A swath generation apparatus (SGA) (10) creates a curved swath path (102) for an agricultural vehicle with an associated implement. The SGA (10) determines orthogonal values of the vehicle heading at at least two location data points (104). At one data point, the operator may apply an adjustment input (254) for the vehicle path for compensating the effects of GPS drift. The SGA (10) modifies the data point positions of the swath path (102) by a portional amount of the orthogonal values based on a difference, relative to the orthogonal coordinate system, between the first and second vehicle headings.
