On-orbit jitter performance of the GOES spacecraft and instruments

This paper presents jitter performance of the GOES spacecraft and instruments. Of primary interest is the validation of design and ground test procedures with on- orbit data. System requirements, spacecraft and instrument disturbances, ground testing techniques, and on-orbit testing are discussed. Dynamic spacecraft signatures during appendage deployment are illustrated and used to determine spacecraft modal response frequency and damping. Specific analysis results form angular displacement sensor data, used to measure jitter dynamics from 0.2 to 160 Hertz, and digital integrating rate assemblies, used to measure low frequency, are detailed with regard to solar array, momentum wheel, and other spacecraft disturbances including those generated by instruments during scanning and slewing. Emphasis is also given to feed-forward pointing compensation and optimization of the solar array stepping. This optimization reduces pointing errors, improves image registration, and reduces pixel smear. Performance is illustrated with sensor statistics, fast Fourier transforms, and Earth images. Both long term as well as short term evaluations are presented.