Transient Detections and Other Real-Time Data Processing from MASTER-VWF Wide-Field Cameras
Figure 5
Average error (a, b, c) and the number of identified stars (d, e, f) as functions of the degree of the polynomial used. The dependences are shown for three different optical systems. Red (a) and (d) Rigter-Slefogt (MASTER) with a field of view of deg, Nikkor 50 mm (b) and (e) with a field of view of deg, and Nikkor 50 mm (c) and (f) with a field of view of deg. The histograms are based on arbitrary frames from various sky areas. A third-to-fourth-degree polynomial approximation can be seen to provide optimum solution (95–99 percent of stars are identified with the minimum average error). A more detailed analysis shows that the third-degree fit yields slightly better results. That is logical, because most of the known aberrations (e.g., distortion) depend on the third power of radial distance.
