NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Exercise #14 Multi-Moon LOP's
From: Jeremy C
Date: 2008 Aug 8, 16:29 EDT
Looking for a car that's sporty, fun and fits in your budget? Read reviews on AOL Autos.
--~--~---------~--~----~------------~-------~--~----~
Navigation List archive: www.fer3.com/arc
To post, email NavList@fer3.com
To , email NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---
From: Jeremy C
Date: 2008 Aug 8, 16:29 EDT
EDIT:
Frederico,
Glad you worked them out. I didn't bother posting a solution as
such. Basically the given 1900 ZT position is a GPS fix, so that is what
we can assume to be the true position, and the celestial fix is an error check
of the GPS position (please no arguments on this point as it is beyond the scope
of this exercise.)
I plugged each moonline into my celestial program (SkyMate Pro) as
individual moon LOP's. The computer then compared them and gave me a fix
of 14 deg 14.9' North; Longitude 142 deg 51.9' East at 1900. This is a 1.7
nm error as compared to the 1900 fix via GPS.
The trouble with crossing an averaged LOP in this case with a course line
is that it does not give us a fix, but rather an "estimated position."
This is an experiment I did to see if a fairly large number of sights of
the same body, shot in a relatively short period of time, could give us a
position of reasonable accuracy away from meridian transit. As we can see,
it is fairly accurate, certainly accurate enough for a deep sea position.
The position probably would be more accurate if the change in azimuth of
the body was greater then 5.5 degrees, but that is why I shot the moon, as the
azimuth is changing rapidly, even away from the time or meridian transit.
Jeremy
Looking for a car that's sporty, fun and fits in your budget? Read reviews on AOL Autos.
--~--~---------~--~----~------------~-------~--~----~
Navigation List archive: www.fer3.com/arc
To post, email NavList@fer3.com
To , email NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---