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Minimization of Maximum Errors in Universal Approximation of the Unit Circle by a Polygon

Józef Borkowski
2011 Metrology and Measurement Systems  
Applying the results of the presented paper to improve the LIDFT method allows one to significantly decrease the errors in estimating the amplitudes and frequencies of multifrequency signal components.  ...  One of the applications of the described approximation is the DFT linear interpolation method (LIDFT).  ...  A set of these methods covers procedures generally based on the Prony method and correlation methods founded on properties of the signal autocorrelation matrix [1] [2] [3] [4] [5] .  ... 
doi:10.2478/v10178-011-0006-x fatcat:aq7333rxt5c5djwexenocp6i64

The Influence of Power Network Disturbances on Short Delayed Estimation of Fundamental Frequency Based on IpDFT Method with GMSD Windows

Józef Borkowski, Mirosław Szmajda, Janusz Mroczka
2021 Energies  
Test models of disturbances were applied, based on real disturbances recorded in power networks, including voltage harmonics and interharmonics, transient overvoltages, frequency spikes, dips and noise  ...  Zero-crossing method (ZC) with signal prefiltering was used as a reference method.  ...  Data Availability Statement: Data and MATLAB scripts available upon request from the corresponding author. Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/en14206465 fatcat:e7wfdrplhfe4rbmb774gg7nycy

MIMO High Frequency Surface Wave Radar Using Sparse Frequency FMCW Signals

Mengguan Pan, Baixiao Chen
2017 International Journal of Antennas and Propagation  
Based on the concept of multiple-input multiple-output (MIMO) radar, we propose a MIMO sparse frequency HFSWR system to synthesize an equivalent large bandwidth waveform in the congested HF band.  ...  Based on the initial 1D IAA algorithm, we propose a modified 2D IAA which particularly fits the deramping processing based range-azimuth model.  ...  Conflicts of Interest The authors declare that there are no conflicts of interest regarding the publication of this paper.  ... 
doi:10.1155/2017/7514916 fatcat:ys4rsqrbzraankmho6rcozyzam

Radial velocity variations in pulsating Ap stars

D. E. Mkrtichian, A. P. Hatzes
2005 Astronomy and Astrophysics  
The RVs were measured using the wavelength range of each spectral order (≈100 Å) of the "2dcoude" echelle spectrograph.  ...  A detailed analysis of the spectral order centered on 5825 Å, which had the largest amplitudes, showed the presence of all published photometric frequencies f 1f 7 .  ...  Fig. 12 . 12 The frequency analysis of the RV measurements of the Nd III 5294.1 Å line obtained on JD 2 450 845. (Top panel) The DFT of original RV data.  ... 
doi:10.1051/0004-6361:20034547 fatcat:bahx5imelfacrpavfhpsmqd5u4

SigSpec

P. Reegen
2007 Astronomy and Astrophysics  
SigSpec is based on an analytical solution of the probability that a DFT peak of a given amplitude does not arise from white noise in a non-equally spaced data set.  ...  Identifying frequencies with low signal-to-noise ratios in time series of stellar photometry and spectroscopy, and measuring their amplitude ratios and peak widths accurately, are critical goals for asteroseismology  ...  P.R. received financial support from the Fonds zur Förderung der wissenschaftlichen Forschung (FWF, projects P14546-PHY, P14984-PHY) Furthermore, it is a pleasure to thank T. Appourchaux  ... 
doi:10.1051/0004-6361:20066597 fatcat:abpeumjhbve37l75r3uc2zfwge

Absolute Calibration for the Hydrogen Epoch of Reionization Array and Its Impact on the 21 cm Power Spectrum [article]

Nicholas S. Kern, Joshua S. Dillon, Aaron R. Parsons, Christopher L. Carilli, Gianni Bernardi, Zara Abdurashidova, James E. Aguirre, Paul Alexander, Zaki S. Ali, Yanga Balfour, Adam P. Beardsley, Tashalee S. Billings (+57 others)
2019 arXiv   pre-print
We discuss calibration strategies for Phase I of the Hydrogen Epoch of Reionization Array (HERA), which aims to measure the cosmological 21 cm signal from the Epoch of Reionization (EoR).  ...  Nonetheless, we demonstrate a standard methodology for sky-based calibration of HERA using point source catalogues and electromagnetic simulations of the primary beam, and discuss its impact on the 21  ...  This is one measure of the uncertainty on the power spectra due to noise, but also represents the theoretical amplitude of the power spectra in the limit that they are noise dominated (as opposed to signal  ... 
arXiv:1910.12943v1 fatcat:ad52rmmxyneyrhwesn34ugmthm

Wideband channel sounder with measurements and model for the 60 GHz indoor radio channel

T. Zwick, T.J. Beukema, Haewoon Nam
2005 IEEE Transactions on Vehicular Technology  
Comparisons of results with a vector network analyzer based system are shown to verify the accuracy of the sounder.  ...  The channel sounder is based on a 1 gigasamples/s dual channel arbitrary waveform generator and A/D converter/software demodulator, which synthesize and detect a baseband PN sequence with 500 MHz bandwidth  ...  The authors also would like to thank the IBM team for the helpful discussions, and especially Mr. C. Baks for his great personal engagement during the measurement campaign. Thanks also go to Prof. T.  ... 
doi:10.1109/tvt.2005.851354 fatcat:dl3ouyfpcvhq5b5zbftdj76ume

Free-Space Materials Characterization by Reflection and Transmission Measurements using Frequency-by-Frequency and Multi-Frequency Algorithms

Fábio Gonçalves, Alfred Pinto, Renato Mesquita, Elson Silva, Adriana Brancaccio
2018 Electronics  
The different role of transmission and reflection measurements on the achievable results is analyzed with regard to experimental uncertainties and different noise scenarios.  ...  For the first, we describe how the Time-Domain Gating can be implemented and used for filtering the signals.  ...  Acknowledgments: This work was supported by the brazilian agencies CAPES, CNPq (scholarship process  ... 
doi:10.3390/electronics7100260 fatcat:f4u3tczwdzfb5c26wlsihkg4iq

Real-time calibration of the AARTFAAC array for transient detection

P. Prasad, S. J. Wijnholds, F. Huizinga, R. A. M. J. Wijers
2014 Astronomy and Astrophysics  
available all-sky monitor based on the LOw Frequency ARray (LOFAR).  ...  Autonomously calibrating and imaging one second snapshots, our approach leads to a typical image noise of ∼10 Jy for a ∼90 kHz channel, reaching dynamic ranges of ∼2000:1.  ...  This work is funded by the ERC grant C.2320.0056 awarded to Prof. Ralph Wijers, University of Amsterdam.  ... 
doi:10.1051/0004-6361/201423668 fatcat:foyzcbjqpjeujj3esokftoic4m

Wilkinson microwave anisotropy probe

Charles Bennett
2007 Scholarpedia  
the microwave signal into a measurable voltage.  ...  The Far-Sidelobe Maps are based on compilations of data from the following sources: • GSFC anechoic chamber antenna range • Princeton outdoor antenna range • In flight lunar data • Physical optics code  ...  wear on tear on the transmitter.  ... 
doi:10.4249/scholarpedia.4731 fatcat:eaex2ehwszax5jva52nsyhh6oy

Adaptive remote sensing with HF skywave radar

S.J. Anderson
1992 IEE Proceedings F Radar and Signal Processing  
A real-time data link to the Australian Bureau of Meteorology was set up in 1985, providing daily wind direction maps covering over one million square kilometres of the NW Indian Ocean, the Timor Sea and  ...  Early programs focused exclusively on military capabilities, such as the detection of aircraft, missiles and ships, but in 1974 a team was formed to design a new OTHR for which a remote sensing mission  ...  Acknowledgments The Jindalee radars are the product of many talented scientists and engineers with whom the present author is proud to have been associated.  ... 
doi:10.1049/ip-f-2.1992.0022 fatcat:ys7fz5jbjrgfrf2qvxpohkvdoe

Remote sensing applications of HF skywave radar: The Australian experience

STUART ANDERSON
2010 Turkish Journal of Electrical Engineering and Computer Sciences  
A real-time data link to the Australian Bureau of Meteorology was set up in 1985, providing daily wind direction maps covering over one million square kilometres of the NW Indian Ocean, the Timor Sea and  ...  Early programs focused exclusively on military capabilities, such as the detection of aircraft, missiles and ships, but in 1974 a team was formed to design a new OTHR for which a remote sensing mission  ...  Acknowledgments The Jindalee radars are the product of many talented scientists and engineers with whom the present author is proud to have been associated.  ... 
doi:10.3906/elk-0912-5 fatcat:worygqnyondi3jcohy3fdjv3la

2021 Index IEEE Transactions on Instrumentation and Measurement Vol. 70

2021 IEEE Transactions on Instrumentation and Measurement  
Article numbers are based on specified topic areas and corresponding codes associated with the publication.  ...  The primary entry includes the coauthors' names, the title of the paper or other item, and its location, specified by the publication abbreviation, year, and article number.  ...  ., +, TIM 2021 8002509 Influence of Antenna Pattern on Synthetic Aperture Radar Image Sidelobe Level in NDE Applications.  ... 
doi:10.1109/tim.2022.3156705 fatcat:dmqderzenrcopoyipv3v4vh4ry

Temporal integration of loudness as a function of level

Mary Florentine, So/ren Buus, Torben Poulsen
1995 Journal of the Acoustical Society of America  
Calculations of the effects of this type of climate change signal, as well as ambient variability on the modal arrival times, will be presented.  ...  Maps of the anthropogenic signal to the ambient noise ratio of the climate system can then be constructed. Acoustic thermometry measures integrals of heat content through these maps.  ...  Does the perceptual magnet effect hold for the [•] category?  ... 
doi:10.1121/1.411567 fatcat:h52442zdrnc6zmr4ephlixbspu

Temporal integration of loudness as a function of level

Mary Florentine, So/ren Buus, Torben Poulsen
1996 Journal of the Acoustical Society of America  
Calculations of the effects of this type of climate change signal, as well as ambient variability on the modal arrival times, will be presented.  ...  Maps of the anthropogenic signal to the ambient noise ratio of the climate system can then be constructed. Acoustic thermometry measures integrals of heat content through these maps.  ...  Does the perceptual magnet effect hold for the [•] category?  ... 
doi:10.1121/1.415236 pmid:8819858 fatcat:tsiit3akb5e4tkzxdzrilpsfzy
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