A first apparatus includes an imaging component configured to capture an earthbound image of the sky from a terrestrial location, a chronometric component, a communication component configured to transmit data representative of a captured earthbound image of the sky, and a controller. The controller...http://www.google.de/patents/US7526381?utm_source=gb-gplus-sharePatent US7526381 - Network aided terrestrial triangulation using stars (NATTS)
