US Navy
United States Naval Observatory Homepage
United States Naval Observatory is a unique observatory run by the Navy. It does some of the grunt work of astronomy -- keeping accurate time, determining positions of stars (astrometry), etc. They are responsible for publishing the...
Other
Nrao: What Is Radio Astronomy?
This page contains an introduction to Radio Astronomy written by the National Radio Astronomy Observatory (NRAO). It contains some basic theory as well as frequently asked questions and teacher resources.