Deployment Method
SIDSEP. The SIDSEP were transported to the beach by pickup truck and
placed near the mllw shoreline with a hand-pushed, four-wheeled cart. A 4-ft by
2-ft by 1-ft hole was dug at the station by hand. The SIDSEP was placed in the
hole, and then the hole was back-filled with sand removed in digging the hole to
restore beach contours (Figure D5). Two 1.5-in.-diam aluminum pipes were
driven 3 to 4 ft vertically into the beach and attached to the upright instrument
supports for added stability.
The SIDSEP were deployed during low tide, and recovered at low tide 3 days
later. Personnel remained in the vicinity of the study site to periodically observe
the equipment; the instruments were checked at each low tide to ensure that they
were positioned correctly and were not in danger of being lost or buried. A
bright orange flag with a 5-ft fiberglass shaft was mounted on the aluminum pipe
to increase visibility of the pods and to inform surfers and swimmers of their
presence while submerged.
A differential GPS receiver mounted on the top of the hand-pushed cart was
used to accurately position the SIDSEP at predetermined locations. When on
station, the SIDSEP was lowered into the excavated hole using the winch system
installed on the cart.
HESTT. The HESTT were partially assembled and transported to Ocean
Shores airport by box truck for final assembly and deployment by helicopter.
The method and hardware for deploying and recovering the tripods essentially
follows that outlined by McGehee and Mayers (2000) with a few minor
modifications and improvements for use of a Sikorsky HH-60J "Jayhawk"
helicopter (Figures D6 and D7).
Assistance was requested from the U.S. Coast Guard (USCG) Air Station
Astoria because personnel there had familiarity with the deployment site and
prior experience with instrument deployments on the Oregon Coast (e.g., Pollock
1995). Advantages of the HH-60J are its capability to remain airborne for
durations up to 7 hr, a 6,000-lb lift capacity, a cargo hook and rescue hoist, and a
Rockwell-Collins HFCS-8000 automated flight management system that
integrates all of the helicopter's communications and navigation equipment. The
pilot can program the autopilot to fly to a predetermined location automatically,
freeing the pilot and co-pilot to assist in visual observation of the deployment
operation. In addition, this system can automatically bring the HH-60J to a hover
at an altitude of 50 ft above a specified location. This feature is especially useful
in rough weather for locating and relocating deployed instruments.
D8
Appendix D
Field Data Collection
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