NavList:

Norman B, you wrote: "I am just following your advice in a previous message and creating an arc correction table by keeping track of my sightings and also the values shown from your app."

Oh well, I do apologize if I didn't understand what you were doing, but you haven't posted anything about your data -- the differences between your sights and the values shown in my app. Instead you have posted numerous position line plots, which clearly contradict what you're saying now, and do not provide any meaningful evidence of what you're doing in the first place. What ARE you doing?

You coninued:
"There seems to be a simple pattern when I compare the values and I am applying some trivial math to it."

So you have claimed, but you're merely repeating yourself without evidence. And then you started talking about a quadratic correction. Why?! What ARE you doing??

A sextant arc calibration table typically provides corrections every 15 or 30° degrees. Since you say your AH sights are limited to the range from 30 to 90 degrees, your table should include values for angles of 30,60,90° or 30,45,60,75,90°. Take a dozen sights within a degree or two of each of those. Then you've got something to work with.

Finally, the claims you're making for your results are "nirvana" ...observationally perfect for that instrument. This seems unlikely. What ARE you doing?? Are you playing a game?

Frank Reed