Sensors in space

A thread of 2 messages, 15 February 1991 to 18 February 1991, in the order they were sent.

#2153 Sensors in space

Iain Fogg · 15 February 1991

Since the current topic of discussion is about distances in space (in
particular, the 100 diameter limit), I's like to pose another related
question: How do you handle sensors in space?

In combat, a sensor ops roll has a difficulty profile according to
whatever sensor array you happen to be using, modified by Sensor Ops
skill or computer model and range. The range DM is -1 per square (or
25000 km). That means that even with a Simple sensor ops task and a
model 9 computer, anything beyond 450000 km is invisible. Here's how I
arrived at that number:

	 Best dice roll:  12
	 Computer model: + 9
	 -------------------
			  21
	Number required: - 3
	 -------------------
	  Maximum range:  18 x 25000 = 450000 km
	   (in squares)

That seems totally unreasonable to me, especially when some of the
sensor packages have a Interstellar range.

Notice that any planet size 5+ can't even detect ships out to its 100
diameter radius (without the help of navigation satellites, etc). That
seems really bizarre.

I don't _think_ I've missed anything entirely obvious, have I?

- - - Iain.

#2154 Re: sensors in space

Paul Dale · 18 February 1991 · reply to #2153

hiya,
	Sorry about the previous message, it escaped be accident and
the configuration we suffer under here, doesn't allow us to stop wayward
messages (anymore).

[That's okay Paul - I fixed it before it got out to the list at large --
James]

Back to the topic itself...

>	 Best dice roll:  12
>	 Computer model: + 9
>	 -------------------
>			  21
>	Number required: - 3
>	 -------------------
>	  Maximum range:  18 x 25000 = 450000 km
>	   (in squares)
>
>That seems totally unreasonable to me, especially when some of the
>sensor packages have a Interstellar range.

After some thought about this problem, I've come up with a possible solution...
The tasks given in the space combat section of the ref's guide are for COMBAT
only.  They represent getting a usefull fix on the target.  At the range of
18 squares = 450000000 m = 4.5 * 10^8, it will take 1.5 seconds for light
to travel the distance (c = 3 * 10^8 approx).  So for a passive sensor, you
wait 1.5 seconds to detect something and and least 1.5 for your response to
get back (for lasers it is 1.5, for most other things it will be longer).
This is a totaly round trip time of 3+ seconds!!  In a combat situation this
is a VERY long time and the target will have maneuvered somewhat before your
response hits it.  For an active sensor things are even worse and the figures
come out at about 3 seconds to detect and 1.5 (min) response.  I agree that
a range of 18 is a but long even for space combat, but going down to a range
of 6 squares, you still have one second response time (which is still quite
large).

Basically, I'd say that the tasks given in the refs guide are for combat
purposes only and that they represent the getting of useful information.
For non-combat sensor scans, a new suite of tasks will have to be devised
which work out to a much longer range.  I haven't defined any such tasks
(yet :-), but I'd be interested in the TML's comments about the idea.


>Notice that any planet size 5+ can't even detect ships out to its 100
>diameter radius (without the help of navigation satellites, etc). That
>seems really bizarre.

This would have to be repaired, a ship that comes out of jump with its
transponder blasting away would have to be detected (it might take a while
for the detection to occur, but it would be known to be present).




							Pauli
seeya

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