The Performance Testing Method of Optical Fiber Time Synchronization in BeiDou Ground-Based Navigation Signal Net

2016 ◽  
pp. 247-253
Author(s):  
Tingsong Tang ◽  
Na Zhao ◽  
Yun Zhao ◽  
Xing Chen ◽  
Fengjuan Wu ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Time Synchronization ◽  
Performance Testing ◽  
Testing Method ◽  
Navigation Signal

scholarly journals Long-Distance Time Transfer in Optical Fiber Networks Using a Cascaded Taming Technology

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ding Chen ◽  
Jiangning Xu ◽  
Yifeng Liang ◽  
Shan Jiang ◽  
Hongyang He
Keyword(s):  
Optical Fiber ◽  
High Precision ◽  
Wavelength Division Multiplexing ◽  
Time Synchronization ◽  
Atomic Clock ◽  
Process Time ◽  
Long Distance ◽  
Time Service ◽  
Time Frequency ◽  
Fiber Link

In order to meet the time service needs of high-precision, long-distance, and multinode optical network, this paper proposes a new time synchronization solution, which combines the wavelength division multiplexing (WDM) technology with cascaded taming clock technology. The WDM technology is used for time synchronization between each pair of master-slave nodes. In the system, there are two wavelengths on the fiber link between the master node and the slave node for transmitting signals. 1 plus per second (PPS) signal, time code signal, and 10 MHz signal are, respectively, and successively, sent to the optical fiber link. By solving the one-way delay through analysis of error contribution and link characteristics of the time transmission process, time synchronization of the master-slave nodes pair is achieved. Furthermore, the authors adopt cascaded taming clock technology to ensure accurate time synchronization of each node. A 700 km long-distance time-frequency synchronization system is constructed in the laboratory. The system uses a cesium atomic clock as the reference clock source and transmits the signals through 8 small rubidium atomic clocks (RB clocks) hierarchically. Results from the experiment show that the long-term time stability is 47.5 ps/104 s. The system’s structural characteristics and the experiment results meet the requirements to allow practical use of high-precision time synchronization in networks. This proposed solution can be applied in various civil, commercial, and military fields.

Acoustic Emission Based Tank Bottom Floor Corrosion Detection

2013 ◽  
Vol 7 (2) ◽  
pp. 205-210 ◽  
Author(s):  
Tao Zhang ◽  
◽  
Hao Feng ◽  
Zhou-Mo Zeng
Keyword(s):  
Acoustic Emission ◽  
Optical Fiber ◽  
Storage Tanks ◽  
Fiber Sensors ◽  
Testing Method ◽  
Actual Application ◽  
Oil Storage ◽  
Crucial Component ◽  
Tank Bottom ◽  
Nondestructive Testing Method

The tank bottom floor is a crucial component of large oil storage tanks, and its status has a pivotal impact on the integrity of the entire tank. Acoustic Emission (AE) monitoring is an advanced, in-service, nondestructive testing method internationally recognized to be capable of assessing the tank bottom floor without the necessity of prior tank cleaning. In this paper, the principle of Time Difference of Arrival (TDOA) is illustrated, and the efficiency of piezoelectric AE sensors is verified through a field experiment. The authors then investigate Mach-Zehnder interferometerbased AE sensors with a view to using optical fiber sensors as a substitute for acoustic emission detecting. The results of the experiment indicate that optical fiber AE sensors based on the Mach-Zehnder interferometer can be used as transducers sensitive to acoustic events, so they can serve as indicators of the imminent failure of a structure. In addition, some suggestions are put forward regarding forthcoming actual application.

scholarly journals Experiments with Small Size Shaped Charges

Hadmérnök ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 99-110
Author(s):  
Lóránd Kugyela
Keyword(s):  
Mild Steel ◽  
Performance Testing ◽  
Productive Performance ◽  
Penetration Test ◽  
Testing Method ◽  
Development Tool ◽  
Practical Development ◽  
Field Works ◽  
Practical Field ◽  
Clear Method

This paper describes the research on testing of small size point focal shaped charges. They were manufactured from composite-B, Semtex and pressed RDX, and binary explosives. As the liner and the whole structure of the charges were identical the mild steel penetration test was a clear method for comparing and quantifying their performance. The target setup was also standardized with different steel discs. During testing I realized that it was a practical development tool, to find a proper mixture for binary explosives. Since most of the shaped charge literature related to their evaluation, I wanted to have a simple, yet productive performance testing method that suited more to practical field works.

Research of Smart Composite Insulator with Optical Fiber Bragg Grating

2013 ◽  
Vol 423-426 ◽  
pp. 2563-2569
Author(s):  
Hong Lei Yang ◽  
Shi Bin Liang ◽  
Xue Peng Miao ◽  
Min Cao ◽  
Ming Chang
Keyword(s):  
Optical Fiber ◽  
Transmission Line ◽  
Fiber Composite ◽  
Short Circuit ◽  
Performance Testing ◽  
Electrical Performance ◽  
Stable Operation ◽  
Composite Insulator ◽  
Electric Transmission ◽  
Electric Transmission Line

On-line monitoring of lightning,ice,short circuit on electric transmission line and insulator's operation state is of great significance to ensure the safe and stable operation of the electric transmission line.An intelligent composite insulator,in which the core rod has fiber Bragg gratings is developed.lightning,ice,short circuit on electric transmission line and insulator's operation state can be reflected by monitoring the center wavelengths of the fiber Bragg gratings.The temperature, strain response and electrical performance testing experiments on 110 kV fiber composite insulator were done,the result indicates that the optical fiber composite insulator can measure the temperature accurately;the load of composite insulator can be monitored approximately by no. 2 and no.4 monitoring sites;the110 kV fiber composite insulator’s dry lightning impulse withstand voltage is 421 kV,the normal polarity of steep wave impulse voltage withstand voltage is 434 kV(steepness:1206kV/μs),the negative polarity withstand voltage is 444 kV(steepness:1132kV/μs)and the dry power frequency withstand voltage is 230 kV at the altitude of 1970m.

Real-Time Validation for Satellite Navigation Signal Simulation System

2014 ◽  
Vol 667 ◽  
pp. 153-156
Author(s):  
Jian Bing Tang ◽  
Qing Song Zhao ◽  
Ya Bing Zha
Keyword(s):  
Real Time ◽  
Time Synchronization ◽  
Complex Structure ◽  
Satellite Navigation ◽  
Simulation System ◽  
Signal System ◽  
The Real ◽  
Time Performance ◽  
Navigation Signal ◽  
Signal Simulation

The satellite navigation signal system is so useful that it can provide autonomous geo-spatial positioning with global coverage. The satellite navigation signal simulation system possesses the traits of large scale, complex structure and various model types, and the real-time performance of the simulation system is exigent. The simulation real-time performance index will be analyzed and tested roundly. Firstly, the framework of the satellite navigation signal simulation system is introduced. Secondly, several index such as simulation step-time, time function and network data transfers, which can affect the real-time performance of the simulation system, are analyzed. Finally, four real-time performance indexes such as frame overflow, the definition of frame synchronization and time synchronization, the precision of time synchronization etc, are tested and validated in detail. By analysis and test, the result shows that this simulation system possessing higher real-time performance and it can meet the real-time simulation requirement of the simulation system. This simulation system can also be used to validate the real satellite navigation signal system.

scholarly journals Software and Performance Testing Tools

2021 ◽  
Vol 2 (1) ◽  
pp. 1-12
Author(s):  
Nishi Srivastava ◽  
◽  
Ujjwal Kumar ◽  
Pawan Singh
Keyword(s):  
Software Testing ◽  
Performance Testing ◽  
Software System ◽  
System Quality ◽  
System Testing ◽  
Testing Method ◽  
Program Application ◽  
Manual Testing ◽  
Verification Techniques ◽  
Automation Testing

Software Testing may be a method, that involves, death penalty of a software system program/application and finding all errors or bugs therein program/application in order that the result is going to be a defect-free software system. Quality of any software system will solely be acknowledged through means that of testing (software testing). Through the advancement of technology round the world, there inflated the quantity of verification techniques and strategies to check the software system before it goes to production and astray to promote. Automation Testing has created its impact within the testing method. Now-a-days, most of the software system testing is finished with the automation tools that not solely lessens the quantity of individuals operating around that software system however additionally the errors which will be loose through the eyes of the tester. Automation take look acting contains test cases that make the work simple to capture totally different eventualities and store them. Therefore, software system automation testing method plays a significant role within the software system testing success. This study aims in knowing differing kinds of software system testing, software system testing techniques and tools and to match manual testing versus automation testing.

Long Distance Optical Fiber Time Synchronization Technology and Accuracy Analysis

2021 ◽  
Author(s):  
Yanting Yu ◽  
Jiangning Xu ◽  
Yifeng Liang ◽  
Fangneng Li
Keyword(s):  
Optical Fiber ◽  
Time Synchronization ◽  
Accuracy Analysis ◽  
Long Distance
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