USACE Field Research Facility
Field Research Facility
Coastal & Hydraulics Laboratory

Radar Inlet Operating System (RIOS)

Developed by Drs. Jesse McNinch and Katherine Brodie and other staff at ERDC CHL's Field Research Facility, RIOS is used to study the real time changes of a river mouth or inlet over a long period of time by utilizing a 25kW X-band, coherent-on-receive radar purchased from Imaging Science Research to measure wave parameters at 5m resolution within a 3km radius of the antenna. Data acquisition and processing are fully automated and capable of hourly observations and web posting from a small, mobile trailer. From this data, one can find the velocity of the ocean wave as it approaches the shore as well as the direction, altitude, and range.

Wave speed and dissipation, obtained from time series of radar spikes generated by the roughened surface of waves, are used to calculate water depths. Wave orbital velocities (radial components) are also explicitly measured and used to determine wave height and surface currents. An error assessment of both acquisition and processing techniques is presented from experiments conducted at the Field Research Facility where many of the critical variables are independently measured by other sensors. RIOS is an observational tool to study morphodynamic processes at tidal inlets and river mouths as well as an applied technique to support civil and military operations and improve navigation safety.

Costal LIDAR and Radar Imaging System (CLARIS)

Collecting simultaneous observations of oceanographic conditions and vulnerable coastal landforms over large areas and during storms has been virtually impossible to date. The coastal research community has long recognized the value of 'during storm' data because most of the relevant processes (e.g. sediment transport, overwash, shoreline change, infrastructure damage) express a very strong signal during these energetic events.

CLARIS represents a significant step in coastal observing techniques, providing high-resolution (sub-meter) measurements of low-lying lands, depths across shallow-water regions, and wave parameters (e.g. direction, wavelength, period), all during storm conditions and over large areas. CLARIS has already yielded scientific breakthroughs in understanding 1) shoreline erosional hotspots, 2) beach overwash, and 3) sediment exchange between the beach and nearshore shoals. CLARIS has also demonstrated success in assessing beach renourishment projects (Benson Beach, NWP District).

The Coastal LIDAR and Radar Imaging System is a fully mobile system that integrates two state of the art remote sensing technologies, a terrestrial laser scanner (Riegl Z390i) and X-Band radar (BASIR [9], a mobile 4kW X-band (9410 +/- 30 MHz)), using precise motion (POS-LV) and location (RTK-GPS) information.

LIDAR (light detecting and ranging system) is a type of optical sensing technology that can measure the distance to and other properties of a target or broad area by sending out pulses of light via laser. This device gives a detailed 3-dimentional scan of the dunes, the beach, the waves, and everything in the surrounding areas. Whereas, radar is another type of object sensing system that uses electromagnetic waves, in particular radio waves, to measure direction, altitude, speed and range of moving objects such as waves.

CLARIS is a robust system capable of rapidly (up to 10 km alongshore in 2 hours) and quantitatively measuring: beach and dune topography (accuracy of 10 cm), nearshore bathymetry from radar-derived wave celerity measurements (to within 10% of the actual depth), and surf-and swash-zone morphology from time-averaged radar images during storms

Coastal Research Amphibious Buggy (CRAB)

The unique three-wheeled vehicle, the CRAB was built by the Wilmington District of the US Army Corps of Engineers, and was modeled after a vehicle originally built by Marine Travelift & Engineering of Sturgeon Bay, for the Great Lakes Dredge and Dock Company, to monitor a Corps of Engineers beach nourishment project.

The CRAB consists of a tripod of 0.2 m schedule-80 aluminum tubing, connected at the base by horizontal members 2.1 m (7 ft) above the ground, and an operations platform 10.7 m (35 ft) above the ground. Power is supplied by a 60-hp turbo charged Volkswagen diesel engine on the deck which drives a variable volume hydraulic pump. This pump transfers hydraulic fluid at 800 psi or higher to hydraulic motors at each of the wheels. The variable stroke feature of the pump allows an infinitely variable gear ratio in either forward or reverse and constant engine speed. For strength and corrosion resistance, all hydraulic lines are stainless steel, except for short flexible sections at the front wheel, which is used for steering.

Total vehicle weight is about 8,200 kg (18,000 lb); the distance between the rear wheels is 8.2 m(27 ft). Though it appears top-heavy, the liquid-filled tires and wide wheelbase make it very stable. The CRAB has passed a 20-deg tilt test and is designed to withstand even steeper angles.

Top speed of the CRAB is 3.2 km/hr (2 mph) on land and somewhat less in the water. Since the maximum significant wave height for operation is 2 m (6 ft), the CRAB is capable of operating in all but the most severe storms. The large tires have a negligible effect on a hard rippled sand bottom; however, scour around the tires has been observed in areas of active wave breaking or strong currents if the CRAB remains motionless. The CRAB cannot be used on soft silty or loose bottoms. The position of the CRAB is determined by a Trimble 4000 SSE GPS.

The LARC-5 (Lighter Amphibious Resupply Cargo)

The LARC-5 is an Army amphibious vehicle that is used to deploy instruments, support diving activities, collect data, and tow a variety of sensor and survey "sleds". An onboard crane can lift 400 kg (900 lb) and its total possible load is 5 tons (hence the five after LARC.) The LARC's maximum speed is typically 5 knots in the water and 18-20 mph on the road. The Army used the LARC to ferry supplies from boats to shore; when purchased by the FRF, our LARC was military surplus.
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Sensor Insertion System (SIS)

From 1993-2011, this crane-like device was used to rapidly deploy instruments anywhere along the pier. It was mounted on the railroad tracks located on the deck and could reach out from 50-75 ft from the pier. The SIS permitted unique measurements to be made even during wave heights up to 18 feet and in winds up to 49 mph. Though large, precision positioning by skilled SIS operators allowed delicate instruments to be situated within a few inches of the seabed without diver assistance. Instruments to measure the waves, currents, and sediment movement were mounted on the boom of the SIS and lowered into the water.

Though now retired, the SIS was used for many different experiments. It was primarily used to collect sediment transport information during extreme events since most of the available sediment transport datasets were collected during low wave conditions. The SIS was used extensively during the DUCK94 and SandyDuck '97 experiments. To learn more about the SIS ...

All-Terrain Forklift

The FRF's all-terrain forklift has a 2700 kg (6000 lb) lift. It is used for carrying instruments, cables, and boats to the beach.







The Pier

The concrete and steel research pier is the centerpiece of the FRF. It took two years to construct and was completed in 1977. It was constructed to survive severe storm conditions. The pier deck is 6 m (20 ft) wide and extends 560 m (1840 ft) from the dune to a nominal water depth of approximately 7 m (21 ft). The deck is supported on 1 m (3 ft) diameter steel pilings which are imbedded 15-18 m (50-60 ft) below the ocean bottom. The pier deck is 7.7 m (25 ft) above the sea surface and was designed to stay above the storm waves. However, the the deck has been overtopped, particularly during the Halloween storm of 1991.

The Video Tower

The Field Research Facility Tower is 43 m (120 ft) tall and was built in 1986. It is used to support radio antennae and video cameras. At the top of the tower is a 7 by 7 foot room equipped with 110 volt power, an intercom to the FRF Building, and coax video cables to the FRF's video lab. This room also has the best view in Duck!!
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Buildings & Offices

There are two major buildings. The main laboratory, completed in 1980, houses the main computer system, electronics repair facility, and offices. The Workshop/Conference Room Facilities include a garage, work shops, SCUBA locker, conference room (26 x 35.5 ft) and technical library. The conference room is equipped with a rear projection screen for video, computer, and slide projection and has a great view of the Atlantic. The conference facility easily handles 30 people and is available for use.