A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Randall Morrow
Date: 2014 Sep 16, 07:34 -0700
Sam, SHA is just longitude of the celestial sphere, and declination is its latitude. The hour circle of Aries is an arbitrary reference that is the Greenwich of the celestial sphere. We assume the earth is stationary and that the celestial sphere turns overhead. It's just one spherical grid turning over another.