Abstract: A method comprises measuring angular coordinates of an object (12) relative to a directional transceiver (10), the directional transceiver being at a first location relative to a reference coordinate system and having an orientation relative to the reference coordinate system, the object (12) being at a second, known location, the angular coordinates (?A, ?A) being measured relative to an axis of a local coordinate system, the orientation of the local coordinate system being defined by the orientation of the directional transceiver (10) and the origin of the local coordinate system being at the first location, wherein at least one of the first location and the orientation of the directional transceiver are unknown, and calculating the unknown at least one of the first location and the orientation of the directional transceiver using the angular coordinates (?A, ?A).