NavList:

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Hewitt,

I see the explanation in the front introduction page XIII-XIV of the Pub 229. A difficult bit of tabular interpolation for a few tenths of positive correction over straight linear interpolation. The improvement in accuracy may get lost with the increased chance of a summing error. This double second difference interpolation step looks like a good candidate for omission to me.

Greg Rudzinski

Greg, it sounds like he is going to use HO 229. I think he is referring to Double Second Difference - used when interpolating high sights - those above 60 degrees. In 229 these sights are in italic and there is a dot alongside.

Hewitt

Sent from my iPad

On Apr 15, 2013, at 3:25 PM, "Greg Rudzinski" <gregrudzinski---com> wrote:

Frank... What is a double second correction ?

Greg Rudzinski

Group Project: USCG student sample problems
From: Frank Reed
Date: 2013 Apr 15, 12:56 -0700
I have volunteered NavList to work on a project. The nautical sciences department at the US Coast Guard Academy is trying to revive a basic program in celestial navigation methods after a hiatus of over 15 years. I've been contacted by Robert Kenney, an instructor there, who is looking for some sample problems based on current navigation data for 2013 if possible.

Here's what he has asked for:
" I am putting together a tutorial on sight reduction and need a few sample problems. The only problems I can find online are well out of date. Would you be able to provide a few problems from 2012 or preferably this year? We would like the cadets to use the nautical almanac instead of old data to give a more realistic feel to the exercise. I was hoping to find one problem for the sun, stars, moon and planet's to illustrate the differences in regards to HP, SHA and v corrections and the like." and "One problem for each the sun, moon, star (any star is fine) and planet will be more than enough to get us started. Could you also include a problem that requires a double second correction?"

I would imagine this would generate some questions first. But feel free to dive right in with sample problems. I doubt that they're looking for ex-meridians, time sights, or lunars! Just standard "modern" celestial navigation sample problems.

-FER
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