To expand the infrared (IR) target detection scope of tank, according to the requirements of real-time recognition and tracking for target with joint transform correlator (JTC) a set of infrared (IR) continuous zoom optical system with 8-12 μm long-wave-band was designed, which applied long-wave 384× 288 element uncooled thermal IR focal plane array detector. In this system, the zoom ratio is 8× , the range of the focal length is 30mm-240mm, F number is 2 and during the zoom process the relative aperture is invariant. This system used the mechanical compensation method, after designed and optimized, it can be composed of 6 spherical lenses with Ge and ZnS only. The design results show that when the cutoff frequency is 14lp/mm, in the whole range of the focal length the MTF curves are all above 0.52 which all approach to the diffraction limit curves. And the spot size is smaller than the pixel size of the receiver. It can meet the requirement of long IR target recognition and tracking in the practical application.
Recognition of low-light level target is attracting more and more concern in modern military areas. However, for the
reason of low contrast, low signal-to-noise ratio and inadequacy information of low-light level target etc, the goal to
detect and recognize the target would not be realized by using photoelectric joint transform correlator. By median
filtering and edge detection with lifting wavelet transform for low-light level target in this paper, the interference of
background noise is reduced and useful information of target and template is enhanced at the same time. Experimental
results show that the brightness and contrast of correlation peaks are both improved obviously after processing the joint
image, which proves the method is very effective in target recognition field by using photoelectric hybrid joint transform
Target tracking has a wide application in varieties of domains and has a rapid development at home and abroad, so the
research on target tracking is more valuable in recent years. In this paper hybrid optoelectronic joint transform correlator
(HOJTC) is implemented for tracking the target, which is considered as one of the most effective methods.
But in practical application, the low contrast character of the target and the moving distortion problems between the
target and the template may cause the phenomenon of low recognition ratio of HOJTC. In order to solve this problem, a
kind of wavelet-based threshold segmentation method is applied to increase the contrast. Through this algorithm the
histogram of the image is firstly decomposed into wavelet coefficients at every scale with wavelet basis function Sym4.
And then according to segmentation norm and wavelet coefficients, the thresholds can be chosen from the reconstructed
histogram. Finally use these thresholds to segment the image into ideal areas. In addition, for the moving distortion
problem, taking temporal state of the target as the template can realize the template update.
To prove this method, many tracking experiments of low contrast targets have been performed with optical correlation
method. As an example a low contrast target “tank” (the gray contrast is less than 2%) is presented. The tracking result
shows that the brightness of the correlation peaks is enhanced and the target recognition ratio is increased. The
conclusion can be drawn that applying this algorithm in optical correlation method can implement the low contrast target
tracking successfully and this algorithm provides an available solution to low contrast target tracking.
The image pattern recognition can accurately identify and locate the target, but image pattern recognition is unable to
accurately recognize the distorted targets (the targets rotated in plane or scale changed), which has restricted the
development of the image pattern recognition. In order to solve the problem of inaccurate recognition for distorted target
in cluttered background among the image pattern recognition, the distorted target images and the training images are
edge extracted by canny operator. The Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter is
synthesized with the edge extracted training images. The low frequency information of the distorted target images and
the filter is enhanced. Then the edge extracted distorted target image is filtered by the OT-MACH filter. Thereby, the
distortion tolerance of the OT-MACH filter is expanded. It can respond higher correlation peaks and have higher
distortion tolerance to recognize various types of distorted targets in cluttered background. By this method, which the
space edge extraction combines with frequency domain filtering, the scale distortion tolerance is 0.72~1.42 times; the
rotation distortion tolerance can reach up to 70 degrees. In order to prove the feasibility of this method, a lot of computer
simulation experiments have been done with the canny operator and the OT-MACH filter.
With the development of the technology of infrared, infrared optical system has been widely used in many fields, especially in tank target detection and recognition. The difficulty and key in the designing of LWIR optical systems for working under temperature range of -60°C~80°C is athermalization. In this paper, the infrared telephoto lens is designed which is composed of four pieces of lenses. The working temperature range is -60°C~80°C. In order to balance the chromatic aberration and thermal aberration, two aspherical surfaces are used in this cooled athermalized infrared optical system. The effective focal length is 100mm and the F-number is 2.The full field of view is 7.0°. The curve of MTF is close to diffractionlimit curve. Within the working temperature, the value of MTF at 17cy/mm is always large than 0.4. The result shows that the infrared optical system achieved better athermal performances at the working temperature range.
This paper presents a master-slave multi-communication system designed with several micro-controllers used as master
and slave controllers to set signal the lamp to realize point-to-point communication through the RS422 interface. By
describing a typical example of this system and the blue print of hardware and the flowchart of software, the reliable
work of the system has been proved. The circuits of system are very simple and practical, and they can be used to realize
all the functions of a pilotless airborne mapping equipment. It also has a strong anti-jamming capability due to its
balanced transfer scheme with single transmitter and multiple receivers. It is very efficient in protecting the integrity and
correctness of transmitted and received signals, avoiding the collision of signals through the bus, satisfying the
communication among several micro-controllers in a single system and forming a special communication network.
Holography has been widely applied in industry measurement, especially in 3D non-contact testing. Combining a high
resolution charge-coupled device (CCD) with a phase modulating liquid crystal display (LCD), holographic interferogram recording and display could be realized by digital holographic technique. Digital holographic technique has a great number of important and practical applications. In the conventional holography hologram was detected and
reconstructed by the holography panchromatic plate, or the photoconductive thermoplastic film, or the BSO crystal and
etc. But in the digital holography--the numerical version of the conventional holographic technique, hologram is
digitally detected by CCD and then displayed on the computer monitor. By reconstruction, the hologram is writted into
LCD, then illuminating the LCD with the reference wave, the tested object may be reconstructed optically. In this paper
the application technique of CCD/LCD in holography is theoretically studied and the bottle techniques have been solved.
According to the resolving power of the CCD and LCD, the angle between the two interfering waves should be less than
3° for recording the interference fringes with high spatial frequency. The simple and prospective optical architecture is
perhaps Twyman-Green interferometer for easy to adjust the required small angle between reference and tested object
waves, and also optical path deference for satisfying the requirement of spatial and temporal coherence. The
disadvantages of CCD/LCD digital holographic technique is the small separation angle between zero-order and ±1-order
diffraction. In order to separate ±1-order from zero-order diffraction, the minimum fringe spacing formed by the
interference of object wave with reference wave should satisfy the sampling theorem. This decides a relationship
between the size of object and the recording distance, which will be discussed in detail in the following text. And also
discussion about the experimental research of LCD in digital holography would be included in our paper.
In the industrial production, it is frequently needed to test the area of the irregular shape plane object. In this paper
optical method is used to perform non-contact area measurement of random shape plane object testing and matrix
CCD-computer system is combined to realize real time automatic measurement. In this paper principle and method for
area measurement of arbitrary shape plane object using matrix CCD-microlens-compute system is present. Testing
device is designed from the hardware and the software. At last the factors affecting on the accuracy are analyzed. By
experiment, it is proved that this method processes fast speed, high accuracy and strong adaptability. The system makes
on-line testing possible and may be applied in the modern industrial testing conveniently.
Hybrid optoelectronic joint transform correlator is very useful for target detection and recognition in military and
industry field. Nowadays, there are two kinds of usual detectors: one is visible detector which is sensitive to the diffusion
of target; the other is infrared detector which is sensitive to the radiation of target. The performance of these two
detectors both depend on their working conditions.
Designing perfect optical system is the first step to target detection. While the merit of infrared optical system is it can
not only detect great distance but also detect the target in the turbid air or smoke, flog and snow no matter at day or night.
So it is much more appropriate to be applied in cluttered and formidable conditions and it can enhance target recognition
In this paper, the infrared detector we adopted is infrared focal plane arrays with working waveband 8-12μm. Its
resolving power is 30 lp /mm. For the infrared optical system, the effective focal length, relative aperture and the field of
view should be large enough to ensure the long distance and large field of view target can be detected. In hybrid
optoelectronic joint transform correlator, the high performance of infrared telephoto lenses is required. Here, we
designed infrared telephoto lenses composed of three lenses. Its structure is simple but its performance is very good. It
has met the requirement of target detection. Thus we can get the longer detection distance and higher recognition
Hybrid optoelectronic joint transform correlator (HOJTC), exploiting the Fourier transform property of a lens, implements target detection in real time. Adaptive nonlinear digital filtering in the joint transform power spectrum (JTPS) plane improves the immunity against the noise and clutter. In this paper, electrically addressed liquid crystal devices (EALCD) are used as the space light modulators (SLM), Charge Coupled Device (CCD) matrix camera as the square law detector and Ar<sup>+</sup> laser as the light source. We develop the hybrid optoelectronic joint transform correlator controlled by computers, which can successfully detect and recognize the target in cluttered scenes in real time. The speed rate of the recognition is 25 frames per second. As the experiment examples, the target recognition of a tank and a car in cluttered scenes is presented. The experiments show that the intensity of cross-correlation peaks after adaptive nonlinear digital filtering is increased greatly, the performance of the joint transform correlator is improved, and it can detect the distorted and noisy targets in cluttered scenes in real time. It was found that using wavelet filter in frequency domain is a very effective way to suppress clutter noise while maintaining high tolerance for distortion.
In the target recognition system using Joint Transform Correlator (JTC), real-time displaying spectral images in electric addressed Liquid Crystal Display (EALCD) is required, under the work condition of non-affecting image capturing and processing, the above requirement can not be satisfied by the graphic device interface. With the aid of DirectDraw, image data can be captured, transmitted and converted. When the spectral images are displayed at a high speed, the high quality of image can still be produced.
High accuracy correlation detection technology of object signal is to search and detect objects by optical correlation, and it can detect in real-time, recognize automatically and orientate precisely. Optical correlation processes images at light speed and its device is simple, and Fourier transform can be realized. In this article, we mainly study how to design optical Fourier transform system which can realize optical correlation.
Optical image recognition is an important branch of optical information processing. It has extensive practical meaning and applied prospects. In recent years, joint transform correlator has taken place of matched filter, and pure optical experiments have developed into optoelectronic hybrid experiments. Optoelectronic Joint transform correlator has not only the optical advantages of parallel processing, large capacity and high speed, but also the advantages of computers, such as flexibility, programmability and accuracy. In this paper, electrically addressed liquid crystal displays (EALCD) are used as space light modulator (SLM), by the use of EALCD and CCD matrix camera which is controlled by microcomputer, and the optical Fourier transform (OFT) system, the moving object is detected and recognized. Because of using CCD matrix camera to detect the power spectrum of OFT, many kinds of digital processing algorithms can be adopted to improve signal noise ration (SNR), and to detect and recognize accurately moving objects.
In this paper, based on the principle oflaser cure, using the semiconductor laser with Wavelength 650 nm, we developed a laser cure instrument for brain blood-oxygen. The arterial part of a nose can be directly irradiated by a laser head, and the laser beams affect directly on the blood of a circulation system. It can decrease the blood viscosity, increase the quantity of blood oxygen and deformation ability ofred blood cell. Simultaneously, both the temples of a brain are also irradiated to dilate the blood vessel and just a neural system. Clinical examination shows that the instrument has not only the function of health protection, but also the therapeutic function for brain arteriosclerosis, and also can cure other illnesses, such as neurasthenic, insomnia.
Used He-Ne laser as a light source, CCD camera as the detector of Twyman-Green interferometer, a Twyman-CCD- Microcomputer systems is consisted. With this setup, high accuracy, non-contact, real-time, auto-measuring displacement is realized. As a practical example, the shrinking of 2- components adhesive is measured for a company.
In this paper, with the aid of Fourier transform and reverse Fourier transform not only 2D contour map, but also 3D plot of a tested aspherical surface is obtained by 1- interferogram method, so a simple method is provided for autocontrolling machine-shaping of an aspherical surface. In order to test a variety of aspherical surface, a quasi- universal compensator is designed. The experiment setup for testing aspherical surface is Tywman-CCD-computer system.
The combined use of the photoelectric and electron-optic properties of BSO crystal leads to realize spatia light modulation. Under some condition BSO crystal can become birefringent depending on a local illuminance. The relationship between the distributions of illuminance and birefringence will be discussed. This spatial light modulator can work in real-time, which converts illuminance into transparence. The experiment shows, in order to increase the sensitivity of BSO crystal, an electric field 6 kv/cm at an atmosphere pressure 15 X 10<SUP>5</SUP> Pa should be applied to BSO crystal. With BSO crystal we have measured 3D deformation by means of real-time holography.
Zr-rich lead zirconate titanate (PZT) thin films with a thickness of 1 micrometer were successfully grown on (111)PLT/Pt(111)/Ti(101)/SiO<SUB>2</SUB>/Si(100) substrates by an rf planar magnetron sputtering equipment using a multi-target which consisted of PbO and metal titanium pellets on a zirconium metal plate. The optimum sputtering conditions were a gas content of Ar:O<SUB>2</SUB> equals 8:2 Sccm, gas pressure of 6 X 10<SUP>-3</SUP> Torr, rf power of 100 W and substrate temperatures of 630 - 650 degrees Celsius. The composition of the films could be controlled by adjusting the area ratio of PbO/Zr/Ti. The crystal structures of films were sensitive to the substrate temperature. The pyroelectric current, relative dielectric constant, remanent polarization and coercive field of the PZT films were measured. These electrical properties depending on the ratio of Zr/Ti in the films are described. The phase transition of low temperature to high temperature rhombohedral ferroelectric phases in as-grown PZT films is also reported. Zr-rich PZT films sputtered on (111)PLT/Pt/Ti/SiO<SUB>2</SUB>/Si substrate possess desirable properties for potential applications to pyroelectric devices.
In this paper, we have discussed how to use a TV-computer system in holographic interferometry. With Ar<SUP>+</SUP> laser as a light source, BSO crystal as a recording material, TV- computer as a detector, holographic interference pattern is automatically scanned, recorded and judged. Not only contour map is reconstructed, 3D plot is also graphed. With BSO crystal, hologram can automatically in real-time be developed. As an example we have measured the deformation of a plate under a stress by real-time holographic interferometry of 4-interferograms method. With respect to common holographic setup, TV-computer system can automatically control shifting the phase of reference beam, exposing holograms, scanning, recording and judging interferograms.