Invisibility in Space
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GypsyComet
Emperor Mongoose
DFW said:
That's sort of the point, though. Finding the Sun would be easy. Picking out that a ship is occluding part of that sun might be a different matter.
As a different matter, the idea of "hiding in the sun" is only going to work for targets whose path is within a few degrees of directly away from or toward the sun. Unless the world you are leaving is inside the Solar jump horizon AND Jump is your destination, that is not going to be a particularly common vector. It is also the most likely to occur with red main sequence stars (which are generally larger in diameter and thus have larger jump horizons) which are cooler than our sun and provide less thermal noise to hide in. Mongoose doesn't usually worry about star types, but a perusal of both the real sky catalog and the big Traveller map sources shows that red stars are the vast majority.
Back toward the other point of view, I keep seeing a tendency to refer to sensors as easily all-seeing by comparing them to either fixed ground-based astronomic installations or to satellite-based survey instruments.
True - but then we're back to 'you can't hit me' stealth rather than 'you can't see me' - see earlier posts.
Dealing with a sensor by decoys or active jamming isn't that hard - a laser of an appropriate frequency washing back and forth over a sensor can blind it at least temporarily quite easily (it's the basis of current airliner anti-MANPAD ecm systems), but it becomes obvious that the bad guys are out there, ditto for 'hostile warship' decoys.
I'm sure some version of the Andromeda FMS* wouldn't be too hard to cook up; plasma-bleed heating elements for IR, dazzlers for laser, radio transmitters for Radar and some variation on grav plating for densitometers. Visual is hardest to trick but then its probably the last one anyone bothers to check!
That aside, making a torpedo or drone look like a frigate or cruiser trying to be sneaky shouldn't be that hard.
* Footprint Magnification System
Well, my reference usually is the kind of equipment today's amateur as-GypsyComet said:
tronomers use, the idea to even attempt to hide a starship from the in-
struments used by the major astronomical observatories would simply
be ridiculous.
Even a simple 1 m telescope with a good CCD can detect objects down
to a size of 15 cm at a distance of 35,000 kilometers through Earth's at-
mosphere (ESA uses such a telescope for space debris monitoring at the
geostationary orbit).
GypsyComet
Emperor Mongoose
It isn't just the equipment, though. If a lowly merchant ship really has high grade, high rate of scan, large aperture, multi-spectrum scanners on every facing, someone probably wasted money. Also, some of these sensors simply cannot be small due to the wavelengths involved. If these sensors are optimized for collision avoidance, landing, and basic nav functions, they aren't full sphere. In such a case a full scan is going to require ceasing thrust and doing a puke spin. Doing that too often cuts into acceleration time, meaning it takes longer to get anywhere. Time is money.
GypsyComet said:
Actually, the equip is cheap. The scan rates have already been posted. With hi-tech, CHEAP equip, you can scan the entire sphere and still use for collision avoidance. Yes, the IR sensors CAN and are small and still handle the needed wavelengths. Sorry, your arguments aren't backed up by current day science, much less high TL (7/8) that are in dev.
For standard visual and infrared sensors the actual sensor, a CCD, would
have the size of a computer chip, and for the usual Traveller sensor ran-
ges the optics would have about the size of a good field scope.
Two such sensors in rotating pop up turrets on opposite sides of the ship's
hull would be able to scan almost the entire sphere.
The price of a sensor would be in the range of a good digital camera with
a zoom - no money at all when compared to the price of a starship.
Radar could require a little more effort, but a 1 m dish should be good
enough for Traveller's sensor ranges.
have the size of a computer chip, and for the usual Traveller sensor ran-
ges the optics would have about the size of a good field scope.
Two such sensors in rotating pop up turrets on opposite sides of the ship's
hull would be able to scan almost the entire sphere.
The price of a sensor would be in the range of a good digital camera with
a zoom - no money at all when compared to the price of a starship.
Radar could require a little more effort, but a 1 m dish should be good
enough for Traveller's sensor ranges.
GypsyComet
Emperor Mongoose
I can separate science from engineering, and both from Traveller. Its a gift that allows me to enjoy the game...
Can these cheap sensors handle the FACT (as defined by you much earlier in this topic) that ships glow like furnaces, including the ships the sensors are themselves mounted on? The lack of atmospheric diffusion would help, I'm sure, but ships are hardly optimal shapes for minimal interference.
Can these cheap sensors handle the FACT (as defined by you much earlier in this topic) that ships glow like furnaces, including the ships the sensors are themselves mounted on? The lack of atmospheric diffusion would help, I'm sure, but ships are hardly optimal shapes for minimal interference.
Since the sensor's optics are pointing away from the hull and the am-GypsyComet said:
bient temperature in space is quite low, there would be no problem.
Only a heat source in front of the optics has its infrared photons direc-
ted onto the CCD (or whatever is used).
It is basically like taking a picture with a camera while standing with the
back towards the sun, not a major problem at all.
Edit.:
To give an impression of the sensor sizes we are talking about, this is a
picture of a current technology startracker CCD - just add the optics to
get the size of the entire sensor:
http://en.wikipedia.org/wiki/File:Frame_Transfer_CCD.jpg
As for the size of the optics, the Schmidt camera of the Hipparcos satelli-
te, probably the best survey camera ever produced, had a diameter of
just 29 centimeters. This would be the upper end for military grade long
range sensors.
Have you'all concidered the harsh environment of space?
I mean solar flare like radiation pulses on your external equipment.
Will it still be cheap?
Will it still be as sensitive? (ie. possible noise degrading detection capabilities)
Just offering off the cuff thoughts.
I am suggesting nothing.
[I think that some have ultimately stacked the deck to get the results that they want.]
I mean solar flare like radiation pulses on your external equipment.
Will it still be cheap?
Will it still be as sensitive? (ie. possible noise degrading detection capabilities)
Just offering off the cuff thoughts.
I am suggesting nothing.
[I think that some have ultimately stacked the deck to get the results that they want.]
GypsyComet
Emperor Mongoose
Fair enough.
Now we need to explain the differences between the standard, survey, and military sensors.
If a penny and a postage stamp will see everything, why spend a dollar?
Now we need to explain the differences between the standard, survey, and military sensors.
If a penny and a postage stamp will see everything, why spend a dollar?
In my view standard sensors will operate with a comparatively low angu-GypsyComet said:
lar resolution and on a small number of wavelengths only, military sen-
sors will have a higher angular resolution and a wider choice of wave-
lengths, and survey sensor will have a high angular resolution and be
designed to cover all wavelengths of scientific interest, including those
useless for military purposes, but important for example to prove the
presence of certain chemicals.
This would make standard sensors the approximate equivalent of a good
amateur astronomy equipment, survey sensors would be high resolution
multi-spectral imagers, and military sensors somewhere in between, de-
pending on technology level and military budget.
If this is approximately right, standard sensors should indeed be cheap,
their computer software could well be a lot more expensive than the ac-
tual sensor. Survey sensors would be extremely expensive, for example
because they would actually have to consist of many different sensors
to cover the entire spectrum from radio to gamma rays (and perhaps al-
so particles) - multimillion credit devices. Military sensors would probab-
ly be closer to standard sensors than to survey sensors in their cost.
Edit.:
Thinking of it, standard sensors could well be "black and white only", with-
out the ability to cover several wavelenghts at the same time for a colour
image.
I don't think anybody is saying you can prevent sensors from seeing that something is there. So what this all comes down to is;
Can sensors be spoofed enough to disrupt positive identification or targeting?
If the answer is yes, then yay! space combat becomes a game of cat and mouse between sensor operators and ECM officers...a bit like fighter-jet combat or submarine combat.
If the answer is no, then Yay!... perfect knowledge of possible combatants in space and perfect targeting.. no more dice rolling!
I know which sort of game would be more fun.
oh..btw
but most stars by far are red dwarfs
Can sensors be spoofed enough to disrupt positive identification or targeting?
If the answer is yes, then yay! space combat becomes a game of cat and mouse between sensor operators and ECM officers...a bit like fighter-jet combat or submarine combat.
If the answer is no, then Yay!... perfect knowledge of possible combatants in space and perfect targeting.. no more dice rolling!
I know which sort of game would be more fun.
oh..btw
'M' stars in the main sequence are 'Red Dwarfs'. You must be thinking of Red Giants which are not main sequence and have a size classification of IV ( subgiants ) or III ( giants ) and not 'V'.GypsyComet said:
but most stars by far are red dwarfs
While I think the ability to spoof sensors will be limited, there is a veryIshmael said:
wide field of tactical options to make it difficult to recognize what the
sensor results actually mean.
A simple example, one could receive, copy and transceive the transpon-
der signal of an enemy ship of approximately the same size. The enemy's
sensors could work perfectly well, but without knowing who is who becau-
se of ships of both sides suddenly appearing as identical, the sensor rea-
dings would become useless [yes, I know that IFF is not that easy to
fool, it is just an example].
