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National Geodetic Survey Web Site

Posted by jeffhobbs on May 29, 2008

For a while I’ve been wanting to sanity check my GPS points against a known entity. So, I’ve been looking for a set of survey monuments for Santa Clara County. Up to now, I haven’t been able to find them. My plan is to simply shoot the monument with each of my GPS units and compare the results I receive from the unit to the survey monument coordinates. HOPEFULLY they’ll be very similar….

Anyhow, today I finally got the bright idea to contact the county surveyor’s office. They pointed me to the NGS web site. As it turns out, they host survey monuments for the entire nation on this site. Even better, they allow you to download a shapefile with the control points. So next I’ll be loading the shapefile into GeoMedia and then writing a couple of simple functional attributes to translate from lat/long to California State Plane coordinates. After that, I’ll be able to shoot the survey monuments and finally double check the horizontal accuracy of my GPS systems.

Not very GeoMedia related, but did want to pass the site along to others looking to do something similar.

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One Response to “National Geodetic Survey Web Site”

  1. Richard Morgan said

    Gentlemen,

    I’m curiopus what the geodetic shift would do to a property line after 50 Years. I have a 1″ difference from a previously issued variance. Although I know it is insignificant, I’m curious what the real geodetic shift can cause in property lines.

    V/R

    Richard A. Morgan

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