What is a "triangulation" method in surveying?

Triangulation is a surveying method that utilizes the principles of geometry, specifically the properties of triangles, to determine the positions of points in space. In this technique, two or more known points create a triangle with an unknown point, allowing surveyors to calculate the unknown point's location through angle measurements. By measuring the angles from multiple points, surveyors can use trigonometric principles to accurately establish the position of the target.

This method has historical significance in surveying and was widely used before the advent of modern technologies such as GPS. It operates under the fundamental concept that the positions of points can be determined by angles and the lengths of sides of triangles formed between known and unknown points. Surveyors ensure high accuracy by carefully measuring these angles and, when necessary, applying corrections for factors like the curvature of the Earth.

The other options relate to different methods and technologies in surveying but do not describe triangulation. The use of satellite images refers to remote sensing techniques, GPS involves satellite navigation for positioning, and measuring large distances typically involves other specialized tools and methods not specifically aligned with the traditional triangulation approach.