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TuefelHundenIV Night Clerk of the Apocalypse from Doomsday Facility Corner Store. Since: Aug, 2009 Relationship Status: I'd need a PowerPoint presentation
Night Clerk of the Apocalypse
#2126: Jan 6th 2015 at 5:35:40 PM

Except that picture wouldn't drown out IR in fact we can see many distinctly individual stars in that IR picture rather then a giant fuzzy blur. Also stars may wobble slightly but in general they don't move. A moving ship that is a lot closer is going to be noticeable. Even better if it passes any of the background stars.

Matt: Pot calling the kettle black for someone who completely fails to grasp even the basics of the concept. March on in ignorance.

edited 6th Jan '15 5:37:51 PM by TuefelHundenIV

Who watches the watchmen?
MattII Since: Sep, 2009
#2127: Jan 6th 2015 at 5:41:49 PM

I understand the concept, but I also understand its (very many) limitations, and also why it wouldn't work. If you want to test it, go wrap yourself in cotton wool and do some exercise, and I guarantee you'll be sweating in no time.

Among the limitations those tiles have is that no matter how you work them, you can't effectively disguise yourself from side-on viewers and front-corner views no matter how skillful you are.

And you can't see the IR of an object passing in front of a star, or at least not in the normal sense of the word, because the star is outputting so much more IR.

edited 6th Jan '15 5:56:06 PM by MattII

TuefelHundenIV Night Clerk of the Apocalypse from Doomsday Facility Corner Store. Since: Aug, 2009 Relationship Status: I'd need a PowerPoint presentation
Night Clerk of the Apocalypse
#2128: Jan 6th 2015 at 6:41:30 PM

That's great but you just demonstrated you don't understand the concept at all and grossly so. Your example greatly fails even basic logic and is not even related to the concept. The difference is closer to a person wearing a wool blanket being looked at in IR vs a person wearing a cold weather survival blanket. One of them sticks out like a sore thumb the other has a seriously reduced IR signature. Only instead of just insulating the heat the masking system cools the surface reducing the IR picture that way instead. Even the vehicle with its engine constantly running is not given away. Yes you can mask from nearly any angle because you cover the surface in the tiles. Can't mask from the side what bullshit coming from the guy who said it only works from the side.

A cooler body which would be darker in contrast passing in front of a hotter body is visible. IR does show contrast. The distant star isn't heating the ship which is closer to the sensor array in the first place. They have found astral bodies like meteorites by simply seeing something just like that.

Who watches the watchmen?
MattII Since: Sep, 2009
#2129: Jan 6th 2015 at 7:14:10 PM

The difference is closer to a person wearing a wool blanket being looked at in IR vs a person wearing a cold weather survival blanket. One of them sticks out like a sore thumb the other has a seriously reduced IR signature.
Then the guy in the survival blanket dies of heatstroke.

Actually, no, it's more like trying to run a car without the radiator.

Yes you can mask from nearly any angle because you cover the surface in the tiles.
Which works only to make it invisible to IR, not to make it look like another vehicle, and it doesn't in any case fool image-intensifiers, which are also commonly used.

They have found astral bodies like meteorites by simply seeing something just like that.
They have found NE As against distant stars like that, but in the stars' own system, only large planets show up at all. And even that doesn't tell them much more than the approximate mass.

EchoingSilence Since: Jun, 2013
#2130: Jan 6th 2015 at 7:48:01 PM

I think at this rate several pages are going to be filled with Matt and Tuefel throwing punches at each other about who doesn't know physics.

MattII Since: Sep, 2009
#2131: Jan 6th 2015 at 7:59:35 PM

Tuefel believes in magic bullets, I don't. I mean I disagree with Major Tom over how easy it would be to spot a ship at any distance, but at least he's not positing ideas that are demonstrably ignorant of physics.

edited 6th Jan '15 8:00:31 PM by MattII

EchoingSilence Since: Jun, 2013
#2132: Jan 6th 2015 at 8:15:18 PM

The idea that if you are out in space all ships can see you because you are in space?

I have missed a lot and apologize if I am wrong.

TuefelHundenIV Night Clerk of the Apocalypse from Doomsday Facility Corner Store. Since: Aug, 2009 Relationship Status: I'd need a PowerPoint presentation
Night Clerk of the Apocalypse
#2133: Jan 6th 2015 at 8:17:34 PM

Matt: You clearly have no clue what you are yapping about. Funny you mention violating physics your bogus statements do just that. You can't even get the simple small details right never mind the big picture. You certainly be relied for anything resembling reason.

You change the IR Image by selectively telling certain tiles to cool or warm up. That is how they make a CV90 IFV weighing 23-35 tons look like a ton and half 4 door 4 cylinder car. The tiles act like pixels but just like pixels they have limited definition so close examination exposes the lie. It works pretty well from a distance but get a good look at the object or spot it without using IR/Thermal and it doesn't work so well. Again that is pretty much true of all forms of camo though. Holds up at a distance but the closer you get the more likely it is to be spotted.

Yeah sure regular optics could possibly spot it but that might be easier said then done though. There is a lot of sky at the varying focal lengths to cover and the further out you go the more their is to cover. Though if you are talking a FTL tech society putting enough optic scanners with the built in computational tools to do that shouldn't be difficult at all.

As for spotting things in IR contrast that has been done in our system before. You guys were just explaining it earlier. It is also possible to use it as described especially if you have the help of a computer crunching the information like you pointed out. A few of those discoveries were made by alert humans with nothing more then their MK 1 Eyeballs just examining images. While no definitely not perfect it is certainly possible.

edited 6th Jan '15 8:20:14 PM by TuefelHundenIV

Who watches the watchmen?
EchoingSilence Since: Jun, 2013
#2134: Jan 6th 2015 at 8:25:51 PM

Okay so there has been a lot of talk. How plausible is the ship sending out a broadcast signal of sorts that negates it from properly being targeted or viewed?

TuefelHundenIV Night Clerk of the Apocalypse from Doomsday Facility Corner Store. Since: Aug, 2009 Relationship Status: I'd need a PowerPoint presentation
Night Clerk of the Apocalypse
#2135: Jan 6th 2015 at 8:33:00 PM

Visual and thermal can still see you. Unless you just vent heat in a way that makes you a large innocuous blob to thermal but someone will likely know something is up. Spamming signals to futz with radar is easy enough. As far as I know there is nothing to hide you visually unless you hide behind something like a moon, planet, or another ship provided those angles are not covered. There is no smoke screen in space as far as I know.

The other methods you are kinda broadcasting hey something is here. You might not know what yet but you are likely to get someone's attention.

Who watches the watchmen?
Belisaurius Since: Feb, 2010
#2136: Jan 6th 2015 at 8:39:28 PM

[up] Near impossible. Black body radiation doesn't have any regular patterns in wave orientation and light travels so fast that by the time you recognize what you need to send to cancel it out the ray is out of your reach.

If you want to reduce your IR sig you could try hanging a mylar sheet between your ship and the enemy. The sheet will inevitably warm up but it'll make you look pretty small in comparison to your actual size.

You could also try flushing coolant to reduce heat to almost nothing and just drift to where you want to go but you have to shut everything, and I mean everything, down. Any crew is going to end up extra frosty. Again, not fool proof and difficult to pull off but you'll be harder to notice.

So yeah, you could make yourself almost unnoticable but you'll never be truly invisible. Attract attention and you're SOL. Meanwhile, in attempt to make yourself that stealthy you've essentially crippled yourself.

MattII Since: Sep, 2009
#2137: Jan 6th 2015 at 8:42:52 PM

The idea that if you are out in space all ships can see you because you are in space?
That's the one. Now I admit, Major Tom may have a point regarding processing all of that, the disagreement there is in when (if ever) the time will come a full sky scan of the detail needed to reliably pick out a ship against the background.

You change the IR Image by selectively telling certain tiles to cool or warm up. That is how they make a CV 90 IFV weighing 23-35 tons look like a ton and half 4 door 4 cylinder car. The tiles act like pixels but just like pixels they have limited definition so close examination exposes the lie. It works pretty well from a distance but get a good look at the object or spot it without using IR/Thermal and it doesn't work so well. Again that is pretty much true of all forms of camo though. Holds up at a distance but the closer you get the more likely it is to be spotted.
Yes, it's basically a big IR TV. Thing is though that it only works from one side, if you have one guy looking at it from the side, and one 40 yards away looking from the front quarter, it's going to look completely false.

But it doesn't work in space, because it does nothing about the heat you need to get rid of, except make more of it, which means yet bigger radiators, and more mass for the engine to have to move. For no net gain.

As for spotting things in IR contrast that has been done in our system before. You guys were just explaining it earlier.
Against a black background it works, but not against a star, the reason being that a star isn't putting out lasers, it's putting out light, which flows so that to a distant observer, the result is merely a drop in the level of light from the star, and to get that far you need either an object that's either very big, or very distant. But seeing the IR of a small object against a star, no, not happening.

As far as I know there is nothing to hide you visually unless you hide behind something like a moon, planet, or another ship provided those angles are not covered.
That's easy enough, cover as much of your ships as possible in vantablack. Might lead to a bit of IR absorption in system, but if you didn't build your safety factors into your radiators you can't really expect much sympathy.

If you want to reduce your IR sig you could try hanging a mylar sheet between your ship and the enemy. The sheet will inevitably warm up but it'll make you look pretty small in comparison to your actual size.
You also need a method to deploy and retract the sheet, unless you plan to throw it away.

You could also try flushing coolant to reduce heat to almost nothing and just drift to where you want to go but you have to shut everything, and I mean everything, down. Any crew is going to end up extra frosty. Again, not fool proof and difficult to pull off but you'll be harder to notice.
I do wonder how much of a differential you could build up.

edited 6th Jan '15 9:39:27 PM by MattII

TuefelHundenIV Night Clerk of the Apocalypse from Doomsday Facility Corner Store. Since: Aug, 2009 Relationship Status: I'd need a PowerPoint presentation
Night Clerk of the Apocalypse
#2138: Jan 6th 2015 at 9:56:20 PM

Does Vanta also absorb radar waves? I know it gobbles up light like crazy but doesn't that convert to heat after a while? Compared the to empty bits of background in space how black is Vanta black? Part of the reason I ask is that I recall it being so black that people described it as being rather jarring to witness at first. They described it as not really seeing the center so much as the outline kinda like the predators optical camo only not see through with only the edges having definition.

I know they wanted to use it to calibrate space based IR and Optic sensors by showing them the blackest thing they can to make them more effective at detecting more finite light and IR sources.

Who watches the watchmen?
MattII Since: Sep, 2009
#2139: Jan 6th 2015 at 10:55:06 PM

Does Vanta also absorb radar waves? I know it gobbles up light like crazy but doesn't that convert to heat after a while?
Doesn't absorb radio waves AFAIK, and yes, stuff would turn to heat, which now I come to think about it might not be such a good idea, unless you could find a substance that's both black and yet doesn't interfere overmuch with IR (I remember hearing about such a substance somewhere).

Compared the to empty bits of background in space how black is Vanta black?
It absorbs 99.965% of all light hitting it, so, really black.

Actually, now I come to think of it, trying to disguise yourself from visual wavelengths is probably not great, as it would make it easier to pick out given that it will produce mostly only on IR wavelengths, but not visual.

TuefelHundenIV Night Clerk of the Apocalypse from Doomsday Facility Corner Store. Since: Aug, 2009 Relationship Status: I'd need a PowerPoint presentation
Night Clerk of the Apocalypse
#2140: Jan 6th 2015 at 11:17:37 PM

There are some IR paints and I could have sworn the Russians had a coating or something for tanks that was an all around radar and IR reducing signature but mostly from anything short of active emission. I know the USMC Digi Cams use various polymers to create a reduced IR view along similar lines as well.

Who watches the watchmen?
EchoingSilence Since: Jun, 2013
#2141: Jan 7th 2015 at 3:44:33 AM

Practicality of a Klingon style cloak system?

MajorTom Since: Dec, 2009
#2142: Jan 7th 2015 at 4:31:44 AM

^ If you can actually get it to work and not give much if any sensor return? Very. Current light refraction aka "cloaking device" projects make things kinda disappear but only in the visible spectrum. Throw in a FLIR or UV camera and the thing just shows up like normal.

TacticalFox88 from USA Since: Nov, 2010 Relationship Status: Dating the Doctor
#2143: Jan 10th 2015 at 3:20:10 PM

What do you guys think of an exceptionally large Surface-to-Void Rail Gun meant to take out invading starships coming into orbit? Practicality? Costs?

New Survey coming this weekend!
TairaMai rollin' on dubs from El Paso Tx Since: Jul, 2011 Relationship Status: Mu
rollin' on dubs
#2144: Jan 10th 2015 at 4:11:30 PM

[up]Only in Low Orbit. Escape Velocity is a thing. Now, it could be part of a defense in depth. Ships on patrol, orbital weapons and then ground based systems. And they can send materials into orbit as a mass driver.

edited 10th Jan '15 4:12:25 PM by TairaMai

I tried to walk like an Egyptian and now I need to see a Cairo practor....
TuefelHundenIV Night Clerk of the Apocalypse from Doomsday Facility Corner Store. Since: Aug, 2009 Relationship Status: I'd need a PowerPoint presentation
Night Clerk of the Apocalypse
#2145: Jan 10th 2015 at 4:48:25 PM

By Surface to Void I am assuming you mean an Anti-Orbit gun of some sort. Read up on the HARP Project run by Gerald Bull. Using nothing but propellants and common gun tech of the time he made some good strides to shooting something into orbit.

It might be possible but you would need a large and rather powerful gun set up. It would certainly be rather expensive to build the gun and it's power supply.

A downside is even rail guns have a visible blast impulse. The rail gun now produces a fair bit of fire and flare as well as a really hot round as it is under way. The thermal impulse would be very noticeable from some distance owing to being so hot from a sufficiently large and powerful gun. Any force watching the face of the planet that could deploy such weapons would see the impulse. Unless that round is moving really really damn fast the closing speed from surface to say even high orbit would take a long time and could leave room for basic evasion or interception.

Are you using dumb projectiles or guided ones? The plasma envelope that would coat the projectile at speeds needed for it to be a good interceptor would make it difficult at best to guide while in atmosphere. Once it left the atmosphere though the plasma would disperse and guidance could begin. You would need something like thrusters for the KKV on the SM3 intercept vehicle to guide it.

Other possible options to make the round more useful is for it to be a carrier vehicle that disperses say about a dozen DU or Tungsten darts with a calculated dispersal to get at least one hit from a center mass aim point. Not pretty but it could get the job done.

Another idea is to use the rail gun to help assist in rocket launches with the initial velocity possibly up to LEO begin gained from the gun alone with high velocity booster package saved for the rest of the trip.

Lets talk speed. Lets say the target is at the borderline of HEO and GEO-Sync orbit. It would roughly be 35,786 km from sea level. This is assuming a shot from Sea Level to HEO with a projectile that can withstand the forces of the acceleration and air friction heating from the speeds in the first place. The projectile has a blistering speed of 15 km/s and another assumption that by whatever means you choose moves at this speed consistently from launch to impact. The reality of the shot will have a lot of variables that would be rather difficult to calculate.

So the quick and dirty formula looks like this based on the basic formula for R*T=D. 35,786 divided by 15 k/ms to give us the estimate for time to travel. At 15 klicks a second it would take 2385.73 seconds to reach the target or converted to minutes 39.7 minutes. Stepping up the velocity of course shortens the time but there is a catch. If we divide the velocity increases into 5 km/s bands you decreasing differences in travel time improvement between adjacent bands. But compared to the base band of 15 km/s is noticeable. Also the side by side differences match the decreasing time returns as velocity goes up. Something else that goes up drastically the amount of energy required to achieve each band of velocity.

Have a simplified rough table for examples of increasing velocities vs time to intercept from launch, difference in adjacent velocity bands, and the difference from the base speed of 15 km/s.

Base Distance to Target 35,786 km
Speed k/s Time To Target est. Minutes Difference from previous velocity band Difference from 15 k/m s Starting Velocity
15 39.7 N/A N/A
20 29.8 9.9 9.9
25 23.8 6 15.9
30 19.8 4 19.9
35 17.0 2.8 22.7
40 14.9 2.1 24.8
45 13.25 1.65 26.45
50 11.92 1.33 27.78

Bust out the Hand Wavium.

edited 10th Jan '15 4:50:26 PM by TuefelHundenIV

Who watches the watchmen?
MajorTom Since: Dec, 2009
#2146: Jan 10th 2015 at 5:42:41 PM

If it takes more than half an hour to reach your target, you're out of effective range. Nobody's gonna let you hit them with that kind of evasion/interception window.

Hell if it takes you more than ten minutes you might be too far away.

edited 10th Jan '15 5:43:09 PM by MajorTom

TacticalFox88 from USA Since: Nov, 2010 Relationship Status: Dating the Doctor
#2147: Jan 10th 2015 at 5:50:40 PM

[up] So, essentially, best bet would be Orbital Defense Platforms as anything on the Surface would travel too slowly to reach a target in time?

New Survey coming this weekend!
TuefelHundenIV Night Clerk of the Apocalypse from Doomsday Facility Corner Store. Since: Aug, 2009 Relationship Status: I'd need a PowerPoint presentation
Night Clerk of the Apocalypse
#2149: Jan 10th 2015 at 9:59:29 PM

The 'Good News Everybody' is unless the enemy can meet the energy to achieve the same

Well there are a few options actually. Taira already mentioned the best idea.

Divide up the orbital bands into their own sections and use a layered defense in depth. Make them wade through multiple rings of protection. You are not going to be defending the HEO type orbits with speed with single shots from a single gun.

If you have projectiles that have at least some self direction and fire multiple shots at a single target at once you could possibly bracket them. But that requires careful coordination, calculation, and multiple platforms at least reasonably close together to even try that. The projectiles also need to be guided to make the intercept box a reasonable size.

If you want your shore defense gun to work at all you are going to need more then one. You are going need large batteries that can fire several shots in close succession to create a hit bracket. Even then that is not exactly ideal. Having something waiting out in the HEO like Tom mentioned would be far more effective.

But all hope is not lost for your big gun necessarily just not really for the high orbitals. Lets stick with the 15km/s velocity and take a quick peek at the other orbital bands. For the sake and ease of keeping it more compact I am going to start with 15 then 20 and then change those "bands" into 10 km/s blocks instead. See the tables below for what I mean.

This handy pic is the reference point for the quick and dirty data To note the HEO/MEO line is also where they usually sit the GEO/GSO objects. The next band down is the MEO band. The dirty calc was done right at the border as if the target was sitting there or in a stable orbit.

To hit something right at that line as the minimum it has to travel through all the other orbital bands. before it. Also of note these bands are only good for Earth. Other planets may have variations in their bands for any number of reasons. For the sake of comparison I will include the band where they like the GPS Satellites at about 20 thousand + km out which is closer in to the planet by an appreciable degree then the MEO/HEO boundary. The Next One will be at the LEO/MEO boundary.

Going to do a double post to keep the post from being massive and the tables need the room :P

Who watches the watchmen?
TuefelHundenIV Night Clerk of the Apocalypse from Doomsday Facility Corner Store. Since: Aug, 2009 Relationship Status: I'd need a PowerPoint presentation
Night Clerk of the Apocalypse
#2150: Jan 10th 2015 at 9:59:44 PM

Because I am bored have more tables because I remembered how to make the damn things and it is easy to do a big chunk of comparisons all at once.

HEO Table in 10 kms Bands
Base Distance to Target 35,786 km
Speed km/s Time To Target est. Minutes Difference from previous velocity band Difference from 15 km/s Starting Velocity
15 39.7 N/A N/A
20 29.8 9.9 9.9
30 19.8 10 19.9
40 14.9 4.9 24.8
50 11.92 3 27.78

Common GPS Orbit Table in 10 kms Bands
Base Distance to Target 20,350 km
Speed km/s Time To Target est. Minutes Difference from previous velocity band Difference from 15 k/m s Starting Velocity
15 22.6 N/A N/A
20 16.9 5.1 5.1
30 11.3 5.6 11.3
40 8.4 2.9 14.2
50 6.7 1.7 15.9

LEO Orbit Table in 10 kms Bands
Base Distance to Target 2,000 km
Speed km/s Time To Target est. Minutes Difference from previous velocity band Difference from 15 k/m s Starting Velocity
15 2.2 N/A N/A
20 1.6 .6 .6
30 1.1 .5 1.1
40 .83 .27 1.37
50 .66 .17 1.54

The 15 km/s shot at the three bands
General Band at the borders of each band Time in Minutes to target
HEO 35,786 km 39.7
Common GPS 20,350 km 22.6
LEO 2,000km 2.2

Shots with range bands in in 10K km bands.
Distance in increments of 10K km Base speed of 15km/s= Time to target in minutes for base comparison Velocity in increments of 10km/s band starting with 20 km/s = Time to Target in minutes
10K K/M 15 km/s=11.11 20 km/s=8.3 30 km/s=5.5 40 km/s=4.1 50 km/s=3.3
20K K/M 15 km/s=22.22 20 km/s= 16.6 30 km/s=11.1 40 km/s=8.3 50 km/s=6.6
30K K/M 15 km/s=33.33 20 km/s=25 30 km/s=16.6 40 km/s=12.5 50 km/s=10
40K K/M 15 km/s=44.44 20 km/s=33.3 30 km/s=22.2 40 km/s=16.6 50 km/s=13.3
50K K/M 15 km/s=55.55 20 km/s=41.6 30 km/s=27.7 40 km/s=20.8 50 km/s=16.6

edited 9th Feb '15 8:30:50 PM by TuefelHundenIV

Who watches the watchmen?

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