An Algorithm for self-adjusting Sun tracking for solar spectrophotometers

A great number of geophysical instruments based on measurements of direct solar radiation are used for monitoring of and research into atmospheric composition. One of the necessary requirements for the correct operation of such instruments is to provide precise orientation to the source of radiation. We present a general algorithm for defining solar trajectory in the instrument coordinate system. It provides holding the Sun in the field of view of the tracking system after minor events of solar exact tracking, despite some imperfections in mechanical units of the device. A distinctive feature of the algorithm presented here is increasing the accuracy of the definition of trajectory parameters during operation. The efficiency of the proposed decision has been illustrated through the operation of a universal solar ultraviolet spectrometer-ozonometer designed by the National Ozone Monitoring Research and Education Centre (NOMREC, Minsk, Belarus).