Omni sonar glossary
Every term you'll meet on the screen or in the manual.
- Omni sonar
- A full-circle scanning sonar that transmits and receives in every direction at once, redrawing the whole area around the boat on every ping. More →
- Searchlight sonar
- A sonar with one narrow beam that is stepped around the circle a few degrees at a time. Slower to cover the full circle than omni. More →
- Transducer
- The underwater part that turns electrical pulses into sound and echoes back into signals. On an omni it is a cylinder of many elements. More →
- Dome
- The protective housing around the transducer. The CSH-10's new dome guards against line chafe, impact and corrosion. More →
- Hull unit (hoist)
- The motorized unit that raises and lowers the transducer through the tank. More →
- Travel
- How far the transducer drops below the tank when lowered: 400 mm or 600 mm on Furuno omni. More →
- Tank (hull tube)
- The tube through the bottom of the hull that the transducer passes through. Furuno's 8-inch-class tubes are 190 mm inside diameter. More →
- Tilt
- How far below the horizon the center of the beam points. Low tilt looks far and shallow; more tilt looks deeper and closer. More →
- Range scale
- How far out the display reaches. The CSH-10 offers 50 to 2,000 m. More →
- Gain
- How much the received echoes are amplified. Too little hides weak targets; too much fills the screen with noise. More →
- AGC
- Automatic gain control. Reduces gain automatically on strong echoes, such as a heavy bottom or dense bait, so weaker targets near them stay visible. More →
- Beam width
- The angle the beam covers. The CSH-10 transmits 360° horizontally and 6° vertically; it receives on a 10° by 9° beam. More →
- Pulse length
- How long each ping lasts. Longer pulses carry farther; shorter pulses separate targets that are close together. The CSH-10 uses 0.5 to 20 ms. More →
- Head-up, north-up, course-up
- Display orientations. Head-up puts the bow at the top; north-up and course-up need heading or course data. More →
- Motion sensor
- Measures the boat's roll and pitch so the sonar can stabilize its beam. Standard on the CSH-10 (CSH-1042). More →
- Beam stabilization
- Electronically re-aiming the beam to cancel the boat's roll and pitch, so the beam stays at the tilt you set. More →
- Target lock
- Keeps a chosen school or spot on screen. On the CSH-10 it reports distance, depth, speed and course in fish mode. More →
- Fish estimate mark
- A CSH-10 mark that measures a school's length, width and area and gives an index for comparing two schools. More →
- Event mark
- A reference point you drop on screen to come back to. More →
- Interference rejecter
- A filter that suppresses noise from other sonars and electronics. More →
- Echo average
- Smooths the picture by averaging successive pings. Reduces flicker and noise at some cost in fast detail. More →
- Noise limiter
- Suppresses low-level background noise. More →
- TX cycle
- How often the sonar transmits. Captains adjust it alongside gain as conditions change. More →
- Thermocline
- A boundary where water temperature changes quickly with depth. It bends sound and can shorten detection range. More →
- Auto-retraction
- Raises the transducer automatically above a set speed to protect it. More →
- Sonar overlay
- On NavNet TZtouchXL, the CSH-10's echoes drawn on the chart and bottom contours. More →
- RotoKey
- Furuno's rotary menu control, added to the CSH-10 control unit. More →
- Audio search
- Listening to echoes through a speaker. The CSH-10 outputs a 1 kHz tone at 10 W. More →