초록 ▼

Pixels within a satellite camera (1, 2) image are precisely located in terms of latitude and longitude on a celestial body, such as the earth, being imaged. A computer (60) on the earth generates models (40, 50) of the satellite\s orbit and attitude, respectively. The orbit model (40) is generated f

Pixels within a satellite camera (1, 2) image are precisely located in terms of latitude and longitude on a celestial body, such as the earth, being imaged. A computer (60) on the earth generates models (40, 50) of the satellite\s orbit and attitude, respectively. The orbit model (40) is generated from measurements of stars and landmarks taken by the camera (1, 2), and by range data. The orbit model (40) is an expression of the satellite\s latitude and longitude at the subsatellite point, and of the altitude of the satellite, as a function of time, using as coefficients (K) the six Keplerian elements at epoch. The attitude model (50) is based upon star measurements taken by each camera (1, 2). The attitude model (50) is a set of expressions for the deviations in a set of mutually orthogonal reference optical axes (x, y, z) as a function of time, for each camera (1, 2). Measured data is fit into the models (40, 50) using a walking least squares fit algorithm. A transformation computer (66 ) transforms pixel coordinates as telemetered by the camera (1, 2) into earth latitude and longitude coordinates, using the orbit and attitude models (40, 50).

대표청구항 ▼

Apparatus for locating any pixel within a satellite camera image in terms of latitude and longitude, said apparatus comprising: a satellite in orbit around a celestial body; an imaging camera on board the satellite for taking images of scenes on the celestial body, wherein each image is divided into

Apparatus for locating any pixel within a satellite camera image in terms of latitude and longitude, said apparatus comprising: a satellite in orbit around a celestial body; an imaging camera on board the satellite for taking images of scenes on the celestial body, wherein each image is divided into a plurality of pixels; modeling means which uses measurements taken by the cameras to generate an estimate of the satellite\s orbit and an estimate of the camera\s attitude; and coupled to said modeling means, means for transforming pixel locations as announced by the camera into latitude and longitude coordinates with respect to the celestial body.