Optimization of Matched Chaotic Frequency Modulation Excitation Sequences for Multichannel Simultaneously Triggered Ultrasonic Ranging System

2012 ◽  
Vol 4 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Zhen-Jing Yao ◽  
Tao Gao
Keyword(s):  
Frequency Modulation ◽  
Ultrasonic Sensors ◽  
Narrow Bandwidth ◽  
Correlation Characteristic ◽  
Ultrasonic Ranging ◽  
Working Together ◽  
Spectrum Matching ◽  
Nondominated Sorting ◽  
Lfm Excitation ◽  
Modulation Excitation

The matched spectrum and correlation characteristics are both important to realize the multichannel ultrasonic sensors working together. The spectrum matching can make full use of the bandwidth of the ultrasonic ranging system, and the good correlation characteristic can eliminate crosstalk among multichannel ultrasonic sensors triggering simultaneously. Linear frequency modulation (LFM) excitation sequences have been used as transmission signals for ultrasonic sensors. Due to the narrow bandwidth of the ultrasonic ranging system, the number of available LFM excitation sequences is limited. The chaotic frequency modulation (CFM) excitation sequences, which can generate more available excitation signals, are proposed in this paper. The nondominated sorting genetic algorithm-II is adopted to optimize both the spectrum and correlation characteristic of the CFM excitation sequences. After optimization, the CFM excitation sequences are spectrally matched to the ultrasonic ranging system as well as have best correlation characteristic. Real experiments have been implemented using an ultrasonic ranging system consisting of eight-channel SensComp 600 series electrostatic sensors excited with 2 ms CFM sequences. Experimental results show that spectra of the optimized CFM excitation sequences can match to the system and can work together without crosstalk.

Sensors Network for Ultrasonic Ranging System

2013 ◽  
Vol 5 (3) ◽  
pp. 47-59
Author(s):  
Tao Gao ◽  
Zhenjing Yao
Keyword(s):  
Band Pass Filter ◽  
Nsga Ii ◽  
Pass Filter ◽  
Multiple User ◽  
Correlation Characteristic ◽  
Ultrasonic Ranging ◽  
Band Pass ◽  
Excitation Sequence ◽  
Spectrum Matching ◽  
Sequence Match

The spectrum matching and correlation characteristic are both important in the multiple-user ultrasonic ranging system. As people know, an ultrasonic ranging system, which has a bell-shaped magnitude spectrum, acts like a band-pass filter. If the spectrum of the excitation signal does not match that of the ultrasonic ranging system, some of energy cannot be transmitted by the ultrasonic system. In other words, it does not make full use of the bandwidth of the ultrasonic ranging system. The good correlation characteristics can eliminate cross-talk among multichannel ultrasonic sensors firing simultaneously. To the authors’ knowledge, not many researchers considered how to make the spectrum of the excitation sequence match to that of the ultrasonic ranging system as well as improve the correlation characteristics. In this paper, the chaotic frequency modulation (CFM) excitation sequences are proposed for multiple-user ultrasonic ranging system. To obtain the excitation sequences which are spectrally matched to the ultrasonic ranging system as well as have the best correlation characteristic, the NSGA-II is applied to optimize the CFM excitation sequences.

scholarly journals Spectrum of frequency modulation of serpentine emission as a reflection of the solar fluctuation spectrum

2017 ◽  
Vol 3 (1) ◽  
pp. 59-62
Author(s):  
Борис Довбня ◽  
Boris Dovbnya ◽  
Борис Клайн ◽  
Boris Klain ◽  
Анатолий Гульельми ◽  
...  
Keyword(s):  
Emission Spectrum ◽  
Frequency Modulation ◽  
Carrier Frequency ◽  
Observation Time ◽  
Signal Frequency ◽  
Frequency Range ◽  
Fluctuation Spectrum ◽  
Using Data ◽  
Spectrum Matching ◽  
Serpentine Emission

We study frequency modulation of serpentine emission (SE), using data from the Vostok Antarctic station. It is shown that the previously observed 5-minute modulation of the SE carrier frequency is the most prominent and stable in the emission spectrum. Frequency fluctuations of this period are present in about 70 % of the total SE observation time under moderately quiet geomagnetic conditions (Kp=0–2). We performed a per-pixel processing of SE dynamic spectra and found that the power spectrum of the signal frequency modulation contains a clearly visi-ble peak at periods close to 5 minutes. A detailed study shows the emission spectrum matching the frequency range of the solar photospheric oscillations. The results of the analysis allow us to conclude that the 5-minute modulation of the SE carrier frequency can be viewed as a reflection of photospheric fluctuations with the same period that is typical for the solar eigenoscillations.

Wideband dipole logging based on segment linear frequency modulation excitation

2018 ◽  
Vol 15 (2) ◽  
pp. 197-207
Author(s):  
Xue-Shen Cao ◽  
Hao Chen ◽  
Ping Li ◽  
Hong-Bin He ◽  
Yin-Qiu Zhou ◽  
...  
Keyword(s):  
Frequency Modulation ◽  
Linear Frequency Modulation ◽  
Linear Frequency ◽  
Modulation Excitation

Frequency modulation excitation spectroscopy

1982 ◽  
Vol 41 (5) ◽  
pp. 369-373 ◽  
Author(s):  
W. Lenth ◽  
C. Ortiz ◽  
G.C. Bjorklund
Keyword(s):  
Frequency Modulation ◽  
Modulation Excitation Spectroscopy ◽  
Modulation Excitation
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