Tool with integrated navigation and guidance system and related apparatus and methods

A hand tool comprising:

• a hand-holdable body;
• a tool member coupled to the body;
• a field generator coupled to the body, the field generator operable to emit a field for detection by a sensor of a position-sensing system, the field permitting determination of the position of the sensor relative to the field generator;
• and
• a correction unit configured to correct a position of the sensor based at least in part on the determined position of the sensor relative to an axis of the tool member and a fixed point on the tool member to which the field generator has a known spatial relationship;
• wherein the tool member has an axis of rotation and the coupling is configured to permit rotation of the field generator about the axis of rotation of the tool member, wherein the field generator is coupled to the body by an adjustable coupling permitting the field generator to be moved relative to the body, wherein the coupling is configured to maintain a fixed radial spacing of the field generator to the axis of rotation of the tool member and the tool comprises a plurality of mounting couplings and the field generator is detachably affixable to each of the plurality of mounting couplings.