NavList:

   

Reply

Michael,
But what did you expect?
In general, the lunar distances method gives you
an error which is about 30 times your measurement error.
So if you measure the distance with 12"=0.2' error,
the error in your result (longitude) will be 6'.

But few days earlier, in the discussion on this list,
the general agreement was that you cannot do better with a modern
sextant:-)

(I am accumulating evidence that they could do better in early
XIX century when Lunars were indeed important for practical
navigators).

Besides, Venus was "not recommended for Lunar distances"
by one of our experts on the Lunars (I think this was Frank Reed).

Alex.

On Sat, 9 Oct 2004, Michael Dorl wrote:

> As I was sitting in the hot tub this AM watching the
 spectacular heavens
> with the moon and venus about 15 degrees apart,
 it occurred to me to wonder
> about lunar distance measurements using venus.
 I've never tried to measure
> any lunar distances but I went ahead anyway.
  My results were consistently
> about 5 to 7 minutes lower than predicted by a program
 I wrote that uses
> the Mosier JPL AA routines.  I wonder if this is some fault in my measurements,
> calculations, or the AA routines.
>
> I'd really appreciate it if someone could independently work out the moon
> venus distance for
>
> 89.50 west 42.85 north
> altitude 290 meters
> temperature 5 degrees C
> tick.usno.navy.mil time 6-13-06 CDT 11-13-06 Greenwich
>
> I assumed a 15 minute moon semi-diameter.
>
> Maybe send the results to the list so everyone knows when to stop.
>
> Thanks in advance
>

   

Reply