Track-loop bandwidth, sensor sample frequency, and track-loop delays
Steven L. Chodos · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1998
In determining the processing requirements for a track processor, which is most easily specified in terms of processing delay, it is necessary to have a relationship between the system requirement of track loop bandwidth, the sensor sample frequency and all the delays in the track loop processing. These delays include the sensor integration time, the sensor integration time, the sensor readout time, the time for A/D conversion and reformatting, the track processor delay and any D/A conversion and transportation delays associated with getting the rate commands to the servo system. This paper documents a methodology used in determining the relationship between bandwidth, sample frequency and system delays. This is done algebraically in terms of an 'effective' sampling frequency that takes into account the phase loss due to system delays. While more sophisticated analysis can be done, the simplified methods presented here will often be helpful to the systems analyst without the need for more direct control system analysis.