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Underwater video camera. The Sony Hi-8 CCD V99 video camera is put 

 underwater and aimed towards a reference grid on the wall of the channel to 

 measure sand ripples. The video signal is sent through cable to a shore-based 

 video recorder. Camera features are directly controlled with a shore-based 

 computer. 



Location 



ACP. The x, y, and z coordinates of the sensor were 205.13 ft (62.52 m), 

 9.73 ft (2.97 m), and -10.91 ft (-3.32 m), respectively, in the SUPERTANK 

 coordinate system (Chapter 1). All electronic components were installed in a 

 3.5-in.- (8.9-cm-) square, 8.2-in.- (20.8-cm-) long, gold anodized aluminum 

 alloy housing. The unit was attached to a steel bracket which was in turn 

 clamped on the wall-mounted vertical steel rod. DC power, a TTL- 

 compatible trigger source, and analog output were connected through a single 

 6-pin underwater connector to the shore station. 



OBS sensor. Two sensors were deployed. The jc, y, and z coordinates of 

 the sensor closer to the ACP were 205.12 ft (62.52 m), 9.72 ft (2.96 m), 

 and -10.989 ft (-3.35 m), respectively. The x, y, and z coordinates of the 

 sensor closer to the bottom were 205.10 ft (62.51 m), 9.70 ft (2.96 m), and 

 -12.530 ft (-3.82 m), respectively. Sensor components are potted in glass- 

 filled polycarbonate with optical-grade epoxy. The unit was attached to a 

 steel clamp, which was connected to the wall-mounted vertical steel rod. 

 Electronic connection to the underwater package was made through an 

 underwater pie connector. 



EMCM. The x, y, and z coordinates of its center were 205.11 ft 

 (62.52 m), 9.82 ft (2.99 m), and -11.74 ft (-3.58 m), respectively. The unit 

 was attached to a steel clamp which is connected to the wall-mounted vertical 

 steel rod. It was adequately oriented such that the cross-shore and vertical 

 components of flow velocity were measured. Electronic connection to the 

 underwater package was made through a permanent connector. 



Pressure sensor. The x, y, and z coordinates of its center were 205.13 ft 

 (62.52 m), 11.39 ft (3.47 m), and -7.917 ft (-2.41 m), respectively, from 

 August 12 to 16. This unit was built into the underwater package. The 

 underwater package was installed to a wall-mounted bracket above the other 

 instruments. The sensor was at one end of the package cylinder and in line 

 with the ACP from 12 to 16 August, but it was approximately 1 ft offshore 

 from the other instruments over 5 to 9 August. 



Pore pressure sensor. The x, y, and z coordinates of the sensor were 

 205.13 ft (62.52 m), 9.75 ft (2.97 m), and -13.207 ft (-4.03 m), respectively. 

 The sensor is housed in a Plexiglas pipe, which was attached to a wall- 

 mounted clamp. The clamp and sensor were buried in bed soil such that the 

 distance from the sensor to the bed surface was approximately 6 in. (15 cm). 



Chapter 10 Intermittent Near-Bed Sediment Suspension 



