Two-dimensional Calibration of a Sun Attitude Sensor

Attitude sensors are used in spacecrafts for measurement and control of its attitude to meet the mission goals. Sensors using the sun for attitude determination are very effective and often applied. The calibration of the sensor gives an important impetus to improve the quality. Calibration helps to reduce systematic errors of the measurement method, of tolerances of the used components due to manufacturing, deviations in the assembly, misalignment etc. An important advantage of the multi-linear and the spline interpolation is the continuous improvement of the accuracy by increasing the number of calibration coefficients. Both methods are applied to a sun sensor using fuzzy logic. The necessary number of parameters or interpolation cells depends on the global input-to-output behaviour of the sensor and can be predicted by means of a sensor model. Simulations show the ability to compensate systematic errors and allow finding an optimal number of calibration cells. This contribution shows, that effective calibration with the belonging software can reduce the expense of spacecraft hardware. Copyright © 2002 IFAC