SONAR AND TRANSDUCER
WHY DO I NEED A SONAR AND HOW DO THEY WORK?
WHY DO I NEED A SONAR AND HOW DO THEY WORK?
With sonar, you can focus your fishing on areas where you see fish or fish-holding areas like rocks, drop-offs, ditches, trees, logs, etc. Without sonar, it is much harder to catch fish since you don’t know where they are or where to find areas they like to hide.
DOWNSCAN WITH FISH REVEAL
DownScan Imaging™ makes it easier to identify how fish are relating to structure, providing photo-like images of rocks, trees, bottom composition and other underwater structure directly beneath the boat. FishReveal™ takes the high-resolution images from DownScan Imaging and combines them with the target separation and traditional sonar fish arches of CHIRP sonar, making it easier to see fish.
SIDESCAN - ACTIVE IMAGING
Perfect for searching large areas for fish-holding structure, SideScan provides views up to 600 feet to each side of the boat, allowing you to cover more water in a shorter period of time, and view areas too shallow for your boat – like next to the shore or bank. Active Imaging 3-in-1 brings our most popular sonar – Lowrance CHIRP, SideScan and DownScan Imaging™ – together into one transducer.
FORWARD VIEW - ACTIVETARGET LIVE SONAR
View what’s happening in front of your boat. ActiveTarget Live Sonar delivers high-resolution images of fish swimming around structure and responding to your lure – as it happens. With real-time views of fish relating to structure and responding to lure presentations, you can make quick adjustments to make them strike. ActiveTarget also has down and scout views.
Get a real-world, three-dimensional view of ﬁsh, structure and bottom contour that makes it easier to know where ﬁsh and structure are located in relation to your boat.
Transmitting at 455kHz or 800kHz frequencies, scanning sonar provides high-resolution views to the sides (SideScan) and beneath (DownScan Imaging) the boat. 800kHz provides the sharpest resolution at shallower depths, while 455kHz delviers the best overall image quality and depth penetration.
HDI is a transducer that combines a round traditional sonar element, and a DownScan bar.
SINGLE ELEMENT TRANSDUCERS
Transducers with a single element are capable of transmitting two alternating frequencies. The Lowrance Skimmer for example, can transmit 83 and 200kHz frequencies or Medium and High CHIRP ranges.
MULTIPLE ELEMENT TRANSDUCERS
Act like a single element transducer, but are made out of several (sometimes many) elements. This allows them to ping up and down more quickly - thus improving signal to noise ratio and to be more robust as large single elements are more delicate.
HOW DOES SONAR WORK?
Sonar is a technique used to detect water depth and the presence/depth of objects in the water by sending a signal (ping) underwater and then receiving its echo. The echo is created when the original signal bounces off the bottom and objects in the water column between the transducer and the bottom. For fish-finding applications, sonar will show fish as an arch shape, partial arch or as a straight line, depending on the movements of the fish and the boat.
An older technology, Broadband sonar sends single-frequency sonar signals (pings) at 200kHz, 83kHz or 50kHz frequencies. High frequencies (200kHz) yield the best resolution, while low frequencies (50kHz) can reach greater depths.
Delivers higher resolution views by continuously sweeping through a range of frequencies – typically 28-51kHz (Low), 85-155kHz (Medium) or 140-250kHz (High) – which creates a more complete picture of the bottom and objects in the water column.
Traditional sonar always transmits its sound waves in the shape of a cylindrical cone. The angle of the beam and the size of the cone vary depending on the frequency that is output from the transducer.The size of the cone dictates how much of the body of water you can see at any given time, the wider the angle the greater the area.
For example, most traditional 200khz transducers have a cone angle of less than 20 degrees. If you’re fishing in less than 10 feet of water, the cone diameter on the bottom is less than 3 feet across which makes it less likely that a fish will come into range at that depth. So, as a rough guide, the wider the beam angle the lower the resolution.
IMPORTANCE OF FREQUENCIES
For shallow water you need medium to high frequency transducers (around 80 and 200 kHz). High frequencies produce higher resolution images but they don’t penetrate very far into the water. For bottom deep water fishing, you need a low frequency transducer (around 50 kHz)
Some transducers are capable of multiple frequencies or ranges, which you can use both at the same time.
CHOOSING THE RIGHT TRANSDUCER
INSTALLING AND MOUNTING TRANSDUCERS
Check out some of the most popular basics of sonar videos on our YouTube channel.
Check out some of the most popular Sonar and Transducer pages on our website.