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
    Name or NavList Code:
    Email:
       
    Reply
    Re: stange results from AM and PM sun shots
    From: Gary LaPook
    Date: 2012 Sep 27, 11:18 -0700
    You didn't state the times of your observations, if they were taken at about sunrise and sunset then the azimuths of the sun should be almost straight east and west. This is due to the declination being close to zero. On the dates of the equinoxes the sun rises on an azimuth of 090 and sets on an azimuth of 270 as observed from everyplace on earth. At low latitudes, say within the tropics, the azimuths at rising and setting are very close to  90 (or 270) plus or minus the declination.

    gl

    --- On Thu, 9/27/12, Brad Morris <bradley.r.morris@gmail.com> wrote:

    From: Brad Morris <bradley.r.morris@gmail.com>
    Subject: [NavList] Re: stange results from AM and PM sun shots
    To: NavList@fer3.com
    Date: Thursday, September 27, 2012, 10:08 AM

    Agreed.

    Alan - Try taking your sights about 6 hours apart, as 6 hours * 15 degrees per hour is 90 degrees of separation between azimuths.

    Best Regards
    Brad

    On Sep 27, 2012 1:05 PM, "David Fleming" <d.l.fleming.1@gmail.com> wrote:

    Alan,

    Your situation has nothing to do with Delination of sun being close to equator.

    The problem is the azimuths are nearly reciprocals of each other. Essentially a morning and evening sight on reciprocal azimuths are equivalent to two sights taken at approximately the same time. We can average them for improved accuracy but we can not produce a fix because they are not really that independent of each other.

    Dave F.
    ----------------------------------------------------------------
    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
    ----------------------------------------------------------------

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

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

    Email Settings

    NavList ID 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