US Patent 8989769 Positioning system using light information

An apparatus and method for initiating a search mode of a mobile device based on the light information in the environment of the mobile device is described herein. The light information may include at least one of color temperature or illuminance, which may be used to determine if the environment of the mobile device is indoors or outdoors. A threshold may be predetermined or adjusted based on received position assistance information. The position assistance information may include at least one of time, day, solar angle, motion information, location information, or weather information.