[Laser] coherence and scintillation

[James Whitfield]

Chuck

The test data link you are working on sounds like an interesting project.

I am curious about the different effects that multiple lasers will have
versus spacing relative to atmospheric cell size.  If you have not already
included it in your planned testing, I would like to suggest that you try to
compare the effects of close spaced lasers to wider spacing.   I am sure
that multiple beams will reduce scintillation.  It is not clear to me how
much of the system improvement would be due to phase difference ( and phase
rate of change ) of two or more lasers alone and not how much spacing there
is between the the lasers.

It may be that there is more benefit from two lasers separated by 20 inches
than four lasers clustered within a four inch circle.

Best Wishes

James
 n5gui



----- Original Message -----
From: "Chuck Hast" <wchast at gmail.com>
 >
> Clint,
> Have you tried multiple laser transmitters, this appears to be one of the
> ways that this issue is handled. It appears that 4 of them spaced around
> the receiver lens opening is one way to handle it. A separation of about
> 8 inches between the lasers appears to be a good starting point. I am
> building a test data link using 4 of them one above the telescope opening
> and one below and one on each side.
>