We will of course continue using the discrete form of the power spectrum described via calculation of α and β.
|
|
- Dina Potter
- 5 years ago
- Views:
Transcription
1 The present lecture is the final lecture on the analysis of the power spectrum. The coming lectures will deal with correlation analysis of non sinusoidal signals. We will of course continue using the discrete form of the power spectrum described via calculation of α and β. Throughout the course we have discussed the use of statistical weights and we have especially considered weights that are estimated as 1/variance. In this lecture I will discuss how to obtain weights even if we do not have access to individual scatter estimates. Earlier in the course I showed this example of how statistical weights can be used to reduce the noise level in the amplitude/power spectrum significantly.
2 In the present time series the scatter per data point is known and this will directly allow allocation of statistical weights to each data point. The efficiency of the statistical weighting is clearly seen in this and the next figure... noise is significantly reduced after applying the weights. An example of a situation where scatter may be calculated for individual data points is a time series of radial velocity measurements where the velocity is obtained by cross correlating the observed spectrum with a reference. The cross correlation will not only give the wavelength shift (radial velocity) between the spectrum and the reference it also allows an estimate of the error/scatter on the individual data point.
3 As an example of radial velocity measurements I show here the time series for the radial velocity of the stars α Centauri B. Each point in time we have a radial velocity measurements and a scatter values for that given point. In blue I show the non-weighted spectrum while the red contain the weighted spectrum (1/VAR). Shown here again for a zomm of the spectrum.. In blue I show the non-weighted spectrum while the red contain the weighted spectrum (1/VAR).
4 The statistical weights are only valid if they represent the noise at the frequency of interest. The weights that are calculated for individual data points correspond normally to the scatter at high frequencies and we should therefore verify that the signal is indeed represented by the noise level at high frequencies. In case of α Centauri B this seems to be the case. Let me then turn to an example of a star where we have no direct information on the scatter of the individual data points and we need to calculate those. An example of this is the time series on the sdb star PG In this figure I show he raw data. I then run CLEAN and remove the 100 major peaks. The signal contained by the 100 major peaks is the following. and the residual noise with no signal is plotted in this figure.
5 If I look at the signal zooming in at a narrow point in time one can clearly see that this star is a multi periodic pulsating star. Zooming even more also demonstrated that there is a main oscillation and a series of lowamplitude oscillations that are seen as a modulation on top of the primary oscillation. which is also seen in this figure. In order to improve the SNR of low-amplitude pulsators we need to use statistical weights. On this figure you see the same area as shown above but this time including the scatter on the signal.
6 The idea is now to use the residual signal (where the major signal is CELANed away) to estimate the error signal throughout the series and use this scatter for the statistical weighting. We will now calculate the weights via a box car filter that is moved in time through the time series. The scatter is estimated as N is an even number (the number of data points used in the box car filter). We the calculate: μ = i i+ N / 2 1 N + 1 j= i N / 2 data( t j ) σ i+ N / i = ( data( t j N + 1 j= i N / 2 ) μ ) i 2 The best value for N depends on sampling and how fast the data quality is changing throughout the series. A typical value for N is Based on the scatter (σ) we then calculate the weights. That there is a correlation between weights and scatter via this type of calculation can be clearly seen in the present figure.
7 I then show how those new weights will improve the signal-to-noise ration in the time series. Top is after applying the weights. A close inspection show how efficient this technique is.
8 Of course using weights that are very variable will have other effects on the time series. One way the data is affected is via a change in the window function. As shown before a uninterrupted time series will show a window that is represented by the sincfunction. Any gabs or non-uniform weights will give rise to other peaks... and this can be seen if we calculate the window function. First it is seen in case of no weights.... and here with the weights. The sampling is clearly more non-uniform that in case of no weighting.
9 .. and here shown in amplitude.. and zoomed in.
10 However the degraded window function will not necessary be a problem. We will locate the oscillation modes by use of CLEAN and this will in case of the improved signal-to-noise make thing much better. In fact after using the weights we can extract 24 different oscillation modes in the time series... and there seem to be some more modes that contain the power seen in the spectrum after CLEAning.
11 The final thing I will discuss is an example of how the bad pass filter can be used to isolate oscillation properties of single oscillation modes. In the present example I will look at solar oscillation (they are damped and re-excited). Using band-pass we can isolate power from a single mode. In the following I will consider 5 days of GOLF (SoHO) data.
12 This time series contain clearly the oscillations.. but what is seen is the combined signal of all modes. If we calculate the power spectrum of this signal.. and isolate the power for one frequency and then from the α and β values calculate time series corresponding to this signal we find.... a signal where it is clear that the mode is not coherent. The lifetime is shorten than one day for this mode.
13 If we take another mode (with lower frequency) we find in the same way.. a signal with a much longer lifetime... clearly seen when the amplitude for those two modes a shown. In this way we can map the variation in power for different modes as a function of time.
Astronomy 310/510: Lecture 2: In stars, hydrostatic equilbrium means pressure out cancels gravity in.
Astronomy 310/510: Lecture 2: Newton s laws, his second law in particular: F = ma. If a = 0, then no net forces act. In stars, hydrostatic equilbrium means pressure out cancels gravity in. When pressure
More informationSUPPLEMENTARY INFORMATION
doi:10.1038/nature10389 Observations The Kepler satellite gathered 30 days of uninterrupted data for HD 187547 (KIC 7548479) between October 19 and November 18, 2009, corresponding to Kepler s observing
More informationTIME SERIES ANALYSIS
2 WE ARE DEALING WITH THE TOUGHEST CASES: TIME SERIES OF UNEQUALLY SPACED AND GAPPED ASTRONOMICAL DATA 3 A PERIODIC SIGNAL Dots: periodic signal with frequency f = 0.123456789 d -1. Dotted line: fit for
More informationDo red giants have short mode lifetimes?
Mem. S.A.It. Vol. 77, 406 c SAIt 2006 Memorie della Do red giants have short mode lifetimes? D. Stello 1,2,3, H. Kjeldsen 1, T. R. Bedding 2, and D. Buzasi 3 1 Institute for Fysik og Astronomi (IFA), Aarhus
More informationKepler photometric accuracy with degraded attitude control
Kepler photometric accuracy with degraded attitude control Hans Kjeldsen, Torben Arentoft and Jørgen Christensen-Dalsgaard KASOC, Stellar Astrophysics Centre, Aarhus University, Denmark - 25 July 2013
More informationThe physics of red-giant oscillations
The physics of red-giant oscillations Marc-Antoine Dupret University of Liège, Belgium The impact of asteroseismology across stellar astrophysics Santa Barbara, 24-28 oct 2011 Plan of the presentation
More informationStochastic Dynamics of SDOF Systems (cont.).
Outline of Stochastic Dynamics of SDOF Systems (cont.). Weakly Stationary Response Processes. Equivalent White Noise Approximations. Gaussian Response Processes as Conditional Normal Distributions. Stochastic
More informationLIGO Status and Advanced LIGO Plans. Barry C Barish OSTP 1-Dec-04
LIGO Status and Advanced LIGO Plans Barry C Barish OSTP 1-Dec-04 Science Goals Physics» Direct verification of the most relativistic prediction of general relativity» Detailed tests of properties of gravitational
More informationFrequency analysis of five short periodic pulsators
Comm. in Asteroseismology Volume 162, February 2011 c Austrian Academy of Sciences Frequency analysis of five short periodic pulsators A.Liakos & P.Niarchos National and Kapodistrian University of Athens,
More informationRømer Science Mission Plan
Institute of Physics and Astronomy, University of Aarhus Rømer Science Mission Plan Danish Small Satellite Programme Document No.(issue): MONS/IFA/MAN/PLN/0001(1) Date: 2001-05-29 Prepared by: Jørgen Christensen-Dalsgaard,
More informationLecture 10. Lidar Effective Cross-Section vs. Convolution
Lecture 10. Lidar Effective Cross-Section vs. Convolution q Introduction q Convolution in Lineshape Determination -- Voigt Lineshape (Lorentzian Gaussian) q Effective Cross Section for Single Isotope --
More informationHelioseismology: GONG/BiSON/SoHO
Helioseismology: GONG/BiSON/SoHO Asteroseismology: Solar-like oscillations in other stars Study stars of different Masses, Ages and Chemical Composition Stellar Structure and Evolution Solar-like oscillations
More informationarxiv: v1 [astro-ph] 22 Dec 2008
Astronomy & Astrophysics manuscript no. olmo ref c ESO 2008 December 22, 2008 Letter to the Editor Double mode RR Lyrae stars in Omega Centauri A. Olech 1 and P. Moskalik 1 arxiv:0812.4173v1 [astro-ph]
More informationDirect detection of exoplanets using long-baseline interferometry and visibility phase
Direct detection of exoplanets using long-baseline interferometry and visibility phase J. Meisner Sterrewacht Leiden Presentation given in Leiden on 27 June 2003, based on the poster being presented at
More informationParameter estimation in epoch folding analysis
ASTRONOMY & ASTROPHYSICS MAY II 1996, PAGE 197 SUPPLEMENT SERIES Astron. Astrophys. Suppl. Ser. 117, 197-21 (1996) Parameter estimation in epoch folding analysis S. Larsson Stockholm Observatory, S-13336
More informationORBS and ORCS. Reduction and analysis of SITELLE's data
ORBS and ORCS Reduction and analysis of SITELLE's data omas Martin (Université Laval) Laurent Drissen (Université Laval) Laurie Rousseau-Nepton (Université Laval), Alexandre Alarie (Université Laval),
More informationPulsating Radio Emission at Decametre Wavelengths from the Sun
J. Astrophys. Astr. (1981) 2, 59 65 Pulsating Radio Emission at Decametre Wavelengths from the Sun Ch. V. Sastry, V. Krishan and K. R. Subramanian Indian Institute of Astrophysics, Bangalore 560034 and
More informationAnalysis of wavelength shifts reported for X-shooter spectra
Analysis of wavelength shifts reported for X-shooter spectra S. Moehler (SDP) June 15, 2015 Executive Summary I investigated the causes for wavelength offsets seen in telluric lines and sky lines of extracted
More informationSolar-like oscillations in intermediate mass stars
Solar-like oscillations in intermediate mass stars Victoria Antoci SAC (Stellar Astrophysics Centre), Aarhus University, Denmark Why are intermediate mass stars so important? Credit: Kupka & Weiss1999
More informationGuided Acoustic Wave Brillouin Scattering (GAWBS) in Photonic Crystal Fibers (PCFs)
Guided Acoustic Wave Brillouin Scattering (GAWBS) in Photonic Crystal Fibers (PCFs) FRISNO-9 Dominique Elser 15/02/2007 GAWBS Theory Thermally excited acoustic fiber vibrations at certain resonance frequencies
More informationAcoustic holography. LMS Test.Lab. Rev 12A
Acoustic holography LMS Test.Lab Rev 12A Copyright LMS International 2012 Table of Contents Chapter 1 Introduction... 5 Chapter 2... 7 Section 2.1 Temporal and spatial frequency... 7 Section 2.2 Time
More informationModelling stellar micro-variability
Image: GOES-12 / SXI composite of Venus 2004 transit Modelling stellar micro-variability S. Aigrain (IoA, Cambridge) F. Favata (ESA/ESTEC), G. Gilmore (IoA, Cambridge) Outline Motivation in the context
More informationsimulations - 1 J A Sellwood
simulations - 1 J A Sellwood Collisionless stellar systems Manifest a number of complicated collective phenomena spiral arms, bar instabilities, collapses, mergers, etc. too complicated to be calculated
More informationAsymmetric source acoustic LWD for the improved formation shear velocity estimation SUMMARY INTRODUCTION
Asymmetric source acoustic LWD for the improved formation shear velocity estimation Tianrun Chen, Bing Wang, Zhenya Zhu and Dan Burns, ERL, Department of Earth, Atmospheric and Planetary Sciences, MIT
More informationTemperature and Radiation. What can we learn from light? Temperature, Heat, or Thermal Energy? Kelvin Temperature Scale
What can we learn from light? Temperature Energy Chemical Composition Speed towards or away from us All from the spectrum! Temperature and Radiation Why do different objects give off different forms of
More informationSUPPLEMENTARY INFORMATION
doi:10.1038/nature10612 1. Supplementary Notes 1.1 Data and data analysis The analysis of the three stars presented in this report is based on 510 days of consecutive photometric observations (quarters
More informationSolve the problem. 2) If tan = 3.7, find the value of tan + tan ( + ) + tan ( + 2 ). A) 11.1 B) 13.1 C) D) undefined
Assignment Bonus Chs 6,,8 Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. In the problem, t is a real number and P = (x, y) is the point on the
More informationCHALLENGES RELATED TO DETECTION OF THE LATENT PERIODICITY FOR SMALL-SIZED GEO DEBRIS
CHALLENGES RELATED TO DETECTION OF THE LATENT PERIODICITY FOR SMALL-SIZED GEO DEBRIS I. Korobtsev and M. Mishina 664033 Irkutsk, p/b 291, Institute of Solar-Terrestrial Physics SB RAS mmish@iszf.irk.ru
More informationDigital Band-pass Modulation PROF. MICHAEL TSAI 2011/11/10
Digital Band-pass Modulation PROF. MICHAEL TSAI 211/11/1 Band-pass Signal Representation a t g t General form: 2πf c t + φ t g t = a t cos 2πf c t + φ t Envelope Phase Envelope is always non-negative,
More informationEmittance preservation in TESLA
Emittance preservation in TESLA R.Brinkmann Deutsches Elektronen-Synchrotron DESY,Hamburg, Germany V.Tsakanov Yerevan Physics Institute/CANDLE, Yerevan, Armenia The main approaches to the emittance preservation
More informationTowards a 6-beam fringe tracker for SPICA
Towards a 6-beam fringe tracker for SPICA F. Cassaing Onera, the French aerospace Lab DOTA/HRA, Châtillon Frederic.Cassaing@onera.fr Département Optique et Techniques Associées, Unité Haute Résolution
More informationDigital Signal Processing
COMP ENG 4TL4: Digital Signal Processing Notes for Lecture #3 Wednesday, September 10, 2003 1.4 Quantization Digital systems can only represent sample amplitudes with a finite set of prescribed values,
More informationRelativity and Astrophysics Lecture 15 Terry Herter. RR Lyrae Variables Cepheids Variables Period-Luminosity Relation. A Stellar Properties 2
Stellar Properties Relativity and Astrophysics Lecture 15 Terry Herter Outline Spectroscopic Parallax Masses of Stars Periodic Variable Stars RR Lyrae Variables Cepheids Variables Period-Luminosity Relation
More informationModeling stellar pulsations (mostly correctly)
Modeling stellar pulsations (mostly correctly) László Molnár Konkoly Observatory, MTA CSFK, Budapest Motivations Stellar pulsations: related to stellar structure Goal: reproduce periods and amplitudes
More informationWhite Dwarf Stars as Probes of Physical and Astrophysical Processes
White Dwarf Stars as Probes of Physical and Astrophysical Processes M I K E M O N T G O M E R Y D E P A R T M E N T O F A S T R O N O M Y, M C D O N A L D O B S E R V A T O R Y A N D T H E T E X A S C
More informationSupporting Online Material for
www.sciencemag.org/cgi/content/full/science.1201939/dc1 Supporting Online Material for Kepler-Detected Gravity-Mode Period Spacings in a Red Giant Star P. G. Beck,* T. R. Bedding, B. Mosser, D. Stello,
More informationToday in Astronomy 328: binary stars
Today in Astronomy 38: binary stars Binary-star systems. Direct measurements of stellar mass and radius in eclipsing binary-star systems. At right: two young binary star systems in the Taurus star-forming
More informationNew Statistical Model for the Enhancement of Noisy Speech
New Statistical Model for the Enhancement of Noisy Speech Electrical Engineering Department Technion - Israel Institute of Technology February 22, 27 Outline Problem Formulation and Motivation 1 Problem
More informationLecture 20. Wind Lidar (2) Vector Wind Determination
Lecture 20. Wind Lidar (2) Vector Wind Determination Vector wind determination Ideal vector wind measurement VAD and DBS technique for vector wind Coherent versus incoherent Detection Doppler wind lidar
More informationBackground error modelling: climatological flow-dependence
Background error modelling: climatological flow-dependence Yann MICHEL NCAR/MMM/B Meeting 16 th April 2009 1 Introduction 2 A new estimate of lengthscales 3 Climatological flow-dependence Yann MICHEL B
More informationASTR-1010: Astronomy I Course Notes Section VI
ASTR-1010: Astronomy I Course Notes Section VI Dr. Donald G. Luttermoser Department of Physics and Astronomy East Tennessee State University Edition 2.0 Abstract These class notes are designed for use
More informationPROGRAM WWZ: WAVELET ANALYSIS OF ASTRONOMICAL SIGNALS WITH IRREGULARLY SPACED ARGUMENTS
Odessa Astronomical Publications, v. 26, No. 1 (2013) PROGRAM WWZ: WAVELET ANALYSIS OF ASTRONOMICAL SIGNALS WITH IRREGULARLY SPACED ARGUMENTS Ivan L. Andronov 1, Alevtina V. Naumova 2 Department High and
More informationStochastic Structural Dynamics Prof. Dr. C. S. Manohar Department of Civil Engineering Indian Institute of Science, Bangalore
Stochastic Structural Dynamics Prof. Dr. C. S. Manohar Department of Civil Engineering Indian Institute of Science, Bangalore Lecture No. # 33 Probabilistic methods in earthquake engineering-2 So, we have
More informationSingle Emitter Detection with Fluorescence and Extinction Spectroscopy
Single Emitter Detection with Fluorescence and Extinction Spectroscopy Michael Krall Elements of Nanophotonics Associated Seminar Recent Progress in Nanooptics & Photonics May 07, 2009 Outline Single molecule
More informationDistortion Analysis T
EE 435 Lecture 32 Spectral Performance Windowing Spectral Performance of Data Converters - Time Quantization - Amplitude Quantization Quantization Noise . Review from last lecture. Distortion Analysis
More informationBME 50500: Image and Signal Processing in Biomedicine. Lecture 5: Correlation and Power-Spectrum CCNY
1 BME 50500: Image and Signal Processing in Biomedicine Lecture 5: Correlation and Power-Spectrum Lucas C. Parra Biomedical Engineering Department CCNY http://bme.ccny.cuny.edu/faculty/parra/teaching/signal-and-image/
More informationTHE OBSERVATION AND ANALYSIS OF STELLAR PHOTOSPHERES
THE OBSERVATION AND ANALYSIS OF STELLAR PHOTOSPHERES DAVID F. GRAY University of Western Ontario, London, Ontario, Canada CAMBRIDGE UNIVERSITY PRESS Contents Preface to the first edition Preface to the
More informationLecture 9. PMTs and Laser Noise. Lecture 9. Photon Counting. Photomultiplier Tubes (PMTs) Laser Phase Noise. Relative Intensity
s and Laser Phase Phase Density ECE 185 Lasers and Modulators Lab - Spring 2018 1 Detectors Continuous Output Internal Photoelectron Flux Thermal Filtered External Current w(t) Sensor i(t) External System
More informationPhysics of capnography
Strona 1 z 7 Physics of capnography Bhavani Shankar Kodali MD There are five Physical methods 1. Infra-red Spectrography 2. Molecular Correlation Spectrography 3. Raman Spectrography 4. Mass Spectrography
More informationCorrelated noise and the retina s population code for direction
Correlated noise and the retina s population code for direction Eric Shea-Brown Joel Zylberberg Jon Cafaro Max Turner Greg Schwartz Fred Rieke University of Washington 1 DS cell responses are noisy Stimulus
More informationThe Investigation on the 160-min Solar Oscillation: A historical perspective
The Investigation on the 160-min Solar Oscillation: A historical perspective Pere L. Pallé, Teodoro Roca Cortés Instituto de Astrofísica de Canarias (IAC) Universidad de La Laguna (ULL) Pere L. Pallé 50
More informationAsteroseismology. Conny Aerts. Universities of Leuven and Nijmegen. Material: Springer Monograph, 2010 FAMIAS software package (W.
Asteroseismology Conny Aerts Universities of Leuven and Nijmegen Material: Springer Monograph, 2010 FAMIAS software package (W. Zima) Sir Arthur Stanley Eddington: The Internal Constitution of the Stars
More informationOSE801 Engineering System Identification. Lecture 09: Computing Impulse and Frequency Response Functions
OSE801 Engineering System Identification Lecture 09: Computing Impulse and Frequency Response Functions 1 Extracting Impulse and Frequency Response Functions In the preceding sections, signal processing
More informationSpacecraft Bus / Platform
Spacecraft Bus / Platform Propulsion Thrusters ADCS: Attitude Determination and Control Subsystem Shield CDH: Command and Data Handling Subsystem Payload Communication Thermal Power Structure and Mechanisms
More informationSI 1. Figure SI 1.1 CuCl 4
Electronic Supplementary Material (ESI) for Dalton Transactions. This journal is The Royal Society of Chemistry 2014 SI 1 FFT analysis of residuals was carried out. The residuals were obtained by fitting
More informationA Multivariate Time-Frequency Based Phase Synchrony Measure for Quantifying Functional Connectivity in the Brain
A Multivariate Time-Frequency Based Phase Synchrony Measure for Quantifying Functional Connectivity in the Brain Dr. Ali Yener Mutlu Department of Electrical and Electronics Engineering, Izmir Katip Celebi
More informationThursday March 30 Topics for this Lecture: Simple Harmonic Motion Kinetic & Potential Energy Pendulum systems Resonances & Damping.
Thursday March 30 Topics for this Lecture: Simple Harmonic Motion Kinetic & Potential Energy Pendulum systems Resonances & Damping Assignment 11 due Friday Pre-class due 15min before class Help Room: Here,
More informationEE 230 Lecture 40. Data Converters. Amplitude Quantization. Quantization Noise
EE 230 Lecture 40 Data Converters Amplitude Quantization Quantization Noise Review from Last Time: Time Quantization Typical ADC Environment Review from Last Time: Time Quantization Analog Signal Reconstruction
More informationLecture 9: Speckle Interferometry. Full-Aperture Interferometry. Labeyrie Technique. Knox-Thompson Technique. Bispectrum Technique
Lecture 9: Speckle Interferometry Outline 1 Full-Aperture Interferometry 2 Labeyrie Technique 3 Knox-Thompson Technique 4 Bispectrum Technique 5 Differential Speckle Imaging 6 Phase-Diverse Speckle Imaging
More informationspring mass equilibrium position +v max
Lecture 20 Oscillations (Chapter 11) Review of Simple Harmonic Motion Parameters Graphical Representation of SHM Review of mass-spring pendulum periods Let s review Simple Harmonic Motion. Recall we used
More informationSound radiation and transmission. Professor Phil Joseph. Departamento de Engenharia Mecânica
Sound radiation and transmission Professor Phil Joseph Departamento de Engenharia Mecânica SOUND RADIATION BY A PISTON The piston generates plane waves in the tube with particle velocity equal to its own.
More informationSolar Magnetism. Differential Rotation, Sunspots, Solar Cycle. Guest lecture: Dr. Jeffrey Morgenthaler Jan 30, 2006
Solar Magnetism Differential Rotation, Sunspots, Solar Cycle Guest lecture: Dr. Jeffrey Morgenthaler Jan 30, 2006 Neutrino Summary Principle of CONSERVATION OF ENERGY led to proposal of neutrino by Wolfgang
More informationAsteroseismology in Action: Probing the interiors of EHB stars
Asteroseismology in Action: Probing the interiors of EHB stars Suzanna Randall, ESO Garching Betsy Green, University of Arizona Gilles Fontaine, Université de Montréal Stéphane Charpinet, Observatoire
More informationChemistry Instrumental Analysis Lecture 2. Chem 4631
Chemistry 4631 Instrumental Analysis Lecture 2 Electromagnetic Radiation Can be described by means of a classical sinusoidal wave model. Oscillating electric and magnetic field. (Wave model) wavelength,
More information10. OPTICAL COHERENCE TOMOGRAPHY
1. OPTICAL COHERENCE TOMOGRAPHY Optical coherence tomography (OCT) is a label-free (intrinsic contrast) technique that enables 3D imaging of tissues. The principle of its operation relies on low-coherence
More informationImage requirements for the detection and caracterisation of Earth-like planets and hot Jupiter s
Image requirements for the detection and caracterisation of Earth-like planets and hot Jupiter s Alain Chelli Laboratoire d Astrophysique de Grenoble & Jean-Marie Mariotti Center Content The Optical system
More informationAdvanced Optical Communications Prof. R. K. Shevgaonkar Department of Electrical Engineering Indian Institute of Technology, Bombay
Advanced Optical Communications Prof. R. K. Shevgaonkar Department of Electrical Engineering Indian Institute of Technology, Bombay Lecture No. # 15 Laser - I In the last lecture, we discussed various
More informationSoil Dynamics Prof. Deepankar Choudhury Department of Civil Engineering Indian Institute of Technology, Bombay
Soil Dynamics Prof. Deepankar Choudhury Department of Civil Engineering Indian Institute of Technology, Bombay Module - 5 Machine Foundations Lecture - 31 EHS Theory, Vibrational Control Let us start our
More informationNoise and Vibration of Electrical Machines
Noise and Vibration of Electrical Machines P. L. TIMÄR A. FAZEKAS J. KISS A. MIKLOS S. J. YANG Edited by P. L. Timär ш Akademiai Kiadö, Budapest 1989 CONTENTS Foreword xiii List of symbols xiv Introduction
More informationTemperature and Radiation. What can we learn from light? Temperature, Heat, or Thermal Energy? Kelvin Temperature Scale
What can we learn from light? Temperature Energy Chemical Composition Speed towards or away from us All from the spectrum! Temperature and Radiation Why do different objects give off different forms of
More informationPeriodogram of a sinusoid + spike Single high value is sum of cosine curves all in phase at time t 0 :
Periodogram of a sinusoid + spike Single high value is sum of cosine curves all in phase at time t 0 : ( ) ±σ X(t) = µ + Asin(ω 0 t)+ Δ δ t t 0 N =100 Δ =100 χ ( ω ) Raises the amplitude uniformly at all
More informationTurbulence models and excitation of solar oscillation modes
Center for Turbulence Research Annual Research Briefs Turbulence models and excitation of solar oscillation modes By L. Jacoutot, A. Wray, A. G. Kosovichev AND N. N. Mansour. Motivation and objectives
More informationLECTURE 3 CMOS PHASE LOCKED LOOPS
Lecture 03 (8/9/18) Page 3-1 LECTURE 3 CMOS PHASE LOCKED LOOPS Topics The acquisition process unlocked state Noise in linear PLLs Organization: Systems Perspective Types of PLLs and PLL Measurements PLL
More informationUVIT IN ORBIT CALIBRATIONS AND CALIBRATION TOOLS. Annapurni Subramaniam IIA (On behalf of the UVIT team)
UVIT IN ORBIT CALIBRATIONS AND CALIBRATION TOOLS Annapurni Subramaniam IIA (On behalf of the UVIT team) Calibrations: : Calibrations are of two types: 1. Ground calibrations 2. In orbit calibrations In
More informationTypical anisotropies introduced by geometry (not everything is spherically symmetric) temperature gradients magnetic fields electrical fields
Lecture 6: Polarimetry 1 Outline 1 Polarized Light in the Universe 2 Fundamentals of Polarized Light 3 Descriptions of Polarized Light Polarized Light in the Universe Polarization indicates anisotropy
More informationarxiv: v2 [astro-ph] 4 Nov 2008
Comm. in Asteroseismology Vol. number, publication date (will be inserted in the production process) On the nature of HD 207331: a new δ Scuti variable arxiv:0810.0476v2 [astro-ph] 4 Nov 2008 L.Fox Machado
More informationAnalyzing Spiral Galaxies Observed in Near-Infrared
Analyzing Spiral Galaxies Observed in Near-Infrared Preben Grosbøl European Southern Observatory Karl-Schwarzschild-Str. 2, D-85748 Garching, Germany Abstract A sample of 54 spiral galaxies was observed
More informationStimulated Emission. Electrons can absorb photons from medium. Accelerated electrons emit light to return their ground state
Lecture 15 Stimulated Emission Devices- Lasers Stimulated emission and light amplification Einstein coefficients Optical fiber amplifiers Gas laser and He-Ne Laser The output spectrum of a gas laser Laser
More informationSpectral Line Shapes. Line Contributions
Spectral Line Shapes Line Contributions The spectral line is termed optically thin because there is no wavelength at which the radiant flux has been completely blocked. The opacity of the stellar material
More informationENVIRONMENTAL DATA ANALYSIS WILLIAM MENKE JOSHUA MENKE WITH MATLAB COPYRIGHT 2011 BY ELSEVIER, INC. ALL RIGHTS RESERVED.
ENVIRONMENTAL DATA ANALYSIS WITH MATLAB WILLIAM MENKE PROFESSOR OF EARTH AND ENVIRONMENTAL SCIENCE COLUMBIA UNIVERSITY JOSHUA MENKE SOFTWARE ENGINEER JOM ASSOCIATES COPYRIGHT 2011 BY ELSEVIER, INC. ALL
More informationPoles, Zeros and System Response
Time Response After the engineer obtains a mathematical representation of a subsystem, the subsystem is analyzed for its transient and steady state responses to see if these characteristics yield the desired
More informationThe BRITE satellite and Delta Scuti Stars: The Magnificent Seven
Comm. in Asteroseismology Vol. 152, 2008 The BRITE satellite and Delta Scuti Stars: The Magnificent Seven M. Breger Institut für Astronomie, Türkenschanzstrasse 17, 1180 Vienna, Austria Abstract This paper
More informationAsteroseismology from Line-profile variations
Asteroseismology from Line-profile variations Paul Beck Juan de la Cierva Fellow Sismologia Solar y Estelary Busquedade Exoplanetas(SSEBE) Institutode Astrofisica de Canarias, Tenerife, Spain. @BeckPaulG
More informationThe Pulsation Properties of the Double-Mode RR Lyrae Variable V79 in Messier 3
336 The Pulsation Properties of the Double-Mode RR Lyrae Variable V79 in Messier 3 Christine M. Clement Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON, M5S 3H8, Canada Mike
More informationarxiv: v1 [astro-ph] 3 Jul 2008
Transiting Planets Proceedings IAU Symposium No. 253, 2008 c 2008 International Astronomical Union DOI: 00.0000/X000000000000000X Measurements of Stellar Properties through Asteroseismology: A Tool for
More informationIndirect Methods: gravitational perturbation of the stellar motion. Exoplanets Doppler method
Indirect Methods: gravitational perturbation of the stellar motion Exoplanets The reflex motion of the star is proportional to M p /M * This introduces an observational bias that favours the detection
More informationEE 435. Lecture 32. Spectral Performance Windowing
EE 435 Lecture 32 Spectral Performance Windowing . Review from last lecture. Distortion Analysis T 0 T S THEOREM?: If N P is an integer and x(t) is band limited to f MAX, then 2 Am Χ mnp 1 0 m h N and
More informationMERIS US Workshop. Instrument Characterization Overview. Steven Delwart
MERIS US Workshop Instrument Characterization Overview Steven Delwart Presentation Overview On-Ground Characterisation 1. Diffuser characterisation 2. Polarization sensitivity 3. Optical Transmission 4.
More informationLecture 8: Signal Detection and Noise Assumption
ECE 830 Fall 0 Statistical Signal Processing instructor: R. Nowak Lecture 8: Signal Detection and Noise Assumption Signal Detection : X = W H : X = S + W where W N(0, σ I n n and S = [s, s,..., s n ] T
More informationFrequency Resolution Effects on FRF Estimation: Cyclic Averaging vs. Large Block Size
Frequency Resolution Effects on FRF Estimation: Cyclic Averaging vs. Large Block Size Allyn W. Phillips, PhD Andrew. Zucker Randall J. Allemang, PhD Research Assistant Professor Research Assistant Professor
More informationSONG overview. Jørgen Christensen-Dalsgaard Department of Physics and Astronomy Aarhus University
SONG overview Jørgen Christensen-Dalsgaard Department of Physics and Astronomy Aarhus University The SONG concept Network of 8 telescopes with a global distribution Long, nearly continuous observations
More informationLecture Hilbert-Huang Transform. An examination of Fourier Analysis. Existing non-stationary data handling method
Lecture 12-13 Hilbert-Huang Transform Background: An examination of Fourier Analysis Existing non-stationary data handling method Instantaneous frequency Intrinsic mode functions(imf) Empirical mode decomposition(emd)
More informationBasics of the Kramers-Kronig- and the Z-Hit algorithms Lecture at the Kronach Impedance Days 2015 Dr. Werner Strunz
Theoretical Aspects for Testing Impedance Data Basics of the Kramers-Kronig- and the Z-Hit algorithms Lecture at the Kronach Impedance Days 215 Dr. Werner Strunz 1 Motivation The entire process of measurement,
More informationLocal Warming: Climate Change Comes Home
Local Warming: Climate Change Comes Home Robert J. Vanderbei November 2, 2011 Wharton Statistics Univ. of Pennsylvania http://www.princeton.edu/ rvdb Introduction There has been so much talk about global
More informationA METHOD FOR NONLINEAR SYSTEM CLASSIFICATION IN THE TIME-FREQUENCY PLANE IN PRESENCE OF FRACTAL NOISE. Lorenzo Galleani, Letizia Lo Presti
A METHOD FOR NONLINEAR SYSTEM CLASSIFICATION IN THE TIME-FREQUENCY PLANE IN PRESENCE OF FRACTAL NOISE Lorenzo Galleani, Letizia Lo Presti Dipartimento di Elettronica, Politecnico di Torino, Corso Duca
More informationLecture 8: MIMO Architectures (II) Theoretical Foundations of Wireless Communications 1. Overview. Ragnar Thobaben CommTh/EES/KTH
MIMO : MIMO Theoretical Foundations of Wireless Communications 1 Wednesday, May 25, 2016 09:15-12:00, SIP 1 Textbook: D. Tse and P. Viswanath, Fundamentals of Wireless Communication 1 / 20 Overview MIMO
More informationGravitational-Wave Data Analysis: Lecture 2
Gravitational-Wave Data Analysis: Lecture 2 Peter S. Shawhan Gravitational Wave Astronomy Summer School May 29, 2012 Outline for Today Matched filtering in the time domain Matched filtering in the frequency
More informationMeasurement Techniques for Engineers. Motion and Vibration Measurement
Measurement Techniques for Engineers Motion and Vibration Measurement Introduction Quantities that may need to be measured are velocity, acceleration and vibration amplitude Quantities useful in predicting
More informationAnalysis algorithm for surface crack detection by thermography with UV light excitation
Analysis algorithm for surface crack detection by thermography with UV light excitation * University West, University West, SE-461 86 Trollhättan, Sweden, patrik.broberg@hv.se by P. Broberg* and A. Runnemalm*
More informationPhysics 7Em Midterm Exam 1
Physics 7Em Midterm Exam 1 MULTIPLE CHOICE PROBLEMS. There are 10 multiple choice problems. Each is worth 2 points. There is no penalty for wrong answers. In each, choose the best answer; only one answer
More information