Last updated: 26 Oct 2002

Sofware to convert RA/Dec to alt/az, and then to convert to 'protractor' and 'tape measure'

In this 'starter pack' you will get the following files:
SIDEREAL.BAS - QBASIC file that does the math and displays coordinate conversion
BSTARS.TXT - data file of bright stars for alignment
5MAGSTAR.CSV - larger data file of alignment stars to magnitude 5
MESSIER.CSV - data file of Messier objects to observe

Copy them all to C:\mg-iii
Start up QBASIC.EXE and load SIDEREAL.BAS, then run the program.  This will get you a feel for what questions the software needs answered from you.  Make note of the hot key menu options that are available, including the option to save your telescope's alignment data in a file.  This is handy when you take a nap and power down the computer...when you wake up, start the program and load the saved alignment data.

To use the program you need to have the base of your dobsonian levelled.  After that, alignment on one known object is all that is needed to get correct conversion/display information from the software.  You do not need to orient your azimuth setting circle so that you get a reading of zero when the scope is pointed true north, or that your altitude setting circle reads zero when the tube is horizontal...the use of the hotkeys A and E will shift/adjust the displayed values to match your mount.

Note - this software is not ready to use out of the box.  You will have to modify lines of code to suit your specific needs, such as your lat/longitude of observing sites, your time zone, your azimuth tape measure circumference, etc.  Also, you will have to determine which way your scope's setting circle displays elevation (higher value with higher elevation, or the opposite) and which way your scope's setting circle displays azimuth (increasing with increasing azimuth, or decreasing with increasing azimuth)...and make sure the code works appropriately.

If you find this code useful, and want more data files (NGC objects, etc.) please ask and I'll send them your way.

If you are not comfortable modifying the code yourself, please let me know and I can help you along.


Please contact me if you have any questions.
Tom Krajci
Tashkent Uzbekistan
Tkrajci@san.osd.mil
