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Finding my property lines

I have a Magellan car gps I bought in 2010 I was wondering if I can locate the lat/long numbers I see written on the property survey by using the gps. Has anyone done this to find your cornors?

Comments

  • Tim 1480 Points
    It might depend on which model you have as car GPS devices are not really designed to do that kind of thing. But with some models you might be able to create a "favorite" using the coordinates from your map, put the GPS into "pedestrian" mode, and then walk to the corners. With a handheld GPS (outdoor model) you could do it much easier.

    Keep in mind GPS is generally accurate to within about 5 meters which isn't terribly good accuracy for things like property boundaries or doing anything "official" with that info. That applies to both the car models and the handheld models.
  • ok thanks. the gps shows the lat/long as it goes so we figured we could go to the property and turn it on and watch the gps to hit the same lat/long as written on the survey then wed know we are at the point or near by anyways.
  • Tim 1480 Points
    You could do that. It will take a little practice to see how much the numbers are moving as you get closer to the spot, but that approach would work with a little patience.
  • :-/ :-O [-O<
  • Boyd 1985 Points
    Are you sure those are lat/lon numbers on your survey? That would be unusal in my experience. Surveys usually consist of vectors that tell you what compass heading to take and how far to go to reach the next corner of your property.

  • your right it is degrees or something not lat/long :( that sucks lol
  • alanb 539 Points
    There are several online calculators for converting bearing/distance to coordinates. To find one, just Google "bearing distance calculator". Of course, this assumes you know the coordinates of the start point.
  • Boyd 1985 Points
    Garmin handhelds have a feature called "waypoint projection" that lets you create waypoints at a specified distance and bearing from your present location, so this will accomodate the data in a survey like yours.

    However, it doesn't work very well from my experience. For one thing, you cannot enter fractional degress, so errors are compounded with each point that you enter. And then there is the +/- 5 meter accuracy limit of all consumer gps units.

    Try searching online for parcel data that you can download. Most localities make this available for free on a state/county/city website. The data will probably be in the form of shapefiles, so you will need some software to convert it, and it is not usually survey grade. But should be better than what you can create on your own.
  • Keep in mind that the bearings on land surveys are almost never based on true north. Instead, those bearings are based on a north that the surveyor makes up to suit that job. Do a google search on: survey "basis of bearing".

    The difference between that artificial north and true north can easily be 5 degrees or more. Thus, in order to try and follow the bearings on a land survey you first need to know the "basis of bearing" so you can rotate all the survey bearings so they are based on true north.

    Alas, it is extremely rare for a survey to state a numerical basis of bearing. As a result, all you can do is guess.
  • Property surveys can be a little cryptic but they are pretty easy once you crack the code. It took me a while to figure out but I had a great surveyor as a teacher. Try this explanation:

    http://platplotter.blogspot.com/2014/01/survey-metes-and-bounds-from-deed.html

    And while it may look like surveyors 'make up' true north, in reality magnetic north changes over time so there is an adjustment (declination angle) required when compensating for the difference between true north, magnetic north and the map 'grid north.' What that means is that once you've plotted the survey it still may need to be rotated a little to line up on the map.

    As for getting the survey into a GPS, there's an app for that ;-)

    I was converting surveys into GPS coordinates with a spreadsheet and decided to put the process online as an excuse to learn a few new programming skills. Here's an overview:

    http://platplotter.blogspot.com/p/blog-page_10.html

    Give it a try at http://platplotter.appspot.com/ and let me know what you think. Make sure to get to the "GPX download" part: that's where you save a file that goes in your Magellan.
  • Boyd 1985 Points
    Very cool! B-)
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