NavList:

   

Reply

daveweilacher@earthlink.net wrote:
>> It is the
>> ZENITH that the navigator is attempting to locate in the celestial
>> sphere. Once that has been accomplished, he projects it down via the
>> local vertical, simply by renaming declination latitude, and GHA
>> longitude, and calls it his  position . This works on an egg, a pear, a
>> lemon or an onion.

Rodney Myrvaagnes  replies:
> This is rigorously true, but it dodges the question that I think
> people meant to ask, vis: If the local vertical (gravitationally
> determined) doesn't point to the center of the earth or the celestial
> sphere, then where is the position so measured?

The actual (meaning the astronomical) latitude and longitude of a
place is what is measured.  In other words, the position so measured
is exactly that place where it is measured. Due to local gravitational
anomalies there may even be other places nearby with the same
astronomical latitude and longitude.

   

Reply