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    Re: Definition of estimated position?
    From: Joel Jacobs
    Date: 2004 Sep 27, 16:40 +0000

    I would like to add that the DR should be corrected for current and LEEWAY in arriving at the the EP.

     

    Joel Jacobs

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    -------------- Original message from "Henry C. Halboth" : --------------

    > 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 po! sition 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 L! OP perpendicular from the LOP to the DR position.
    > > http://jimthompson.net/boating/CelestialNav/CelestNotes/Plotting.htm
    > >
    > > Jim Thompson
    > >
       
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