The Distance Calculation module GCP20 performs a mathematical function — no database file reads are required for distance calculation. Also for batch processing, GCP20, takes existing latitude/longitude coordinates (which act as points on an imaginary grid covering the Earth's surface) and calculates the distance between them. Output is the distance, to a thousandth of a mile, between the two points, taking into consideration the curvature of the Earth's surface. The following figure illustrates how GCP20 interacts with your driver program.
