TRIAD for WINDOWS
Survey Retracement & Analysis Software
OVERVIEW: Triad is a very unique tool that
allows surveyors to best fit a map, deed or coordinate system
to an unlimited number of known points in considerably less time
than any other method. Triad will perform an analysis of
all points common to two coordinate systems accurately, easily
and quickly. The more points, the better it works. Triad
is a powerful program that organizes and documents the process
of analyzing a survey retracement. The surveyor can focus on professional
judgment, not the tedious task of crunching numbers. The results
are summarized and statistically qualified.
TYPICAL APPLICATION: It is a well-known
principal that the intent of a boundary retracement is to re-establish
the lines and corners of a prior survey in their most probable
locations. A common method of analysis uses coordinates to compute
the inverses or connections between found monuments and compare
the bearings and distances with the corresponding points on a
plat or map. If the inverses are consistent in rotation and distance
then those monuments are acceptable for controlling the boundary.
This process will become more difficult to organize and quantify
as the number of points increase. For example, four points have
six possible inverses. Eight points have 28, doubling to 56 inverses
when comparing the map and the field points. The time spent analyzing
found monuments in this way is time consuming and costly. Triad
is the ultimate solution to handle this problem.
HOW IT WORKS: Triad works by determining
the parameters for a two dimensional transformation: rotation,
scale and translation. These are solved simultaneously by best
fitting the points in one coordinate system to the same points
in a second coordinate system. The points in the first system
are treated like a figure, the angular relationship between points
is retained while the figure is scaled, rotated and shifted to
best fit all the points in the second system. New coordinates
can be computed for the boundary based on a best fit of all acceptable
monuments. Alternately, if one prefers, the two best points can
be fixed. A summary report is created for the job file.
ERROR TRAPPING: The trick is to quickly
identify acceptable monuments. A unique feature of Triad
is it's powerful blunder detection routine. This routine will
instantaneously identify individual points contributing the greatest
errors. Simply remove these "bad" points to obtain the best solution.
SUMMARY: Triad is used when it is necessary
to relate different coordinate systems with two or more points
in common. Triad is a more rigorous approach than Corpscon
for an accurate conversion of state plane coordinates from NAD
27 to NAD 83. In control surveys use it to compare the new measured
positions with previous coordinates to get "tied-in" to an existing
survey instantly with confidence. Use it to estimate the compass
and chain index necessary for retracement of ancient surveys.
In GIS applications it is great for hooking record maps together.
Triad has been in wide use in the US and around the world
since 1991. Developed by a GPS consultant, licensed boundary surveyor
and programmer with over 20 years experience. There is no exaggeration
to the statement that Triad will accomplish in seconds,
what otherwise may take hours!.
SYSTEM REQUIREMENTS: WINDOWS 95, 98, ME, 2000, XP & NT - PURCHASE
COPYRIGHT 1990-2002 MCGEE SURVEYING CONSULTING