pot production was a thing a few years back (might still be) so I doubt a basement helps meaningfully.
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09-18-2020, 12:57 PM | #9 |
Join Date: Jul 2008
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Re: [Spaceships] Query: Can dirt shielding reduce an IR Signature?
Yeah, it's not really a barrier situation. IR signature isn't about directly seeing the heat-producing system, anyway, at least in a realistic treatment: it's about seeing the external radiators that are connected to the heat-producing system. Which section the system itself is in doesn't make an appreciable difference.
Being embedded in the ground means that the vacuum radiators can be replaced with a ground-conduction heat sink, probably consisting of a network of heat conductors buried in the surrounding rock. This doesn't reduce the amount of heat available for people to see, but it does make it pretty easy to spread the heat over a large area and a lower visible temperature. It also would be possible to put the heat sink displaced from the main installation. In addition to making detection harder as Anthony notes, this means that when someone does spot your heat signature they still don't know where you are with any precision. So they'll have to do more work before they can shoot you or land an assault team on your roof.
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09-18-2020, 01:06 PM | #10 |
Join Date: Aug 2004
Location: Binghamton, NY, USA. Near the river Styx in the 5th Circle.
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Re: [Spaceships] Query: Can dirt shielding reduce an IR Signature?
You can also create heatsinks to store the heat for later dissipation. The simplest of this would be Frozen water which you then melt and heat up. Eventually, though, you're going to start boiling it and will have to deal with the steam. Something like salts or rocks can take a lot of heat, and in the right conditions can store it for quite a while. You can also use heat transfer pipes which you drill both very deep and very wide, and you just dump the waste heat into the ground. Using these methods you can spread the heat out quite a bit, but eventually it will start to show up on IR meters. The simple problem is that no matter what you do with the heat it still exists and will still show up eventually.
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