8120
Installation and Operation Manual
32
The satellite window has information about
the GPS satellites and GPS position.
To go to the satellite window, press
DISPLAY
,
select
Other
, then select
Satellite
.
The satellite window shows:
8-1 Satellite window
A Status of GPS antenna, for example
Acquiring
,
GPS fix
,
No GPS
. If
the unit is in Simulate mode it displays
Simulate
(see section 2-6).
B Time and date from GPS satellites. Time is
local time (UTC [GMT] plus local offset, see
section 17-12)
C HDOP: The error in the GPS position
caused by satellite geometry. A low value
indicates a more precise fix, a high value a
less precise fix
D Signal strengths of up to twelve visible
GPS satellites. The higher the bar the
stronger the signal
E Boat position
F Positions of visible GPS satellites:
Outer circle is horizon
Inner circle is 45° elevation
Centre is directly above
North is at top of window
G If the boat is moving, COG is a line from
centre
9 Sonar fishfinding: Introduction
Sonar functions require an optional sonar
transducer to be installed and set up.
This section explains how to interpret the
sonar displays, when and why to use the
different frequencies and how fish are
detected and displayed.
It also describes Gain and Range and shows
examples of some of the different sonar
displays.
9-1 Using the Instrument
The Instrument uses a sonar transducer
attached to the hull. The transducer
generates an ultrasonic pulse (sound that is
above the hearing range of the human ear),
which travels down towards the bottom at
a speed of about 4800 ft/sec (1463 m/sec),
spreading out into a cone shape.
When the pulse meets an object, such as a
fish or the bottom, it is partly reflected back
up towards the boat as an echo. The depth
of the object or bottom is calculated by the
Instrument by measuring the time taken
between sending a pulse and receiving the
echo. When an echo has been returned, the
next pulse is sent.
The Instrument converts each echo into an
electronic signal, displayed as a vertical line
of pixels. The most recent echo appears on
the extreme right of the window, with the
older echoes being scrolled towards the left,
eventually disappearing off the window.
The scroll speed depends upon the water
depth and scroll speed setting. See sections
17-3 and section 8-2, for more information.
G
A
B
C
D
E
F
