NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David C
Date: 2017 Jan 21, 16:58 -0800
John wrote:
I was thinking that the GPS and the almanac should be on the same datum and I do not know what the almanac uses.
The purpose of this thread is to discuss positions determined by celestial observation not charted positions. At the risk of going off track and further confusing things I make the following comments. They may help explain where John and I are confused.
I had a look at chart NZ4633 Wellington Harbour. The chart uses the WGS84 datum. A note states:
"Positions obtained from satellite navigation systems referring to the WGS84 datum can be plotted directly on this chart."
But I am an old timer stuck in my ways and I use astro. How do I plot my position on the chart? I can use bearings or horizontal angles because these refer to marked positions on the chart. But how do I plot a position referred to the sun, not gps satellites?
See http://www.linz.govt.nz/sea/charts/paper-charts/nz202-chart-catalogue/4633
