Aerodynamic Drag (drag.dat)
This file determines the drag profile for a projectile flying though the atmosphere. It defines the way that the drag changes based on the mach number (speed relative to the speed of sound) of the projectile. The sample file shown in the appendix displays some example values for the file.
VBS2Combined Arms will ignore the first line of the file, and then read the Mach number entries in order, performing a linear interpolation between entries. In other words, the Mach numbers should always be present in ascending order in the file. They correspond to points on a chart, with straight lines used to join the specified points up to each other.
The Aerodynamic Drag is defined in a file called drag.dat.