High accuracy sun sensor - phase 1A and 1B

Work is reported on a system definition of a high accuracy sun sensor for a spaceborne instrument pointing system to be applied in solar research. Several principles on which the sensor could be based were investigated and compared: a collimator approach with slit aperture, an interferometric solution with two apertures, and an imaging system with a CCD detector at focus. The sensitivity to irregular features of the sun played an important role in selecting the preferred concept. Final tradeoff resulted in selection of the collimator in combination with a linear CCD detector. The performance of this system was analyzed, resulting in the assessment of an error budget, the sensor's physical parameters, and its reliability. The aspect of calibration was also considered.