A Study for Optimum Survey Method of Underwater Structure Using the Dual Sonar Sensor

Table 4

Sample data.

Number	Depth (m)	① Towfish (L) (wall)		② Towfish (L) (bed)		③ Towfish (R) (bed)
		Angle (R)	Distance (m)	Angle (R)	Distance (m)	Angle (R)	Distance (m)
1	4.6	53.6	1.6	−2.7	14.0	140.0	3.9
2	3.8	51.2	1.5	−2.4	13.6	141.0	3.8
3	3.1	50.6	1.4	−2.1	13.3	143.0	3.7
4	9.1	51.3	1.6	−3.1	16.1	137.0	3.9
⋮	⋮	⋮	⋮	⋮	⋮	⋮	⋮
15	7.3	50.4	1.3	−3.0	15.2	138.5	3.6
16	3.9	51.5	1.2	−3.1	13.6	139.9	3.5
17	4.8	51.2	1.2	−2.7	14.0	139.5	3.5
20	8.2	50.2	1.4	−3.0	15.7	138.1	3.7