Experimental research on the statistical characteristics of radar signal spikes at small grazing angles

1994 ◽  
Vol 5 (1) ◽  
pp. 49-55 ◽  
Author(s):  
V. V. Malinovsky
Keyword(s):  
Experimental Research ◽  
Statistical Characteristics ◽  
Radar Signal ◽  
Grazing Angles

scholarly journals Experimental Research of Statistical Characteristics of Wind Wave Breaking

2019 ◽  
Vol 25 (6) ◽  
Author(s):  
A. E. Korinenko ◽  
V. V. Malinovsky ◽  
V. N. Kudryavtsev ◽  
◽  
◽  
...  
Keyword(s):  
Experimental Research ◽  
Wave Breaking ◽  
Wind Wave ◽  
Statistical Characteristics

STABILITY PROBLEMS OF STEEL‐CONCRETE MEMBERS COMPOSED OF HIGH‐STRENGTH MATERIALS

2010 ◽  
Vol 16 (3) ◽  
pp. 352-362 ◽  
Author(s):  
Zdeněk Kala ◽  
Libor Puklický ◽  
Abayomi Omishore ◽  
Marcela Karmazínová ◽  
Jindřich Melcher
Keyword(s):  
Theoretical Analysis ◽  
Experimental Research ◽  
Carrying Capacity ◽  
High Strength ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Load Carrying ◽  
Geometrical Imperfections

The presented paper deals with the stochastic analysis of the ultimate limit states of steel‐concrete building members. The load carrying capacity of steel‐concrete columns, comprising of steel profiles encased in high strength concrete, in compression is analyzed. The first part of the paper lists assumptions for the determination of the theoretical load carrying capacity of the column. Principles of elasticity and plasticity are used to determine stresses in the concrete and steel sections. Statistical characteristics of input material and geometrical imperfections are listed. Results of the theoretical analysis are then compared with results of experimental research. Statistical characteristics of obtained results of the theoretical analysis were verified using statistical characteristics obtained from experimental research. Numerical simulation LHS and Monte Carlo methods, which take into account the influences of variability of input imperfections, were employed. The influence of the utilization of the plastic reserve in the determination of the load carrying capacity of the analysed strut is shown. The influence of the initial geometric imperfections of initial strut curvature on the load carrying capacity is also presented. Santrauka Straipsnyje pateikta plienbetonio pastatu elementu didžiausiu ribiniu būkliu stochastine analize, analizuojama plienbetonio kolonu, sudarytu iš plieniniu profiliuočiu, padengtu didelio stiprio betonu, laikomoji galia gniuždant. Pirmoje straipsnio dalyje išvardytos kolonos teorines laikomosios galios nustatymo prielaidos. Tamprumo ir plastiškumo principai taikyti itempiams betono ir plieno skerspjūviuose nustatyti. Nustatytos medžiagu ir geometriniu defektu statistines charakteristikos, teorines analizes rezultatai palyginti su eksperimentiniu tyrimu rezultatais. Teorines analizes metu gautu rezultatu statistines charakteristikos patikrintos taikant iš eksperimentiniu tyrimu gautus statistinius rodiklius. Pritaikytas skaitinis modeliavimas LHS ir Monte Karlo metodais, kurie ivertina pradiniu defektu kintamumo itaka. Parodyta plastiškumo atsargos naudojimo itaka, nustatant analizuojamojo statramsčio laikomaja galia, pateikta pradinio statramsčio išlinkio pirminiu geometriniu defektu itaka laikomajai galiai.

RAY CHAOS IN UNDERWATER ACOUSTIC WAVEGUIDES

2008 ◽  
Vol 18 (09) ◽  
pp. 2693-2700 ◽  
Author(s):  
A. L. VIROVLYANSKY
Keyword(s):  
Random Perturbation ◽  
Hamiltonian Formalism ◽  
Statistical Characteristics ◽  
Acoustic Waveguides ◽  
Ray Trajectories ◽  
Grazing Angles ◽  
Ray Path ◽  
Wave Induced ◽  
Ray Chaos ◽  
Analytical Expressions

The chaotic motion of a ray path in a deep water acoustic waveguide with internal-wave-induced fluctuations of the sound speed is investigated. A statistical approach for the description of chaotic rays is discussed. The behavior of ray trajectories is studied using Hamiltonian formalism expressed in terms of action-angle variables. It is shown that the range dependence of the action variable of chaotic ray can be approximated by a random Wiener process. On the basis of this result, analytical expressions for probability density functions of ray parameters are derived. Distributions of coordinates, momenta (grazing angles), and actions of sound rays are evaluated. Numerical simulation shows that statistical characteristics of ray parameters weakly depend on a particular realization of random perturbation giving rise to ray chaos.

scholarly journals Experimental Research of Statistical Characteristics of Wind Wave Breaking

2018 ◽  
Vol 34 (6) ◽  
Author(s):  
A. E. Korinenko ◽  
V. V. Malinovsky ◽  
V. N. Kudryavtsev ◽  
◽  
◽  
...  
Keyword(s):  
Experimental Research ◽  
Wave Breaking ◽  
Wind Wave ◽  
Statistical Characteristics

scholarly journals Identification of Human Motion Using Radar Sensor in an Indoor Environment

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2305
Author(s):  
Sung-wook Kang ◽  
Min-ho Jang ◽  
Seongwook Lee
Keyword(s):  
Signal Processing ◽  
Indoor Environment ◽  
Human Motion ◽  
Sensor Data ◽  
Statistical Characteristics ◽  
Radar Signal ◽  
Radar Sensor ◽  
Wave Radar ◽  
The Moment ◽  
Human Motions

In this paper, we propose a method of identifying human motions, such as standing, walking, running, and crawling, using a millimeter wave radar sensor. In our method, two signal processing is performed in parallel to identify the human motions. First, the moment at which a person’s motion changes is determined based on the statistical characteristics of the radar signal. Second, a deep learning-based classification algorithm is applied to determine what actions a person is taking. In each of the two signal processing, radar spectrograms containing the characteristics of the distance change over time are used as input. Finally, we evaluate the performance of the proposed method with radar sensor data acquired in an indoor environment. The proposed method can find the moment when the motion changes with an error rate of 3%, and also can classify the action that a person is taking with more than 95% accuracy.

scholarly journals Development of an optimization method for measuring the Doppler frequency of a packet taking into account the fluctuations of the initial phases of its radio pulses

2021 ◽  
Vol 2 (9 (110)) ◽  
pp. 6-15
Author(s):  
Serhii Yevseiev ◽  
Oleksandr Kuznietsov ◽  
Sergey Herasimov ◽  
Stanislav Horielyshev ◽  
Anton Karlov ◽  
...  
Keyword(s):  
Radio Pulse ◽  
Internal Noise ◽  
Doppler Frequency ◽  
Frequency Measurement ◽  
Optimization Method ◽  
Statistical Characteristics ◽  
Radar Signal ◽  
Time Range ◽  
Phase Fluctuations ◽  
Time Frequency

The necessity of estimating the decrease in the accuracy of measuring the informative parameters of a radar signal in real conditions of its propagation and reflection has been substantiated. The results of the estimation determine the requirements for optimizing this measurement to achieve the required efficiency. A numerical analysis of the decrease in the accuracy of measuring the Doppler frequency of a coherent packet is presented, depending on the statistical characteristics of fluctuations of the initial phases of its radio pulses. Expressions are given for calculating the fluctuation component of the measurement error of radio pulse packet frequency for various coefficients of interpulse correlation of phase fluctuations. An assessment is made of the possibility of increasing the accuracy of Doppler frequency measurement, which can be ensured by statistical optimization of the algorithm for time-frequency processing of a given radar signal by taking into account its phase fluctuations. The conditions for the multiplicative influence of phase fluctuations of radio pulses of the received packet are substantiated, which determine the efficiency of optimization of Doppler frequency measurement. Based on the results of the study, an optimization method for measuring the Doppler frequency of the packet taking into account fluctuations in the initial phases of its radio pulses is proposed. The accuracy of Doppler frequency measurement under the influence of both the internal noise of the radar receiver and the correlated phase fluctuations of its radio pulses is estimated. The efficiency of optimization of measuring the Doppler frequency of the packet is estimated taking into account fluctuations of the initial phases of its radio pulses by means of computer simulation. It is proved that, under the influence of phase fluctuations, the accuracy of Doppler frequency measurement can be increased due to the performed optimization from 1.86 to 6.29 times. This opens the way to improving the existing algorithms for measuring the higher time range derivatives to improve the quality of tracking complex maneuvering aerodynamic objects. This explains the importance and usefulness of the work for the radar theory.

scholarly journals Distribution Characteristics of Ground Echo Amplitude and Recognition of Signal Grazing Angle

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8315
Author(s):  
Guangwei Zhang ◽  
Ping Li ◽  
Guolin Li ◽  
Ruili Jia
Keyword(s):  
Grazing Angle ◽  
Recognition Rate ◽  
Amplitude Distribution ◽  
Statistical Characteristics ◽  
Radar Clutter ◽  
Ground Clutter ◽  
Network Training ◽  
Terahertz Technology ◽  
Glancing Angle ◽  
Grazing Angles

With the continuous advancement of electronic technology, terahertz technology has gradually been applied on radar. Since short wavelength causes severe ground clutter, this paper studies the amplitude distribution statistical characteristics of the terahertz radar clutter based on the measured data, and provides technical support for the radar clutter suppression. Clutter distribution is the function of the radar glancing angle. In order to achieve targeted suppression, in this paper, selected axial integral bispectrum (selected AIB) feature is selected as deep belief network (DBN)input to complete the radar glancing angle recognition and the network structure, network training method, robustness are analyzed also. The ground clutter amplitude distribution can follow normal distribution at 0~45° grazing angles. The Weibull distribution and G0 distribution can describe the amplitude probability density function of ground clutter at grazing angles 85° and 65°. The recognition rate of different signal grazing angles can reach 91% on three different terrains. At the same time, the wide applicability of the selected AIB feature is verified. The analysis results of ground clutter amplitude characteristics play an important role in the suppression of radar ground clutter.

scholarly journals Waveform Optimization of Compressed Sensing Radar without Signal Recovery

Information ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 271
Author(s):  
Quanhui Wang ◽  
Ying Sun
Keyword(s):  
Signal Processing ◽  
Compressed Sensing ◽  
Optimization Method ◽  
Statistical Characteristics ◽  
Iteration Step ◽  
Radar Signal ◽  
Signal Recovery ◽  
Waveform Optimization ◽  
Inference Problems ◽  
Output Sinr

Radar signal processing mainly focuses on target detection, classification, estimation, filtering, and so on. Compressed sensing radar (CSR) technology can potentially provide additional tools to simultaneously reduce computational complexity and effectively solve inference problems. CSR allows direct compressive signal processing without the need to reconstruct the signal. This study aimed to solve the problem of CSR detection without signal recovery by optimizing the transmit waveform. Therefore, a waveform optimization method was introduced to improve the output signal-to-interference-plus-noise ratio (SINR) in the case where the target signal is corrupted by colored interference and noise having known statistical characteristics. Two different target models are discussed: deterministic and random. In the case of a deterministic target, the optimum transmit waveform is derived by maximizing the SINR and a suboptimum solution is also presented. In the case of random target, an iterative waveform optimization method is proposed to maximize the output SINR. This approach ensures that SINR performance is improved in each iteration step. The performance of these methods is illustrated by computer simulation.

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