Aspect determination for the AFGL infrared survey experiments

The AFGL probe borne infrared celestial survey experiments are designed to obtain the inertial aspect of the payload reference frame with an accuracly comparable to the spatial size of a resolution element in the infrared telescope. Constraining the axis of payload rotation to known inertial coordinates through maintaining lock onto a selected pole star with a star tracker co-aligned to the roll-axis, and by careful geometric alignment of the optical elements and dynamic balancing the payload, the desired accuracy was achieved. Further refinement in position was obtained from the stellar detections by the infrared sensor, with an ultimate knowledge of the inertial aspect being within 1.5 artc minutes root mean square deviation between the measured and catalogued positions for known infrared stars. The procedures used to obtain this accuracy are described. Also detailed is a method of aspect determination using only a star mapper with an N slit focal plane reticle. (Author).