Linear Wide Angle Sun Sensor For Spinning Satellites

The V-slit, N-slit, and crossed slit sun sensors that are normally used for sun elevation angle measurement on spinning spacecraft suffer from two defects, namely, nonlinearity of response and limitation in range. This paper describes a concept which overcomes both of these defects. Two versions of sensors based on this concept which give a linear output and have a range of nearly +/-90° of elevation angle are described. The first version has already been flown on three Indian spacecraft, and a flight model of the second improved version is under testing for another satellite to be flown shortly.