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    Re: USCG Student Sample Problem #4
    From: Greg Rudzinski
    Date: 2013 Apr 26, 07:33 -0700

    Antoine,

    My guess on the Sun difference of 0.2' would be the way rounding of semi diameter is done between your program and USNO.

    G

    Re: USCG Student Sample Problem #4
    From: Antoine Couëtte
    Date: 2013 Apr 26, 00:51 -0700
    RE : http://fer3.com/arc/m2.aspx/USCG-Student-Sample-Problem-4-Rudzinski-apr-2013-g23675


    Hello Greg,

    Hard to keep up with all your many publications ... , especially after the delicious BBQ and Beverages in Prisoners Harbour ! :-)

    A few comments about your Sample Problem #4

    I first compared your Celestial Coordinates values with the ones I have derived : they all fit within 0.1' . Very Good !

    I then computed the Intercepts and Azimuths from your various Auxiliary Positions.

    The 3 Stars intercepts are within +/- 0.1' and Azimuths are the same.

    For the SUN I find i = -19.8' / AZ = 126°2 , vs. your published result i = - 20.0 / AZ = 126.2°

    Nothing to really worry about this 0'2 difference between these SUN intercepts. It still remains a bit surprising given the otherwise excellent match between all the other Stars intercepts.

    I have (again) computed an Observed position at 06:00:00 LT through a software which automatically updates the DR Positions to each observation time. I am getting the following results :

    UT 20:00:00 / N 25°09'9 / E 143°49'6 , with a LOP's dispersion of 0.1 NM (Excellent !).

    This position seems to be quite close (certainly within 1 NM) from your graphic determination.

    As a conclusion - and with the exception of the minor comment about the SUN intercept - I can see that our results are essentially the same.

    Thank you again and

    Best Friendly regards

    Kermit
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