Accession Number : ADA304893

Title :   The Effects of Variable Time Window Width and Signal Position Within FFT Bin on WISPR Performance.

Descriptive Note : Final rept.,

Corporate Author : NAVAL RESEARCH LAB STENNIS SPACE CENTER MS CENTER FOR ENVIRONMENTAL ACOUSTIC S

Personal Author(s) : George, Jacob ; Wagstaff, Ronald A.

PDF Url : ADA304893

Report Date : 09 FEB 1996

Pagination or Media Count : 19

Abstract : The effect of variable width of the time window in time frequency analysis on WISPR performance is investigated, along with the effect of signal position within the signal bin. The results demonstrate that variable width of the time window in FFT/DFT calculations has only a small effect on WISPR performance, as long as the full signal energy is contained within the signal bin. But the loss of even a small portion of the signal energy from the signal bin has a dramatic effect on the WISPR level, and causes deterioration in WISPR performance by several decibels. The average power level is only slightly affected by such changes. The sensitivity of the WISPR level to the signal position within the signal bin provides a means to determine the signal frequency more precisely, avoiding the necessity to carry out calculations using much larger data sets.

Descriptors :   *FAST FOURIER TRANSFORMS, *NOISE REDUCTION, *UNDERWATER SOUND SIGNALS, DATA BASES, POWER LEVELS, TIME SERIES ANALYSIS, DISCRETE FOURIER TRANSFORMS, NOISE(SOUND), ACOUSTIC WINDOWS.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE