Welcome to the NavList Message Boards.

NavList:

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

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Revised Nautical Almanac Concise Sight Reduction Tables
    From: Robert Bernecky
    Date: 2015 Feb 16, 06:08 -0800

    Yes, the tables work.  I assume you do not have a copy of the NA?  FYI, here is the work for both of your examples:

    Example 1 :
    Lat 45°00'0 N, LHA 89°00'0, Dec 44°00'0 N
    Result: H= 30°00'3 , Zn = 303.8°

    Using NA's tables:
    enter with (Lat, LHA)= (45,89), A= 44 59,  B= 01 00,  Z1= 1.4
    F= Dec+B= 44 00 + 01 00 = 45 00
    enter with (A, F)= (45, 45), H= 30 00,  P= 35 16,  Z2= 54.7
    corrn= +1.  H= 30 01
    Z= 1.4+54.7= 56.1, Zn= 360-Z= 303.9
    NA result:  H= 30º 01', Zn 303.9º

    Example 2:
    Lat 45°00'0 N, LHA 45°00'0, Dec 02°10'0 N
    Result: H= 31°45'7 , Zn = 236.2°

    Using NA's tables:
    enter with (Lat, LHA)= (45,45), A= 30 00,  B= 35 16,  Z1= 54.7
    F= Dec+B= 02 10 + 35 16 = 37 26
    enter with (A, F)= (30, 37), H= 31 25,  P= 54 08,  Z2= 69.4
    corrn= +21.  H= 31 46
    Z= 54.7+69.4= 124.1, Zn= 360-Z= 235.9
    NA result:  H= 31º 46', Zn 235.9º
     

    As you can see, for these two examples, the H from the table is within 1' of an exact computation.

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    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)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site