Horizontal TX Sector function
In a horizontal swath the SN90 system transmits with a maximum horizontal opening angle of 160 degrees. Use the Horizontal Tx Sector function to control the opening angle - and thus the size - of the horizontal search sector (swath). This is the physical area that is covered with each transmission ("ping").
Specifications
Maximum Other options
Horizontal swath 160 degrees 90, 120 degrees
Vertical swath Normal Narrow
Plane swath 160 degrees 90, 120 degrees
Inspection beams SLL -13, -17, -22, -23, -26, -30, -35 dB
How to open
You open this function from the Active menu.
Image
Description
The Horizontal Tx Sector function controls the "width" of the transmission. Select the middle of the button to open it for access to the available options.
Note
The options provided by this function depend on your current active view.
If the Horizontal TX Sector value in a horizontal swath is smaller than its maximum value, the centre of the sector is defined by the Bearing function. In the Horizontal view the transmit sector is shown as a triangle originating from the vessel symbol.
SLL is short for sidelobe levels.
Small sidelobes are generally your best choice. With small sidelobes, the main beam becomes wider. You achieve small sidelobes when you select a high numerical value. (Example: ‑30 dB)
The main beam narrows with large sidelobes.
A wide beam is often useful if you are looking for echoes close to the bottom. SLL set to ‑17 dB is an average value that works in most cases.
Image
A This is the horizontal TX sector in a horizontal swath.
B This is the vertical TX sector in a horizontal swath.
C This is the vertical TX sector in a vertical swath.
D This is the horizontal TX sector in a vertical swath.
Tip
In some cases, you may want to use Horizontal TX Sector to control the direction of the acoustic transmissions. This can be useful to avoid reverberation if you work close to land, or interference from other sonars in the same area.
Related functionality
The Mk2 Operating Panel is fitted with three rotary switches. The switches are identified with numbers. Each switch can be assigned a function related to range, gain, bearing or tilt.