Edgetech USBL BROADBAND ACOUSTIC TRACKING SYSTEM, User Hardware Manual, Page: 93 / 102

5-3
Hysteresis is incorporated into TrackMan to eliminate sharp boundary at 45° and 70° Depression Angles.
In
F
IGURE
5-2 , the values X, Y, and Z are RS-232C outputs. These values are distinct from the X, Y, and Z
offsets shown in F
IGURE
5-1 . The distance X is the projection of the Horizontal Range on a Vertical Plane
perpendicular to the centerline of the vessel and passing through the Vessel Reference Point. The distance
Y is the projection of the Horizontal Range on a Vertical Plane parallel to the centerline of the ship and
passing through the target. X and Y and HR form a right triangle. Depth (Z) is the depth of the target below
the water surface.
Under ideal conditions the transducing element plane is parallel to the surface of the water and
perpendicular to a Vertical Plane through the vessel centerline. In a real application, the vessel and
hydrophone are in motion, and the system must therefore correct measurements taken from the
hydrophone for pitch and roll.
The rotation of the vessel about its X-axis, a line drawn perpendicular to the vessel centerline at its
midpoint, is known as pitch. Roll is the rotation of the vessel about the vessel centerline, or Y-axis. The
Vertical Reference Unit measures pitch and roll in degrees, with zero degrees being the "at rest" position,
and calculates the necessary compensation. For dynamic motion compensation, an EdgeTech MRU is
recommended, and would typically be interfaced with TrackMan.
The Embedded PC, located in the Transceiver, receive information from the hydrophone array for each
received pulse. TrackMan converts information received from BATS Transceiver into a real-time graphic
representation of the tracked target(s) relative to the Vessel Reference Point, shown in the display-screen
tracking window. Digital values are continuously updated in the status block.
F
IGURE
5-3
and
F
IGURE
5-4
,
the Transceiver Block Diagram, presents an overview of the BATS. The individual components of the
system function as described in the following sections.
Figure 5-1: Slant Range Depiction