[TML] A little tinkering with Lasers

[Timothy Little]

Glenn M. Goffin wrote:
> Ships in orbit on opposite sides of a planet have to rely on relays
> to find each other.  The time lag caused by using sensor relays is
> the same as the time lag caused by using communications relays.

Only for the initial setup of the communication link, and only if that
setup happens when they are out of line-of-sight.

If they are already in communication, they are able to keep each other
updated on their positions.  They can adjust their meson communicators
to maintain a solid signal.


It may not even be necessary to use a relay for the initial handshake.
It may be possible to broaden the meson beam and time the decay to
happen just past the planet's atmosphere on the opposite side.  The
beam will pass unhindered through the planet, decay on the other side,
and the decay products will continue on through space.  In theory the
other ship could then pick up the signal.  Just noting the direction
of arrival should be sufficient to establish a much tighter return
path, which should suffice for communicating a full 3D position.

The width of the beam might be a tradeoff between signal strength and
time taken to sweep the area in which the ship may reside.
Alternatively the detection sensitivity may be sufficient to just
broadcast.  It's rather likely that background noise of that type
would be quite low!


In principle this is not much different from how two ships would
establish laser communication.  One ship picks up broadcast emissions
from the other (transponder, IR, radio message, or simply sunlight
reflecting from the hull), and uses that to establish the direction to
send a more collimated beam.


- Tim