摘要 |
At geosynchronous and other high altitudes a dual cone scanner has been a convenient way of determining both pitch and roll utilizing a single horizon sensor positioned on an orbiting spacecraft whose attitude is to be determined. However, for large roll angles, one of the scans may leave the earth or reference body defeating the purpose of the sensor. In accordance with the present invention, a third cone angle is scanned between the original two, thereby providing two good scans preserving the pitch and roll attitude information, even if one of the scans has rolled off of the reference body.
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