Re: Sensors

>At 7:17 AM +0200 5/30/01, Derk Groeneveld wrote:
>[snip]
>But as for actives being a little pen light, well, I'm not sure I
agree.
>Active _tracking_ is a little pen light, but active search sensors are
>more like a whopping wide beam.

Thing is, unless you are talking about the SPY Phased array systems, 
most are distinct systems. The general search not being very good at 
figuring accurate range and height (in the Anti-air role).

>
>Mmmm. I guess you can use mm radar in space at a lot longer ranges than
on
>earth; on earth atmospheric dampening greatly limits mm waves.

Lots less water vapor to absorb your signals.

>
>I'm not familiar with Cepheid variables? As for
>triangulation, with the ranges involved with space combat, I doubt you
>could do it with the sensors on one ship alone. I'm not familiar with
>inferometric ranging, so I have no clue how that'd work for you ;)

Cepheid variables are stars that pulse regularly and are used to 
determine how far objects are. They are a medium sized yard stick. 
Distances being from inside our galaxy to the Amdromeda Galaxy or so.

Inferometry is where you use two widely spaced telescopes to give you 
a much wider 'virtual' lens. The use of the Very Large Array in the 
South Western American desert is an infero-metric array. Larger 
arrays have been coordinated by tying the inputs for two (or more) 
telescopes on opposite sides of the country or even the world at the 
same time at the same targets. In radio telescopes and in opticals it 
gives you a bigger "lens" to look through.

This larger lens allows a better clarity of the object. Figure two 
ships operating at a great distance 10-20 MU's communicating over 
tight whisker beam to coordinate their efforts. They'd get a very 
good idea of what's there.

Given a good set of lenses you can determine ranges based on angles 
between two prisms space a few meters apart over thousands of meters. 
The distance of the Earths orbit (2 AU) has been used to determine 
distances of stars in our side of our galaxy over tens of thousands 
of AU.

Two Telescopes of about 40 inches across on either side of a 
Vandenberg should be good for a few tens of thousands of kilometers 
at least. When I want to shoot him, I zap him with a ranging laser 
for final accurate distance and let fly with my big beams and torps.

In game terms this would be dealt with by two ships adding their 
passive die rolls to see what the target is. If you really want to 
figure it out, but it uses several ships to figure it out. I wonder 
if range should play a part.

(there are system now that can track a star and keep tracking a star, 
why not a tight comm laser that can track to an object and back, 
after all NASA bounces lasers off mirrors on the moon regularly).

>
>Also, the drives might have unique resonance frequencies etc? Sir,
we've
>seen this ship before, it's .... Then again, there might be a wartime
>tuning of this frequency to a different one than peacetime?
 
Yep, witness the way in which magnetic fields of US vessels is 
manipulated upon leaving port.

--
- Ryan Montieth Gill		DoD# 0780 (Smug #1) / AMA / SOHC -
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