Patent attributes
A position location system and method, the system including: an infrared (IR) transmitter, a first and a second ultrasound (US) transmitter, the first and a second US transmitters arranged at respective predetermined distances from a reference plane, an IR receiver configured to receive an IR signal from the IR transmitter, a US receiver configured to receive a first US signal from the first US transmitter and a second US signal from the second US transmitter; and a processor coupled to a memory and further coupled to the IR receiver and the US receiver, the processor configured to detect: a time of flight (ToF) of the first US signal from the first US transmitter to the US receiver; and a ToF of the second US signal from the second US transmitter to the US receiver.