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The Research On Imaging System For Infrared Thermal Weapon Sight

Posted on:2016-01-02Degree:DoctorType:Dissertation
Country:ChinaCandidate:X M ChenFull Text:PDF
GTID:1108330503453378Subject:Mechanical and electrical engineering
Abstract/Summary:PDF Full Text Request
Weapon sight is the eye of modern light weapon system such as gun, rocket launchers and it infuences the weapon system’s attack accuracy and lethality to enemy target directly. In this paper, based on aiming at infrared detection sight as research object, "the research on imaging system of infrared themal sight" has been accomplished. The research will provides the powerful support for infrared sighting equipment of our army, and has the vital significance to development of our country’s infrared thermal weapon sight and high-tech motivation of the military equipment.In this paper, research of infrared image processing algorithm and engineering implementing of imaging system of infrared thermal weapon sight are developed as our focus.The basic criterion for researching algorithm is that algorithm should be designed from the system point of view, which means algorithms complement each other to achieve optimal results. With drawing on the experience of a variety of successful algorithms, which means taking their advantages, and taking corresponding measures to weaken the defect(s) or compensating the defect(s) with other algorithm, a new complete image processing algorithm flow of infrared imaging system is proposed to aim at the application of our system. It includes non-uniformity correction algorithm based on ROIC, image enhancement algorithm with adaptive noise suppression, and wavelet de-noising algorithm for infrared image based on redundancy information. The non-uniformity correction algorithm based on ROIC performs one point pre-correction firstly, and then executes online multi-point points fitting correction algorithm by using shutter. It not only has the similar correction performance with the conventional correction method which uses black-body to calibrate imaging systems, and also it overcomes the shortage, that conventional pre-stored correction parameters fails when working condition and/or working state change. Image enhancement algorithm with adaptive noise suppression combines global enhancement algorithm and local enhancement algorithm by which global contrast enhancement and image detail enhancement are achieved. And also it employs noise estimation to suppress noise reasonably and to suppress the phenomenon of noise amplification. The simulation results show that the proposed algorithm has good performance on image enhancement. Wavelet de-noising algorithm for infrared image based on redundancy information firstly preserves the redundant coefficients, which are discarded when under-sampled in the process of wavelet decomposition of image. And all levels’ wavelet coefficients are used to estimate noise and the estimation results guide non-linear transformation of wavelet coefficients. Then the non-linear transformed wavelet coefficients are reconstructed in single level, and the redundancy information is averaged to get the reconstructed image of single level. The final de-noised image can be obtained after reconstructing wavelet coefficients level by level. The quality of infrared image can be further improved by the proposed de-noising algorithm, which filters the noise accordingly by estimation of noise and preserves the details by using image similar and employing the non-linear transformation for wavelet coefficients.In terms of engineering implementing of imaging system of infrared thermal sight, top scheme of the system has been designed based on analyzing the performance goals. Then the system functions have been partitioned, which include imaging function, system function of weapon sight and analogous circuit function. The implementation of correction module, enhancement module and de-noise module, which are part of imaging function, are researched thoroughly. The design idea based on SOPC, which integrates NIOSII soft cores, is employed to establish imaging system and to implement the system function. The experiment on the system have proven the designed imaging system of infrared thermal sight achieves the performance goals and satisfies the system requirements. Because of combining the flexible hardware design of FPGA and strong software function of embedded processor, the imaging system not only processes infrared image in real-time, and also has good maintainability for system functions.The infrared imaging sight has superiority of being used in all-weather conditions, and the research achievement will provides the effective technology support to the design and development of this class of weapon systems.
Keywords/Search Tags:infrared thermal sight, un-cooled infrared detectors, infrared imaging algorithm and simulation, non-uniformity correction, image enhancement, wavelet de-noising, SOPC & FPGA’s application
PDF Full Text Request
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