'75%, IDS 



Direction at which cumulative distribution function equals 

 0.50 at frequency f^ 



Direction at which cumulative distribution function equals 

 0.75 at frequency fj, 



Direction at which integrated direction spectrum 

 cumulative distribution equals 0.25 



Direction at which integrated direction spectrum 

 cumulative distribution equals 0.50 



Direction at which integrated direction spectrum 

 cumulative distribution equals 0.75 



'25% n Direction at which cumulative distribution function at 

 frequency f^ and for mode k equals 0.25 



'50% n Direction at which cumulative distribution function at 

 frequency f „ and for mode k equals . 50 



?^5^ ^ Direction at which cumulative distribution function at 

 frequency f^, and for mode k equals 0.75 



6' Wave direction (in radians), equals 27r^/360 



p Water density 



4> Wave phase 



"^mn Wave phase at n*'^ frequency and m*'^ direction 



<f>2 Specific wave phases 



B5 



