2. Surveying Control . 



a. Local Control . There is extensive monumentation on both the sound and 

 ocean sides of the FRF site (Fig. 10). Large-scale versions of Figure 10 with 

 complete monumentation are available from the FRF. The primary oceanside mon- 

 uments are along a base line located landward of the laboratory and perpendic- 

 ular to the pier centerline. U.S. Army Engineer District, Wilmington (SAW), 

 has established a series of concrete monuments along this base line at 45.72- 

 and 152.4-meter (150 and 500 feet) intervals. Other monuraents at varying 

 intervals have been established in support of CERC beach and bathymetric sur- 

 veys. Many of the monuments along the base-line have permanent pipe monuments 

 (front and back) to define profile azimuths perpendicular to the base line. 

 Table 4 provides a summary of the base line monumentation according to dis- 

 tance along the base line and distance from the pier centerline. All these 

 have been surveyed to third-order accuracy. Documentation on each monument is 

 available. 



One concrete monument and two series of profile lines have been estab- 

 lished on the sound side to monitor sound changes. Further details about 

 these lines are given in Section VI. 



A series of very stable monuments, which will eventually be tied into 

 first-order control, has been established by the National Oceanic and 

 Atmospheric Administration (NOAA) in support of the tide gaging program. 

 Information about these monuments is available at FRF. 



Because of the profusion of monuments at the FRF, users are requested to 

 use established monuments if possible. Temporary monuraents, stakes, pipes, 

 etc. , must be clearly labeled as to owner and must be removed on completion of 

 study. To ensure that valuable monuraents are not removed or lost during 

 extended studies, the monuraents should be documented as to location, markings, 

 date of installation, etc., using form DA 1959 (copy in App. C) ; a copy of the 

 form is then given to the FRF Chief. Special care should be taken to minimize 

 pedestrian effects on the dune and beach. 



b. Island Control . The CERC monuments indicated in Table 4 are part of 

 the series of 62 profile lines shown in Figure 11. Each line has three monu- 

 raents: a brass disk on a concrete post and two pipes (front and rear) to 

 define the profile azimuth. Additionally, third-order vertical control has 

 also been established on each of the five fishing piers. Complete docuraenta- 

 tion for the profile lines may be obtained from the FRF Chief. All the lines 

 are on private property, so written permission to survey must be obtained in 

 advance from the owners. Data collected at these lines under CERC's Beach 

 Evaluation Program (BEP) from May 1974 to January 1977 are discussed in 

 Section V and summarized in Section VIII. 



3. Bathymetric Surveying . 



The accuracy of the bathymetric surveys depends on the survey mettiods 

 used. The current procedure consists of dividing the survey lines into beach 

 and nearshore zones. 



The area from the beach to the 9-meter (30 feet) contour is surveyed using 

 the innovative three-legged vehicle, the Coastal Research Amphibious Buggy 

 (CRAB), shown in Figure 12. Designed and constructed by the Wilmington 



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