Influence of photodetector response time on operation of monostatic and bistatic airborne meters of turbulence. Ⅰ

摘要

The paper presents the basic theoretical equations, needed for the measurement of turbulence characteristics from observations of the jitter of astronomic images from onboard a flying aircraft. Two optical detectors: monostatic and bistatic differential ones, were used as recording devices. The method allows us to record the integral turbulence intensity (integral of the structure characteristic of refractive index fluctuations C_n~2 along the optical path). The theoretical equations are derived for the correlation functions of jitter of astronomic images taking into account the finite response time of a photodetector (CCD array). The relations have been found between the variances of image jitter in detectors with finite and zero response times. The relations are obtained for the both types of detectors under consideration. The article consists of two parts. In the first part we are gained theoretical equations for the time correlation function of image jitter for a point source. In the second part we are made analysis and comparison of correlation functions of image jitter for a point source in the cases of monostatic and bistatic detectors.