Which assumption is the basis of the transit rule in surveying?

The basis of the transit rule in surveying relies on the understanding that angular measurements are inherently more precise than chaining measurements. This principle is critical because the accuracy of a survey can significantly depend on the method used to gather information. Angular measurements, which involve the use of instruments like theodolites or transits to measure angles between lines, often yield more reliable results as they are less susceptible to errors that can arise from physical measurement of distances, such as chaining.

In practice, while chaining can be affected by terrain, human error, or equipment limitations, angular measurements benefit from the geometric properties of triangles, which can be used to derive additional data through triangulation. This makes them a more robust choice for determining positions and distances, particularly over long stretches or uneven terrain where chaining can introduce significant errors. Hence, this understanding directly supports why the second assumption about angular precision underpins the transit rule in modern surveying.