There are two subtleties here. First, you have happened to use “elevation” and “altitude” to mean the opposite of what the two terms mean in the PyEphem library — so you are calling the spot in the sky its “elevation / azimuth" position instead of its “altitude / azimuth” position. Second, it appears that PyEphem has forgotten to provide an easy way to convert dates from Julian to its own format. While there is a function julian_date() that will go the other direction, we will have to do a bit of work ourselves to go the other direction by figuring out what ephem's name is for.
With those stipulations in mind, I think this script might answer your question:
import ephem
az = 3.30084818 #rad
el = 0.94610742 #rad
lat = 34.64 #deg
lon = -103.7 #deg
alt = 35800.26 #m
ut = 2455822.20000367 #julian date
# Which Julian Date does Ephem start its own count at?
J0 = ephem.julian_date(0)
observer = ephem.Observer()
observer.lon = str(lon) # str() forces deg -> rad conversion
observer.lat = str(lat) # deg -> rad
observer.elevation = alt
observer.date = ut - J0
print observer.date
print observer.radec_of(az, el)
Does the answer it produces look correct for this particular observation? Here is what the script prints for me:
2011/9/17 16:48:00
(9:16:24.95, -0:45:56.8)
Let me know if that makes physical sense for this particular observation, or if one of the numbers is wrong here and still needs to be tweaked!
