Optoelectronics, Instrumentation and Data Processing (v.54, #3)
Combining Classifiers in the Problem of Thematic Processing of Hyperspectral Aerospace Images by E. V. Dmitriev; V. V. Kozoderov; A. O. Dementyev; A. N. Safonova (213-221).
This paper describes a problem of thematic processing of hyperspectral aerospace images. A recommended technique is based on a decoding algorithm and makes it possible to construct an effective algorithm of multiclass classification based on combining standard algorithms of binary classification of various complexity. The reason for choosing the configuration of the classification algorithm is given. Test calculations based on model and real data are used to show the effectiveness of the proposed approach to recognizing objects from hyperspectral images.
Keywords: remote sensing; hyperspectral images; pattern recognition; thematic processing; classification
Planetamonitoring Software Complex in Applied Remote Sensing Problems by V. V. Asmus; A. A. Buchnev; V. A. Krovotyntsev; V. P. Pyatkin; G. I. Salov (222-229).
This paper describes a PlanetaMonitoring software complex, developed jointly by the Scientific Research Center “Planeta” and the Institute of Computational Mathematics and Mathematical Geophysics of the Siberian Branch of the Russian Academy of Sciences, which implements the software for pre-processing and thematic processing of multispectral satellite images of optical, infrared, and microwave ranges. This work also touches upon the pre-processing of satellite data, particularly brightness and geometric transformations, geocoding, and compilation of survey installation. Thematic processing of multispectral satellite images by software for object recognition (without and with training), detection and mapping of lineaments and circular structures, as well as determination of spatial displacements of natural objects (ice fields, water masses, and cloud formations in the atmosphere) over time-different satellite images is described. This software is used to solve a number of applied problems of Earth remote sensing.
Keywords: remote sensing; multispectral satellite images; software; pre-processing; classification with training; cluster analysis; statistical detection of linear and circular structures; spatial displacements of natural objects
Creation of Panoramic Aerial Photographs on the Basis of Multiband Blending by M. N. Favorskaya; A. I. Pakhirka; A. G. Zotin; V. V. Buryachenko (230-236).
A panoramic aerial photograph composed of a series of consecutive images obtained from an unmanned aerial vehicle helps identifying visual objects more accurately. Automatic combining of aerial photographs is a complex technical problem, especially in the presence of artefacts of the recording equipment and video-recording conditions. It is assumed that a sequence of combined images is known and determined by the flight trajectory. The proposed method for combining aerial photographs is based on illumination leveling and multiband blending. The possibilities of application of SURF, FAST, FAST-ER, and KAZE point descriptors for combining images are studied. It is shown that the point descriptors on the basis of nonlinear diffuse filtering yield the best results with regard to accuracy in the presence of global and/or local visual distortions of combined images.
Keywords: aerial photograph; panorama; point descriptors; illumination leveling; multiband blending
Seismic Signal Processing for Estimating the Path of a Moving Vehicle by Yu. V. Morozov; M. A. Raifel’d; A. A. Spektor (237-242).
The application of signal energy parameters to estimate the motion of objects with continuous influence on soil in systems of passive seismic location is considered. Statistics for measured values of signal powers with account for energy properties of the medium are proposed. The influence of displacement of the object on the ratio of signal powers on different sensors is analyzed. The results of testing the algorithm for estimating the parameters of the path of rectilinear motion of a car are given.
Keywords: passive seismic location; path estimation; maximum likelihood method; energy properties of the medium; geophone
WEB Geographic Information System and the Hardware and Software Ensuring Rapid Assessment of Air Pollution by O. E. Yakubailik; A. A. Kadochnikov; A. V. Tokarev (243-249).
This paper touches upon the experience of research and development of hardware and software for air pollution monitoring of industrial cities, carried out at the Institute of Computational Modeling of the Siberian Branch of the Russian Academy of Sciences. Functional possibilities, architectural features, and user interface of the distributed web geographic information system of ecological monitoring of the city of Krasnoyarsk, which is being developed in service-oriented architecture, are discussed. Data are collected from automated posts for observing the state of atmospheric air and services of aggregation and representation of information in the form of interactive graphs and thematic maps in the web interface. An original device is developed for measuring the pollution level of the atmosphere with fine dust (PM2.5), the data from which is fed in real time to the system via a cellular network. A system is formed for integral assessment of the pollution level of the atmosphere based on Air Quality Index (AQI) calculations.
Keywords: web GIS; web services; environmental monitoring; AQI; atmospheric pollution; suspended particles; fine dust; spatial data; geoportal; Arduino; aerosol
Estimation of the Scanning Speed of Random Texture by a Multirow Focal Plane Array by G. I. Gromilin; V. P. Kosykh; B. N. Drazhnikov; K. V. Kozlov; V. N. Vasil’ev (250-255).
Scanning devises based on a set of mutually shifted focal plane arrays to increase the sampling rate in a direction orthogonal to the scanning direction require a high degree of stabilization of the scanning speed in order to obtain high-quality images. A new method for estimating the scanning speed is proposed based on the analysis of shifts of arbitrary random texture images generated by subarrays during scanning. The dependence of the accuracy of various methods of estimating the scanning speed based on the statistical characteristics of the texture is studied by simulation modeling. It is shown that even at a sufficiently high random noise level (SNR = 10) in images with texture satisfying the Nyquist criterion for each subarray, scanning speed estimation errors do not exceed 0.1% of the nominal value.
Keywords: scanning device; focal plane array; time delay and integration; scanning speed; random texture; power spectrum
Method of Reversible Compression of Frames of Measurement Data Based on Parquet Partition by I. V. Bogachev; A. V. Levenets; E. U. Chye (256-261).
Bit space representation of measurement data is considered. A method and its associated algorithm for reversible geometric compression of measurement data frames are proposed. The algorithm is based on the conversion of a data frame into bit form with subsequent mapping onto a plane and partition into strictly homogeneous regions. Experimental results are presented showing that the proposed algorithm provides high overall compression efficiency..
Keywords: measurement data; data frame; compression; compression ratio
Wavelet-Recognition of the Type of Dynamic Object Detected by an Optoelectronic Device by A. N. Katulev; M. F. Malevinsky (262-269).
An algorithm for automatic recognition of the type of dynamic object detected by an optoelectronic device with a priori uncertainty about the current background-target environment is proposed. Recognition is carried out from samples of statistics in the form of the energies of wavelet spectra of elevation and azimuth measurements and the calculated maximum range of the detected object. The recognition criterion is unbiased and maximum-power one. Modeling has shown that the algorithm is highly efficient and implementable in real time on modern PC.
Keywords: optoelectronic device; type of dynamic object; statistics and recognition criterion
Effect of Surface Waves from a Moving Object on Its Image During Reconstruction using Aperture Synthesis by V. P. Yushchenko; V. N. Legkii; S. A. Litvinenko; S. A. Budnov (270-276).
The reconstruction of an image of the cross section of a thin wire obtained by an ultrasonic detector in an aqueous medium at a frequency of 1.3 MHz with a monochromatic probing signal is considered. The image was reconstructed using a synthesized aperture by correlation processing of a trajectory Doppler signal with calculated reference trajectory signals from point objects. The disturbing effect of the ultrasonic wave reflected from the surface wave generated by the moving wire on the image reconstruction is taken into account. The results of reconstruction of the image of the wire cross-section from model and experimental trajectory signals in the presence of a surface wave are given.
Keywords: surface wave; ultrasound; monochromatic probing signal; aperture synthesis; image reconstruction; trajectory signal; tomography
Methods of Improving the Contrast of Combined Images and the Linearity of the Eye Accommodation Stimulus in Multifocal Three-Dimensional Displays by E. V. Vlasov (277-283).
The contrast of a combination of two plane images spaced along the visual axis of the eye for stimulating the accommodation in 3D displays is analyzed. Two methods of normalization based on individual and group calculations of optimal coefficients of combinations for different eye pupil diameters with a specified image resolution are proposed.
Keywords: 3D image; plane image; accommodation; combined images; contrast
Spectral Method of Detection of Laser Doppler Velocimeter Signals in Turbulent Flows by A. V. Klimov; V. G. Meledin; Yu. A. Anikin; D. V. Kulikov; S. V. Krotov; I. K. Kabardin (284-291).
A spectral method of detection of laser Doppler velocimeter signals in turbulent flows is proposed. The method is based on estimating the signal/noise ratio adapted to the width of the power spectral density of the signal and comparing its value with the recognition threshold. Numerical simulations show that the error of the signal/noise ratio estimates is 1% for different velocities of the turbulent flow. Physical experiments aimed at measuring turbulent aerodynamic processes show that the proposed method offers a possibility of eliminating the errors of calculating the mean value and the velocity deviation equal to 15 and 78% by means of eliminating the signals with low signal/noise ratios from the processing system. Application of the proposed method also ensures lower nonuniformity of the signal/noise ratio estimates than that ensured by the famous method developed by Tropea for a wide range of turbulent velocities.
Keywords: signal detection; nonuniform detection; signal/noise ratio; spectral method; laser Doppler velocimeter; turbulent gas–liquid process
Estimation and Compensation for Signal-Signal Beating Interference in Direct Detection Fiber-Optical Transmission Systems of OFDM Signals by V. A. Vardanyan (292-300).
A mathematical model is developed for calculating the beating noise that occurs during photodetection of a single-band optical OFDM signal. The model allows one to estimate the spectral distribution of the beating noise and the distortion of the OFDM signal subcarrier levels due to fiber dispersion. The influence of the beating noise on orthogonal subcarrier channels, possible ways of increasing the system transmission capacity, and the method of noise compensation on the receiving side are investigated.
Keywords: fiber-optical transmission systems; direct detection (DD); signal-signal beating interference (SSBI); orthogonal frequency division multiplexing (OFDM); single sideband (SSB); Q-factor
Method of Increasing the Spatial Resolution in Digital Holographic Microscopy by V. I. Guzhov; S. P. Il’inykh; I. O. Marchenko (301-306).
A new method of increasing the spatial resolution in digital holographic microscopy is considered. The method is based on supplementing the initial hologram with results measured in the case of photodetector shifting in space by a value smaller than the resolution used. In contrast to other known approaches, this method does not require a system of equations to be solved.
Keywords: digital holography; holographic microscopy; interferometry; spatial shift; super-resolution; synthesized aperture
Features of the 85Rb Spectrum in a Cell with an Antirelaxation Coating by A. Krasteva; R. K. Nasyrov; N. Petrov; S. Gateva; S. Cartaleva; K. A. Nasyrov (307-313).
Distortion of the spectrum of the D 1-line of 85Rb in optical cells with an antirelaxation coating on the inner walls of the cell is studied. The spectrum shape is found to be significantly dependent on the velocity and direction of changes in the laser frequency. A physical explanation is provided for these features, which are confirmed by numerical simulations. The effect of the magnetic field on the spectrum shape is discussed.
Keywords: magneto-optical resonance; antirelaxation coating; laser radiation
Control of an Adaptive Optical System with Deformable Mirrors of Low and High Frequency Resolution by A. N. Borshevnikov; D. A. Dement’yev; E. V. Leonov; D. M. Lyakhov; G. N. Sokhareva; A. V. Chernykh; Yu. I. Shanin; V. I. Shchipalkin (314-320).
Control methods with the use of two deformable mirrors (correcting aberrations of high and low spatial frequencies, respectively) are briefly described. Results of preliminary experiments aimed at developing algorithms for deformable mirror control are reported.
Keywords: atmospheric turbulence; wavefront; adaptive optical system; deformable mirror; wavefront sensor; woofer corrector; tweeter corrector