The following is a list of publications cited in this report:
Beach, R.A.; Holman, R.A.; and Stanley, J., 1996. Measuring nearshore bathymetry on high energy beaches. American Geophysical Union Fall Meeting, 1996, F286.
Cote, J.M., 1999. The measurement of nearshore bathymetry on Intermediate and dissipative beaches. Unpublished Masters Thesis, Oregon State University, Corvallis, Oregon, 102 pp.
Gelfenbaum, G., Sherwood, C.R., Kerr, L.A., and Kurrus, K., 2000, Grays Harbor wave refraction experiment 1999: Data report, U.S. Geological Survey Open File Report, OF 00-44, 132 pp.
MacMahan, J., 2001. Hydrographic surveying from a personal watercraft. Journal of Surveying Engineering, 127(1), 12-24.
Ruggiero, P., and Voigt, B., 2000. Beach monitoring in the Columbia River littoral cell, 1997-2000, Washington Department of Ecology Publication # 00-06-26, Olympia, WA, 112 pp.
Additional information about the data collection field activity, W-1-05-PS, is at URL: <http://walrus.wr.usgs.gov/infobank/w/w105ps/html/w-1-05-ps.meta.html>.
The PWC used for the CPSIII is a 2003 Honda AquaTrax F-12 chosen because of its stability, compartment space, and relatively low price. The 3-man PWC measures 3.20 m in length, 1.25 m in width, and 1.06 m in height. During normal surveying operation, the wave runner travels at approximately 3 m/s (6 knots) and can operate for approximately 5 hours on one 60-L fuel tank. The instruments are placed on a bracket at the stern of the vessel, and forward upper part of the vessel in front of the handlebars. On the stern bracket are three large watertight cases, which house the GPS, computer, echo sounder electronics and batteries. In the computer case, the echo sounder and the laptop computer are mounted. This case has six external watertight connectors: one is for serial communication with the GPS, one for the echo sounder transducer, one for the external screen, one for the external 17 button keypad, one for power, and one spare. The complete system is powered by two gel cell 12-volt marine batteries, configured in parallel and housed in a Pelican box mounted on the bracket at the stern of the PWC. The system draws 12 volts at approximately 5 amps.
Horizontal and vertical positioning of the CPSIII is obtained using a Trimble 4700 GPS receiver, which is enclosed in a waterproof Pelican box placed on the bracket at the stern of the PWC. Also within the GPS case is the GPS radio modem (Pacific Crest) that is used to communicate with the shore base station. A small bracket is attached to the topside stern of the vessel for mounting the L1/L2 microcentered GPS antenna and the radio antenna. The GPS antenna is mounted approximately 119 cm directly above the echo sounder transducer.
The echo sounder is an ESE-50 single frequency echo sounder with a 200 kHz transducer manufactured by Flash Fire Technology, Inc. This echo sounder has adjustable gains, offset, and serial outputs. The sampling rate is a function of water depth with an approximate sampling rate of 8 Hz applied in shallow water (0-10 m). The transducer has a 10 - degree conical beam width and generates a pulse at 200 kHz. The echo sounder transducer is mounted on a removable and adjustable arm at the stern of the vessel. The electronics of the echo sounder were reconfigured along with a Big Bay Technologies Inc. P3 mini PC, placed in a watertight Pelican Case. The CPSIII collects data at 5 Hz and while traveling at 3 m/s generates a depth sounding every 0.6 meters along the sea floor.
Navigation and surveying are aided by the use of a monitor (12 inch Big Bay Technologies outdoor high bright display) which is mounted in a watertight case on a bracket forward of the handlebars. A small 17-button programmable Logic Controls keypad (24 cm X 8.9 cm X 3.2 cm) is placed in a waterproof radio bag mounted on the handlebars.
HYPACK allows for surveying within a user-defined coordinate system, in this case NAD83 Washington State Plane (4602) - North and NAVD88. As the GPS base station is set up over a monument and survey accurate data is stored in HYPACK in the appropriate datum.
The CPSIII has the ability to survey preset track lines and data is collected only when the PWC operator selects a line. The PWC operator maneuvers the vessel to one end of the line and drives along the track until the vessel is in a water depth of approximately 1 m.
The salinity is fixed at 31 psu for all lines as its small variations in the sampling region (Gelfenbaum et al., 2000) had a negligible effect when performing a speed of sound correction to the data.