Proceedings Volume 1978

Coherent Measuring and Data Processing Methods and Devices

Valery I. Mandrosov
cover
Proceedings Volume 1978

Coherent Measuring and Data Processing Methods and Devices

Valery I. Mandrosov
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 3 September 1993
Contents: 3 Sessions, 43 Papers, 0 Presentations
Conference: Coherent Measuring and Data Processing Methods and Devices: Selected Papers 1993
Volume Number: 1978

Table of Contents

icon_mobile_dropdown

Table of Contents

All links to SPIE Proceedings will open in the SPIE Digital Library. external link icon
View Session icon_mobile_dropdown
  • Information Capacity of Scattered Coherent Fields
  • Coherent Methods of Measuring the Object: Geometric and Dynamic Parameters
  • Coherent Devices and Elements for Data Processing
Information Capacity of Scattered Coherent Fields
icon_mobile_dropdown
Statistical models of coherent fields scattered by moving objects and their use for object parameter determination
Valery I. Mandrosov
A detailed analysis of coherent fields scattered by moving objects is provided. It includes systematic investigation of statistical characteristics of speckle structures in these fields and in object coherent images and development of coherent images processing using the statistical decision theory. It enables development of various remote methods determining the object parameters and object recognition even in the presence of noticeable noises and even when parts of object surface are not resolved by conventional systems. In addition, it enables estimating the accuracy of various coherent field methods of information acquisition and processing, notably holographical and speckle interferometrical methods. Dependence of the contrast and the correlation radius of the speckle structure of the coherent images on the imaging system resolving power by non-Gaussian statistics of coherent fields is investigated. This is dictated in these images when the imaging system is high resolution. Methods using this dependence for the determination of the mean square deviation and the correlation radius of the surface roughness heights prove effective.
Neuroadaptive undistorted coherent image formation algorithm
Mark V. Zolotarev, Aleksandr N. Safronov
On the base of probability density function (PDF) a self-learning neural-network approach is synthesized for the restoration of arbitrary atmospherically distorted coherent images. Learning capabilities and potential accuracies of the synthesized algorithm are studied. Electro-optical implementation and results of numerical simulation of this approach are discussed.
Spectral vision: production of longitudinal images of diffusely scattered objects by spectral interferometric method
V. V. Bogolepov, Yuri T. Mazurenko, V. S. Udaltsov
The spectral interferometric method of the objects longitudinal spatial structure observation is developed. It is based on spectral distribution correlation analysis of the radiation scattered by diffusely scattering objects. For this reason the developed method is called a spectral vision.
Suppression of speckle fluctuations in a coherent image
Leonid M. Veselov, Ivan A. Popov
Fluctuations in an image generated by a scanning coherent beam are suppressed by using a focused converging beam. The small-scale speckle structure in the optically resolvable element is averaged by low frequency filtering.
Image generation with partially coherent lighting
A. V. Gitin
The generation of images by an isoplanar optical system with quasihomogeneous radiation of the object is shown to be described by convolution of intensities.
Correlation characteristics of radiation scattered by laminar gradient flow with probing by inhomogenious laser beam
Vladimir G. Kolinko, Alexander V. Priezzhev
A calculation of the autocorrelation function of a signal from a laser homodyne spectrometer generated by laminar flow of a liquid with a velocity gradient in the case of probing inhomogeneous laser beam is reported. It is shown that under certain conditions the time correlation scale of the spectrometer signal represents the velocity gradient and is independent of the coherence radiation. The results are given of a numerical modeling of the spectrometer signal energy spectra.
Statistical characteristics of coherent radiation scattered by a rotating surface in the image plane of an optical system
Leonid M. Veselov, Ivan A. Popov
Correlation and spectral characteristics of coherent radiation intensity scattered by a rough surface which rotates in its own plane are analyzed. With the laser spot smaller than the distance from the spot center to the rotation axis the correlation functions of intensity for a rotating and a rectilinearly moving surface are shown to be equal. The experimental power spectrum of scattered radiation with (lambda) equals 0.63 micrometers fits the theoretical findings.
Statistical causal description of space-time structure of quasi-coherent optical fields
Andrey E. Krasnov
Existing multiple applications require informative description of spatial or temporary structure of the fields scattered on the objects under study. In virtue of the random nature of scatter, descriptions of partially or quasi-coherent fields must be in statistical terms and reflect at the same time spatial or temporal structural regularities of the observed physical variables related to scattered fields. The paper considers descriptions preserving important phase relations between spatial or temporal components of scattered fields. A description is proposed dwelling upon the observed estimate of the field density operator and having the form of joint distribution of physical variables related to the space-time field envelope and its Hilbert- image. The description is oriented to recognition and estimation of the parameters of both stationary and non-stationary optical fields.
Description of nonstationary scattered fields in light-beating spectroscopy problems
Andrey E. Krasnov, A. Lunin, Yu. O. Druzhinin
The present paper proposes a statistical description of random temporal structure of scattering field observed by LBS that may be useful for integral description and diagnostics of processes causing scattering and having time and space scales much exceeding the characteristic molecular scales of Rayleigh scattering. A description is proposed based on construction of joint distribution of physical variables corresponding to the real and imaginary parts of the scattered field. The description is used for estimating the mean values of parameters of transients in continuous media controlled by scattered fields.
Information capacity of random coherent fields scattered by moving rough objects
Valery I. Mandrosov, A. I. Nekrasov, V. V. Ratushnyi
By the use of statistical decision theory and space-and-time correlation function of coherent field, scattered by moving rough object, probability density function (PDF) of these fields in the presence of additional background fields is deduced. The PDF is used as an information capacity measure of random coherent field, scattered by moving object, so it enables development of an algorithm for processing the coherent field scattered by the object with an arbitrary surface shape and motion parameters during the observation time of the scattered field. This algorithm requires forming the coherent image of the moving object and taking the Fourier-Fresnel transform of the field in each point of this image. The algorithm can be used for determining the dynamic parameters and shape of moving objects even if the imaging system has very low resolution.
Speckle field decorrelation nature in holographic interferometry with spatially modulated reference wave
Boris B. Gorbatenko, Igor S. Klimenko, Vladimir P. Ryabukho
The influence of reference wave spatial modulation on visibility of the interference fringes in holographic interferometry of diffusely scattering objects is considered. It is shown that the presence of the points with null intensity in the speckle fields causes the distortion of micro- structure of the reconstructed speckle fields even using a reconstructing wave identical to the reference one. As a result, the interfering fields became partially decorrelated and this leads to the noticeable decrease of the holographic interferograms visibility.
Nulls of visibility and branching of interference fringes at superposition of identical speckle fields
Igor S. Klimenko, I. R. Sataev, Vladimir P. Ryabukho, et al.
The regularities of spatial distribution of amplitude nulls of the visibility complex function and areas of branching the low-frequency interference fringes in two relative displaced identical fields superposition are considered. The character of the spatial distribution of the null visibility surfaces in the volume of the superposition speckle field has been investigated by the stationary phase method. It is shown that in the character transverse and longitudinal sections of the superposition field the phase deviation and the interference fringe branching have an effect differently depending on the shape of aperture limiting the input pupil of the imaging system. The results of the experiments have shown good correspondence with the conclusions of the theory.
Common approach to description of interference and moire effects
N. G. Vlasov, Yu. P. Presnyakov
The classical coherence theory and analogy of time and spatial frequencies are combined in a common approach to interference effects in the classical holographic and speckle interferometric and moire effects.
Coherent Methods of Measuring the Object: Geometric and Dynamic Parameters
icon_mobile_dropdown
Determining the vibration parameters by the speckle interferometry method
Leonid M. Veselov, Ivan A. Popov
The space-and-time correlation function and the associated intensity fluctuation power spectrum of coherent radiation scattered in a vibrating body is analyzed. Experimental spectrograms clearly demonstrate a line structure attributable to periodicity of the motion. The frequency of oscillations is found from the frequency spacing between the harmonics and the oscillation amplitude, from the equivalent number of harmonics in the spectrum.
Spectrum of coherent infrared radiation scattered by a rotating rough body
Leonid M. Veselov, Ivan A. Popov, Nikolay V. Sidorovsky
The findings are reported of an experimental study of the spectrum of coherent radiation scattered on a rotating flat rough surface. The dependence of the spectrum width on the wavefront curvature and the beam radii of radiation, incident on this surface with wavelength (lambda) equals 10.6 micrometers is analyzed. The experimental data is in satisfactory agreement with the existing theory.
Determining geometric and dynamic parameters of objects from intensity distribution of their coherent images
Valery I. Mandrosov, A. I. Nekrasov
The possibility is investigated of determining geometrical and dynamic parameters of the objects through space-and-time analysis of intensity distributions of their coherent images. When the objects are satisfactorily resolved by the imaging system, Fourier-Fresnel time transform of the intensity distribution of their coherent images determines the object shape and surface roughness parameters and the distributions of velocities and accelerations along the surface of an arbitrarily moving shape changing object. When the moving objects are not resolved, this transform enables obtaining autocorrelation function of coherent images which provides determination of the object shape.
Heterodyne holographic method of data acquisition on thickness variation of transparent plates and films
E. I. Krupitsky, S. V. Morosov, Tatyana N. Sergeenko
The holographic method to control transparent plate and film thickness variations by heterodyne measurement of the phase of transversed coherent light is theoretically and experimentally analyzed. It provides very high accuracy (about 1 nm) of the thickness variations measurements in visible range.
New principle of moving object image reception
A. N. Anuashvili
The new principle of moving object image reception is offered. It follows from the fact that, as a moving object moves against the background of radiation from a stationary object the intensity of complex amplitude of this radiation averaged in the observation time reduces as a result of interaction with the moving object as a function of the movement. As a result highly contrasting images of any moving objects are obtained, including transparent object and objects, having scattering properties, which coincide with those of the background.
Principle of time averaging of coherent wave fields and its application to determining the parameters of moving objects
A. N. Anuashvili, Valery I. Mandrosov, Ya. Tsveraidze
The geometrical and dynamic parameters of any moving objects, reflecting, transparent or absorbing, can be determined by time averaging of fields in the coherent image of the moving object and randomly inhomogeneous background surface along which the object moves. Applications of this principle with the system resolution ranging from very high to very low are reported.
Time averaging of coherent radiation as a tool to determine the parameters of moving smooth-surface roughness
A. N. Anuashvili, Valery I. Mandrosov
Time averaging of coherent radiation is applied to determining the roughness parameters of moving smooth surfaces by using their coherent images. Two methods are described which average the field and the intensity in coherent images of the surfaces. They may be used for simultaneous estimation of r.m.s. deviation and correlation radius distribution of smooth surface small roughness in large areas.
Optoelectronic spectrum analyzers and direction finders for fast processing of coherent acoustic signals
A. M. Gorelov, Oleg V. Rozhkov, Nina M. Verenikina
The paper presents principles and design considerations of optoelectronic multi-module spectrum analyzers (direction finders) for fast processing of coherent acoustic signals. The results of theoretical investigations are discussed and the module design is considered for the systems implementing both amplitude-only and amplitude/phase processing of coherent low- frequency signals by means of radial and turn shearing interferometers.
New method for the measurement of the structure function constant in turbulent atmosphere with a cw Doppler lidar
We have elaborated and experimentally verified a new method of non-destructive long-range measurement of the parameters of the atmospheric turbulence with a cw Doppler lidar. The method is based on certain processing of the heterodyne Doppler spectra. In addition to the wind direction and magnitude the method yields the value of the velocity structure coefficient. The method has been experimentally verified. The measurements of structure function constant were carried out in parallel with the Doppler lidar and with the equipment (rumbo- anemometers) of the High Meteorological Mast in Obninsk (Russia). The results are in good agreement.
Method of phase portrait for analysis of nonstationary coherent optical fields
Andrey E. Krasnov
The method dwells upon the observed estimate of nonstationary field density operator in the form of two-dimensional joint distribution of variables related to the field envelope or correlation function and their Hilbert-images. It is oriented to recognition and estimation of the parameters of both stationary and non-stationary optical fields. Consideration is given to apply it for experimental study of low-frequency transients in optical quantum generators and nonstationary light scattering in liquid media.
Time background holography of moving objects
A. N. Anuashvili, I. V. Prangishvili, Valery I. Mandrosov, et al.
Time background holography of moving objects is a new technique in which the reconstructed pattern of the objects is a spectrum of coherent radiation which is scattered by these objects and by the background, along which the objects move, and modulated by the moving object. This is a new kind of holography which is applicable to obtaining two-dimensional patterns or images of a small (unresolvable) moving object and to determining the coordinates, dimensions, and velocities of small objects, reflecting, transparent, and absorbing.
Moving object detector operating by time averaging of coherent acoustic fields
A. N. Anuashvili, Ye. A. Kharlamov
A tool is described which detects weakly scattering moving underwater objects by time averaging of coherent acoustic waves that are scattered by a randomly inhomogeneous background surface along which the objects move.
Localization and visibility of fringes in holographic and speckle interferometry with extended reconstructing source
Igor S. Klimenko, Boris B. Gorbatenko, Vladimir P. Ryabukho, et al.
The peculiarities of localization of the interference fringes and distribution of their visibility in the localization area at receiving holographic and speckle interferograms radiation with extended reconstructing sources are considered. It is shown that observing the interferograms it is necessary to have the value of relative displacement of the speckles at their recording which is not resolved by the imaging system and does not exceed the volume of spatial coherence of the radiation lighting the hologram and specklegram. Extension of localization area of the interference fringes and spatial distribution of their visibility in dependence on the fact that the imaging system resolves or does not resolve the area of the spatial coherence is determined, respectively, by sizes and shape of the lighting source (and for holographic interferograms by its time coherence as well) and by sizes and shape of the imaging system aperture.
Coherent Devices and Elements for Data Processing
icon_mobile_dropdown
Use of thermal dynamic holograms for widening the range of the registered intensity of light beams
Alexandra M. Berezinsky, Anatoliy Mikhailovi Dukhovniy
The holographic recording of the mirror and diffuse scattering object in the traditional way and with the use of the pulse optical image amplifier, based on the thermal dynamic holograms in the absorbing gases, is investigated. Experimental investigation of the reconstructed image contrast magnitudes and of the hologram diffraction efficiency in the low intensity of the registered radiation range shows that the use of this amplifier for the object beams amplification makes it possible to widen the registered intensities range and to increase by more than two orders of magnitude the sensitivity of the method of the holographic image recording on the silver halide media.
Two-wavelength heterodyne interferometer with extended measurement range
E. A. Baklagin, V. V. Ridiger, P. P. Zaharov
The article describes the circuit of a two-wavelength heterodyne interferometer operating in a spectral region of 10.6 micrometers and intended for control of the shape of the primary segment mirror of an infrared telescope. The experimental data obtained for a model of a three-element segment mirror is presented. The design of a two-wavelength interferometer to be used for aspherical mirrors testing and polished optical surfaces is proposed.
Holographic correlator with thin holograms as an optical neural network
O. V. Dubrovskaya, Eugene I. Shubnikov
It is shown that a holographic correlator with thin holograms application can be regarded as an optical neural network based on the outer product model. This network has a complete array of interconnections. Two versions of optical neural networks based on holographic correlators with interconnections fixed in different places are presented.
Possible algorithms of image processing in an optical neural network based on a Vander Lught correlator
Types of solutions are shown to which the process can converge in an optical neural network made of a Van der Lught correlator inside a linear resonator. Conditions for obtaining the desired type of solution are specified. For this architecture associative memory is a particular case of a more general form of solutions. The results of experimental testing are reported.
Holographic associative memory and information transmission by solitary waves in biological systems
We consider some specific problems and phenomena of morphogenetic information storage, reproduction, and transfer including phantom leaf effect and field-induced morphogenetic translations between different taxonomic units. Several experimental results are presented and their explanation is given using a new approach to morphogenesis which combines some physical models of holographic associative memory and mathematical formalism of Fermi- Pasta-Ulam recurrence for solitary waves in deoxyribonucleic acid.
Holographic associative memory and optical logic using 4W mixing in a liquid crystal light valve
E. I. Galavanova, Igor N. Kompanets, G. A. Lunyakova, et al.
A holographic associative memory in a feedforward network is implemented using photosensitive liquid crystal light valve (LCLV) as a phase conjugate mirror (PCM). In the case of three simple binary images stored in the Fourier hologram the completely reconstructed single output image (rectangle) is observed with only a quarter of the image present as an input. Because of non-zero cross correlation and high gain the restoration remains even if the input image is rotated by 25 degree(s) about the optical axis and is either tilted or swung horizontally by up to 45 degree(s). Parallel analog and digital optical computing operations are demonstrated by using an interferometric arrangement with a LCLV-based PCM. Image subtraction, coherent and incoherent image addition, OR, XOR, and NOT optical gates are achieved by controlling the phase difference between two spatially multiplexed signal-bearing waves.
Application of the phase methods to analog and digital optical processors
E. I. Krupitsky, S. V. Morosov
Use of phase methods in data input/output and for operations execution in optical processing and data transmission along internal communication channels is considered. Spatial phase difference modulation in digital optical matrix processors and similar time modulation in superfast internal communication channels can be applied for these purposes.
Method of adaptive image coordinate transformation
A new method of image coordinates transformation is suggested, it is based on the preliminary complexity calculation of transformed images, extraction and transformation only of coordinates highly informative part. The ways of realization of the proposed method using different computer means are being considered. The structure of optical-electronic system, that combines algorithmic flexibility of an ordinary computer and high speed of images preprocessing with the help of optical means, is being suggested.
Adaptive cellular matrix system for image processing
A new approach to work out the computing means, the architecture of which depends on the complexity of input images, is being suggested. The evaluation of the necessary number of images digitization elements to be input and processed has been given and the possibility of operative estimation of image parameters has been considered. The adaptive cellular matrix computer system has been developed and researched.
Optical-digital image classifier using a correlation algorithm for invariant feature extraction
V. V. Dadeshidze, Anatoly A. Vasiliev
An approach to hybrid optical/digital pattern recognition and scene analysis is described which uses a correlation procedure to compare the initial image (object, scene) with its rotated copy. The correlation function of object description obtained via this procedure is shown to possess scale and rotation invariance and to contain information about the object location in the scene being analyzed. The possibility of locating the objects and their classification using the correlation procedure is demonstrated by computer simulation and experiments performed in a coherent optical correlator with a liquid crystal light valve in the Fourier plane.
Vanadium oxide light spatial modulator in an optical real-time correlator
O. V. Dubrovskaya, M. I. Mikhal'chik, I. A. Khakhaev, et al.
The main requirements to light spatial modulators (LSM) recording in Fourier filters of a real time correlator are discussed. A read-out diffractional efficiency (RDE) increasing technique of LSM is proposed. RDE is calculated for different wavelengths and different LSM structures.
Spatial frequency 2D filters synthesized for reconstruction of sea-surface spectra from images
Alexander B. Murynin
A method of reconstruction sea wave heights spectra using the nonlinear model of transfer function relating wave slopes with sea surface images is developed. The method includes the numerical simulation of optical images under various illumination conditions and the synthesis of the spatial-frequency 2-D filters for reconstruction of sea-surface slope spectra from optical images spectra. The developed filters have been approximated with a parametric function. The dependencies of the approximation parameters on various imaging conditions are discussed.
Speed of response analysis of optically controlled transparent photoconductor liquid crystal plates in a holographic correlator
Fiodor L. Vladimirov, Aleksander N. Chaika, Ivan E. Morichev, et al.
Speed of response is a major characteristic of light space and time modulators (LSM) in coherent optical data processing, notably in holographic correlators. The response of a photoconductor-liquid crystal (PCLC) modulator is a function of the delay in the electro- optical LC response, in the PC photoresponse, and the delay caused by the redistribution of charges in the PCLC structure. In the case of high resistance PCs the redistribution makes the decisive contribution to the response. The typical values of the PCLC structure time constant in the case of high resistance semiconductors amount to tens or hundreds of milliseconds while the delay in the photoresponse is measured in single numbers of milliseconds. With typical values of the control voltage the electro-optical response of usual LCs amounts to single digits of milliseconds while the relaxation time ranges from 10 to 20 milliseconds.
Design of optical systems with diffractive and gradient-index elements
Grigoriy I. Greisukh, Sergei A. Stepanov
Optical hybrid systems, i.e., systems containing the optical elements of different types (diffractive and gradient-index lenses), are considered. The correction possibilities of two- and three-element hybrid objectives are analyzed. It is shown that the two-element objective may be corrected for all monochromatic third-order aberrations. As a result the space frequency of diffractive lens structure and the magnitude of the refractive index change of gradient-index lens can be decreased. Various fifth-order aberrations can also be corrected. This objective forms a high resolution image and wide linear field in the image space. The three-element hybrid objective consists of one diffractive and two gradient-index lenses. This objective has a symmetric configuration and unit magnification. It is shown that in such an objective, which is free from all third-order aberrations, it is possible to eliminate simultaneously three out of four different fifth-order aberrations. In particular, this result remains valid if the optical power of the diffractive element is equal to zero. The design of a three-element hybrid objective is reported. The resulting designs are compared with homogeneous objectives.
Two-dimensional location-sensitive sensor using new holographic element and Multiscan photodetectors
Svetlana A. Pisarevskaya, B. G. Podlaskin, N. A. Tokranova, et al.
The possibility to build a high precision two-dimensional location-sensitive light spot position sensor using the holographic beamsplitter and two linear location-sensitive photodetectors is considered.
Signal and noise distribution in the correlation field of holographic recognition systems
The influence is analyzed of the angular orientation of images on the signal and noise distribution in the correlation fields of holographic recognition systems invariable with change of scale and aspect of the objects. Models of the signal and noise are built, and the signal-to- noise ratio is estimated as a function of image orientation and diffraction efficiency of the different holograms.
Rainbow holography and its applications
N. G. Vlasov, Vladimir S. Ivanov
The general equations of the rainbow holography are deduced. Their analysis makes it possible to offer different methods of the rainbow holographic images production. A new way of using the rainbow holograms as optical elements for effective color illuminating of transparent, specular, and polished objects is proposed. Application fields are the advertising industry, shop windows design, etc.