Fundamentals of Surveying (FS) Practice Exam

How does the scale factor in a Lambert projection vary?

1. With longitude

2. With latitude

3. With both latitude and longitude

4. It remains constant

The correct answer is: With latitude

In a Lambert projection, the scale factor varies with latitude due to the nature of the projection itself. Lambert conformal conic projections are designed to maintain shape and angles over a certain range of latitudes, and they achieve this by distorting distances differently as one moves away from the standard parallels, which are the latitudes where the projection is most accurate. In this projection, as you move away from the standard parallels toward the poles or to lower latitudes, the scale factor changes. Specifically, the scale is true along the two standard parallels and gradually increases or decreases as you move away from these latitudes. Hence, the scale factor is more directly impacted by changes in latitude rather than longitude, as the projection's integrity is primarily dependent on the distances in the latitude direction. This relationship highlights the importance of understanding how distortions occur in conic projections and aids in selecting appropriate projections for specific surveying applications, where maintaining accurate distances and areas is critical.