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SPECTRAL ANALYSIS PROCEDURES

• Communication signal identification and analysis
• Signal interference monitoring
• Control systems analysis
• Audio system analysis
• Voice recognition and speech processing
• Signature analysis
• Vibration analysis
• Acoustical analysis
• Radar signal analysis
• Analog circuit testing
• Signal detectors
• Sea spectra study
• Astrophysics

DATA MANAGEMENT

• Graphical And Numerical Sectioning ; graphically enable or disable data points.
• Spreadsheet - like data editing
• Signal Generate tool
• Data transformation of variables
• Local options to change data set during current procedure include sectioning, detrending, Fourier filtration, Eigendecomposition filtration

GENERAL FEATURES

Interface

• Full 32-bit performance
• Toolbars and menu-driven for all functionality
• No programming of procedures, algorithms or graphing
• Advanced on-line help system

Non-Parametric Spectral Analysis

• AR spectral methods offer accurate frequency estimation with short data records
• AR spectrum methods: AR spectrum, AR with order exploration, AR with algorithm comparison
• 14 AR algorithms: autocorrelation method, maximum entropy method (Burg), least-squares normal equations, least-squares covariance models and modified covariance models, singular value decomposition methods
• Model order selection and order exploration
• Moving average spectrum
• ARMA spectrum
• Prony Spectrum offers fitting of damped sine and damped exponential that occur in multi-component exponential decays
• Minimum Variance Spectrum

Eigen Analysis Spectrum

• Eigen Analysis Spectrum provides accurate and robust spectral procedures for estimating harmonic frequencies
• Provides excellent signal-noise separation
• Graphically select signal and noise sub-space; also available in certain parametric procedures

Data Processing

• Non-Linear Optimization offers parametric refinement of spectral estimates: least-squares, maximum likelihood
• Fourier Interpolation
• Fourier Upsampling
• Parametric Interpolation and Prediction
• Graphically inspect the autocorrelation series
• Detrend: Constant, Linear, Quadratic, Cubic, Logarithmic, Exponential, Power, Hyperbolic
• Difference the data with adjustable order and lag, compute various cumulatives and normalize for unit area, unit power, unit standard deviation and zero mean
• Add or subtract a reference signal
• Compare imported reference signals
• Gaussian deconvolution or exponential deconvolution to remove instrument response smearing
• Find long-term "memory effects" in flat frequency response signals with Fractal Dimension option

Numeric Review

• Full component numeric summary report include: procedure, algorithm, listing of interpolated spectral peaks, frequency analysis and linear least-squares fit summary
• List data offers extended data summary with results from each of the procedure such as frequency, magnitude, phase and power spectral density
• Goodness of fit statistics: r2, degrees of freedom adjusted r2, fit standard error, F-statistic
• Evaluation option with automated table generation, includes function, derivatives, roots and cumulative volume; X values can be generated or imported from file

Output and Export

• Publication-quality printed graphs
• Image formats include bitmaps, metafiles, enhanced metafiles and device-independent bitmaps
• File formats include ASCII, Excel, Lotus, SYSTAT, SPSS
• Export numerical summaries and graphs to MS Word RTF documents

Data Input

• Up to 65,536 points in data table
• Over 65.4 million points can be filtered into table using decimation import filter
• ASCII (Single, X-Y and Multi-column)
• Excel (Excel 97, Excel 95, v5, v4, v3)
• Lotus 123 (WK4, WK3, WK1)
• Quattro Pro (WB2, WB1)
• SigmaPlot (JPG, SPW, SP5)
• SPSS (SAV v7.5, v8 and v9)
• SYSTAT (SYD v8)
• Waveform (WAV MS PCM 8, 16, 32 bit)
• DIF (Single, X-Y and Multi-column)
• dBase (DBF III+, IV)
• Import Preview graphs prospective data
• Separate append options that automatically averages replicates

Fourier Spectral Analysis

• Procedures: Fourier Spectrum, Fourier Spectrum with Data Window, Fourier Spectrum with Data Window Comparison, Fourier Spectrum of Segmented Data, Fourier Multitaper Spectra, Fourier Spectrum of Unevenly Sampled Data (Lomb-Scargle)
• Transforms: FFT Radix2, Prime Facto, Mixed Radix, Chirp-Z, Best Exact-N
• Zero pad
• 30 tapering windows:
• Fixed: none, Welch, Bisquare, Bartlett, cs2 Hanning, Tukey-Hanning, cs2 Hamming, Bartlett Mod, cs3 Nuttall C3, cs3 Blackman, cs3 Blackman-Harris 3, cs3 Nuttall C1, cs3 Blackman Exact, cs3 Blackman-Harris min, cs3 Nuttall min, cs4 Nuttall C5, cs4 Blackman-Harris 4, cs4 Nuttall C3, cs4 Nuttall C1, cs4 Blackman-Harris min, cs4 Nuttall min Adjustable: Beta, csx max Roll-off, Kaiser-Bessel, VanderMaas, Chebyshev, Chebyshev Appr, Slepian DPSS, Gaussian, Tapered-Cosine
• Compare up to 4 tapering windows simultaneously
• Measure data window properties: mainlobe, sidelobe, roll-off

Time-Frequency Spectral Analysis

• Short-Time Fourier Transform Spectrum uses a series of segmented and overlapped FFTs to find Fourier spectral information for non-stationary data
• Continuous Wavelet Spectrum multi-resolution time-frequency techniques: 3D surface, contour, power integration across time or frequency
• Wavelet spectra can be generated with up to 100 linear or logarithmic frequencies
• Adjustable mother wavelets: Morlet, Paul, Gaussian Derivative
• Zero padding available
• Full critical significance limits available as 3D gradients
• Graphical rendering of cone of influence
• Automated power analysis by integrating interpolated wavelet spectrum surface

Filtering and Reconstruction

• Fourier Smoothing and Denoising: frequency or signal threshold filtration
• Eigen decomposition Smoothing and Denoising: signal strength threshold filtration
• Wavelet Smoothing and Denoising: thresholds in the time-frequency domain for non-stationary data
• Fourier Filtering and Reconstruction: Fourier domain filtering and component isolation procedure
• Eigen decomposition Filtering and Reconstruction: isolates individual oscillatory components in signals
• Wavelet Filtering and Reconstruction: isolates in the time-frequency domain
• Savitzky-Golay Smoothing filter: includes smoothing to 1st through 4th derivative
• Spline Estimations: cubic, cubic constrained, smoothing cubic, B-spline, B-Spline Fix knots, B-spline Optimal knots, NURBS
• Adjustable order Loess with tricube and Gaussian weighting

Significance Levels

• Unique Peak-based critical limit levels to ascertain the significance of the spectral components
• Critical limits plotted are: 50%, 90%, 95%, 99%, 99.9% (uses color gradients for wavelets)
• Peak-type critical limits are based on Monte Carlo trials with algorithms exactly as implemented
• Can specify AR-1 red-noise background spectrum option

Production Facility

• Batch process large numbers of data sets in an unattended procedure
• Import up to 64,515 data sets from Excel 95/97 with up to 255 worksheets and multiple columns per worksheet
• Acquire data using simple DLL interface
• Automatically export numerical summaries and/or graphs to MS Word RTF documents
• Automatically export results of analysis to an Excel 95/97 file

 

GRAPH OPTIONS AND TYPES

• Customization: Titles, axis labels, font size, font selection, grid, color schemes, point formats, axis scaling, log axis scaling, toggle data, reference data and function label display, modify contour and mesh properties.
• Save and import Views for standardized layouts.
• 3D Graph View: View angles, size in frame, illumination angular shifts, perspectives, backplanes, add contour plots.
• 3D Graph Types: Wire frame, mesh plot, 15 gradient plots, 4 shaded plots.
• Gradient and shaded plots use up to 48 colors.
• Plot formats: Real, Imaginary, Magnitude, Maginitude2, Phase, Mag/Phase (dual plot), Amplitude, Ampl/Phase (dual plot), dB, dB Norm, PSD SSA, PSD MSA, PSD TISA, Variance, Lomb, Prony ESD, Min Variance spectrum, MUSIC eigenvector, Wavelet spectrum.

Graphical Review

• Spectral peaks are identified graphically; select the number of peaks to detect
• Display maxima with spectral peak labels: frequencies, spectral magnitudes, both frequencies and spectral magnitudes, none
• Statistical feedback: set confidence/prediction intervals, show confidence/prediction intervals, error bars, critical limits, display residuals, display residuals as % of Y, residuals as fraction of SE, display residuals distribution, display delta SNP (stabilized normal probability) plot
• 3D Graph animation
• Intellimouse rotation of 3D view angles
• Mesh resolution up to 300 x 300
• View residuals, plot roots and plot AR selection criteria