scholarly journals Application of Biphase Complete Complementary Code for Ionospheric Sounding

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2811 ◽  
Author(s):  
Guobin Yang ◽  
Peng Duan ◽  
Chunhua Jiang ◽  
Tongxin Liu ◽  
Ting Lan ◽  
...  
Keyword(s):  
Signal Processing ◽  
Cross Correlation ◽  
Technical Feasibility ◽  
Performance Results ◽  
Ionospheric Sounding

This paper illustrates the processes carried out for the application of biphase complete complementary code (CCC) for ionospheric sounding to address the coherent interference problem in multi-station ionospheric sounding. An algorithm to generate the biphase CCC is described, and the detailed process of waveform construction and signal processing is presented. Characteristics of the autocorrelation and cross-correlation are analyzed through simulations, and the technical feasibility of the application of CCC is explored. Experiments of ionospheric sounding with the CCC are also implemented to verify performance. Results demonstrate that the CCC performs well in multi-station ionospheric sounding, and is capable of eliminating the coherent interference in the network of ionosondes, compared to the conventional complementary code.

scholarly journals Performance Evaluation of Traditional Signal Processing Methods in Localizing Tursiops truncatus Whistles in a Reverberant Aquatic Environment

2019 ◽  
Author(s):  
SF Woodward ◽  
MO Magnasco
Keyword(s):  
Signal Processing ◽  
Aquatic Environment ◽  
Tursiops Truncatus ◽  
Cross Correlation ◽  
Correlation Method ◽  
Extraction Methods ◽  
Phase Transform ◽  
Atlantic Bottlenose Dolphin ◽  
Signature Whistles ◽  
Signal Processing Methods

AbstractRelative to individually distinctive signature whistles, little is known about the “non-signature” calls – particularly the non-signature whistles – of the common Atlantic bottlenose dolphin, Tursiops truncatus. While such calls are suspected to serve social function, tracking their exchange among conspecifics and correlating their usage with non-acoustic behavior has proven challenging, given both their relative scarcity in the dolphin repertoire and their characteristic shared use among dolphins, which precludes the unique identification of callers on the basis of whistle properties alone. Towards the goal of robustly identifying the callers of non-signature whistles (equivalently, attributing non-signature whistles to callers), we present a new, long-term audiovisual monitoring system designed for and tested at the Dolphin Discovery exhibit of the National Aquarium in Baltimore, Maryland. In this paper, we confirm the system’s ability to spatially localize impulse-like sounds using traditional signal processing approaches that have already been used to localize dolphin echolocation clicks. We go on to provide the first rigorous experimental evaluation of the component time-difference-of-arrival-(TDOA) extraction methods on whistle-like tonal sounds in a (reverberant) aquatic environment, showing that they are generally not suited to sound localization. Nevertheless, we find that TDOA extraction under these circumstances is performed significantly better using a Generalized Cross-Correlation with Phase Transform (GCC-PHAT) method than a standard circular cross-correlation method, a potentially important result.

Cross-Correlation Signal Processing for Axion and WISP Dark Matter Searches

2019 ◽  
Vol 66 (1) ◽  
pp. 236-243
Author(s):  
Ben T. Mcallister ◽  
Stephen R. Parker ◽  
Eugene N. Ivanov ◽  
Michael E. Tobar
Keyword(s):  
Signal Processing ◽  
Dark Matter ◽  
Cross Correlation ◽  
Correlation Signal Processing

scholarly journals Phase and Frequency Matching-based Signal Processing Method for Coriolis Mass Flowmeters

2016 ◽  
Vol 16 (2) ◽  
pp. 62-67 ◽  
Author(s):  
Yaqing Tu ◽  
Yanlin Shen ◽  
Haitao Zhang ◽  
Ming Li
Keyword(s):  
Signal Processing ◽  
Phase Difference ◽  
Cross Correlation ◽  
Measurement Accuracy ◽  
Frequency Estimation ◽  
Correlation Method ◽  
Processing Method ◽  
Transform Method ◽  
Frequency Matching ◽  
Signal Processing Method

AbstractSignal processing precision of Coriolis mass flowmeters affects the measurement accuracy directly. To improve the measurement accuracy of Coriolis mass flowmeters, a phase and frequency matching-based signal processing method for Coriolis mass flowmeters is proposed. Estimated phase difference is obtained by means of frequency estimation, 90° phase shift, generating reference signals and cross-correlation. Simulated results demonstrate that the proposed method has better phase difference estimation and anti-interference performance than the Hilbert transform method, cross-correlation method, data extension-based correlation method, and quadrature delay estimator. Measurement results of Coriolis mass flowmeters verify the effectiveness and superiority of the proposed method in practice.

Nondestructive Testing Method in Artificial Intelligence Real Time Systems

2004 ◽  
Vol 97-98 ◽  
pp. 71-76
Author(s):  
Egidijus Kazanavicius ◽  
Antanas Mikuckas ◽  
Irena Mikuckiene
Keyword(s):  
Signal Processing ◽  
Correlation Function ◽  
Nondestructive Testing ◽  
Cross Correlation ◽  
Reduction Method ◽  
Reference Signal ◽  
Floating Point ◽  
Real Time Systems ◽  
Reflected Signal ◽  
Time Systems

Modern sonar and radar measurement systems are widely used in the field of nondestructive testing for a long time. Usually reference signal is emitted towards the object to be investigated and we get a signal, which is the sum of reference signal reflected from different plies. The task of signal processing is to determine time instances corresponding positions of certain ply, which allow analyzing structure of object. Usually the cross correlation function (CCF) of transmitted sequence and received sequence is calculated. If peaks were clearly identified in the cross correlation function (CCF), it would be easy to determine time instances. Due to the noise some coherent peaks, additive to the expected peaks, appear on the CCF, which are confusing in regard to the clear distinction of target. In order to cancel effects of noise as much as possible some measures have to be taken for data manipulation noise cancellation, such as averaging, inverse filtering and so on. These signal-processing methods need a lot of floating point floating point operations and are time consuming. That is why the usage of such ultrasonic systems is limited in real time systems, which are the base for self-organizing systems. Amount of calculations depends on the length of reference signal, the length of reflected signal to be processed and the noise reduction method used in such system. A new system with reduced amount of calculations is considered in this article. In this system only parts of reflected signal corresponding peaks of CCF are processed. These parts are defined in acquisition mode and afterwards system enters measurement mode. New noise reduction method based on wavelet transforms coefficients thresholding is applied in this system. The length of reference signal impacts system noise immunity and amount of calculations. The main problem in ultrasonic non-destructive testing systems is to cancel out effects of the noise. The optimal length of reference signal for wavelet based signalprocessing method is defined. All these measures allowed significantly reduce amount of calculations in the self-organizing systems.

Sign in / Sign up

Export Citation Format

Share Document