CST Level 1 Land Surveyor Certification Practice

Which of the following describes the measurement performed by a back bearing?

1. A measure of lateral distances

2. A vertical distance to a known point

3. A vertical distance to a reference elevation

4. A measure of angles up to 180 degrees

The correct answer is: A vertical distance to a reference elevation

A back bearing is defined as the opposite direction of a forward bearing, typically used in surveying to determine the location from which a line was observed. The choice that specifies a vertical distance to a reference elevation relates more to vertical measurements rather than the concept of a back bearing, which does not describe a vertical distance in the context of surveying calculations. In surveying, when referring to a back bearing, it primarily relates to referencing a horizontal or angular relation, thus providing a full circle measurement (0 to 360 degrees) rather than confining it to vertical assessments. The back bearing allows surveyors to return to a previously established point, ensuring accuracy in measurements and calculations. Understanding the role of back bearings in returning to or confirming a location reinforces the essential framework of triangulation and alignment in surveying tasks, thus negating the other options that do not accurately fit the definition or implication of back bearings in surveying practices.