Transmission; Optional Functionality - Simrad SX90 - REFERENCE MANUAL REV D Reference Manual

Optional functionality

307670/D
Note that scattered fish can be perceived as reverberation. The
RCG filter must therefore be used with care if scattered schools
are to be detected.
Ping-to-ping filter
Thee Simrad SX90 Fish finding sonar is equipped with a
ping-to-ping filter (PP Filter) to provide a clean and steady
presentation by reducing the interference and noise. This filter
compares the echoes from a selected amount of transmissions
(pings), and an echo has to be present in the selected amount of
pings in order to be presented on the display.
Note that in rough seas, when the beam easily can miss the target
in several pings, the PP Filter must be used with care.
TVG (Time Variable Gain)
The TVG function controls the gain of the receiver so that
a school with a given size and density is presented with
approximately the same strength on the display, inside the
regulated TVG range. This can also be seen as a filter, because it
reduces the noise close to the vessel.
The regulated strength of the TVG can be selected in the menu.

Transmission

The transmitting is controlled by the signal processor in the
Transceiver Unit. The parameters you have chosen are used.
There are 256 separate transmitters in the unit distributed on
eight transceiver circuit boards. Each transmitter is individually
addressed and controlled from the signal processor. The
controlled parameters include power output and time delay for
each transducer element in order to form a beam with the selected
tilt angle.
When the stabilising system is active, the tilt angle for each beam
will automatically be corrected relative to the vessel's pitch and
roll movements.
The standard Simrad SX90 Fish finding sonar is a multiple
frequency sonar with maximum 4500 meters range, and with
beam stabilising.
The options described below are preprogrammed into the
standard software version, and a code word is required to make
the actual option available. Simrad offers a 1 month free test
period for certain options. The Scientific Output function is not
Simrad SX90 Fish finding sonar
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