NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
DATUM was sight reduction with GPS receiver
From: Michael Dorl
Date: 2005 Mar 22, 07:59 -0600
From: Michael Dorl
Date: 2005 Mar 22, 07:59 -0600
At 10:48 PM 3/21/05 -0500, you wrote: >Frank > >My 2001 Garmin 76 (firmware 2.06) had book had approx. 56 datums listed. > >Bill > > > Frank, > > > > I looked into the instruction book for my > > GPS 48 (Dated Dec 1999) and found over > > 100 datums listed. I was interested in datum stuff a while ago, the best source (with XYZ offsets) I found was at http://www.globalsecurity.org/military/library/policy/army/fm/3-09-70/appj.htm I guess, it's part of a manual for long range artillery. The Astronomical Almanac App K (page K11 - K13 in my 1998 copy) has some information on transforming one datum to another. I have found some references that imply there may be some rotation of the spin axis between datum in addition to the translation of the origin but I have never found any actual rotation numbers. If anyone could point me to actual data on such rotations or a reference saying there are none, I'd appreciate it. BTW, is datum plural or singular, does it have a plural?
