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    Re: Distance Measurement - Tape vs Google
    From: Gary LaPook
    Date: 2013 Apr 11, 23:14 -0700
    The 15 foot value was just an estimate, no way to measure it. I just stood on the adjacent beach and looked at the side of the breakwater and estimated eye level and then used multiples of that to estimate the height of the breakwater.


    --- On Thu, 4/11/13, Brad Morris <bradley.r.morris@gmail.com> wrote:

    From: Brad Morris <bradley.r.morris@gmail.com>
    Subject: [NavList] Re: Distance Measurement - Tape vs Google
    To: garylapook@pacbell.net
    Date: Thursday, April 11, 2013, 8:32 PM


    On Apr 11, 2013 11:26 PM, "Bruce J. Pennino" <bpennino.ce---net> wrote:

    My intent was to show everyone and myself that Google Maps Distance Calculator is just excellent for all distances starting at even 100 ft or 200 ft. The precision/accuracy increases so that at 500, 1000 ft or more vertical angular measurements achieve very reasonable precision with devices other than a theodolite.
    With a channel width of over 500 ft, I'm still curious to reconcile the HoE difference of 22.5 ft and 15 ft.  Which is the more correct value?  I believe that was in Gary's posting....but now I'm unsure of which message. Sorry, sometimes I lose track of the original message in a discussion..

    ----- Original Message -----
    Sent: Thursday, April 11, 2013 9:05 PM
    Subject: [NavList] Re: Distance Measurement - Tape vs Google

    Hi Bruce

    Gary LaPook wanted a very long baseline with the bubble sextant measured angle to improve the accuracy of his HoE, in his "Dip Meter Again" post. I think that's one of the reasons why he did it that way, using Google earth.

    You can use a lesser distance because of the greater angular precision of your theodolite. Hence the 200' restriction of your tape isn't a restriction! Nicely done.

    The bubble sextant, of course, cannot really compete with a theodolite for angular measure and thus HoE determination at a distance of 200'. Note that a larger population of bubble sextant owners are in the audience than theodolite owners. So for the benefit of those who have one and not the other, using a long baseline helps when determining HoE by bubble sextant.


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