2. VIDEO SOUNDER OPERATION

2.1Principle of Operation

The video sounder determines the distance between its transducer and underwater ob- jects such as fish, lake bottom or seabed and displays the results on screen. It does this by utilizing the fact that an ultrasonic wave transmitted through water travels at a nearly constant speed of 4800 feet (1500 meters) per second. When a sound wave strikes an underwater object such as fish or sea bot- tom, part of the sound wave is reflected back toward the source (transducer). Thus by cal- culating the time difference between the transmission of a sound wave and the re- ception of the reflected sound wave, the depth to the object can be determined.

The entire process begins in the display unit. Transmitter power is sent to the transducer as a short pulse of electrical energy. The elec- trical signal produced by the transmitter is converted into an ultrasonic signal by the transducer and transmitted into the water. Any returning signals from intervening objects (such as a fish school) are received by the transducer and converted into an electrical signal. The signals are then amplified in the amplifier section, and finally, displayed on screen.

The picture displayed is made up of a series of vertical scan lines, one for each transmis- sion. Each line represents a snapshot of what has occurred beneath the boat. A series of snapshots are accumulated side by side across the screen, and the resulting contours of the bottom and fish between the bottom and surface are displayed.

Figure 2-1 Underwater conditions and video sounder display

2-1

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Furuno GP-1850F, GP-1850DF manual Video Sounder Operation, Principle of Operation
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GP-1850F, GP-1850DF specifications

Furuno is renowned for its high-quality marine electronics, and the GP-1850DF and GP-1850F are no exceptions. These advanced GPS chart plotters are designed to meet the needs of both professional mariners and recreational boaters alike.

The GP-1850DF is equipped with a powerful 12-channel GPS that provides fast and accurate positioning information, while the GP-1850F features a sturdy built-in fish finder, making it ideal for anglers. Both units boast a brilliant color display that enhances visibility in various lighting conditions, ensuring that users can easily read information on the screen, even in direct sunlight.

One of the standout features of these models is their compatibility with a variety of chart formats, including C-MAP, and Furuno’s proprietary raster charts. This flexibility allows users to choose from a broad range of navigational charts, catering to specific regional needs and preferences. The intuitive interface of the GP-1850 series simplifies navigation, offering menu-driven commands and support for multiple languages.

Furuno has integrated advanced sonar technology in the GP-1850F model, including a high-resolution fish finder capable of detecting fish signatures with remarkable precision. The dual-frequency capabilities enable users to switch between higher frequencies for shallow water fishing and lower frequencies for deeper waters. This enriches the fishing experience while improving catch rates.

Moreover, both devices feature a built-in waypoint register, allowing users to store up to 1,000 waypoints, which can be essential for returning to promising fishing spots or navigating back to port. The navigation functions also include routes and track recording, empowering boaters to create custom paths and review their previous journeys.

The GP-1850 series also places a high emphasis on safety, incorporating features like man overboard (MOB) alarms and route alarms to enhance on-water safety. Additionally, they are designed to withstand the harsh marine environment, with waterproof housings that ensure durability during adverse weather conditions.

In conclusion, the Furuno GP-1850DF and GP-1850F models provide an exceptional combination of performance, reliability, and user-friendly features, making them a preferred choice for both fishermen and navigators. Their adaptability in various maritime situations, alongside advanced technologies, cements their reputation as essential tools for successful and safe voyages on the water.
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