초록 ▼

A method for controlling orbiting spacecraft uploads a plurality of parameters to an onboard processor, the parameters including a plurality of quaternion elements describing an inertial to orbit reference frame, and including radial position, radial velocity and angular rate of the spacecraft. Para

A method for controlling orbiting spacecraft uploads a plurality of parameters to an onboard processor, the parameters including a plurality of quaternion elements describing an inertial to orbit reference frame, and including radial position, radial velocity and angular rate of the spacecraft. Parameters are input for processing one of a plurality of propagation algorithms, preferably calculating said propagation algorithms with the uploaded parameters, computing enhanced time of day vectors, and computing ground time of day angles from the enhanced time of day vectors for adjusting the payload pointing angle, such as an antenna pointing angle, of the satellite. Preferably, the calculating step comprises integrating an orbital state vector with a second order Runge-Kutta integration algorithm. In addition, enhanced time of day fault processing provides an internal check on integration accuracy and is checked every time of day update. Preferably, quaternion normalization deviation from unity shall be compared to commandable threshold values in the fault processing.

대표청구항 ▼

[ What is claimed is:] [1.] A method for controlling orbiting spacecraft payload pointing by determining spacecraft orbital position using quaternion representations of the orbital state, comprising:uploading a plurality of parameters to an onboard processor including a plurality of quaternion eleme

[ What is claimed is:] [1.] A method for controlling orbiting spacecraft payload pointing by determining spacecraft orbital position using quaternion representations of the orbital state, comprising:uploading a plurality of parameters to an onboard processor including a plurality of quaternion elements;inputting said uploaded parameters to a propagation algorithm;calculating said propagation algorithm with said uploaded parameters for computing enhanced time of day vectors, wherein said calculating step comprises integration of an orbital state vector;computing ground time of day angles from said enhanced time of day vectors; andadjusting payload pointing angle of the satellite.