136 



wave ray 



1.6 m 



^JXi' 



t_ 



Pressure Gauges 

 Figure 6.1: Layout of DWG- 1 pressure array 



equations in 15 unknowns. 



The solid lines are the dynamic pressure, water surface, and kinematics as com- 

 puted from the Fourier solution. The circles are the predictions of the LFI method, 

 with each circle being located at the center of a separate window. The kinematics 

 are measured at a depth of 1.5m below the surface, just under the trough. The LFI 

 method has captured the location of the water surface and the kinematics essentially 

 exactly, including the pronounced sharp crest. As with the single pressure gauge 

 (Sec. 3.4), a fairly high order solution (J = 5) was necessary to capture the sharp 

 crest of this shallow water wave. The additional data provided by the three gauges 

 allowed for a narrower window than with the single measurement, even at this high 

 order. 



Deep Water Figure 6.3 is a steady deep water wave generated by 10th order Fourier 

 theory with the following parameters: wave height = 10m, period = 10s, water depth 

 = 100m, direction of travel 10 degrees from the x-axis, and zero Eulerian current. The 

 pressure array is located 10m below the surface. The parameters of the LFI solution 

 are: window width = Is (tq = O.lTj), second order(J = 2), with 3 samples on the 

 water surface, and 3 samples on each of the pressure records (M = / = 3), resulting 



