Configuring the Uplink, Up and Down Settings
You can configure different settings for uplink, down and up soundings.
Before you begin
About this task
Remember: Always click Apply after you change a setting and make sure there is a
green check mark .
Procedure
Click the tab Trawl Explorer.
Uplink
Procedure
From TE Uplink
Frequency, enter a frequency
for the signal toward the vessel.
Important: This parameter must be the same in the sensor settings
in Scala2.
Up/Down Soundings
Procedure
-
From NBTE Setup Options, select the sounding
mode (see Sounding Modes for more information).
Important: Down 1 + Down 2 sounding mode: configure Down 1 sounding in Down settings and Down 2 sounding in Up settings (Up Sounding Range, Ping Up Length, Ping Up Frequency, Up channel minimum TS, Up TVG Mode, TVG Up).
-
From Down Sounding Range and, if applicable, Up Sounding Range, select the range according to how many meters
you want to see under the sensor.
Note: Range influences the display of echogram images. The smaller the range, the shorter the listening time and the better the quality of images. But if you set a bigger range, data arrives slower which results in poorer image quality. If you are using Down 1 + Up or Down 1 + Down 2 sounding mode, the image quality is even lower, as explained in Sounding Modes.Note: The range of the down sounding can automatically change to 20 meters if the distance to the bottom becomes lower than 20 meters and if you entered a trawl opening lower than 20 m. See next step to activate or not this feature.Important: This parameter must be the same in the sensor settings in Scala2.
-
If you want the range of the down
sounding to automatically change to 20 m when the bottom is closer (< 20
m):
- Make sure you only use Down 1 sounding mode.
- Enter the height of the trawl opening. It must be lower than 18.5 m. This is to make sure the sensor will search for the bottom beginning from this distance. This way, the sensor will not confuse the footrope with the bottom of the sea. For example, if the footrope is at 4 meters, enter a greater distance, such as 5 meters.
Note: With the autorange feature, the echogram displays better quality images when the distance to the bottom is smaller.Important: Do not use the autorange feature if using Down 1 + Up or Down 1 + Down 2 sounding mode: you will have wrong data on the echogram. - If you do not want the range of the down sounding to automatically change, enter 20 m or more.
-
From Ping Down Length and, if applicable,
Ping Up Length, enter a pulse length. Choose a
pulse length according to the distance at which you need to detect
fish. (the
longer the pulse, the further you can see, but with a lower
resolution):
- Detection between 20 cm and 2 m: enter 0.1 ms
- Detection between 50 cm and 160 m (V2: up to 80 m): enter 0.4 ms .
Note: The maximum detection depth depends on ping frequency and type of bottom. The lower the ping frequency is, the longer the detection depth is. -
From Ping Up/Down
Frequency, enter frequencies for
down and, if applicable, up soundings. You can choose the same frequency
for both because they do not transmit at the same time.
Important: Frequency needs to be between 120-210 kHz.Important: Do not change ping frequency on a V3 sensor or it will have to be returned to a Marport sales' office for target strength calibration.
Target Strength
Procedure
-
For V3 version of sensors, Down channel minimum
TS and
Up channel minimum
TS helps you
detecting targets on the echogram. You can put -79 dB if you want to detect
small targets. Otherwise, leave the default settings at -73 dB.
Important: This parameter must be the same in the sensor settings in Scala2.
-
Select the appropriate TVG (Time Variable Gain) mode. See About Time Variable Gain for more information.
For V3 version of sensors, go to Down TVG Mode and, if applicable, Up TVG Mode:
- 20 log: focus on bottom or school of fish.
- 40 log: focus on individual targets.
- 30 log: compromise between the two above settings.
For V1 and V2 versions of sensors, go to TVG Down and, if applicable, TVG Up:- In TVG Coefficient, enter between 0.500 and 0.520 to have approximately the equivalent of 20 log, 0.75 for 30 log or 1 for 40 log.
- In Attenuator Coefficient, enter 25.
- Leave VCO Coefficient default settings at 3.