Figure 6-1 . Optical Backscatter Sensor (OBS) and cut-away view (Downing, 

 Sternberg, and Lister 1981) 



OBS: AM1-AM5, BM1-BM5, P01-P03. These 13 sensors are Model 

 OBS-1P from Downing and Associates. They are individual sensors but were 

 primarily deployed in vertical stacks (Figure 6-3). The distances between 

 sensors in the vertical arrays were not necessarily constant between stacks, 

 project runs, or over the entire experiment. The three PO sensors were pri- 

 marily used to augment the vertical stacks AO, BO, and CO. These 13 sen- 

 sors were on loan to R. Beach and are the property of Dick Sternberg (eight 

 sensors, University of Washington) and Dave Cacchione (five sensors, U.S. 

 Geological Survey, Menlo Park, California). 



Location 



All OBS locations coincided with the fixed wall positions where current 

 meters and wave staffs were deployed. Table Fl (contained in Volume II of 



Chapter 6 Suspended Sediment Concentration 



109 



