I'm going to have to split this topic off the Spin Stabilized thread.
Ok I'm looking at 2 Star trackers
1: Nasa Low Cost Star Tracker Software Highly accurate attitude
information for low cost COTS hardware.
2: OpenStarstacker a robust, high performance startracker
The camera for the Nasa tracker is the Lumenera LW230 monochrome with
FUJINON HF35SA-1 35mm lens and a star database from Hipparcos catalog
Position computation is derived from Euler Angles not Quaternions
The attitude is computed as a set of Euler angles: right ascension (RA),
declination (Dec), and roll. The first two Euler angles are computed by
using a linear system that is derived from vector algebra and the
information of two identified stars in the image. The roll angle is
computed using an iterative method that relies on the information of a
single star and the first two Euler angles.
The OpenStarstracker uses Bayesian startracker algorithms (Solar System
based frame of reference) and a star database from the same catalog
Hipparcos
The camera is left up to you to choose and they have a calibration
technique where you send an image from the camera and the it tries to
determine if your camera will work.
The position is accomplished by Using OpenCV centroiding and the
positional math I can not find a reference to but they must use Euler
angles, Quarternions or DCM (Direction Cosine Matrix) as far as I know.
So I'm offering this up so people can punch holes in the
quality/usefulness issues of actually trying to fly a spacecraft using
them.
Monroe