RA & Dec to Alt, Az

rmcpb (Rob) · #1 12-07-2006, 03:14 PM

Does anyone know of the location of a formula to convert the RA and Dec of an object to the Alt/Az.

I know I can get this info from any number of programs but there must be a formula that can be applied to get the correct coordinates for an object in live time.

ving (David) · #2 12-07-2006, 03:30 PM

cos Z = sin(lat) sin(dec) + cos(lat) cos(dec) cos(hr)

Z is the zenith distance and hr is the hour angle.

cos A = (sin(lat) cos (Z) - sin (dec)) / cos(lat) sin (Z)

A is the Azimuth.
http://astro.umsystem.edu/atm/ARCHIV.../msg00355.html
http://astro.umsystem.edu/atm/ARCHIV.../msg00357.html

ving (David) · #3 12-07-2006, 03:34 PM

http://idlastro.gsfc.nasa.gov/ftp/pro/astro/eq2hor.pro

http://www.geocities.com/kellertuber.../software.html

bojan · #4 12-07-2006, 03:34 PM

Hi Rob, have a look at
http://astro.berkeley.edu/~heiles/ha...ay120coord.pdf
There you will find the answer to your question :-)
Bojan

ving (David) · #5 12-07-2006, 04:02 PM

a proggy i think:
http://home.att.net/~srschmitt/celestial2horizon.html

rmcpb (Rob) · #6 13-07-2006, 09:34 AM

Thanks Bojan and Dave. Talk about quick service

ving (David) · #7 13-07-2006, 09:50 AM

who was talking about quick servive?

no problem rob