Global competition compels farmers to modify cultivation practices by exercising more cost-effective farming techniques and acquiring more efficient machinery. In doing so, farmers have turned to larger machinery as well as sophisticated technology that automates and optimizes the operation of agricultural vehicles and towed implements. As farming becomes increasingly mechanized, and farm implements faster and larger, accurate positioning of equipment becomes a more significant factor in operational efficiency.
Automatic steering of a main vehicle e.g., a tractor and its towed implement, is often used on large farms where high value crops are grown and operators are not well trained in driving. Many vehicle guidance systems rely on steering inputs from Global Positioning System (GPS), Global Navigation Satellite System (GNSS), or similar satellite navigation systems. As known in the art, signals from a plurality of satellites can be used to calculate a geographical position of a vehicle. While an effective means of providing accurate location data when a vehicle is moving on fairly level terrain, position data derived from satellite signals may not accurately represent actual ground position when the vehicle is operated on a sloped surface. Inertial sensors are often employed to detect one or more inclination angles of a vehicle. The detected inclination angle can be used to determine an inclination compensation factor (ICF) that represents the effects of vehicle inclination on ground position determination. The satellite-based position and the ICF can be used to provide an adjusted position that compensates for ground slope and better represents the actual vehicle ground track. In general, ICF computations are based on vehicle's inclination angle(s), such as a roll angle, and the height above ground of the antenna receiving the satellite transmissions. Because antennas are typically deployed on the top of a vehicle for optimum satellite reception, the vehicle height is generally be used to represent antenna height. However, vehicle height, and consequently antenna height, can fluctuate with tire height, and differences in antenna height due to varying tire heights can lead to measurable differences in ICF's, resulting in differences in the adjusted positions. Current methods allow the manual configuration of such height parameters; however a change in tire height is not readily associable with steering performance, and thus not reconfigured to a correct value. As a result, the methods can be plagued by errors that can adversely affect guidance system performance, particularly those systems that use real-time kinematic (RTK) techniques that are sensitive to accuracy.