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A method of using liquid-crystals (LCs) to generate a partially coherent beam in real-time is described. An expression for generating a partially coherent beam is given and calculated using a graphic processing unit (GPU), i.e., the GeForce GTX 680. A liquid-crystal on silicon (LCOS) with 256×256 pixels is used as the partially coherent beam generator (PCBG). An optimizing method with partition convolution...
Cylindrical panoramic image mosaic has a severe flaw that the focal length must be known. Our article proposes a new method based on image feature points to calculate the focal length in the process of image mosaic. The observation equations can be gotten from the transmission matrix between stitching images. Then the Bundle Adjustment is used to solve equations and optimize the focal length. The...
The effect of angle-of-arrival fluctuation caused by atmospheric turbulence seriously influences the performance of the communication system in the free-space-optical communication. Variance of angle-of-arrival fluctuation is deduced from the theory of turbulent inner-and-outer scale. An experiment for angle-of-arrival fluctuation was carried out on 0.893 km line of sight link, 15000-frame grayscale...
To investigate the effect of atmosphere turbulence on laser communication, the effect of arrival of angle (AOA) fluctuation and scintillation are measured at a horizontal distance of 890 meters. During the experiments, 15000-frame images are grabbed by the high speed camera every ten minutes at a sampling frequency 1736Hz. The probability density distribution and power spectrum of scintillation and...
In order to investigate the effects of atmospheric turbulence on laser communication, an experiment is carried out to research intensity scintillation which caused by atmospheric turbulence. 15,000-frame gray images which grabbed by high-speed camera every ten minutes are processed and analyzed. Diurnal variation trend of scintillation index in different seasons are provided in the experiment, and...
In order to investigate the effects of atmospheric turbulence on laser communication, an experiment is carried out to research intensity scintillation which caused by atmospheric turbulence. 15,000-frame gray images which grabbed by high-speed camera every ten minutes are processed and analyzed. Diurnal variation trend of scintillation index in different seasons are provided in the experiment, and...
In the research of space-borne platform vibration, There are some problems such as modeling complex, bad realtime, long modeling cycle, hard to deployment exists in the traditional simulation method. Combining with the theory of six axis parallel positioning platform and multidiscipline physical modeling and simulation tools Maplesim, adopts the non-causal modeling method to set up a satellite vibration...
Laser communication with its large capacity communication, strong confidentiality, structure of light and other advantages is becoming research focus. Space laser communications networking technology is communicated network of bi-directional and multi-directional network, which is made of satellites, ground station, near the space vehicle and so on. This paper uses the STK (Satellite Tool Kit) on...
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