Adaptive Absolute Attitude Determination Algorithm for a Fine Guidance Sensor

In order to ensure the attitude determination accuracy and speed of a fine guidance sensor (FGS) in space telescope with limited onboard hardware computing resources, an adaptive absolute algorithm was proposed. The more stars involved determination, higher accuracy, but resources will be consumed. By analyzing relationship between number (NOS) field view (FOV), detector exposure time NOS, method adjusting NOS FOV proposed keep observed at target value. star map recognition based on improved log-polar transformation has than traditional cannot accurately identify match corresponding guide when is less stars. Thus, comparison-AND identification polar coordinates case given line-of-sight pointing 100-frame image simulation calculation, root mean square (RMS) value error 37 mas direction right ascension, 25 declination, as concluded from experimental simulation.