[time-nuts] Sidereal time

Lux, Jim (337C) james.p.lux at jpl.nasa.gov
Fri Jan 15 17:21:47 UTC 2010




On 1/15/10 9:13 AM, "J. Forster" <jfor at quik.com> wrote:

> Heresy:
> 
> Why do you really NEED super accurate siderial time? If you are using it
> to point a telescope, you only need it accurate enough to get the guide
> stars into the field. Remember, the atmosphere refracts kinda randomly.
> 
> -John
> 
> =

Celestial Navigation?  Essentially, one determines longitude by figuring out
what the difference between local solar time and sidereal time is. Now, what
is super accurate?  40,000 km =24hrs, so 1 second is about 460 meters.  




More information about the time-nuts mailing list