Fundamentals of Surveying (FS) Practice Exam

In a transverse Mercator projection, the mapping angle primarily varies with which measurement?

1. Longitude

2. Latitude

3. Both latitude and longitude

4. Equatorial distance

The correct answer is: Latitude

In a transverse Mercator projection, the mapping angle primarily varies with latitude. This type of projection is designed to be more accurate for areas that are elongated in the north-south direction, as it minimizes distortion along the central meridian. As one moves away from the central meridian, the distortion increases, particularly in terms of scale. Latitude affects how the earth's surface is projected onto a flat plane; as latitude increases toward the poles, the transition from three-dimensional to two-dimensional representation causes greater distortion. Longitude does not primarily influence the mapping angle in this projection, as the transverse Mercator is oriented to have a central meridian around which the projection is constructed. The projection mathematically compensates for variations with respect to longitude, meaning that the mapping angle remains more stable in relation to this measurement when compared to latitude. Other considerations, such as equatorial distance, are generally less relevant to the fundamental premise of how angles are affected in this projection style.