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    Distance Measurement - Tape vs Google
    From: Bruce J. Pennino
    Date: 2013 Apr 11, 17:00 -0700


    I've compared my taped measurements with results from "Google Maps Distance
    Calculator" (GMDC). The results are excellent as shown below. GMDC provides great circle distance for longer routes just as we would calculate from latitudes and longitude.

    I used a low cost $25.USD 200 ft fiberglass tape for the measurements. I compared the first 100.00 ft length of the fiberglass tape to a 100.00 ft nylon clad steel tape. The steel tape has not been abused or stretched. The length of the nylon tape to my surprise was within 0.02 ft of the steel tape. Good enough!

    When I used GMDC, which is very easy, I took my first clicks for the Google computed distance. By using the "zoom in" function, it is easy to click on well defined points. That is probably why my GMDC results are so good compared to the taped measurements. I will probably never scale a distance on my computer again.

    Results Tape Google Map Distance Percent
    Measured ft Calculated Difference %

    Narrow driveway 13.8 12.7 -8

    House driveway 26.3 25.6 - 2.7

    Tennis court 120.0 120.1 + 0.1

    Entrance to 305.7 306.0 + 0.1
    Radio Tower

    Road length 992.7 993.7 +0.1

    This is useful for determining height of eye.

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