ATLAS North America Proprietary
Sea Scan® ARC Explorer™ Manual
1 of 1
Page: 57
Issue: 4.2.1
2SFT1-0001
Manual
acoustic shadow
Literally, the shadow an object on the bottom casts to its
side in relation to the transducer; the transducer must “see”
this entire shadow so that the height of that object can be
calculated
acoustic signal
The fan of sound emitted from the transducer
active sonar
A system that transmits an acoustic signal through the water
that reflects off objects, then is returned
angle of incidence
The angle at which a straight-line sonar pulse hits an object
ARC
Adaptive Resolution CHIRP
AUV
Autonomous Underwater Vehicle
axial layback
The offset distance from the position of the towfish to the
navigation antenna
backscatter
Reverberation caused generally by sea conditions, bottom
roughness, and angle of incidence
baud rate
A unit for measuring data transmission speed, where one
unit equals 1 bit per second
beam spreading
The widening angle of a sonar beam as it moves farther
from the transmitter
BMP
Bitmap, a graphic file format commonly used in Microsoft
Windows© applications
Bow
The front section of a boat or other vessel
buffer
To load, as in loading a file. Also, pulling information
from a file and putting it into memory
CD
compact disk
channel
Another term used to describe the transducer track from
either side of the towfish that appears in the sonar window.
The left channel refers to the left (port) transducer track;
the right channel refers to the (starboard) track.
COG
Course Over Ground; also known as Course Made Good
color look-up table
A way of mapping data by assigning an artificial color
contrast stretching
An operation that remaps the color look-up table based on
the lower and upper threshold limits the operator elects
from the histogram
CPU
Central processing unit
CSV
Comma-Separated Values; in computers, a CSV file
contains the values in a table as a series of ASCII text lines
organized so that each column value is separated by a
comma from the next column's value and each row starts a
