Abstract

Systems and methods derive spatial information associated with an object that is deployed in association with at least one beacon or at least one interrogation unit. The at least one beacon has a reflector antenna that has an adjustable internal impedance, and an impedance modulation unit that varies the internal impedance of the reflector antenna such that the reflector antenna produces impedance-modulated reflected signals in response to impinging interrogation signals. The at least one interrogation unit transmits an interrogation signal to impinge upon the reflector antenna, and receives reflected signals from the reflector antenna. A processing unit is associated with the at least one interrogation unit and processes the reflected signals received by the at least one interrogation unit to derive the spatial information.

IPC Classes  ?

• G01S 1/48 - Broad-beam systems producing at a receiver a substantially continuous sinusoidal envelope signal of the carrier wave of the beam, the phase angle of which is dependent upon the angle between the direction of the receiver from the beacon and a reference direction from the beacon, e.g. cardioid system wherein the phase angle of the direction-dependent envelope signal is a multiple of the direction angle, e.g. for "fine" bearing indication
• G01S 5/02 - Position-fixing by co-ordinating two or more direction or position-line determinationsPosition-fixing by co-ordinating two or more distance determinations using radio waves
• G01S 1/02 - Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmittersReceivers co-operating therewith using radio waves
• G01S 13/02 - Systems using reflection of radio waves, e.g. primary radar systemsAnalogous systems
• H01Q 19/10 - Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces
• G06K 7/10 - Methods or arrangements for sensing record carriers by electromagnetic radiation, e.g. optical sensingMethods or arrangements for sensing record carriers by corpuscular radiation