| 20110004405 | EARTH HORIZON SENSOR - An Earth horizon sensor that images the vicinity of the Earth horizon or limb to locate the non-thermal airglow emissions and calculates the orientation of the horizon plane or alternately the vector pointing towards the center of the Earth based on the location of the said airglow emissions. The orientation of the horizon plane in turn can be used to calculate the pitch and roll of the platform upon which the Earth horizon sensor is mounted. Yaw angle can be calculated with an additional celestial reference located in the same image or made available from another source. The orientation of the horizon plane can also be used to calculate the latitude and longitude of Earth coordinates, provided that three axis inertial attitude and time are also available. The Earth horizon sensor can be adapted to operate in space upon spacecraft in Earth orbit or in the atmosphere upon aircraft flying at altitudes of 10K ft or more. For operation in the atmosphere during daytime, the location of the solar scatter peak can be used instead of airglow emission intensity profiles. | 01-06-2011 |
