NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: We need a backup to GPS
From: Brian Walton
Date: 2019 Jul 20, 22:08 -0700
From: Brian Walton
Date: 2019 Jul 20, 22:08 -0700
Hi,
GPS already has a back-up built in.
If the problem is loss of signal, or spoofed signal, don’t switch it off. Do CN.
Enter best position as start point. Enter almanac GHA/Dec as destination, and get miles. Divide by 60, get degrees, divide remainer by 60 to get minutes. Take away from 90°: there’s your Hc.
Brian Walton
