Yansong Song

Modeling and reality analysis of beaconless spatial acquisition for intersatellite laser communication system

Abstract. For an optical satellite link, the error sources that influence the pointing accuracy of the terminals include the attitude estimation error, ephemeris accuracy, and the boresight alignment error. It means an uncertainty cone (UC) exists for the spatial acquisition process. The acquisition process is a continuous adjustment for the visual axis of the two communication terminals, to enable them to detect the light signal from the other end, and finally realize the light closed loop. Beaconless acquisition algorithm and the corresponding acquisition process, modeling for spiral scan pattern and the simulation results of staring-scanning mode are presented. The UC scan range is 5 mrad, through the overlap with a spot divergence angle of 80  μrad, the total acquisition time is 98 s.

Research on the intelligent control simulation target with IR imaging target for hardware-in-the-loop simulation test

The intelligent control of simulation target with infrared imaging target in the indoor and outdoor environment can effectively and quantitatively evaluated the parameters such as the minimum resolution temperature difference（MRTD）and spatial resolution of airborne forward looking infrared, infrared detection and tracking, infrared alarm, and etc. This paper focused on introducing the working principles of the intelligent control simulation target of Infrared imaging target, studying the thermal radiation characteristics of the infrared target surface material, analyzing the influences of the infrared radiation energy distribution, and developing the intelligent control simulation target with IR imaging target for hardware-in-the-loop simulation test. The intelligent control simulation target which area was 5 ㎡ and concluded 44 infrared targets including two kinds of infrared targets ,0.25ｍ×0.25ｍ, and 0.25m×0.5m, achieved 1℃～10℃ temperature simulation of target and the background, and temperature control precision better than 0.5℃. Field test requirements were achieved by actual test.

Development of the infrared target simulation system

In order to provide a set of field test equipment for the infrared system of modern weapon equipments and other optics instruments, a set of large-scale resistance-type infrared target system was designed. First, the large-scale infrared target was designed in modular construction. It was decomposed into several independent and controllable units. Then the working principle of the system was introduced. Three modes of thermal exchange (conduction, convection and radiation) and the computing methods for each mode were given under thermal equilibrium conditions through modeling and simulating. Periphery electro-circuit and control software were carried out as well. Finally, the performance of the system was tested. Meanwhile novel ways of temperature compensation to improve the uniformity of the surface temperature of the target was introduced. The experimental results show that the infrared target could meet test requirements for infrared imaging weaponry which wavelengths from 8 μm to 14 μm. The temperature control precision can reach 0.5ms. In conclusion, the infrared target system can satisfy requirements of reliability, high precision, as well as strong anti-jamming and stabilization.

Research on the liquid crystal adaptive optics system for human retinal imaging

The blood vessels only in Human eye retinal can be observed directly. Many diseases that are not obvious in their early symptom can be diagnosed through observing the changes of distal micro blood vessel. In order to obtain the high resolution human retinal images,an adaptive optical system for correcting the aberration of the human eye was designed by using the Shack-Hartmann wavefront sensor and the Liquid Crystal Spatial Light Modulator(LCLSM) .For a subject eye with 8m-1 (8D)myopia, the wavefront error is reduced to 0.084 λ PV and 0.12 λRMS after adaptive optics(AO) correction ,which has reached diffraction limit.The results show that the LCLSM based AO system has the ability of correcting the aberration of the human eye efficiently,and making the blurred photoreceptor cell to clearly image on a CCD camera.

Research on power measurement device of jamming bomb based on Infrared Radiation

In order to realize the non-connect measurement on the power and character of jamming bomb, we carried out the research on power measurement device of jamming bomb based on Infrared Radiation. First, the power and infrared radiant band of the jamming bomb was summarized and refined. Then, ensuring the feature and power of jamming bomb was characterized by the magnitude of Infrared Radiation. Afterwards, based on the theory of the above, a power measurement device of Infrared Radiation was simulated and developed. Including the selection of detector and the detector application design, analog signal processing and digital signal processing, using correlation measurement method to detect and calculate the power of device. Finally, the specific method and advantage of the device was introduced. The results of the experiment show that: the response time of the device is less than 3ms; the detection sensitivity is better than 3 x 108cm √HZ / W . The device successfully accomplished the accuracy measurement of Infrared Radiation between 1 to 20um wavelength with higher detection sensitivity and lower response time.