USING THE 450TX
CONTROL FUNCTIONS
Second Returns. When a sonar signal is reflected off the bottom back to the transducer, there is often enough energy left in the signal to be reflected off the surface of the water back to the bottom a second time. Second returns appear as a slightly weaker bottom representation exactly twice the depth of the primary bottom return. The second return is most likely to occur in shallow water and in areas of relatively hard bottom.
Fish ID. The 450TX uses advanced signal processing to further evaluate any sonar return between the surface and the bottom. For instance, a small school of bait fish usually appears as a dense cluster of individual dots. If the return meets certain additional
criteria, a fish symbol will be
assigned. There are three different size fish symbols used
to indicate the intensity of the sonar return. While signal intensity is a good indicator of
relative fish size, different species of fish have different
sonar characteristics, so it is not always possible to distinguish
fish size between varying
species. The signal intensity is "normalized" for depth so that
a small fish close to the boat
does not appear as a large fish symbol.
ID+ adds an additional piece of information to help the user locate fish. On selected fish symbols, the digital depth of the designated fish is drawn to help locate the fish vertically. This is especially helpful in setting bait depths or for downrigger operation.
The specific fish symbol indicates the type of sonar beam the fish is detected |
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in. This gives you a reliable indicator of side to side location relative to boat |
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movement. Fish symbols which are hollow are detected in the outside two |
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beams. Hollow fish symbols facing to the right are in the right beam and |
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therefore are to the right side of the boat (as viewed from the driver seat facing |
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forward). Hollow fish symbols facing to the left are detected in the left beam, |
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and thus the fish is to the left side of the boat. Solid fish symbols represent fish |
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in the single center beam, and these fish are directly under the boat. | 11 |