StarNav III: a three fields of view star tracker

Italian Space Agency has funded, as one of the possible Italian experiments on board the International Space Station, the development of a new star tracker, called StarNav III, which observes the sky by means of three orthogonal fields of view and focuses all the star images onto a single CCD/CMOS imager. The main characteristics of this sensor are a high gain in the attitude accuracy estimation and in the operating time. These benefits cost, however, in terms of hardware and software design which are, in turn, more complex. The completed StarNav III feasibility study has output a variety of new software approaches (as, for instance, for acquisition, centroiding, star identification, and mirror misalignment), most of which can directly be applied to almost all of the existing CCD/CMOS star trackers. This paper shows the principal aspects of the relevant feasibility study.