NavList:

George wrote:

> 1. The "rounding" problem could cause a significant offset,
> consistently the same way over weeks at a time.

I am not tracking (what's new?).  Are you referring to offset in 4SD?  If
not, please fill me in.

Some find my concerns a bit over the top, but it seems a bit macho to give
away half the margin of error to rounding in some cases when already working
at the man/machine limits.

It would nice to have surveyors' data. For my own use I find the jump before
the date I am using and the jump after, count the pages and divide in half
to find the midpoint.  That gives me a page where SD is close to spot on.
Then I can interpolate by the number of pages from that to a jump point to
get a useable estimate of SD.
>
> 2. That considering the small perturbations that are being
> investigated, local air-layer effects might be significant, if the
> local weather wasn't aware of the standard refraction predictions.
> It's fair to say, however, that at the high Sun altitudes that Bill
> has been quoting in his recent observations, I would certainly not
> expect to see any measurable distortion in its profile.

That is my hope, but as you point out Mother Nature is either not aware or
not compliant with our wishes.  Weather permitting, I would have started the
marathon run about an hour before LAN (LAN nominally 13:48 EDT at my
location) to have the sun up around 70d. This despite a saying here in the
colonies that only mad dogs and Englishmen go out in the noon day sun.  But
I am 3/4 English by blood, so take no heed. <G>

I should finish posting the initial set of experiments this evening, then it
is on to discovering how to use it for a personal correction factor, and
toying with the scope focus/chromatics conundrum.

Bill


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