Text Appendix C 



sf (nf ) Element nf of an array that represents the frequen- 



cy spectrum 



sf rq Sampling frequency 



S(f ) Frequency spectral density at frequency f n 



S( Q m ) Direction spectral density at direction m 



s (f n ■ ®m ) Frequency-direction spectral density at frequency 



f and direction Q m 



thp Peak direction of directional distribution at fre- 



quency f p 



T Peak period 



x Horizontal coordinate increasing northward 



x t Horizontal position vector of gauge i 



x\ Horizontal position vector of gauge j 



y Horizontal coordinate increasing westward 



yymmdd Mnemonic for date 



P Exponential convergence rate parameter in IMLE 



Y Convergence rate coefficient in IMLE 



Circular skewness 



T]j(f B ) Coherence of signals from gauges i and j at fre- 



quency f n 



6 Circular kurtosis 



A0 Quartile directional spread parameter 



e r Convergence check parameter at r' h IMLE itera- 



tion 



Appendix E Notation E5 



