# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Message:αβγ
Message:abc
 Add Images & Files Posting Code: Name: Email:
Re: Question re. A and B factors (corner cosines) lunars
From: Magnus Sjoquist
Date: 2012 Jan 24, 12:25 +0100

As I understand the matter:

Both bodies on the same vertical:

?A-factor? (cosine Moon-corner):

Moon above Sun:

ZMS = 180 deg.

Moon below Sun:

ZMS = 000 deg.

?B-factor? (cosine Sun-corner):

Sun above Moon:

ZSM  = 180 deg.

Sun below Moon:

ZSM = 000 deg

(With both bodies on the same vertical the resulting correction is the difference in corrections for the two).

/Magnus

----Ursprungligt meddelande----
Från: lars.h.bergman@gmail.com
Datum: 2012-01-24 11:40
Till: <NavList@fer3.com>
Ärende: [NavList] Re: Question re. A and B factors (corner cosines) lunars

In 17914 Frank wrote:
"If the Moon is directly above the Sun (its altitude would then be 75 degrees), the angle ZMS is zero and its cosine is +1. If the Moon is directly below the Sun (necessarily at an altitude of 15 degrees), the angle ZMS is 180 degrees and its cosine is -1."

Isn't it the other way around?

Lars, 59N 18E
----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------

Browse Files

Drop Files

### Join NavList

 Name: (please, no nicknames or handles) Email:
 Do you want to receive all group messages by email? Yes No
You can also join by posting. Your first on-topic post automatically makes you a member.

### Posting Code

Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
 Email:

### Email Settings

 Posting Code:

### Custom Index

 Subject: Author: Start date: (yyyymm dd) End date: (yyyymm dd)