Object detection

A system configured to detect the presence of an object in a zone, the apparatus comprising:

• a wireless detector located proximal to the zone, the wireless detector comprising an orientation sensor configured to sense the spatial attitude of the detector;
• a user interface whereby a user can define a solid angle relative to a first spatial reference plane such that at least part of the zone is within that solid angle when the solid angle is projected from the location of the detector;
• and
• a processor;
• the detector being configured to detect a wireless signal from the object, and thereby estimate the direction of the object from the detector with reference to a second spatial reference plane fixed relative to the detector, and to sense at the orientation sensor the spatial attitude of the detector;
• and
• the processor being configured to compare the solid angle and the estimated direction in dependence on the sensed spatial attitude so as to determine whether the object is present in the zone.

A server configured to detect the presence of an object in a zone, the server comprising:

• a first communication interface configured to receive, from a wireless detector located proximal to the zone, an estimated direction of the object with reference to a second spatial reference plane fixed relative to the detector, and a spatial attitude of the detector;
• a second communication interface configured to receive, from a user interface, a solid angle defined relative to a first spatial reference plane such that at least part of the zone is within that solid angle when the solid angle is projected from the location of the detector;
• and
• a processor configured to compare the solid angle and the estimated direction in dependence on the sensed spatial attitude so as to determine whether the object is present in the zone.