> I'm contemplating organising some form of Clear Sky Clock specific to
> the Australian region.

Cool. I wish you the best of luck.

I expect others on this group will weigh in on the technical meterolical stuff.

> Is there a simple algorithm x+y+z/2 = good seeing that's not
> copyrighted and is able to be shared?

I don't know about copyrighted, but I do no that the calculation is
complex. It requires data about temperature gradients and vorticy at
multiple altitudes. Pehaps Allan Rahill will explain.

One thing I suggest is hat you not call it a "clear sky clock". There
is a company in the usa that is perfectly willing to sue people
outside of the usa for using the character string "skyclock".
(Personal experience. )

-ad