Patent ID: 8994799
Filing Date: 2015-03-31
Classification: G01C

Abstract:
1. A method for determining a position of a mobile device using a light-based positioning system, the method comprising: determining an approximate location of the mobile device using geo-location information not derived from visible light received at the mobile device; downloading at the mobile device, from a remote server, a map data structure of positions of a plurality of asynchronous light sources at a location corresponding to the approximate location of the mobile device; receiving at the mobile device an identifier broadcast from one of the asynchronous light sources of the plurality of asynchronous light sources, wherein (i) the identifier identifies the asynchronous light source, and (ii) the identifier corresponds to a pattern of distortions within an image acquired by the mobile device, the pattern of distortions being related to a modulation frequency of modulated light emitted by the asynchronous light source identified by the identifier; matching the identifier to the asynchronous light source stored by the map data structure; and determining the position of the mobile device by setting the position of the mobile device to the position of the asynchronous light source stored by the map data structure.