scholarly journals Design and Processing Method for Doppler-Tolerant Stepped-Frequency Waveform Using Staggered PRF

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6673
Author(s):  
Yan Zhang ◽  
Chunmao Yeh ◽  
Zhangfeng Li ◽  
Yaobin Lu ◽  
Xuebin Chen
Keyword(s):  
High Resolution ◽  
Design Method ◽  
Pulse Repetition Frequency ◽  
Waveform Design ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
Electromagnetic Data ◽  
Range Profile ◽  
Stepped Frequency ◽  
High Resolution Range Profile

Stepped-frequency waveform may be used to synthesize a wideband signal with several narrow-band pulses and achieve a high-resolution range profile without increasing the instantaneous bandwidth. Nevertheless, the conventional stepped-frequency waveform is Doppler sensitive, which greatly limits its application to moving targets. For this reason, this paper proposes a waveform design method using a staggered pulse repetition frequency to improve the Doppler tolerance effectively. First, a generalized echo model of the stepped-frequency waveform is constructed in order to analyze the Doppler sensitivity. Then, waveform design is carried out in the stepped-frequency waveform by using a staggered pulse repetition frequency so as to eliminate the high-order phase component that is caused by the target’s velocity. Further, the waveform design method is extended to the sparse stepped-frequency waveform, and we also propose corresponding methods for high-resolution range profile synthesis and motion compensation. Finally, experiments with electromagnetic data verify the high Doppler tolerance of the proposed waveform.

The Research Methodology of AR Spectrum Estimation to Stepped-Frequency Signal Processing

2013 ◽  
Vol 313-314 ◽  
pp. 1243-1246
Author(s):  
Jian Bai ◽  
Wei Zhang ◽  
Hou Jun Sun
Keyword(s):  
Signal Processing ◽  
High Resolution ◽  
Research Methodology ◽  
Linear Prediction ◽  
Ar Model ◽  
Spectrum Estimation ◽  
Frequency Signal ◽  
Range Profile ◽  
Stepped Frequency ◽  
High Resolution Range Profile

This paper uses modern spectrum setimation to process stepped-frequency signals which have extracted to obtain high resolution range profile. This paper use FPE criteria and AIC criteria to estimate the order of AR model, and linear prediction is used to test the performance of AR model. Compared with conventional IFFT processing, the results of spectrum estimation is satisfactory, and the exact location of high resolution range profile is determined.

Weighted ℓ2,1 minimisation for high resolution range profile with stepped frequency radar

2012 ◽  
Vol 48 (18) ◽  
pp. 1155-1156 ◽  
Author(s):  
C. Zheng ◽  
X. Wang ◽  
X.-G. Xia ◽  
G. Li
Keyword(s):  
High Resolution ◽  
Range Profile ◽  
Stepped Frequency ◽  
High Resolution Range Profile

Parameter Design Method of Stepped-Frequency Radar to Suppress Clutter

2011 ◽  
Vol 130-134 ◽  
pp. 2042-2046
Author(s):  
Ying Wang ◽  
Hong Yan Su ◽  
Huai Cheng Zhu ◽  
Qi Yuan
Keyword(s):  
High Resolution ◽  
Frequency Domain ◽  
Design Method ◽  
Low Velocity ◽  
Stationary Target ◽  
Range Resolution ◽  
Resolution Imaging ◽  
Low Altitude ◽  
Stepped Frequency ◽  
High Resolution Range Profile

The stepped-frequency radar can measure the velocity between radar and target as while as obtain high range resolution. The Doppler shift of moving target may make its high resolution range profile move away from high resolution imaging region of stationary target. Consequently stepped-frequency radar possesses the ability of detecting dim target in clutter, which is suitable for attacking low-altitude dim target with low velocity. In this paper, the distribution of clutter is analyzed in frequency domain firstly. Then the design method of signal parameters is put forward based on the analysis in frequency domain. Finally, the simulation results demonstrate the effectiveness of the method.

scholarly journals Effects of Non-thermal Ultrasound on a Fibroblast Monolayer Culture: Influence of Pulse Number and Pulse Repetition Frequency

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5040
Author(s):  
Silvia Ronda Peñacoba ◽  
Mar Fernández Gutiérrez ◽  
Julio San Román del Barrio ◽  
Francisco Montero de Espinosa
Keyword(s):  
Short Pulse ◽  
Pulse Repetition Frequency ◽  
Pulse Number ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
Treatment Protocols ◽  
Culture Plate ◽  
New Treatment ◽  
Long Pulse

Despite the use of therapeutic ultrasound in the treatment of soft tissue pathologies, there remains some controversy regarding its efficacy. In order to develop new treatment protocols, it is a common practice to carry out in vitro studies in cell cultures before conducting animal tests. The lack of reproducibility of the experimental results observed in the literature concerning in vitro experiments motivated us to establish a methodology for characterizing the acoustic field in culture plate wells. In this work, such acoustic fields are fully characterized in a real experimental configuration, with the transducer being placed in contact with the surface of a standard 12-well culture plate. To study the non-thermal effects of ultrasound on fibroblasts, two different treatment protocols are proposed: long pulse (200 cycles) signals, which give rise to a standing wave in the well with the presence of cavitation (ISPTP max = 19.25 W/cm2), and a short pulse (five cycles) of high acoustic pressure, which produces a number of echoes in the cavity (ISPTP = 33.1 W/cm2, with Pmax = 1.01 MPa). The influence of the acoustic intensity, the number of pulses, and the pulse repetition frequency was studied. We further analyzed the correlation of these acoustic parameters with cell viability, population, occupied surface, and cell morphology. Lytic effects when cavitation was present, as well as mechanotransduction reactions, were observed.

Aqueous Benzene Oxidation in Low-Temperature Plasma of Pulsed Corona Discharge

2016 ◽  
Vol 19 (2) ◽  
Author(s):  
Iakov Kornev ◽  
Sergei Preis
Keyword(s):  
Low Temperature ◽  
Corona Discharge ◽  
Gas Phase ◽  
Pulse Repetition Frequency ◽  
Repetition Frequency ◽  
Pulse Repetition ◽  
Benzene Oxidation ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Pulsed Corona

AbstractWastewaters polluted with non-biodegradable volatile organic compounds (VOCs), such as aromatic substances, present a growing problem meeting no adequately affordable technological response. Low-temperature plasma generated in the gas-phase pulsed corona discharge (PCD) presents competitive advanced oxidation technology in abatement of various classes of pollutants, although the process parameters, the pulse repetition frequency and the liquid spray rate, require optimization. The experimental research into aqueous benzene oxidation with PCD was undertaken to establish the impact of the parameters to the energy efficiency. The oxidation reaction was found under the experimental conditions to mostly proceed in the gas phase showing little influence of the pulse repetition frequency and the gas-liquid contact surface. Oxidation of benzene and, presumably, other volatile pollutants in the volume of PCD reactor compartment presents an effective strategy of aqueous VOCs abatement.

Adaptive Pulse Repetition Frequency Technique for an Ultrasonic Transit-Time Gas Flowmeter for Hot Pulsating Gases

2006 ◽  
Vol 6 (4) ◽  
pp. 906-915 ◽  
Author(s):  
M. Kupnik ◽  
A. Schroder ◽  
P. O'Leary ◽  
E. Benes ◽  
M. Groschl
Keyword(s):  
Transit Time ◽  
Pulse Repetition Frequency ◽  
Repetition Frequency ◽  
Pulse Repetition
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