摘要 |
Optical ranging (e.g. for hitching purposes) utilises at least one first reference indicium comprised by a subject (e.g. a vehicle); at least one reflector; at least one second reference indicium, for being comprised by an object behind the subject; and optionally at least one third reference indicium; such that during suitable relative motion towards each other of the subject and object, the first and second reference indicia and optionally the third reference indicium are observed suitably to come into coincidence whereby a predetermined distance of separation (e.g. a hitching distance will exist between the subject and object.
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