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    Re: Sextant Positions versus Map Datums?
    From: Pierre Boucher
    Date: 2002 Jan 17, 10:11 PM

    >Interestingly enough I have gotten a response on this from the
    >ask@usgs.gov folks.
    >They directed me to a datum conversion program (CORPSCAN) which is
    >publicly available but mainly limited to NAD27 and NAD84, NAD84 arguably
    >being "substantially identical" etcetera to the later US domestic datums.
    Never heard of NAD84!!!!
    maybe you meant WGS84 which is equivalent to NAD83
    >Anyway...using CORPSCAN in the area of N40d 35.703m, W073d 29.596m and
    >inputting that as NAD84, that position shifts by some 38 meters when
    >translated to NAD27. (38 meters found by taking the offsets produced by
    >the program and calculating the length of the diagonal.)
    You don't need any software is you have a GPS.  Just switch from one datum
    to another on any waypoint that you have in the machine.  You will see the
    shift in position.
    Pierre Boucher
    Pierre Boucher N
    Escadrille des Mille-�les

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