Control Point 



Easting 



Northing 



El, m (ft) 



Land Monuments 



CA0107 



5,965,856.06 



2,054,910.17 



+598.975 (+1965.14) 



CA 01 09 



5,977,097.54 



2,245,544.72 



+38.173 (+125.24) 



CA01QB 



5,952,362.82 



2,162,176.82 



+14.176 (+46.51) 



North Jetty Monuments 



54+00 



5,942,965.89 



2,169,931.69 



+5.648 (+18.53) 



68+00 



5,942,006.38 



2,170,950.68 



+6.593 (+21.63) 



74+00 



5,941,577.59 



2,171,370.19 



+9.629 (+31.59) 



South Jetty Monuments 



62+00 



5,942,018.17 



2,167,724.07 



+6.239 (+20.47) 



84+00 



5,940,585.64 



2,169,390.80 



+7.184 (+23.57) 



90+05.21 



5,940,173.12 



2,169,833.40 



+9.984 (+32.46) 



In addition, targets were established on selected dolos armor units to serve as 

 control to check the accuracy of the photogrammetric work. Targets were 20.3 cm 

 (8 in.) in diameter and divided into four quadrants, which were painted alternately 

 white and black. A typical target is shown in Figure 9. This style of contrasting 

 target provides a precise center point for which measurements can be made by both 

 land and photogrammetric surveys. A high quality epoxy-based marine paint was 

 used to minimize the need for repainting, and a 0.64-cm (1/4-in.) hole was drilled at 

 the center of each target for identification in subsequent surveys. 



A total of 34 dolosse on the north jetty and 33 dolosse on the south jetty were 

 selected for targeting. Fifteen dolosse on the north jetty were painted with three 

 targets (dolosse 101 - 1 15) and nineteen dolosse were painted with a single target 

 (dolosse 1-19). On the south jetty, 16 dolosse were painted with three targets 

 (dolosse 201 - 216) and 17 dolosse were painted with a single target (dolosse 51 - 

 67). An example of a dolos with three targets is shown in Figure 10. Note the tar- 

 gets are labeled A, B, and C. Three targets on individual armor units allow for very 

 precise measurements depicting individual armor unit movement. Armor units 

 selected for targeting were distributed along the length of the jetties on both the sea 

 sides and channel sides of the structures and around the heads. They were also dis- 

 tributed from the crest to the waterline. Figures 1 1 and 12 show the locations of 

 targeted armor units on the north and south jetties, respectively. Units chosen for 

 targeting had flat surfaces close to horizontal to maximize their visibility in aerial 

 photography and allow for accurate representation of armor unit movement. 



16 



Chapter 2 Monitoring Plan and Data 



