Nyquist frequency 



The highest frequency treated in a Fourier analysis, corresponding 

 to the inverse of twice the data spacing. 



Orthogonal 



An orientation in which all axes intersect perpendicularly. 



Phase 



The location of a periodic function along an axis relative to 

 some arbitrary origin. 



Planetary Rossby waves 



A large-scale, stable wave motion in the global ocean. 



Power 



The squared amplitude of a periodic function. 



Power law 



A mathematical relationship of the form y=ax'^. This function 

 plots linearly in log-log space. 



Prewhitening 



A technique which reduces the effect of spectral leakage in ana- 

 lyzing non-white-noise signals. 



Process (geological) 



A natural continuing activity or function. 



Process (statistical) 



Any quantity which is defined in terms of its relationship to some 

 independent variable, usually time or space. 



Provincing 



Techniques which divide a sample space into discrete regions based 

 on some predefined statistical property. 



Random walk 



A stochastic process of independent increments. 



Regression model 



A functional description of a relationship between a dependent 

 variable and independent variable(s), usually derived by the method 

 of least-squares. 



Round-off error 



The level of uncertainty in a data set due to the finite number of 

 digits retained. 



SASS 



Sonar Array Sub-System. A multibeam sonar system operated by the 

 U.S. Navy. 



SEABEAM 



A commercially available multibeam sonar system. 



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