US Patent 7592908 Universal display exposure monitor using personal locator service

Systems, methods and devices for gathering data concerning exposure of predetermined survey participants to media displays are provided. A portable monitor is arranged to receive certain types of terrestrial-based signals, and in some specific cases, satellite-based signals, and to use such signals to generate location data indicative of a location of the portable monitor. The location data and stored media display data is analyzed to evaluate the survey participant's exposure to one or more media displays.