NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: I and C pages of the NA
From: Gary LaPook
Date: 2014 Sep 26, 18:36 -0700
From: Dale Lichtblau <NoReply_Lichtblau@fer3.com>
To: garylapook@pacbell.net
Sent: Friday, September 26, 2014 9:56 PM
Subject: [NavList] Re: I and C pages of the NA
From: Gary LaPook
Date: 2014 Sep 26, 18:36 -0700
Look at the "v" correction values for the moon which are tabulated for each hour since they change so rapidly.
Here is an example for you Look for in the "v" and "d' increments for 59 minutes and 60 seconds, which is the same as one hour, and you will see that correction is equal to the value of "v". This is because the "v" (the change per hour)
multiplied by one hour equal "v." Now look at 30 minutes and zero seconds (one-half hour) and you will see that the correction is one-half of the "v" value because the "v" value is being multiplied by 0.5, one-half, for half an hour. (You might note that they correction might be off by 0.1 and this is because the correction is for the whole minute so is based on the proportion that the minute + 30 seconds is to 60 minutes. So, for 30 minutes the correction is based on 1830 seconds/3600 seconds times the "v" value.)
gl
From: Dale Lichtblau <NoReply_Lichtblau@fer3.com>
To: garylapook@pacbell.net
Sent: Friday, September 26, 2014 9:56 PM
Subject: [NavList] Re: I and C pages of the NA
Thanks Bill (and Gary and Greg).
It's actually the d factor for the sun's daily/hourly
declination value that has been puzzling me.
I think I got the equation of time (explaining the d values of 0.0 and 1.0 around the solstices and equinoxes?), but I'm still not clear as to how the correction values have been calculated and tabularized. And exactly how are the I&C tables a multiplication table? An example or two...maybe?
One can enter the table with a value ranging from 0.0' to 18.0' (why this range?), particularly in light of the fact that the largest v value I can find is for Venus at 4.1 back in January.
Thanks.
