6

A client has a very old Certificate of Ownership document for a plot of land. We need to show the outline of the plot on Google maps to potential developers.

Sadly the description of the plot is in archaic coordinate system. how do i get this represented on Google maps?

enter image description here

Here is an additional piece of information I could scrape from the document:

enter image description here

Those are some form of coordinates for point A.4589 in the diagram.

Seems i've made some good progress Map Location

9

You need to know the coordinates of at least one point in lat/lon degrees. If you don't have any surveying points, you might take coordinates from a GPS unit if the point is visible.

Using QGIS, you could create the other points of the polygon with the Azimuth and Distance Plugin. Take care to convert the degree-minute bearings into decimal degrees.


With the additional Information, it is easy to locate the points next to the Abuja-Kaduna Highway. I have taken the Nigerian Minna Datum with UTM 32N EPSG:26332. The accuracy of the Minna datum is reported to be about 3 to 6 meters.

enter image description here

For use in Google Earth, you can convert the corner points into KML format in a last step:

<?xml version="1.0" encoding="utf-8" ?>
<kml xmlns="http://www.opengis.net/kml/2.2">
<Document id="root_doc">
<Folder><name>corners</name>
  <Placemark>
    <name>A.4589</name>
      <MultiGeometry><Point><coordinates>7.213681182925083,9.242681685792601</coordinates></Point></MultiGeometry>
  </Placemark>
  <Placemark>
    <name>A.4590</name>
      <MultiGeometry><Point><coordinates>7.21464061889053,9.244143155822583</coordinates></Point></MultiGeometry>
  </Placemark>
  <Placemark>
    <name>A.4591</name>
      <MultiGeometry><Point><coordinates>7.215811177177327,9.243701475697776</coordinates></Point></MultiGeometry>
  </Placemark>
  <Placemark>
    <name>A.4592</name>
      <MultiGeometry><Point><coordinates>7.215774243544854,9.242327697539729</coordinates></Point></MultiGeometry>
  </Placemark>
  <Placemark>
    <name>A.4593</name>
      <MultiGeometry><Point><coordinates>7.214939943530562,9.242397736493757</coordinates></Point></MultiGeometry>
  </Placemark>
</Folder>
</Document></kml>
  • Please is there any simple on-line conversion tool that will translate the given coordinates into more usable format? – Charles Okwuagwu Nov 4 '14 at 14:28
  • what does A.4590 stand for? – Charles Okwuagwu Nov 4 '14 at 14:29
  • It is just the name of one of the surveying points that were created when the parcel was surveyed. There is no online tool to get the coordinates. Maybe the local surveying authority has the original surveying document. – AndreJ Nov 4 '14 at 15:55
  • @CharlesO It's not really a coordinate system (and certainly not archaic), but rather a land survey system describing the shape of the boundaries as Andre shows. This type of description is typically referenced to a land survey grid. Point A.4590 may either be simply a named point in the survey as Andre suggests, or it could be the tie to the land survey grid. The grid and its reference points might be available from local or regional government sources. Here in the US it's the Public Land Survey System or PLSS. – Chris W Nov 4 '14 at 18:39
  • 1
    See my extended answer. – AndreJ Nov 6 '14 at 13:44
1

There is a free online tool at Underhill's map check page

I used your metes data, but started at A.4589 (the one with known coordinates) and got these results (the remaining point numbers are assumed to increase by one each time, and luckily they do match the raw data numbering):

Azimuth Distance        Pt#     Northing    Easting
                        4589    22054.320   3837.680
 33 24 00   193.000     4590    22215.446   3943.923
111 05 00   137.600     4591    22165.947   4072.312
181 49 00   152.010     4592    22014.014   4067.493
275 07 00    92.010     4593    22022.220   3975.849
283 06 00   141.800     4589    22054.359   3837.740
                Misclosure          0.039      0.060
                 Precision      1 : 10085
                    Area =      31432.0

An actual screen shot:

enter image description here

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