NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Brian Walton
Date: 2018 Jan 5, 20:50 -0800
Tracy,
We’re talking the same language. Here are some refinements.
To reduce “dome correction” try and get a body where the line of sight crosses the window at 90° near the middle. The 747 has awful thick curves near the edges, the 767 a nice flat window.
Definitely do Coriolis corrections. Groundspeeds go up to 700 kts eastbound.
The more single shots you do, the easier it is to recognize a good one and discard a bad one. I used the side of the bubble, not the middle. Backlash on the gearing might mean it’s better to refine always tracking up, or always down. I don’t like tracking for 2 minutes; nasty things creep up behind you.
Oceanic routes often have legs following a parallel of latitude. Perfect, since Lat won’t change whilst you shoot for Long. Running fixes aren’t necessary. I discarded running fixes since my yacht calculator refused to accept ground speeds of hundreds of kts. I was able to fix this with my own programs in a Psion.
Your accuracy is adequate. Minimum time taken to get a fix is more important. Keep practicing; as with any artisan skill, you can forget how to do it. Love your PBY story. I guess the R in CRJ means long trips are rare. Winter westbound Pacifics are up there with your Catalina!
Brian Walton
