spVIEW: Signal Processing Viewer User Guide

Introduction

spVIEW™ is an IMAT™ application for plotting multiple datasets of measurements. It was originally intended for viewing the spectral function results from the IMAT application spFRF™ (Signal Processing for Frequency Response Functions). However, spVIEW’s scope has since expanded to viewing time response, mode indicator functions (MIF), and sound pressure level (SPL). While spVIEW’s primary purpose is plotting, it also has some signal processing and computational capabilities, such as filtering, resampling, decimation, and octave band reduction.

spVIEW can read time response and spectral functions from ADF files, Universal files, or from the MATLAB workspace, and can write sieved and truncated datasets of functions to the same. spVIEW has four modules (Time Response, Spectra, MIFs, and SPL) and some data can be sent between the modules.

Time Response Module: In addition to plotting time response functions, the instantaneous spectra of a time frame can also be computed and plotted. Some properties of time signals (e.g., min, max, mean, RMS) in an overlapped frame can also be plotted in this module.

Spectra Module: The frequency domain measurement functions that can be plotted are frequency response functions (FRF), ordinary, multiple, and reference coherence, spectra, auto-spectra, power spectral density, energy spectral density, cross-spectra, and principal components. While optimized for plotting the results from spFRF, spectral functions from other origins can also be plotted in this module.

MIFs Module: Mode indicator functions are typically computed from FRF and are a means to condense some information from a large number of measurements into a few functions. The mode indicator functions that can be plotted in this module are the power spectral (PSMIF), complex (CMIF), quadrature (QMIF), normal (NMIF), and multivariate (MMIF). The force patterns computed with MMIF can also be plotted.

SPL Module: Spectra, auto-spectra, and power spectral density functions with a data type of pressure or sound pressure can be plotted as sound pressure level. The functions can also be reduced to octave bands in this module.

This user guide will explain the spVIEW IMAT application procedures and features.

 

 

 

spVIEW, spFRF, AFPoly, and IMAT are trademarks of ATA Engineering, Inc. Other trade names are trademarks of their respective organizations.