In one embodiment, a method comprising, receiving a three-dimensional map of one or more obstructions associated with a field, the one or more obstructions presenting an obstacle to line of sight reception from a satellite to a global navigation satellite systems (GNSS) receiver; receiving almanac data corresponding to an orbit of the satellite; determining anticipated accuracy of positioning in the field at plural locations and plural times based on the almanac data and the map; and determining waylines for autonomous traversal through the field based on the anticipated accuracy at the plural locations and the plural times.
