Patent ID: 6807478
Filing Date: 2004-10-19
Classification: G01C,G01S

Abstract:
A navigation system for detecting a current position of a user in a building, the navigation system comprising:at least one light source including a driver and an encoder, the driver and the encoder coupled to the light source so that the light source produces a modulated light signal in accordance with a predetermined signature, wherein said light source is stationary; a receiver, the receiver held by the user when in use, including a photosensitive detector capable of detecting the modulated light signal produced by said stationary light source and a decoder capable of decoding the predetermined signature said receiver further comprising: a memory; a controller communicatively coupled to the receiver and the memory; and an output device coupled to the controller, wherein the controller is arranged to receive the decoded predetermined signature, and based upon the decoded predetermined signature, retrieve information as to the location of said at least one light source in a digital map of the building, thereby detecting a current position of the user, to obtain at least one navigation instruction stored in the memory, and output the navigation instruction to the user using the output device.