passes by the two sensors. This figure represents a snapshot of the pattern 

 of crests and troughs along the array at, say, t = . Solid circles mark 

 the two sensor locations. The sensor at y = sees the full amplitude a 

 of a wave. The sensor at J = Jz sees a smaller amplitude a-cos(kyy2) , as 

 defined by Equation A2 with both x and t set to zero. 



12. Figure A2b shows a vertical cross section of the same wave, but it 

 is now incident at direction d^ . where 62 < 6-^ . Sensor locations are the 



t = 



a. large angle from normal 



o cos(l< 72) 



b. smaller angle from normal 



Figure A2 . Vertical sections through water surface along two-element 

 array (dots) of waves incident at two different angles 



A6 



