scholarly journals Issues of technical implementation of ground-based microwave radiometric system calibration

2021 ◽  
Vol 2140 (1) ◽  
pp. 012029
Author(s):  
I N Rostokin ◽  
E V Fedoseeva ◽  
E A Rostokina ◽  
G G Shchukin
Keyword(s):  
Horn Antenna ◽  
External Source ◽  
Noise Signal ◽  
Noise Generator ◽  
Signal Source ◽  
Antenna Aperture ◽  
System Calibration ◽  
Calibration Signal ◽  
Radiometric System ◽  
The Common

Abstract The theoretical bases of a method of carrying out calibration of microwave radiometric system on a noise signal of the external noise generator are analysed, the parameters setting value of gain of antenna temperature at introduction in structure of system of such external source of a calibration signal are determined. The questions of technical realization of an external source of a calibration signal for microwave radiometric system are considered, the structural scheme is presented, the place of its arrangement in structure of the antenna is determined. The necessity of using a horn antenna to create directional radiation towards the mirror antenna emitter is shown. The data on the design of such a calibration signal source for the case of its use in a three-band microwave radiometric system with the reception of a noise signal at the common antenna aperture and a sequential separation of the input signals of the three bands in the feeder path of the common mirror irradiator are presented. The influence of the design and, accordingly, the directional properties of the horn antenna of a microwave radiometric system calibration signal source on the coefficient characterizing the radiation divergence created by the noise generator horn, as well as the frequency properties of this coefficient are analysed. The results of measurements of radio-thermal radiation by a three-band microwave radiometric system when two calibration periods with reception of a radio-noise signal from an external calibration signal source located at the base of the antenna mirror are presented.

scholarly journals Calibration of a three-band microwave radiometric system by an external noise signal source

2021 ◽  
Vol 1991 (1) ◽  
pp. 012027
Author(s):  
E V Fedoseeva ◽  
I N Rostokin ◽  
E A Rostokina ◽  
G G Shchukin
Keyword(s):  
External Noise ◽  
Noise Signal ◽  
Signal Source ◽  
Radiometric System

scholarly journals SMART SHIELD PANEL AC VOLTMETER CELL

2021 ◽  
Vol 2021 (60) ◽  
pp. 65-74
Author(s):  
B.A. Kromplyas ◽  
◽  
A.S. Levytskyi ◽  
Ie.O. Zaitsev ◽  
◽  
...  
Keyword(s):  
Alternating Current ◽  
Measuring Instruments ◽  
Operating Parameters ◽  
Signal Source ◽  
Structural Scheme ◽  
Calibration Process ◽  
Calibration Signal ◽  
Operational Characteristics ◽  
Calibration Algorithm

In this paper smart shield panel electrical operating parameters meters of energy generating facilities functionality is analysis. The list of functions of measuring instruments supplemented, which allowed increasing their operational characteristics. Methods and results of realization of these functions given for the panel board intellectualized voltage meter of alternating current. The structural scheme of the developed panel board intellectualized meter is described and its main technical characteristics are given.A method of mobile calibration of the device is proposed, in which a calibration signal source with a separate fixed value is used, and the calibration process itself is controlled from the device keyboard. A modernized detailed and simplified calibration algorithm is present. Ref. 12, fig. 5, tabl. 2.

A Hypothesized Mechanistic Model of Longitudinal Wall Motion at the Common Carotid Artery

2019 ◽  
Author(s):  
Zhili Hao ◽  
Leryn Reynolds ◽  
John M. Herre
Keyword(s):  
Carotid Artery ◽  
Elastic Wave ◽  
Common Carotid Artery ◽  
Wall Motion ◽  
Mechanistic Model ◽  
External Source ◽  
Arterial Tree ◽  
Longitudinal Elastic Wave ◽  
Longitudinal Wall ◽  
The Common

Abstract In light of recently recognized independent clinical values of longitudinal wall motion ux(t) at the common carotid artery (CCA) and the struggle on appropriate arterial indices for interpreting ux(t), this paper hypothesizes a mechanistic model of ux(t) and explores clear implications of the antegrade amplitude ux0-ante and retrograde amplitude ux0-retro of ux(t) in systole to the cardiovascular (CV) system. By examining findings on ux(t) and other relevant findings through the lens of the engineering essence of ux(t), a mechanistic model of ux(t) is hypothesized: the left ventricle (LV) base rotation is the excitation source for initiating the longitudinal elastic wave propagating along the arterial tree; wall shear stress at an artery serves as a local external source for supplying energy to the longitudinal elastic wave; and longitudinal elasticity at the arterial wall dictates the wave propagation velocity. Integrating the mechanistic model with findings on ux(t) gives rise to interpretation of ux0-ante and ux0-retro for their clear implications: longitudinal elasticity Exx at the common carotid artery (CCA) is estimated from ux0-ante, and ux0-retro is an inverse indicator of the maximum base rotation of the LV and a positive indicator of longitudinal elasticity at the ascending aorta (AA). For the first time, this model reveals the mechanisms underlying those statistical-based findings on ux(t).

Health effects of vibration

2019 ◽  
pp. 381-397
Author(s):  
Ian Lawson ◽  
Roger Cooke
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Health Professionals ◽  
Occupational Diseases ◽  
Vibrational Energy ◽  
External Source ◽  
Health Surveillance ◽  
Potential Sources ◽  
Tunnel Syndrome ◽  
The Common ◽  
Case Assessment

Hand–arm vibration syndrome (HAVS) is one of the commonest occupational diseases and occupational health professionals are often called upon to give advice on health surveillance and fitness for work in workers exposed to hand-transmitted vibration. There are many potential sources of HTV, the common feature being tools and equipment capable of transmitting an external source of vibrational energy to the hand–arm system. This chapter covers the clinical features, case assessment, and management of HAVS cases that will assist in providing such advice. It also covers other regional vibration disorders including carpal tunnel syndrome, Dupuytren’s contracture, musculoskeletal effects, hypothenar and thenar hammer syndromes, and some less commonly reported and putative vibration disorders.

Study of Electrical Thickness Measurement System Technology of Composite

2013 ◽  
Vol 821-822 ◽  
pp. 1252-1255
Author(s):  
Xing Yu ◽  
Hao Gu ◽  
Hong Quan Feng ◽  
Bing Heng Wu ◽  
Yuan Yun Liu ◽  
...  
Keyword(s):  
Measurement System ◽  
Network Theory ◽  
Horn Antenna ◽  
Simulation Method ◽  
Thickness Measurement ◽  
System Technology ◽  
Antenna Aperture ◽  
Inner Surface ◽  
Electrical Thickness ◽  
Thickness Measurement System

Based on four-terminal network theory, a multilayered model for reflective electrical thickness measurement system is presented in this paper. Using the simulation method of finite element, two crucial parameters of the measurement system are given. One parameter is the distance between the inner surface of composite and reflective mold, the other is the outer surface of composite and horn antenna aperture. This work will guarantee the design of the electrical thickness measurement system of composite.

The Design of Adaptive Noise Cancellation Filter Based on DSP Chip

2014 ◽  
Vol 971-973 ◽  
pp. 1786-1790
Author(s):  
Xiu Min Wang ◽  
Ting Ting Li ◽  
Liang Shan
Keyword(s):  
Digital Filters ◽  
Noise Cancellation ◽  
Noise Signal ◽  
Lms Algorithm ◽  
Speech Communication ◽  
Adaptive Noise Cancellation ◽  
Change Characteristics ◽  
The Common ◽  
Adaptive Noise

The speech signal usually could not be extracted correctly from the digital speech communication system with strong interference. As for this kind of system, the common fixed coefficient digital filters (FIR, IIR) are unable to achieve the best effect of filtering. Whereas the adaptive filter could extract the available signals properly by adjusting the filter coefficient automatically without knowing the change characteristics of the noise signal. In this paper, we designed an adaptive noise cancellation filter based on LMS algorithm on the DSP chip and verification of the filter was done on the TMS320C5509 platform. The results show that the adaptive noise cancellation designed in this paper could extract the available signals properly and improve the quality of the speech communication.

scholarly journals Energy Transfer Using Gradient Index Metamaterial

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Boopalan Ganapathy ◽  
Subramaniam Chittur Krishnaswamy
Keyword(s):  
Refractive Index ◽  
Energy Transfer ◽  
Spherical Wave ◽  
Beam Width ◽  
Horn Antenna ◽  
Index Structure ◽  
Side Lobe Level ◽  
Antenna Aperture ◽  
Gradient Refractive Index ◽  
Directive Gain

The gradient refractive index structure in this paper is used to increase the quantum of energy transfer. This is done by improving the directive gain of the pyramidal horn antenna at a frequency of 10 GHz. A three-dimensional array of closed square rings is placed in front of the horn antenna aperture to form a gradient refractive index structure. This structure increases the directive gain by 1.6 dB as compared to that of the conventional horn antenna. The structure nearly doubles the wireless power transfer quantum between the transmitter and the receiver when placed at both ends. The increase in the directivity is achieved by converting the spherical wave emanating from the horn to a plane wave once it passes through the structure. This transformation is realized by the gradient refractive index structure being placed perpendicular to the direction of propagation. The gradient refractive index is constructed by changing the dimensions of a closed square ring placed in the unit cell of the array. The change in the refractive index gives rise to an improvement of the half power beam width and side lobe level compared to that of the normal horn. The design and simulation were done using CST Studio software.

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