Robust Tracking Time-Varying High-Frequency CW Telegraph Signal

2012 ◽  
Vol 155-156 ◽  
pp. 435-439
Author(s):  
Guo Jun Li ◽  
Xiao Na Zhou ◽  
Nai Qian Liu ◽  
Shao Hua Li
Keyword(s):  
High Frequency ◽  
Continuous Wave ◽  
Impulsive Noise ◽  
Model Simulation ◽  
Time Varying ◽  
Simulation Studies ◽  
Robust Tracking ◽  
Robust Kalman Filter ◽  
Tracking Time ◽  
Nonlinear Statistical Model

Continuous wave (CW) telegraph is a crucial communication means for high-frequency tactical communication. But there is serious frequency deviation and impulsive noise in High-frequency channel, thus the conventional tracking method based on Gaussian noise assumption may lose the track of time-varying CW signal. A new robust kalman filter-based tracker is proposed in this paper to extract the time-varying CW signal in presence of impulsive interference, which uses a nonlinear statistical model. Simulation studies show this method can dynamically track nonstationary CW signal and effectively suppress burst impulse noise.

scholarly journals Ionospheric Clutter Model for HF Sky-Wave Path Propagation with an FMCW Source

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Xuguang Yang ◽  
Aijun Liu ◽  
Changjun Yu ◽  
Linwei Wang
Keyword(s):  
High Frequency ◽  
Peak Power ◽  
Continuous Wave ◽  
Model Simulation ◽  
Hf Radar ◽  
Electron Density Fluctuation ◽  
Vertical Drift ◽  
Wave Radar ◽  
Wave Path ◽  
Simulation Results

A theoretical model of the sky-wave path propagation with frequency modulated continuous wave (FMCW) source for high frequency (HF) radar is proposed in this paper. Based on the modeling of pulsed source, the expression of the received electric field with an FMCW source is derived for the reflection case from the ionospheric irregularities. Subsequently, the ionospheric reflection coefficient with different phase power spectrums for vertical and oblique backscattering propagation paths is incorporated into the ionospheric clutter model. Simulation results show that the peak power of FMCW in average is lower than that of pulsed waveform. Furthermore, different incident angles and magnetic field in mid-latitude can also influence the power density of the backscattering ionospheric clutter. Finally, the data analysis results from the high frequency surface wave radar (HFSWR) and Ionosonde collected in Yellow Sea preliminarily verify the inversion of the variance of the electron density fluctuation and the vertical drift velocity of the irregularities within ionosphere.

Tracking Time-Varying Powerline Interference in Electrocardiogram Using Robust Extended Kalman Filter

2012 ◽  
Vol 155-156 ◽  
pp. 127-132
Author(s):  
Guo Jun Li ◽  
Shu Ting Zhang ◽  
Nan Xiao ◽  
Xiao Na Zhou
Keyword(s):  
Adverse Effect ◽  
Kalman Filter ◽  
Ecg Signal ◽  
Time Varying ◽  
Qrs Complex ◽  
Robust Kalman Filter ◽  
Simulation Results ◽  
Powerline Interference ◽  
M Estimation ◽  
Tracking Time

Powerline interference (PLI) often exhibits variations in frequency and amplitude, whose frequency lies in the spectrum range of the ECG signal. Most previous attempts of tracking time-varying PLI signal are based on Least Squared (LS) algorithm. This makes their methods susceptible to QRS complex in tracking low-level PLI signal. This study presents a new robust Kalman filter-based PLI suppressor to overcome the limitation of existing methods. M-estimation is incorporated into the kalman filter to combat the adverse effect of QRS impulsive. Simulation results indicate that our method outperforms the former LS-based PLI cancellers in both suppressing interference and preserving meaningful ECG components at various interference levels.

scholarly journals A CONFIDENCE-GUIDED TECHNIQUE FOR TRACKING TIME-VARYING FEATURES

2020 ◽  
pp. 1-1
Author(s):  
Soumya Dutta ◽  
Terece Louise Turton ◽  
James Ahrens
Keyword(s):  
Time Varying ◽  
Tracking Time

Dynamic Anti-Saturation Integral Controller Used in Time-Varying Delay System

2011 ◽  
Vol 467-469 ◽  
pp. 766-769
Author(s):  
Gui You Pu ◽  
Ge Wen Kang
Keyword(s):  
Variable Structure ◽  
Delay System ◽  
Time Varying ◽  
Control Methods ◽  
Simulation Studies ◽  
Motor Speed ◽  
Intelligent Controller ◽  
Time Varying Delay ◽  
Integral Controller ◽  
Varying Delay

Systems with large variable delay, traditional control methods can’t performance well. In this paper, a controller combined with the human-simulated intelligent controller (HSIC) and newly dynamic anti-saturation integral controller, is used in the time-varying delay motor speed control. Simulation studies show, there is no chatter in this controller which is always in norm variable structure controller and this method reaches good performance in the time-varying delay system.

scholarly journals Frequency variations of gravity waves interacting with a time-varying tide

2013 ◽  
Vol 31 (10) ◽  
pp. 1731-1743 ◽  
Author(s):  
C. M. Huang ◽  
S. D. Zhang ◽  
F. Yi ◽  
K. M. Huang ◽  
Y. H. Zhang ◽  
...  
Keyword(s):  
Gravity Waves ◽  
High Frequency ◽  
Lower Atmosphere ◽  
Horizontal Wind ◽  
Frequency Variation ◽  
Time Varying ◽  
Transient Nature ◽  
Critical Layers ◽  
Favorable Conditions ◽  
Frequency Variations

Abstract. Using a nonlinear, 2-D time-dependent numerical model, we simulate the propagation of gravity waves (GWs) in a time-varying tide. Our simulations show that when a GW packet propagates in a time-varying tidal-wind environment, not only its intrinsic frequency but also its ground-based frequency would change significantly. The tidal horizontal-wind acceleration dominates the GW frequency variation. Positive (negative) accelerations induce frequency increases (decreases) with time. More interestingly, tidal-wind acceleration near the critical layers always causes the GW frequency to increase, which may partially explain the observations that high-frequency GW components are more dominant in the middle and upper atmosphere than in the lower atmosphere. The combination of the increased ground-based frequency of propagating GWs in a time-varying tidal-wind field and the transient nature of the critical layer induced by a time-varying tidal zonal wind creates favorable conditions for GWs to penetrate their originally expected critical layers. Consequently, GWs have an impact on the background atmosphere at much higher altitudes than expected, which indicates that the dynamical effects of tidal–GW interactions are more complicated than usually taken into account by GW parameterizations in global models.

An Algorithm of Complete Coverage Path Planning for Autonomous Underwater Vehicles

2011 ◽  
Vol 467-469 ◽  
pp. 1377-1385 ◽  
Author(s):  
Ming Zhong Yan ◽  
Da Qi Zhu
Keyword(s):  
Path Planning ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Time Varying ◽  
Simulation Studies ◽  
Complete Coverage ◽  
Biologically Inspired ◽  
Coverage Path Planning ◽  
Underwater Environment ◽  
Global Cost

Complete coverage path planning (CCPP) is an essential issue for Autonomous Underwater Vehicles’ (AUV) tasks, such as submarine search operations and complete coverage ocean explorations. A CCPP approach based on biologically inspired neural network is proposed for AUVs in the context of completely unknown environment. The AUV path is autonomously planned without any prior knowledge of the time-varying workspace, without explicitly optimizing any global cost functions, and without any learning procedures. The simulation studies show that the proposed approaches are capable of planning more reasonable collision-free complete coverage paths in unknown underwater environment.

Sign in / Sign up

Export Citation Format

Share Document