An Experimental Study of Covariance Functions of Reverberation from a Lake Surface.
Abstract
This report describes the results of an experimental study of the space-time covariance function of reverberation. The experimental data for the study were obtained from the wind driven surface of a fresh water lake. Two types of signals were transmitted to obtain the reverberation data: a pulsed continuous wave (CW) signal with a duration of 1.0 msec and a carrier frequency of 80 kHz, and a linear frequency modulated (LFM) signal with a duration of 1.0 msec and a sweep bandwidth of 10 kHz centered at 80 kHz. The outputs of six different elements of a horizontal, linear receiving array operating in each type of reverberation environment were simultaneously measured, and measurements of 98 different events were made for each type of reverberation to obtain the sample ensemble for calculating ensemble averages. Using two statistical tests the validity of the data ensembles were first examined for the independence of the members of each ensemble (the one-sample runs test) and for the homogeneity of each ensemble (the Kolmogorov-Smirnov test). When the sample ensemble proved to be valid, the second-order statistics, such as the intensity and the space-time covariance function, of the reverberation process were estimated.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 20, 1975
- Accession Number
- ADA013282
Entities
People
- Yoshitsugu Omichi
Organizations
- University of Texas at Austin