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    Re: Definition of estimated position?
    From: Henry Halboth
    Date: 2004 Sep 26, 19:15 -0400

    There are probably as many definitions of "Estimated Position" as
    there are navigational texts. The Navigation Dictionary, once
    published by the US Navy Hydrographic Office as HO 220
    summarizes American definitions about as well as anyone can,
    and as follows ...
    
    "Estimated Position = The most probable position of a craft
    determined from incomplete data or data of questionable accuracy.
    Such a position might be determined by applying a correction
    to the dead reckoning position, as for estimated current; by plotting
    a line of soundings; by dropping a perpendicular from a dead
    reckoning position or previously estimated position to a single line
    of position; or by plotting lines of position of questionable accuracy.
    If no better information is available, a dead reckoning position is an
    estimated position, but the expression estimated position is not
    customarily used in this case. The distinction between an estimated
    position and a fix or running fix is a matter of judgement."
    
    In the context of your question, the estimated position probably sought
    is the intersection of the body's azimuth with the LOP at the intercept
    distance or, in other words, dropping a perpendicular from the DR
    position to the LOP. This was the accepted definition many years ago -
    a differentiation, however, being made to insure use of the DR position,
    as opposed to the assumed position employed in many of the short
    tabular methods. In using the time sight, the estimated position would be
    
    the intersection of the longitude calculated with the latitude used in
    the
    calculation - also a point on the LOP established - remember Sumner
    
    On Sun, 26 Sep 2004 16:35:35 -0300 Jim Thompson 
    writes:
    > > -----Original Message-----
    > > From: Navigation Mailing List on Behalf Of Russell Sher
    > > A navigational problem in the Jan/Febr. 2004 edition of Ocean
    > > Navigator Magazine (#135) posed a question which involved a
    > > navigator shooting the sun to obtain an LOP. Since there is only
    > > one LOP there is therefore no fix, but the one of questions asked
    > > is �What is the Estimated Position?� I imagine that it is the
    > > position plotted on the LOP as being the closest from the DR.
    > > Does anyone agree?
    >
    > That is how it is taught in the Power and Sail Squadrons' CN course
    > -- the
    > point on the LOP perpendicular from the LOP to the DR position.
    > http://jimthompson.net/boating/CelestialNav/CelestNotes/Plotting.htm
    >
    > Jim Thompson
    >
    
    
    

       
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