Thermal imaging system is a kind of equipment that is widely used, its static performance parameters are always measured in library. The paper comes up with a new method to estimate the static performance parameters based on image quality evaluation, which can more easily and more quickly to compare performance of two instruments.
Using a knife-edge to measure the MTF of optical system is a basic way, the paper discuss the influence of slit edge error on MTF by building a mathematical model. The quantitative analysis result was given that it can reach the given precision by only measuring limited area. The qualitative analysis result was also given that fitting-curve-method is better than averaging method for precision.
According to the imaging procedure an infrared picture include an object image, a background image and a noise image. The object image and the background image are main body of an infrared image; noise image is the disturbance on the main body. This paper discusses the infrared image quality from three aspects: information capacity, image detail and pseudo-s/n ratio, it has fine image quality in comparison.
This paper introduces some new methods for measuring parameters of the telescope system with CCD device such as OTF, parallax, diopter and so on. It doesn’t need man’s subjective judgment. The computer accomplishes the assignment to display, print and save the results automatically. So, these methods have some advantages: high accuracy, digital display, and autoimmunization. Basing on the mentioned theory analysis in the paper, we have realized the digitization checkout of a lot of parameters on same instrument.
Against those problems discovered using single-slit to measure OTF, this paper puts forward the time space filtration method to restrain these noise. Experiments verify that the method has gained better effects. Using CCD to measure other parameters, it also has very good reference value. Increasing the sample times can gain better filtration effect. But the time space filtration of long time and multiposition is not very meaning to the raising of measurement. Compare many filtration times, we find that average of time filtration for 8 frames pictures and space filtration for 20 lines is suitable. This experiment results accord with related theory.
Injected-current density and carrier distribution are crucially important factors in Vertical-cavity surface-emitting laser (VCSEL) characteristics, affecting the laser emission wavelength, distribution of transverse-mode, threshold voltage, available output power and operating laser lifetime. Using a method of finding self-consistent solution for the carrier-diffusion and Poisson's equations, of calculating beginning from electrode voltage and of taking into account the whole structure of distributed Bragg reflectors (DBR), we have studied the two-dimensional current density and carrier distribution characteristics of VCSEL. The calculated results show that the injected-current density and carrier distribution determined by the confined-layer depth in VCSEL. The deeper confined-layer in VCSEL is, the more notable current density and carrier distribution are limited in the active region. So the strong confinement benefits to concentrate the current density in the active region to a higher level, at the same time ofthe reduction ofthe threshold.
In the measurement ofinterference fringe using the linear CCD, thinking ofthe separation of CCD, the integral effect of the pixel, and the sampling speciality of the interference fringe (cosine signal), three problems have been discussed seriously——"how to determine the advisable maximum of the spatial frequency ofthe fringe", "the effect on the sampling ofthe integral effect ofthe pixel", and "the effect on the contrast ratio ofthe fringe ofthe phase matching ofthe pixel".
In many industries there exist high temperature and nuclear radiation and poisonous gas in the production, so the robot technology is emerge, it's asked to make proper response to the objective change by vision. The research on the auto-tracking-technology of objective based on video frequency possesses important meaning. Matching of the correlation tracking is fit for the tracking ofobjective in the complicated background, the template matching method is used. The operation of the image matching is very greatly, not only need to choose the digit signal processor at a high-speed, but also need to distribute the work ofsoftware and hardware reasonably.
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