Patent ID: 9453731
Filing Date: 2016-09-27
CPC Classification: G01C

Claim Text:
1. A system for determining orientation of a fixture relative to the Earth, the system comprising: a fixture configured to be coupled to a structure; at least one sensor coupled to the fixture, the at least one sensor comprising an imaging device and being configured to detect a celestial body and provide signals indicative of a plurality of positions of the detected celestial body relative to the at least one sensor over a period of time, wherein detecting a celestial body comprises receiving an image from the imaging device, and identifying candidate regions of the image and eliminating false detections by comparing the image to a template image; a Kalman filter; and a processor configured to: receive the signals from the at least one sensor, receive information relating to a time and date associated with the period of time during which the celestial body is detected, receive information relating to an expected relationship between the detected celestial body and the Earth at the time and date, and determine the orientation of the fixture relative to the Earth based on the signals from the at least one sensor, the information relating to the time and date, and the information relating to the expected relationship between the detected celestial body and the Earth at the time and date, wherein the Kalman filter is configured to provide a more accurate orientation determination with respect to the Earth when determining at least one of true north, azimuth, elevation angle, and bank angle.