What is the alternate name for mapping angle?

The term "convergence angle" refers to the angle that represents the direction convergence of parallel lines on a projected map. In surveying and cartography, this angle is essential for understanding how features or points relate to one another geographically. When working with mapping, the concept of convergence is vital for creating accurate representations, especially when transforming spherical coordinates onto a flat surface.

In contrast, the other terms listed do not accurately describe what is generally referred to as a mapping angle. Grid angle pertains to angles adjusted to fit within the grid system of a map, apex angle typically refers to angles in geometric shapes, and compression angle does not have a recognized definition in the context of mapping in surveying. Thus, the term "convergence angle" is the most accurate alternate name for what is commonly understood as mapping angle in the field of surveying.