On 08/19/2017 06:38 AM, Cursitor Doom wrote:
On Sat, 19 Aug 2017 07:21:33 +0000, gregz wrote:

It's hard enough to communicate with Voyager when two dishes converge.
Horizontally omni broadcast has low energy and complex signals. Forget
it.

Greg

I'd always suspected so. But is there any respectable research to back up
this figure of 1.5 light years?

The problem with communicating with Voyager is on the uplink side, not
the downlink side. Even at Voyager 1s distance and current power output
of a few 10s of watts, in the appropriate spectrum Voyager 1 is a
blazing beacon far outshining most other objects of interest studied by
radio astronomers.

I think it's possible to do much better than 1.5 light years, if you can
make some assumptions about what area of the spectrum you're looking in,
and what kind of patterns you're looking for. It's not like there aren't
ways to recover periodic signals/signals with structure that have been
corrupted by noise.