Civil Engineering Reference
In-Depth Information
first may be wholly inadequate for the second. However, a single descrip-
tion to accomplish both aims can be prepared by adding to the descrip-
tion through which descent of title is traced, a technical description which
includes the coordinates on the State system of one or more of the comers
of the land
.
102.
For a description of a public-land subdivision, an acceptable use of a State
coordinate system would be the placing of the coordinates of the marked
comers on an official plat, to which specific reference would be made in the
written description. The plat should also, if practicable, show the coordi-
nates of the control stations from which the coordinates of the subdivision
comers were derived
.
103.
103. In other than public-land States, the inclusion of State coordinates
in any form of description is also very desirable, except where there is an
official plat on file showing the State coordinates, in which case a refer-
ence to the plat will make it part of the legal description. A carefully-pre-
pared plat of an area embracing a number of land parcels and showing
the State coordinates of the land comers and of control stations which
define the State coordinate system is a very satisfactory description for
survey purposes. A suitable reference to the plat in the description pre-
pared for title purposes will make that description satisfactory for all
purposes
.
We have seen that coordinate values derived from GPS observations are primar-
ily dependent on the coordinates of the reference station(s) and not from the
coordinates of other boundary or traverse points in the survey project. In other
words, the accuracy of each point stands on its own. Using traditional linear tra-
versing methods a location error of one of the points could propagate and affect
the coordinates of other points. The location of a point from a properly estab-
lished GPS location will have a known probability of error and this error is inde-
pendent of errors in other points comprising the boundary corners of a property.
Based on these considerations, it would seem that a boundary corner established
using properly implemented GPS techniques should be just as reliable, per-
haps even more reliable, than a boundary corner established using angles and
distances.
As GPS is a new technology when compared to more traditional measurement
techniques, it may take some time before the reliability of GPS measurements is
recognized in the courts. Because the roots of real property law go back to feu-
dal times, it has sometimes been said that property law is a constipated discipline.
We now find ourselves besieged by rapidly changing technology, and this creates
a great impetus for change. Like many other electronic technologies, GPS is con-
tinually improving and becoming more accurate and reliable. As the technology
becomes more universally understood and accepted in the courts, we may eventu-
ally see the movement of coordinates from the last place in importance to being at
least as important as distances and angles.
