Equi-Distant, Equi-Angle, And Intermediate Modes; Figure 29: Beam Density; Figure 30: Beam Spacing Vs. Beam Angle - Teledyne SeaBat T Series Operator's Manual

SYSTEM PERFORMANCE AND DATA TYPES

7.2.2 Equi-Distant, Equi-Angle, and Intermediate Modes

As the beam steering angle increases from nadir, the number of beams per degree of swath
stays constant for equiangular spacing while it increases for equidistant spacing. Figure 29
presents the number of beams as a function of steering angle for a 1° nadir beam spacing.
Figure 30 shows that the
horizontal spacing of the
Intermediate mode increases
with beam angle, unlike Equi-
distant mode where the
spacing stays constant.
However, the Intermediate
mode increases the spacing
much slower than the
Equi-angle mode so the outer
beam density is still quite
good.
Assuming a flat bottom and using the beam footprint generated by the nadir beam, it may be
seen that the center-to-center spacing for each beam successively reduces as the departure from
nadir increases until at ±65° the beam density is approximately 2.5 times greater than at nadir.
SeaBat T-Series Subsea Operator's Manual
Version 7

Figure 29: Beam Density

Figure 30: Beam Spacing vs. Beam Angle

Page 58 January 31, 2019