NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Meaning of Tilde
From: David C
Date: 2016 Jun 20, 16:58 -0700
From: David C
Date: 2016 Jun 20, 16:58 -0700
I think that I know what (dec ~ lat) means but I am not completely sure. If I google ~ wikipedia gives dozens of meanings, none of which seem to match the navigation use. Navigation books usually give very wordy explanations if how to calculate it.
My explanation is (dec ~ lat) = mod(dec - lat)
Example 1: dec = N23°, lat = S41°
mod(dec - lat) = 64°
Example 2: dec = S23°, lat = S41°
mod(dec - lat) = 18°
Example 3: dec = S23°, lat = N41°
mod(dec - lat) = 64°
Am I correct?
I have also seen the expression (dec +- lat) (+- symbols stacked vertically). Is this an alternative way of expressing the same idea?
