Thanks a lot. So, does the RA have more of an association with SHA then (which is measured from the Meridian of Aries)? This seems to be academic anyway, if it's not being used by navigators. Now I have to wrap my head around all these meridians....(prime, Aries, geo, celestial...not to speak of the ecliptic etc.) Very confusing, but fascinating. Wish I started this long ago.
Those navigators of old were a very clever lot. Puts most of us to shame.