Next message: Fred Hebard: "Re: Predictor for moon alt/az at twilight?"
For the past couple of springs I have planned the best opportunities for
practising 3-body twilight fixes at nearby Point Prim during the warm
months. We have nearly 270d horizon at that location. The criteria for a
good viewing night include having the moon with sufficient illumination, and
within a good alt/az window for beginners.
The tables I can make at http://aa.usno.navy.mil/data/ are very helpful in
providing all the rest of the data I need for this, but they do not offer
one particular printout:
Is there an online calculator, downloadable program or spreadsheet that
would allow me to print out the altitude and azimuth of the moon at a given
hour for a specific lat/long position at civil twilight daily for a period
of several months? I can find lots of ways to predict the alt/az for a
given day, but I want to build a table to print on one page the moon's
alt/az for all the days in the coming months, at a given hour.
Header: Moon altitude and azimuth at civil twilight by day for the Period
___ to ___ at Position Lat __ Long ___.
Columns: Month/Day, Morning CT, Moon Altitude, Moon Azimuth, Evening CT,
Moon Altitude, Moon Azimuth.
Rows: Day of the month.
Instead of civil twilight, the table could be generated for a set hour in
the morning and a set hour in the evening, and then I could pick out days of
the month where the moon is likely to be in about the right position, and
work out the precise results for each of those days manually.
Jim Thompson
http://jimthompson.net/boating/Celestial_Navigation.htm
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