A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Tony Oz
Date: 2020 Mar 10, 11:47 -0700
I think there should be only one term: either IE or IC, it depends on how you define it. That value - whatever you call it - is just the difference between the true value and the one displayed by an instrument.
Hence the formula: TRUTH - APPARENT = INSTRUMENT ERROR; from which clearly follows if we want to know the TRUTH we must do APPARENT + INSTRUMENT ERROR.
No more "ON-scale/OFF-scale" mumbo-jumbo! Just follow the algebraic rules!