A navigation method for an autonomous vehicle, the navigation method including: receiving an initial model of an object to be inspected by the autonomous vehicle; identifying an inspection target associated with the initial model of the object; determining an inspection location for the autonomous vehicle from which inspection target is inspectable by an inspection system of the autonomous vehicle, wherein the initial model includes convex polygons in a stack representing the object, each convex polygon permitting a projection from the inspection location to the inspection target to be determined, such that the inspection target is defined on an edge of a convex shape of the model and the inspection location is identified by a projection therefrom onto the inspection target; determining an initial inspection plan for the autonomous vehicle to inspect the object based on the initial model of the object, the initial inspection plan including the inspection location; and performing an effectiveness assessment in relation to the inspection location to determine whether the inspection target is inspectable by an inspection sensor of a sensor system of the autonomous vehicle from that inspection location, and characterized in that the effectiveness assessment includes: projecting a field of view of the inspection sensor onto a surface of the initial model of the object which is of interest; and excluding one or more portions of the field of view of the inspection sensor which extend beyond this area of interest. receiving an initial model of an object to be inspected by the autonomous vehicle; identifying an inspection target associated with the initial model of the object; determining an inspection location for the autonomous vehicle from which inspection target is inspectable by an inspection system of the autonomous vehicle, wherein the initial model includes convex polygons in a stack representing the object, each convex polygon permitting a projection from the inspection location to the inspection target to be determined, such that the inspection target is defined on an edge of a convex shape of the model and the inspection location is identified by a projection therefrom onto the inspection target; determining an initial inspection plan for the autonomous vehicle to inspect the object based on the initial model of the object, the initial inspection plan including the inspection location; and performing an effectiveness assessment in relation to the inspection location to determine whether the inspection target is inspectable by an inspection sensor of a sensor system of the autonomous vehicle from that inspection location, and characterized in that the effectiveness assessment includes: projecting a field of view of the inspection sensor onto a surface of the initial model of the object which is of interest; and excluding one or more portions of the field of view of the inspection sensor which extend beyond this area of interest. projecting a field of view of the inspection sensor onto a surface of the initial model of the object which is of interest; and excluding one or more portions of the field of view of the inspection sensor which extend beyond this area of interest.