Now that you have completed the section on single point control.
Let's extend the concept a bit further and apply all we've learned
to another field problem. Our objectives in this section are to
understand the concepts of irregular exterior adjustments and apply
those concepts in known resurvey techniques to a problem with an
irregular boundary line.
An irregular exterior adjustment is a method of distributing the
distance between the record courses and the retracement courses
for purposes of restoring intermediate corners which are lost on
an irregular section or township line. It is a combination of two
types of proportioning, one, done in the direction of the line,
and the other done perpendicular to the line. Generally speaking,
an irregular boundary is one which has a deflection in alignment.
The following examples demonstrate how these irregular exteriors
First, some township lines were surveyed in segments at different
times and from opposite directions. When a connecting survey was
made, it showed a deflection in alignment for that portion of the