Methods For Processing Signals Research Articles

Algorithms for automatic detection and recognition of low contrast radar objects using noise-like broadband signals

An algorithm for automatic detection and recognition of low-contrast ground targets using noise-like broadband signals and the use of combined processing of radar signals against the background of interference is presented; the proposed original method for processing signals from airborne objects during their detection and determination of their coordinates synthesizes optimal algorithms for detecting radar objects in the case of a priori information about useful signals and interference, as well as the ability to determine the range and speed of movement; the block diagram of the mathematical model of signal processing is considered on the basis of the developed algorithms for identifying stationary targets against the background of local objects by the radar portrait, as well as by the envelope of the radar signal; the results of testing mathematical modeling of the algorithm for recognizing signals from stationary targets and a forest with an equal probability of the appearance of these targets in the analyzed space are presented. The results of domestic theoretical and experimental research today characterize the main areas of research in the field of detection and recognition of various radar objects. The main research tool of most works is the search and development of promising mathematical models of objects and the modeling of secondary radiation for their recognition, which in some cases allows obtaining additional information about these objects. Correlation and spectral methods of their processing are currently being considered in relation to the noise sounding signal of a radar station. This article analyzes the application of correlation and spectral methods in processing noise signals with the identification of the disadvantages and advantages of each of the methods; the functioning of the block diagram of the known single-channel noise radar stations with sequential spectral processing of the total signal is considered. The proposed original method for processing signals from airborne objects during their detection and determination of their coordinates synthesizes optimal algorithms for detecting targets in the case of a priori information about useful signals and interference, as well as the ability to determine the distance and speed of movement. It should be noted the promising application of combined processing of radar signals against the background of interference, taking into account simultaneously the spatial, polarization, temporal and frequency features of the signals reflected from objects. With regard to the problem of recognizing the shape of objects, both in Russia and abroad, intensive work is being carried out to improve the resolution of on-board radars with a synthesized broadband antenna array, while raising the range resolution and increasing the angular resolution allow obtaining long-range portraits of these objects, as well as seeing them. elements and obtain images of targets. In the study of methods for detecting radar objects based on Gaussian noise signals with a large base, it is shown that such signals are promising for detecting subtle objects at ranges greater than with conventional monopulse radar. When receiving noise signals with a large base, spectral methods of signal extraction turn out to be more advantageous in comparison with the known correlation method of signal processing. Based on the use of noise signals, recognition of ground and air objects is realized, while the method of long-range portraits can have an advantage over the envelope method. Based on the results of mathematical modeling, the possibility of automatic recognition of stationary ground objects by two different methods was confirmed with a high probability of their recognition.

THEORETIC NUMBER BASIC METHODS OF INFORMATION TECHNOLOGIES FOR DIAGNOSTATION OF TECHNOLOGICAL OBJECTS OF THE OIL & GAS INDUSTRY

The existing methods of formation and coding of technological data at the grass-roots levels of distributed computerized systems for diagnosing technological objects in the oil and gas industry are analyzed. Methods of processing signals are analyzed. The mathematical model of multibase spectral cosine signal transformation, with the possibility of using different theorems of numerical bases, is considered. Correlation analysis of signals can be performed on the basis of different automobile and inter-correlation functions, but the highest speed and the smallest hardware complexity are characterized by functions in the theory of the Haar numerical basis. Where it is evident that in practice the widest use has been found in the form of information converters based on an analog digital converter of various types. The research of analog digital converters has been carried out on hardware complexity as well as on time complexity. The research was carried out on single-channel analogue digital converters with source codes, the theorem of the numerical basis of Haar, Krestinson, Rademacher and unitary basis. The paper deals with the development of digital correlators and transducers where among many structures of analog digital converters the most commonly used with source codes in different theorems of numerical bases and methods of formation of source codes are identified. The structure of the analog digital converter is proposed for the use of comparators with paraphase outputs and the implementation of a logical element that excludes OR on logical elements of I-NE with paraphase inputs and are connected by inverted outputs. Thus, the proposed improvement of the structure allows to increase its speed and reduce the time complexity of transformations by 2.5 -3 times. This reduces hardware complexity by about 30%. The method and structures of the transformation of the input analog signal by the multi-base ADA of Haar-Krestenson using the comparators with paraphase outputs in discrete digital samples for diagnostics of technological objects in the oil and gas industry and further calculation in computer technology are developed

Spectral method for processing signals of a high-accuracy laser radar

A spectral method is proposed to determine the signal frequency and readings of a laser radar with a frequency modulation of the reference channel based on signal preprocessing with a Gaussian window and calculation of its spectral centroid. Numerical simulation and experiments with a frequency modulation band 5–20 MHz wide have shown that this method provides an order of magnitude better accuracy than the conventional spectral analysis methods.

Simulation of the Acoustic Field of Antenna Arrays

The article considers the reconstruction of images by Synthetic Aperture Focusing Technique (SAFT). The work compares additive and multiplicative methods for processing signals from antenna array. We have proven that the multiplicative method gives better resolution. The study includes the estimation of beam trajectories for antenna arrays using analytical and numerical methods. We have shown that the analytical estimation method allows decreasing the image reconstruction time in the case of linear antenna array implementation.

Investigation of the maximum accessible kinetic energy of fragments in the neutron-induced fission of 238U nuclei

The masses, total kinetic energies (TKE), and emission angles of fragments originating from the fission of 238U nuclei that was induced by 5- and 6.5-MeV neutrons were measured by using digital methods for processing signals. A detailed analysis of the shape of digital signals made it possible to reduce substantially the contribution of fragments whose TKE values were distorted because of a superimposition of signals from recoil protons and from alpha particles produced in the spontaneous decay of uranium. The total statistics exceeded two million events for either neutron energy, and this permitted performing a detailed analysis of fission-fragment yields in the region of the highest attainable TKE values. An analysis of fragment yields made it possible to draw specific conclusions on the structure of the potential surface of fissile nuclei.

ASSEMBLY, SYSTEM AND METHOD FOR ACOUSTIC TRANSDUCERS

The invention relates to an assembly of acoustic transducers, a system and a method for receiving and reproducing sound. The assembly comprises a first acoustic transducer having a directional pattern of the shape of a figure of eight in the direction of an X axis of a XYZ coordinate system, and a second acoustic transducer placed perpendicularly relative to a first capsule and pro viding a directional pattern of the shape of a figure of eight in the direction of a Y axis of a XYZ coordinate system. The assembly is characterized in that it further comprises a third acoustic transducer placed perpendicularly relative to the first and second acoustic transducers, enabling the implementation of spatial sound both in a XY plane and in a XYZ plane by using these acoustic transducers placed in accordance with an axis of the axes of the XYZ coordinate system. The invention further provides a system and a method for processing signals received with the assembly.

HEARING AID AND A METHOD OF PROCESSING INPUT SIGNALS IN A HEARING AID

A hearing aid comprises two microphones, directional processing means (Dir1, Dir2) for combining the respective audio signals to form a spatial signal, a beamformer (35) for controlling the directional processing means to provide adaptation of the spatial signal, and means (LFB1, LFB2) for boosting low frequencies of the spatial signal. A feedback estimator generates a feedback compensation signal (7a, 7b), which is combined with the boosted spatial signal. By applying feedback compensation only after directional processing and low frequency boosting, the device avoids interference by the feedback estimator with the function of the beamformer. The invention also provides a method of processing signals in a hearing aid.

Speech Enhancement Using Wavelet Neural Network with Sub-Band Adaptive Matched Filter

Wavelet Neural Network (WNN) Is a Time-frequency Analysis Method, which Detects the Subtle Small Changes in the Signal Frequency Domain. Adaptive Filter Provides a Kind of Simple and Applied Method for Processing Signals in Noise. in this Paper, we Proposed a New Speech Enhancement Technique which Is Based on Wavelet Neural Network Using Adaptive Matched Filter Adjusting Weight. we Choose the Signal with Noise Pollution as the Input Signal and then Put it to the Trained Wavelet Neural Network. Wavelet Decomposition and Wavelet Neural Network Weights Processing Adopt Signal Sub-band Adaptive Matched Filter, the Output Signal of Wavelet Neural Network Is an Approximation Form of Original Signal. the Results Show that the WNN Is a Quite Effective Method for the Speech Enhancement and Improving the Ration of Signal to Noise.

The PULSAR Radar Instrument and Its Use for Comprehensive Examination of Health Status

Medical application of the PULSAR Doppler radar millimeter-wavelength range measuring system is discussed. The possibility for remote measurement and analysis of heart rate and equilibrium function parameters is demonstrated. Various physiological parameters are measured synchronously in the single beam of the radar. To estimate the person’s functional condition, use of fractal parameters defined on phase plane of normal and pathological zones is suggested. An adaptable method for processing signals reflected from the patient is offered. The method reduces measurement errors.

Issues of ultrasonic testing of extended complexly structured items with strong attenuation of signals

These and subsequent articles present the results of the studies of interference resistant methods and devices for ultrasonic testing of extended items made of complexly structured materials. The presented results are based on the radio-engineering R & D that have been conducted for over 30 years by the Department of Electronic Devices of the Moscow Power Engineering Institute. The stud- ies are concurrently focused on the development of methods for separating echo signals from white and structural noise, on the application of complexly modulated signals, on the development of spatial and temporal methods for processing signals, on the development of broadband mosaic transducers, and on the design of multifunctional devices for ultrasonic testing. The necessity of such a comprehensive approach to ultrasonic testing is substantiated in this article by analysis of the problems of ultrasonic testing of complexly structured items with strong integral attenuation of ultrasound.

An integrated adaptive method for constructing radar images in dual-purpose control systems

This paper is devoted to the problem of improving air traffic management systems and air space monitoring on the basis of prospective methods of processing signals reflected by objects in the course of their tracking by coherent-pulse radar stations with many-frequency probing. The main content of the prospective methods for constructing two-dimensional radar images of aerodynamic aircraft is presented. An integrated adaptive method for constructing images that combines partial methods is proposed.

A new pileup-prevention front-end electronic design for high-resolution PET and gamma cameras

A new method for processing signals from Anger position-sensitive detectors used in gamma cameras and positron emission tomography (PET) is proposed for very high count-rate imaging. It has a same concept as high yield pileup-event recover (HYPER) method we introduced before by using 1) dynamically integrating a present event, the integrating will stop immediately before the next event is detected; 2) estimating a weighted-value to indicate the total energy inside the scintillation detector; and 3) remnant correction to remove the residual energy of all the previous events from the weighted-value. This paper introduces two improved practical techniques to get a better weighted-value with low noise sensitivity in order to improve the final pileup-free energy resolution. One applies a low-pass filter combined with multiple sampling to a weight-sum of the instantaneous signal and integrated signal. The other one is weighting the integration value of the income signal; the weighting also includes exponential distortion compensation. This paper also describes the application of the HYPER electronics in a high resolution low cost PET camera with 12 photomultipliers (PMTs)-quadrant-sharing (PQS) detector modules that can decode 38 016 bismuth-germinate (BGO) crystal elements using 924 PMTs. Each detector module has four Anger-HYPER circuits to further increase the count-rate. To use the HYPER circuit in coincidence imaging applications, there is a serious synchronization problem between the arrival time of an event and the end time of integration that is variable from event to event. This synchronization problem is solved by a field programmable gate array (FPGA) circuit with real time remnant correction and a high-resolution trigger delay unit with a small dead-time for recovering the synchronization of data and the event-trigger.

Stable Methods for Processing Signals with Pulsed Components

We analyze problems of processing the results of radiophysical observations, which can be described using the generalized Likhter model. Consistent estimates of the parameters of a signal and interference are found. We describe algorithms for detecting the pulsed processes as well as a detector of harmonic signal against the background of interference having a chaotic pulsed component.

A high count rate position decoding and energy measuring method for nuclear cameras using Anger logic detectors

A new method for processing signals from Anger position-sensitive detectors used in gamma cameras and PET is proposed for very high count-rate imaging where multiple-event pileups are the norm. This method is designed to sort out and recover every impinging event from multiple-event pileups while maximizing the collection of scintillation signal for every event to achieve optimal accuracy in the measurement of energy and position. For every detected event, this method cancels the remnant signals from previous events, and excludes the pileup of signals from following events. The remnant subtraction is exact even for multiple pileup events. A prototype circuit for energy recovery demonstrated that the maximum count rates can be increased by more than 10 times comparing to the pulse-shaping method, and the energy resolution is as good as pulse shaping (or fixed integration) at low count rates. At 2/spl times/10/sup 6/ events/sec on NaI(Tl), the true counts acquired with this method is 3.3 times more than the delay-line clipping method (256 ns clipping) due to events recovered from pileups. Pulse-height spectra up to 3.5/spl times/10/sup 6/ events/sec have been studied. Monte Carlo simulation studies have been performed for image-quality comparisons between different processing methods.

A scintillation detector signal processing technique with active pileup prevention for extending scintillation count rates

A new method for processing signals from scintillation detectors is proposed for very high count-rate situations where multiple-event pileups are the norm. This method is designed to sort out and recover every impinging event from multiple-event pileups while maximizing the collection of scintillation signal for every event to achieve optimal accuracy in determining the energy of the event. For every detected event, this method cancels the remnant signals from previous events, and excludes the pileup of signals from following events. With this technique, pileup events can be recovered and the energy of every recovered event can be optimally measured despite multiple pileups. A prototype circuit demonstrated that the maximum count rates have been increased by more than 10 times, comparing to the standard pulse-shaping method, while the energy resolution is as good as that of the pulse shaping (or the fixed integration) method at normal count rates. At 2/spl times/10/sup 6/ events/sec for NaI(Tl), the true counts acquired are 3 times more than the delay-line clipping method (commonly used in fast processing designs) due to events recovered from pileups. Pulse-height spectra up to 3.5/spl times/10/sup 6/ events/sec have been studied.

Method for processing signals

Method and device for processing signals, in particular audio signals for hearing aids. Delay-free signal processing is achieved by first producing an instantaneous amplitude signal A(t) whose strength is proportional to the instantaneous amplitude of the input signal ui(t) and by using this instantaneous amplitude signal A(t) to process the input signal ui(t).

Processing signals from an inertial sensor using neural networks

An inertial sensor is a device for determining the location of a part by measuring parameters related to its inertia. This paper describes a neural-network-based method for processing signals from an inertial sensor to compute the orientation of a part. This method involves training a multi-layer perceptron (the most commonly applied neural network type) using the backpropagation algorithm to model the operation of the sensor by mapping its natural frequency of vibration to part location information. The paper details the experimental procedure for acquiring data to train and test different neural network models and the results obtained. The latter show that the proposed method yields orientation values with a comparable degree of accuracy to existing techniques while requiring much less computational effort.