Research on source of phase difference between channels of the vector hydrophone

2016 ◽  
Author(s):  
Yu Ao ◽  
Ke Xu ◽  
Jianwei Wan
Keyword(s):  
Phase Difference ◽  
Vector Hydrophone

What Is The Best Distance And Phase Difference Between The Elements Of Linear Antnna Array

2017 ◽  
pp. 1
Author(s):  
Asma M. N. El Ferjani ◽  
Ahmed S. El Barsha ◽  
AlZaroog Saleh Abdulali
Keyword(s):  
Phase Difference

Characterization of Flood Waves by Rating Curves

1997 ◽  
Vol 28 (1) ◽  
pp. 51-64 ◽  
Author(s):  
S.K. Mishra ◽  
M.K. Jain ◽  
S.M. Seth
Keyword(s):  
Phase Difference ◽  
Central India ◽  
Wave Number ◽  
Wave Characteristics ◽  
Travel Wave ◽  
Frame Work ◽  
Rating Curves ◽  
Exact Relationship ◽  
Flood Waves

The flood waves are characterized within the frame-work of loop (or hysteresis) of rating curves. The National Weather Service's Dam Break Flood Forecasting Model is used to generate the flood waves in the downstream valley of the Bargi dam located in Central India. The quantified hystereses, η, of non-dimensional rating curves are related with the corresponding flood wave characteristics, viz., speed of travel, wave number, phase difference, and attenuation. The analysis has led to the development of an exact relationship between η and phase difference. Using the concept of wave zoning, the better performance of the hysteresis based criteria compared with the available criteria is verified using Convex and Muskingum-Cunge routing in the wave zones. η limits are specified for the applicability of these simplified routing models. Furthermore, the envisaged applications of the based analysis are introduced.

UHF RFID Indoor Localization Based on Phase Difference

2021 ◽  
pp. 1-7
Author(s):  
Yanhan Zeng ◽  
Yuxing Liao ◽  
Xiheng Chen ◽  
Hong-zhou Tan
Keyword(s):  
Phase Difference ◽  
Indoor Localization ◽  
Uhf Rfid

scholarly journals Design and implementation of a jellyfish otolith-inspired MEMS vector hydrophone for low-frequency detection

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Renxin Wang ◽  
Wei Shen ◽  
Wenjun Zhang ◽  
Jinlong Song ◽  
Nansong Li ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Low Frequency ◽  
Directivity Pattern ◽  
Stress Distributions ◽  
Strong Response ◽  
Underwater Acoustic ◽  
Frequency Detection ◽  
Vector Hydrophone ◽  
Shock Resistance ◽  
Marine Applications

AbstractDetecting low-frequency underwater acoustic signals can be a challenge for marine applications. Inspired by the notably strong response of the auditory organs of pectis jellyfish to ultralow frequencies, a kind of otolith-inspired vector hydrophone (OVH) is developed, enabled by hollow buoyant spheres atop cilia. Full parametric analysis is performed to optimize the cilium structure in order to balance the resonance frequency and sensitivity. After the structural parameters of the OVH are determined, the stress distributions of various vector hydrophones are simulated and analyzed. The shock resistance of the OVH is also investigated. Finally, the OVH is fabricated and calibrated. The receiving sensitivity of the OVH is measured to be as high as −202.1 dB@100 Hz (0 dB@1 V/μPa), and the average equivalent pressure sensitivity over the frequency range of interest of the OVH reaches −173.8 dB when the frequency ranges from 20 to 200 Hz. The 3 dB polar width of the directivity pattern for the OVH is measured as 87°. Moreover, the OVH is demonstrated to operate under 10 MPa hydrostatic pressure. These results show that the OVH is promising in low-frequency underwater acoustic detection.

Measurement of axial phase difference of density fluctuations owing to spontaneously excited waves by using microwave reflectometer on GAMMA 10/PDX

2021 ◽  
Vol 92 (5) ◽  
pp. 053506
Author(s):  
R. Sekine ◽  
M. Hirata ◽  
R. Ikezoe ◽  
S. Jang ◽  
Y. Kubota ◽  
...  
Keyword(s):  
Phase Difference ◽  
Density Fluctuations

scholarly journals Combined Reduced Phase Dual-Directional Illumination Digital Holography and Speckle Displacements for Shape Measurement

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Davood Khodadad
Keyword(s):  
Phase Difference ◽  
Digital Holography ◽  
Relative Phase ◽  
Groove Depth ◽  
Phase Unwrapping ◽  
Shape Measurement ◽  
Phase Ambiguity ◽  
Holographic Method ◽  
Height Range ◽  
Phase Differences

We present a digital holographic method to increase height range measurement with a reduced phase ambiguity using a dual-directional illumination. Small changes in the angle of incident illumination introduce phase differences between the recorded complex fields. We decrease relative phase difference between the recorded complex fields 279 and 139 times by changing the angle of incident 0.5° and 1°, respectively. A two cent Euro coin edge groove is used to measure the shape. The groove depth is measured as ≈300  μm. Further, numerical refocusing and analysis of speckle displacements in two different planes are used to measure the depth without a use of phase unwrapping process.

scholarly journals Power factor correction using capacitors & filters

2018 ◽  
Vol 7 (2.12) ◽  
pp. 234
Author(s):  
Karthik Subramanian ◽  
Shantam Tandon
Keyword(s):  
Root Mean Square ◽  
Phase Difference ◽  
Power Factor ◽  
Reactive Power ◽  
Power Factor Correction ◽  
Active Filters ◽  
Minimum Amount ◽  
Mean Square ◽  
The Real ◽  
Electrical Consumption

Power factor is the ratio of the real current or voltage received by a load to the root mean square (rms) value of the current or voltage that was supposed to be acquired by the same load. The fact that the two become different is due to the presence of reactive power in the circuit which gets dissipated.Improving the power factor means reducing the phase difference between voltage and current. Since majority of the loads are of inductive nature, they require some amount of reactive power for them to function. Therefore, for the better use of electrical appliances with minimum amount of electrical consumption, the power factor should necessarily be increased and should be brought near to 1. This can be easily done by the help of Automatic Power Factor Correction Capacitors and Active filters.  

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