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: USCG Student Sample Problems #1, #2 and #3
    From: Antoine Couëtte
    Date: 2013 Apr 25, 10:17 -0700

    RE : http://fer3.com/arc/m2.aspx?i=123663

    Hello Greg, and

    Hello Peter (further down)


    This post concerns the first of the (now) 4 problems built up and submitted by Greg.

    Regarding the 02 JUN 2013 SUN shot at UT=01:59:40, Greg, you wrote :

    QUOTE

    To remedy this I have looked at my original notes which shows a UT 1:59:40 for 2 June 2013. Reworking using USNO shows quite a few changes which are shown highlighted on the attachment. There was a change in GHA, assumed longitude, Hc, Hs, Ho, and intercept. This should fix things I hope.

    UNQUOTE

    I have no longer any problem now with your updated value. :-)

    *******

    Regarding the POLARIS shot at 05:00:31 UT, Greg, you wrote :

    QUOTE

    Regarding Polaris. The Pub 249 reduction uses a Q value and a precession nutation correction that are rounded to the nearest minute of arc. I would not expect a close match to USNO or other programs.

    UNQUOTE

    This seems to fully explain our 0.4' difference then. Good News !

    *******

    About POLARIS... and this concerns Peter Hakel this time (are you here Peter ??)


    In
    " : http://fer3.com/arc/m2.aspx/Group-Project-USCG-student-sample-problems-Couëtte-apr-2013-g23602 "
    and from Auxiliary Position 24°N / 143°40' , observing Polaris at UT 05:00:31 at Sextant Height 23°04'1 (corrected for only Instrument Error), I got a Geocentric Height Ho = 22°52'0 (I concur with Greg's published value) and an intercept of -36.4' (Away) in Azimuth 359°5, hence an Observed Latitude of N 23°23'6 at time of observation UT 05:00:31 (or a shifted latitude of N 23°23'7 at UT 05:00:00).

    RE
    ": http://fer3.com/arc/m2.aspx/Group-Project-USCG-student-sample-problems-Couëtte-apr-2013-g23607 " to which I did not read a reply to.

    Peter, while all our other intercepts fully match to +/- 0.1 ' , I still can not reconcile this Latitude I found of 23°23'6 (or 23°23'7) with your value of 23°25'5 published in
    " http://fer3.com/arc/m2.aspx/Group-Project-USCG-student-sample-problems-PeterHakel-apr-2013-g23606 ".

    Any cue from your part, Peter ?


    Best Regards to all,


    Kermit


    ----------------------------------------------------------------
    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