NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Antoine Couëtte
Date: 2015 Dec 9, 11:45 -0800
Dear Frank,
Your reply is quite interesting to me. Thank you for it.
It turns out that a few years ago (maybe 4 or 5 years ago) I checked your On Line Calculator for Occultations of Stars. Some results were in error by up to 0.25' (15") when compared to other reportedly accurate software (e.g. http://www.lunar-occultations.com/iota/iotandx.htm or others) dealing with a spherical Moon shape (no consideration for mountains and valleys which start playing at the 0.1' level).
This result did not surprise me since there are quite appreciable non linear effects when dealing with Occultations, hence the earlier mentioned and well known "5° to 7° minimum distance" caveats applicable to [almost] all [tabular] classical Lunar clearing methods.
When Greg published your On Line Calculator results processed from his own Venus immersion/emersion data, I noticed that the error of his observations were rated by your Computer as being not more that 0.1 '. I then hastily concluded that your had fine tuned your software in between.
Best Regards
Kermit