NavList:

Bob wrote

Astro Navigation and Celestial Navigation appear to be equivalent terms.  If you are from N. America you probably talk about CN.  If you are from Britain or Belgium, it appears to me that you tend to describe the same thing as AN.  It would be interesting to map out the linguistic tendencies of various regions of the world.

An important question is when did  these terms come into use? Before electronic navigation there was no need for a specific term. If you were put of sight of land then you used DR and sun/moon/star sights - all lumped under the term "Practical navigation". For some unknown reason (I have no proof) I have always associated "astro" with the RAF and WWI2.

Did US aircraft have astrodomes or were they called celestial domes?

I entered "astro" into google ngram and there were entries going back to 1800. I decided that "astro"  was too general - for example here may have been  hits related to metaphysics - so I entered the terms "astro navigation" and "Celestial navigation". I have attached the results. I believe that ngram confirms that pre-ww2 tthe word "navigation" included  sun/moon/star observations so there was no need to use a specific term.