Researches indicate that the use of new techniques in agricultural machinery, as controlled traffic by steering systems with the use of Global Navigation Satellite Systems (GNSS) may decrease the energy demand associated to field operations and increase labor efficiency and crop yield. Some authors already use different methodologies to evaluate the parallelism errors in guidance systems for vehicles, but there is no standard methodology to measure them. So, the objective of these work was to develop a specific spreadsheet, determinate and compare the accuracy in the parallelism of two distinct guidance systems (a light bar and an universal autopilot) working at straight path using GPS signal with two differential correction systems (one with internal algorithm and the other with satellite signal and sub metric accuracy). To evaluate both systems a RTK (Real Time Kinematic) differential correction was used, realizing five parallel and successive paths for each system, characterizing five replications for each treatment. The spreadsheet enabled the evaluation method used, and the errors for both equipments and signals analyzed, showed to be compatible with field operations that demand parallelism accuracy in the order of decimeters.
orientation systems; auto pilot; GPS
