How do ships see?

[atpollard]

Originally posted by TheEngineer:
Well, You could use a single cell but simply filter out the well known background frequencies ...
That should keep construction simple, too

A very elegant solution for merchant ships. Plus it opens the door for a pirate ship to “tune” his emissions to the well known background frequencies to buy him a little more time to stalk a merchant undetected (in game terms, it might reduce the civilian detection range by 25 or 50 percent). It would have no effect against a real Navy ship, but it could buy the pirate a small advantage in time.

[and Bill C. just made it abundantly clear to me in another topic that TIME is a pirates greatest enemy – the time from when the victim sends a call for help until help arrives is all of the time a pirate has to stop a ship, loot it and escape.]

 

[atpollard]

Originally posted by TheEngineer:
But don't you think sensors are awfully cheap compared to the rest of a spaceship ?

Unless sensors are part of the bridge cost that increases with ship size (CT is unclear on sensor cost, MT may be completely different).

 

[atpollard]

Originally posted by TheEngineer:
Now, a VERY crude (no concern of sensor types or targets cloaking activities) task for general scanning is given in the MT RefManual:

To scan the area for unidentified starships:
Routine, Sensor Ops, Edu, 10 sec (uncertain)

This points out two things. First it establishes a firm time for a complete scan of the sky (10 seconds) which is useful for the gear-head part of this topic. Second, the fact that “Sensor Ops” skill affects the results indicates that it is not a 100 percent hardware process – the computer analysis is the best part for a technician to “tweak” for better results

 

[atpollard]

Originally posted by SGB - Steve B:
That's why I tend to figure you can "hide" in space. Given just the right set of conditions - you might even be able to ambush somebody. Granted the ambush is a lot harder than just hiding and nearly, if not completely, impossible without special circumstances - but still possible under the right circumstances.

This begs the question: How close is the main world watching things and what resources do they have to investigate. A ship that disappears from sensors near a moon of the nearest Gas Giant in a TL 15 System with a class A starport and a Navy Base will probably receive some “official” attention. A TL 9 world with a class D starport might not even have a ship to send to investigate even if they were watching the sky. Where is the dividing line below which piracy and stealth are plausible. If the only worlds able to suffer piracy are too small, poor and primitive to have trade, then stealth, hiding and piracy are all pointless.

[To avoid drifting too far off topic, this post is intended to focus on a System’s sensors and how they might affect ships sensors and anti-sensor technology.]

 

[atpollard]

Originally posted by Sigg Oddra:
</font><blockquote>quote:</font><hr />Originally posted by atpollard:

Example 2: Gravity bends space, and all reactionless Maneuver Drives bend space around the ship rendering it invisible to detection by EM detectors (light, heat, x-ray, etc.). Sensors detect gravity distortions and so detect ships only indirectly.

This would also shield the ship from weapons fire

</font>[/QUOTE]A good point.

I hadn’t thought about lasers, but yes, that conclusion would follow – unless some wavelengths can penetrate and others can not. Then x-ray detection and lasers might work while IR and visible light would not. This obviously increases the amount of handwavium required, but we already have reactionless drives travelling faster than light, so ANYTHING is possible.

I had thought about particles (like space rocks) being bent harmlessly around the ship. This fits with the lack of any cannon on shielding the hull from small impacts at high velocity. It also agrees with the lack of kinetic kill weapons in CT (where are the railguns?).

Missiles are proximity kill weapons, so compression shock waves could pass through the interface.

This is not my favorite model for how drives and sensors work, but it is plausible within the information given in Classic Traveller. (CT, MT, TNE, etc. do not agree with each other, so no answer will fit ALL systems.)

 

[Valarian]

All these technical answers ... just paint eyes on the front of the ship.

 

[sgbrown]

Originally posted by Sigg Oddra:
</font><blockquote>quote:</font><hr />Originally posted by atpollard:

Example 2: Gravity bends space, and all reactionless Maneuver Drives bend space around the ship rendering it invisible to detection by EM detectors (light, heat, x-ray, etc.). Sensors detect gravity distortions and so detect ships only indirectly.

This would also shield the ship from weapons fire

</font>[/QUOTE]My gut reaction to drives providing shielding is that it's a cool idea.

Then the engineer in me kicks in - even if possible (given traveller tech) would it be practical?

So assuming that a gravitational lens could be created with enough strength to bend light around the ship, what pratical limitations would be imposed IYTU to make such stealth technology less than common place? or would it be commonplace?

 

[sgbrown]

Originally posted by Valarian:
All these technical answers ... just paint eyes on the front of the ship.

I'm partial to sharks teeth over the fuel scoop myself

 

[marvo]

Regarding the Dazzle tactic.

If you are in the habitable zone of a system then the central star is not going to be far off. Keeping yourself between the enemy and the star would make any kind of EM detection very difficult. Just an updated version of the 'Attack out of the Sun' fighter pilot tactic.

Someone else also mentioned detecting reflected light. In MTU it has always made sense that military ships and pirates would be painted matt black to avoid that. Of course this would maximize your heat signature, but you can't have it both ways.. sometimes the laws of physics are a pain.

 

[ElHombre]

But there's no relaistic way a ship is going to stay in that extremely narrow arc for a length of time given the speed at which space travel takes place. An observer will see the ship before it crosses the star and will know almost where it will emerge (unless it jumps).

 

[sgbrown]

Originally posted by ElHombre:
But there's no relaistic way a ship is going to stay in that extremely narrow arc for a length of time given the speed at which space travel takes place. An observer will see the ship before it crosses the star and will know almost where it will emerge (unless it jumps).

I think the intent was to position yourself so as to be able to attack with the star to your back. No crossing would occur - the attack comes "out of the sun."

 

[sgbrown]

Originally posted by Marvo:
-clip-

Someone else also mentioned detecting reflected light. In MTU it has always made sense that military ships and pirates would be painted matt black to avoid that. Of course this would maximize your heat signature, but you can't have it both ways.. sometimes the laws of physics are a pain.

Possible way around that would be directional heat radiation. If you know the enemy location radiating excess heat from the other side of the ship would be the way to avoid detection.

 

[ElHombre]

Originally posted by SGB - Steve B:
</font><blockquote>quote:</font><hr />Originally posted by ElHombre:
But there's no relaistic way a ship is going to stay in that extremely narrow arc for a length of time given the speed at which space travel takes place. An observer will see the ship before it crosses the star and will know almost where it will emerge (unless it jumps).

I think the intent was to position yourself so as to be able to attack with the star to your back. No crossing would occur - the attack comes "out of the sun." </font>[/QUOTE]It still doesn't work. The attacking ship would be needing to use its M-drives just to set up the attack run, which would be noticed. Not to mention that the victim's course is also changing respective to the attacking ship.

Back on tangent, I've been trying to imagine ways to help the pirate trade and I came across the idea of sabotage. Someone programs the PCs ship to ignore a certain kind of sensor reading.

 

[marvo]

Originally posted by SGB - Steve B:
Possible way around that would be directional heat radiation. If you know the enemy location radiating excess heat from the other side of the ship would be the way to avoid detection.

That's not a bad idea. Considering that a lot of ships have liquid hydrogen fuel between the inner and outer hull there is not going to be much of a heat signature from any of that area. If all the heat is channeled to the exhaust ports at the back that would also explain why they glow. Given this scenario, it would be very difficult to detect a ship heading straight toward you by it's heat signature.

M-Drives are still a bit of a handwave technology. If they work via gravity there is no reason to assume they create a heat signature when used. i.e. they are not expelling a cloud of hot exhaust gas. They might be easily detected in other ways though.

You might not be able to get in position infront of a star but from what we know of Jupiter, detecting an SDB in it's atmosphere below you would be very difficult for the same reasons.

 

[sgbrown]

Originally posted by ElHombre:
It still doesn't work. The attacking ship would be needing to use its M-drives just to set up the attack run, which would be noticed. Not to mention that the victim's course is also changing respective to the attacking ship.

Back on tangent, I've been trying to imagine ways to help the pirate trade and I came across the idea of sabotage. Someone programs the PCs ship to ignore a certain kind of sensor reading.

The sabotage idea has a lot of merit - but why not just take out the drives, guns, and comms and have the malfunction set to occur as the ship approaches the 100D limit? A bit of judicious planning as your ships approaching the same jump point and you can waylay the ship fix the "malfunction" and jump out. Added advantage, if you're caught you claim that it gave a weak GK signal and when you docked to render assistance they tryed to bushwack you. Fortunately your crew was very alert and the pirates plan failed. What's the reward for capturing a pirate vessel again?

As for using the star, difficult does not mean impossible! Yeah theres a lot of complicating things to using the sun "in the eyes" trick - there where for the Red Baron as well - but he still used the trick (or ledgend has it he did anyway.) Not 100% effective - but what is? No priateing plan will be foolproof - or commerce will cease and then there'll be nothing to pirate!