Page 57 of 68
Doc. P/N:
WSP-009-002
Version: V2.3
Issue Date: July 2014
Installation Manual
www.wassp.com
Sea Trial - Commissioning Step 14: Beam Width Reduction
The useable area of the swath may be limited due to reduced beam width caused
by low temperatures, turbulent flow, aeration, high sea state, quick temperature
fluctuations or shading of the transducer. Watch the outer edges of the
Sonar
View carefully with the sea-floor line shown. If the outside edges of the sea-
floor line appear to vary much more than the area immediately adjacent consider
reducing the beam width. These variance can be seen as frilly edges on edges
of a mapped area on the
Contour
and
3D
Views and on the
Sonar
display as
perpetually weak echoes on the outer beams. Failure to reduce the beam width
will introduce false data on the outer edges into the backscatter and depth maps.
Figure 37 – Frilly edges on 3D View on outer 5 degrees of each side of the mapped
track caused by low temperature environment. To remove this area we
can reduce the beam width on both port and starboard by 5 degrees.
Good Area
Area where physical Beam Width
is narrower than 120 degrees.
This causes the mapping of the
outer edges to be error prone and
erratic. Care must be taken to not
confuse this with a motion artifact,
or a sound speed artifact.
Figure 36 –Sound Speed Correction Options. In Manual Mode Sound Speed can be
entered directly or calculated from a known or estimated Temperature
and Salinity. When a Temperature Sensor is active a Temperature Offset
can be applied to adjust for errors.
