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NUMBER OF POINTS USED IN ENSEMBLE AVERAGES 



Figure 7-1 Results of ensembling the spectral estimates (a and b) from 

 sixteen parallel profiles collected by a nultlbeam sonar 

 system. Plotted points Indicate the estimated parameters 

 for each of the sixteen profiles and various ensembles of 

 adjacent profile parameters. The calculated standard error 

 (solid line) decreases as /R (dashed line), as predicted by 

 standard statistical theory. 



110 



