Research On Influnence Factors Of Imaging Quality Of Fourier Telescopy System

Fourier telescopy is a new active coherence imaging technique based on multi-beams interfering. It breaks through the traditional imaging concepts for its ability of immunity to atmosphere turbulence without complicated Adaptive Optics system and large aperture segmented mirror. Of all the influence factors on the imaging quality, the transmitter array design, whole-link energy transmission, and interfering fringe quality should not be neglected. However, these factors haven’t been deeply researched. Therefore these works were presented in this paper as following:In the research on transmitter array optimum design, the RST(Redundancy, Strehl Ratio, Target texture distribution) distribution diagram was proposed. It combined the concepts of baseline redundancy, imaging strehl ratio and target information. The combination may help to optimize the transmitter array. Also, this dissertation proposed a scheme of aperture position error distribution and put forward a multi-beam pointing method.The dissertation also studied the energy transmission coefficient of uplink and downlink path and built the energy transmission model. Based on Ratio Factor of the detector NEP, the whole-link energy acquirement design was proposed. The field experiment has validated the correctness of this model. This energy study could be a reference for future Fourier Telescopy system in laser source and receiving scale.The quality of multi-beam fringe pattern is also a crucial factor on imaging quality.The energy equality, polarization identity, and the stability of laser power and frequency were analyzed as well. In order to rectify the frequency drift, two schemes, “radio demodulation” and “confidence interval stacking demodulation”, were proposed. The experiments demonstrated that two methods are both feasible and the method of “confidence interval stacking demodulation” could offer better image quality.In addition to factors mentioned above, the target surface characteristic, system modulation transmission function(MTF) and some other influence factors were analyzed as well.To sum up, this dissertation stressed on the researches of transmitter array optimum design, whole-link energy model, and fringe pattern quality improvement and so on. The researches would provide Fourier telescope with theoretical and technical enhancements and would effectively propel the progress of Fourier telescope.