I don't know the Perl module you are using, and am not able to help, but maybe I can clarify a bit on the celestial coordinate systems.
Azimuth and elevation give the position at a given time of a celestial object compared to the local horizon of the place where the observer is located. The are called horizontal coordinates. Thus it depends on where the observer is located.
Right ascension and declination constitute the equatorial coordinates, which do not depend on the location of the observer, as they are measured against the celestial equator. Declination is the angle of a celestial object to the equator (it is sort of the latitude of the object). Right ascension is analogous to the longitude and is the angle between the vernal equinox point (a special point on the celestial equator) and the object. It is often measured in hours, minutes and seconds (in this case, it is usually called hour angle and it is analogous to the time zone of the celestial object), rather than degrees or radians.
There are other systems of coordinates used in astronomy but that would become off-topic.