Comparison of vibration mitigation controllers for adaptive optics systems. http://dx.doi.org/10.1364/AO.51.004520Revista : Applied Optics
Volumen : 51
Número : 19
Páginas : 4520-4535
Tipo de publicación : ISI Ir a publicación
Vibrations are detrimental to the performance of modern adaptive optics (AO) systems. In this paper, we describe new methods tested to mitigate the vibrations encountered in some of the instruments of the Gemini South telescope. By implementing a spectral analysis of the slope measurements from several wavefront sensors and an imager, we can determine the frequencies and magnitude of these vibrations. We found a persistent vibration at 55 Hz with others occurring occasionally at 14 and 100 Hz. Two types of AO controllers were designed and implemented, Kalman and Hinfinity, in the multiconjugate AO tiptilt loop. The first results show a similar performance for these advanced controllers and a clear improvement in vibration rejection and overall performance over the classical integrator scheme. It is shown that the reduction in the standard deviation of the residual slopes (as measured by wavefront sensors) is highly dependent on turbulence, wind speed, and vibration conditions, rangingin terms of slopes RMS valuefrom an almost negligible reduction for high speed wind to a factor of 5 for a combination of low wind and strong vibrations.