NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Predictor for moon alt/az at twilight?
From: Fred Hebard
Date: 2005 Apr 1, 08:29 -0500
From: Fred Hebard
Date: 2005 Apr 1, 08:29 -0500
Jim, The MICA program, produce by the Naval Obseratory, is linked on their site. I think you can buy it from Wilhemm-Bell. It outputs the complement of the declination, but you can easily change that by pasting the output into a spreadsheet. Fred On Apr 1, 2005, at 6:07 AM, Jim Thompson wrote: > 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 > -------------------- > Outgoing email scanned by Norton Antivirus >