Observation along targets using position lines

Abstract

Determining ordinates (deviations from target lines) according to existing instructions is quite difficult and not accurate enough, and therefore is not always used. It is advisable to offer something more rational. The position lines of angles close to 180° or 0° are almost parallel to the sides of these angles and their gradients are equal to the arithmetic sum or difference of the gradients of the sides of these angles. This makes it easy to use such position lines when obtaining the ordinates of the alignment of benchmarks set to determine the surface displacement. These examples show the fruitfulness of the idea of ​​​​using position lines. They are beginning to be introduced into practice in various areas, such as in matters of finding a lost center, transferring a project to nature, etc. It would be advisable to conduct experiments using the methods proposed here for determining displacements along alignments. It should be noted that these methods allow multiple measurements of angles and thereby increase their accuracy, whereas in other methods such an increase in accuracy is impossible without significantly complicating the measurement process.