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: Oblateness correction
    From: Andrés Ruiz
    Date: 2010 Nov 30, 20:38 +0100
    Yes.
    See at my web the paper "Corrections for Sextant Altitude" +N/-S for B: latitude

    in fact, this correction is significant for the moon, but can be applied to any celestial body.

    Regards
    -- 
    Andrés Ruiz
    Navigational Algorithms
    http://sites.google.com/site/navigationalalgorithms/


    2010/11/30 Lars Bergman <lars.h.bergman---.com>

    In the Sight Reduction Procedure chapter in the Nautical Almanac, the correction for the oblateness of the earth, to be added to the Moon's parallax in altitude, is given (in degrees) as

    OB = -0.0032 (sin Lat)^2 cos H + 0.0032 sin (2 Lat) cos Z sin H

    where H is apparent altitude, Z true azimuth in the range 0 ... 360 and Lat is latitude in the range -90 ... 90. Now, in the second term the sine of two times latitude gets different signs depending on hemisphere. Shall it be like this, or ...?

    Lars, 59N 18E

       
    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