Position Tolerance in Land Surveying

Abstract

Standards of practice or recommended procedures in land surveying, often including statements concerning the accuracy or positional tolerance of surveyed points, are currently being established in many parts of the country. Computational techniques need to be adopted which allow land surveyors to determine whether surveys meet accepted standards. A pseudoinverse or inner‐constraint network solution provides estimates of the variance and covariance of point coordinates independently of any control established to adjust the network. The estimates of coordinate variance and covariance, derived from the inner constraint solution, can then be used to weight pseudo‐observations on the coordinates of legally controlling survey stations in a second solution to develop error ellipses and positional tolerances on newly established survey points and property corners relative to the legally controlling corners.