Survey Retracement & Analysis Software

General Description

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 in a solution, the better it works. Triad is a powerful program that is simple to learn, organizes and documents the process of analyzing a survey retracement. The surveyor can focus on professional judgment, not the tedious task of crunching numbers and comparing record verses measured data. The results are summarized with statistics.

TYPICAL BOUNDARY RE-TRACEMENT 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 original locations. A common method of analysis uses coordinates to compute the inverses or connections between found monuments and compare the inversed bearings and distances with the corresponding inverses on a plat or map. If the inverses are consistent in rotation and distance then those monuments may be acceptable for re-establishing the boundary. This process becomes 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 points with the field points. The time spent analyzing found monuments in this way is time consuming and costly. Triad is a productive and efficient solution for handling this problem.

HOW IT WORKS: Triad works by determining the four parameters of 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 preference in retracing another survey is to quickly identify acceptable monuments. A unique feature of Triad is its optimized Blunder Detection Routine. This routine will instantaneously identify individual points contributing the greatest errors when fitting one system of coordinates with common points to another. Simply remove the unacceptable 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 provides a rigorous approach for an accurate conversion of local coordinates to a different system or, state plane coordinates from NAD27 to NAD83. for control surveys, use it to compare the new measured positions with previous coordinates to get "tied-in" to an existing survey instantly with confidence based on the residuals listed for each point in the solution. Use it to estimate the compass and chain index necessary for retracement of ancient GLO surveys. In GIS applications, it is great for hooking record maps together to build a mosaic. Triad has been in wide use in the US and around the world since 1991. Developed by a GPS/GNSS Consultant, geodesist and licensed boundary surveyor with over 30 years' experience. There is no exaggeration to the statement that an analysis performed with Triad will accomplish in seconds, what otherwise can take hours!.

Tel. 805-964-3520