The STAP Method for Moving Sonar Reverberation Suppression

2015 ◽  
Vol 743 ◽  
pp. 395-398
Author(s):  
S.D. Zhao ◽  
Kun Yan ◽  
T.Z. Zhou
Keyword(s):  
Conventional Method ◽  
Physical Mechanism ◽  
Space Time ◽  
Detection Performance ◽  
Time Characteristic ◽  
New Method ◽  
Clutter Suppression ◽  
Full Dimension ◽  
Reduced Dimension ◽  
Key Steps

The theory of full dimension and reduced dimension STAP was introduced. Based on the physical mechanism of reverberation formation, the suppression of moving sonar reverberation and the possibility of improvement of detection performance were analyzed and discussed, and the solutions of several key steps were given. The analysis shows that reverberation suppression using STAP is more difficult than clutter suppression of AEW, but its implementation is possible. The results of simulation show that the STAP method can achieve better detection performance than conventional method. The STAP method can utilize the space-time characteristic of moving sonar reverberation sufficiently, and so is a promising new method of reverberation suppression.

scholarly journals GPR Pulse Propagation Topography

2021 ◽  
Vol 36 (5) ◽  
pp. 596-602
Author(s):  
Veli Voipio
Keyword(s):  
Conventional Method ◽  
Ground Penetrating Radar ◽  
Pulse Propagation ◽  
New Method ◽  
Depth Range ◽  
Pulse Radiation ◽  
Ground Penetrating

In this article, I propose a new method for calculating and visualizing the pulse radiation within the depth range commonly used by Ground Penetrating Radar (GPR). The text describes the method and illustrates the propagation with several examples. One conventional method is also applied for a quick comparison. The method can be used to optimize GPR antennas and transmit pulse shapes.

scholarly journals Ultrasound assessed a new method of needle insertion at an angle of 90°to the apex of the sacral hiatus for caudal block in newborns: a randomized controlled study

2019 ◽  
Author(s):  
Shangyingying Li ◽  
Yanzhe Tan ◽  
Fei Yang ◽  
Lifei Liu ◽  
Shengfen Tu
Keyword(s):  
Failure Rate ◽  
Conventional Method ◽  
Local Anesthetic ◽  
Needle Insertion ◽  
New Method ◽  
Controlled Study ◽  
Minimal Risk ◽  
Caudal Block ◽  
Sacral Hiatus ◽  
Method Group

Abstract Background Caudal block is widely used in paediatric anaesthetic practice. Many angles for needle insertion were compared to find a optimal angle during caudal block with high successful caudal injection and minimal risk of complications. The aim of this study is to evaluate the safety and effectivity of a new method of needle insertion at an angel of 90°to the apex of the sacral hiatus for caudal block in newborns. Methods Sixty patients were included in our study, aged 0 to 28 days, posted for inguinal hernia surgery, randomly divided into two groups: a conventional method (CM) group and a new method (NM) group. In both groups, 1 ml∙kg-1 0.5% lignocaine at a rate of approximately 0.5 ml∙s-1 was given for caudal blocks after anaesthesia, and ultrasonographic observation of local anesthetic in the epidural space. Failure rate at the first attempt, puncture frequency, complications, and durations of block were recorded. Results The failure rate at the first attempt of caudal block were 16.7% in the conventional method group and 3.3% in the new method group (p<0.05). The mean time required (standard deviation) to perform needle insertion in the conventional method group was 2.6±0.5 minutes and in new method group 1.6±0.5 minutes (p<0.05). There were three cases aspirating the needle to find blood and one case to find cerebrospinal fluid in the conventional method group. The majority level which the local anesthetic reached are L1 by ultrasound imaging, 86.7% in the conventional method group and 83.3% in the new method group. Conclusion The study found that using the new method, the chance of performing a successful caudal injection can be increased, the time and the risk can be minimized compared to conventional technique. It is a safe and effective method.

scholarly journals A New Method to Improve the Detection of Co-Seismic Ionospheric Disturbances using Sequential Measurement Combination

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2948 ◽  
Author(s):  
Seonho Kang ◽  
Junesol Song ◽  
Deokhwa Han ◽  
Bugyeom Kim ◽  
Hyoungmin So ◽  
...  
Keyword(s):  
Time Derivative ◽  
Tohoku Earthquake ◽  
Satellite System ◽  
Detection Performance ◽  
Ionospheric Delay ◽  
New Method ◽  
Ionospheric Disturbances ◽  
The 2011 Tohoku Earthquake ◽  
Sequential Measurement ◽  
Global Navigation Satellite

Earthquakes generate energy that propagates into the ionosphere and incurs co-seismic ionospheric disturbances (CIDs), which can be observed in ionospheric delay measurements. In most cases, the CID has a weak signal strength, because the energy in the atmosphere transferred from the earthquake dissipates as it travels toward the ionosphere. It is particularly hard to observe at reference stations that are located far from the epicenter. As the number of Global Navigation Satellite System stations and their positions are restricted, it is important to employ weak CID data in the analysis by improving the detection performance of CIDs. In this study, we suggest a new method of detecting CIDs, which mainly uses a sequential measurement combination of the carrier phase-based ionospheric delay data, with a 1-second interval. The proposed method’s performance was compared with conventional methods, including band-pass filters and a representative time-derivative method, using data from the 2011 Tohoku earthquake. As a result, the maximum CID-to-noise ratio can be increased by a maximum of 13% when the proposed method is used, and consequently, the detection performance of the CID can be improved.

Method of Examining Surface Cracks on Monocrystalline Silicon

2007 ◽  
Vol 364-366 ◽  
pp. 920-924
Author(s):  
Feng Zhou Fang ◽  
Yu Chan Liu ◽  
Qing Xiang Pei ◽  
Xiao Tang Hu
Keyword(s):  
Conventional Method ◽  
Simple Approach ◽  
Monocrystalline Silicon ◽  
New Method ◽  
Silicon Surfaces ◽  
Surface Cracks ◽  
Absorbed Energy ◽  
Nano Indentation ◽  
Micro Cracks

A new method on examining the micro cracks of monocrystalline silicon during nano indentation is proposed. It is established based on a study of the increasing rate of absorbed energy in nano indentation. This method provides a simple approach in understanding whether cracks on the silicon surfaces occur, while it is tedious in conventional method.

scholarly journals Phase Transition and Entropy Force between Two Horizons in (n+2)-Dimensional de Sitter Space

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yang Zhang ◽  
Wen-qi Wang ◽  
Yu-bo Ma ◽  
Jun Wang
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Physical Mechanism ◽  
De Sitter Space ◽  
Space Time ◽  
Thermodynamic Quantities ◽  
De Sitter ◽  
Time Dimension ◽  
Cosmic Expansion

In this paper, the effect of the space-time dimension on effective thermodynamic quantities in (n+2)-dimensional Reissner-Nordstrom-de Sitter space has been studied. Based on derived effective thermodynamic quantities, conditions for the phase transition are obtained. The result shows that the accelerating cosmic expansion can be attained by the entropy force arisen from the interaction between horizons of black holes and our universe, which provides a possible way to explain the physical mechanism for the accelerating cosmic expansion.

THE DEVELOPMENT OF A NEW METHOD OF SEISMIC VELOCITY DETERMINATION

Geophysics ◽  
1952 ◽  
Vol 17 (3) ◽  
pp. 560-574 ◽  
Author(s):  
F. P. Kokesh
Keyword(s):  
Conventional Method ◽  
Explosive Charge ◽  
Velocity Measurement ◽  
Seismic Velocity ◽  
Seismic Energy ◽  
New Method ◽  
Seismic Velocities ◽  
The Past ◽  
Velocity Information ◽  
Made In

The conventional method of making velocity surveys in bore holes is inherently expensive, time consuming, and inconvenient, and has a tendency towards non‐uniformity of results. With increasing recognition of the importance of seismic velocity information in the evaluation of seismograph data, the attention of geophysicists is turning towards means of overcoming the obstacles standing in the way of obtaining velocity information in greater volume. Considerable interest has recently been aroused in a new method of measuring seismic velocities wherein the explosive charge is placed in the hole and the seismic energy is picked up with multiple detector groups placed on the surface. Experimentation carried on during the past year indicates that the new method is quite workable. Casing perforator guns of the conventional bullet type have given results to depths exceeding 8,000 ft. with complete safety. Some experimentation with primacord as the explosive has given encouragement as a means of increasing the depth at which the method may be used. Substantial improvements have been made in the manner of obtaining the time break. This paper attempts to outline the basic problems of velocities and their measurement and describes the preliminary development that has been done thus far on the new method of velocity measurement.

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