1200

β = 80

1000

β = 60

1000

800

800

2000 m

β = 40

600

600

1000 m

400

200

500 m

400

β = 20

0

200

-200

Shoreline for β = 20

Shoreline for Fixed Radius

Focus of Parabola

-400

Focus of Parabola

0

-1500

-1000

-500

0

-500

0

Distance Alongshore, m

Distance Alongshore, m

Fig. 6. Parabolic shape for selected values of

Fig. 5. Parabolic shape for selected values

)

of angle β (*R*0 = 1,000 m).

150

100

50

Focus

β = 20

β = 25

0

β = 30

Headland

-50

-100

-50

0

50

100

150

200

250

300

Fig. 7. Sensitivity of parabolic shape to selection of control point location.

If the location of the focus is known, and the wave crests are parallel to the *x*-axis,

the values of *R *and ? can be computed for each data point. For each candidate value of

the angle , the right-hand side of Eq. 3 can be computed and, therefore, a value of *R*o

estimated for each point. The selected combinations of focus location, angle of rotation

of the local coordinate system to the absolute coordinate system, *R*o, and are computed

such that the radial rms error achieves a minimum.

Moreno & Kraus

8

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