Figure 6-2. Example of OBS array; AO, BO, or CO. Sensor array is shown 

 displaced 1 ft shoreward from the current meters, Runs 

 A0509A- A0915A 



this report) provides a listing of the along-channel coordinates, x (ft), and 

 sensor elevation above the bed prior to, z b (cm), and after, z a (cm), an 

 experimental run. Any differences between z b and z a indicate bed elevation 

 changes associated with erosion or accretion. Negative z-values indicate that 

 the sensor was buried. Generally, sensor stacks remained at a specific along- 

 channel, x, position for the duration of a test series. 



All vertical stacks of the OBS were cantilevered either from the east wall 

 of the wave channel (Figure 6-2) or from pipes jetted into the bed (Figure 6- 

 4). During the entire project all vertical stack locations coincided with one or 

 more Marsh-McBirney electromagnetic current meters. During the first week 

 of runs, A0509A - A0915A, the vertical stacks of OBS were located 1 ft 

 shoreward, (-jc), of the corresponding current meters (Figure 6-2). During the 

 remainder of the project, OBS and current meters were located at the same x 

 coordinate, but displaced in the cross-channel y direction (Figure 6-4). This 

 "longshore" displacement was typically less than 2 ft. 



110 



Chapter 6 Suspended Sediment Concentration 



