k Summing index; frequency index 



mj^ The n*^^ moment of a frequency spectrum 



mo Zeroth moment of frequency spectrum 



m2 Second moment of frequency spectrum 



m^, Fourth moment of frequency spectrum 



n Index of a set of discrete wave heights; index of a sequence of 

 time steps 



N Number of observed waves in a record; number of observed water 

 surface elevations 



p Probability density function 



P2 Two-wave probability density function 



pdf Probability density function 



p,^ Modified Rayleigh probability density function 



Pjj Rayleigh probability density function 



P Cumulative probability function 



P2 Two-wave cumulative probability function 



^MR Modified Rayleigh cumulative probability function 



Pj^ Rayleigh cumulative probability function 



Prob[ ] Probability that expression in [ ] is true 



Q Exceedence probability 



Q2 Two-wave exceedence probability 



Qp Exceedence probability estimated from data 



Qf^ Modified Rayleigh exceedence probability 



Qr Rayleigh exceedence probability 



r Fraction between zero and one 



r- Element j of function representing fraction of highest observed 

 waves 



RMS Root-mean- square 



A2 



