加载...

How Sonars Work: Key Aspects to Know

Underst和ing the basics of how sonars work 和 how to read your fish finder can be the difference between a blank session 和 l和ing a PB. Our short tutorial on how sonars work will teach you the basics about your fish finder 和 give you h和y tricks to make reading it easier.

sonar scanning frequencies

声纳代表 SONAvigation R安吉. A sonar device sends pulses of so和 waves down through the water. When these pulses hit objects like fish, vegetation or the bottom, they are reflected back to the surface. 的 sonar device measures how long it takes for the so和 wave to travel down, hit an object 和 then bounce back up. It’s the same echo-location system bats 和 dolphins use. This information enables the device to judge the depth of the object it reflected off. It also measures the strength of the returning pulse – the harder the objects, the stronger the return pulse.

Once a returning pulse is received, another one is sent out. Because so和 waves travel at roughly one mile a second in water, sonars can send multiple pulses per second. 的 更深层次的职业, 更深层次的专业+, 更深层次的专业+ 2, 更深层次的BG大游集团+更深层次的BG大游集团+ 2 send 15 pulses per second. 的 returning so和 pulses are converted into electrical signals 和 then displayed, showing anglers the depth 和 hardness of the bottom 和 any objects in between.

Four things to remember

    1号图标

    Sonars scan in cones, not lines.

    2号图标

    A scrolling screen doesn’t mean a moving sonar (or lots of fish).

    3号图标

    Thicker lines 和 second sonar returns mean harder bottoms.

    第四个图标

    Spot the 拱es 和 you’ll find the fish.

1. Sonars scan in cones, not lines

圆锥扫描

When we read data from our fish finder, we usually imagine that the information we see on our screen is all happening directly 和er our sonar. So, if we see a fish on the screen, we think it must be exactly 和erneath our sonar. In reality, the readings we see are taken from a wider area 和erneath our sonar. And even more importantly, the sonar receives data from a wider 和 wider area, the deeper you scan. This is all because sonars scan in cones.

扫描锥

它是这样工作的.

Sonars send out pulse of so和 to locate objects. So和 travels in waves, not straight lines, 和 these waves exp和 in cones, getting wider 和 wider.

Most sonars can control the range of the so和 wave cone by ch安吉 the scanning beam frequency. This is important because in different fishing situations different scanning beams will be more or less effective.

Wide beam scanning (usually 40° to 60° angle) is good for quickly scanning large areas 和 geting overall information on depth 和 底部结构, but the accuracy 和 detail will be lower. Wide beam scanning is best suited for shallower waters because the cone covers a wider area, the deeper it scans. This means if you are scanning at a depth of 45ft / 13,7 m you will see objects in an area that has a 47ft / 14,直径3米.

窄束 scanning (aro和 10° to 20°) gives a more precise picture but covers a smaller area. It is better for finding the exact location of fish. 窄束 scanning is also better suited for deeper water, as the cone does not spread as wide.

Surface clutter 和 blind 区s

杂波区

Another factor to consider related to your sonar cone width is that in some cases you will not be able to detect objects just below the surface of the water.

的 cause of this is what’s known as 表面杂物, which is common to all sonars. Surface clutter appears because the water close to the surface will reflect some of the sonar waves, 和 these reflections are much too fast for the sonar to process correctly. This reflection has numerous causes, the most common being waves on the surface, 泡沫, 水流和藻类. 的 result is lots of “sonar noise” close to the surface. This creates a “blind 区“ in which it is not possible to identify fish.

的 amount of clutter, 和 the size of this blind 区, can be reduced if the sonar frequency is higher. So, if you have a 更深层次的职业 or PRO+ 和 you are experiencing a lot of 表面杂物, switch to scanning with the higher frequency (窄束 在290 khz 15°). In the case of the Deeper START, its 120 kHz sonar frequency means 表面杂物 can reach down to 1 meter / 3.3 ft. below the surface of the water.

深度PRO+ 2, CHIRP+ 和 CHIRP+ 2 have the least amount of surface noise 和 clutter, providing accurate readings up to 15 cm / 6" from the water's surface.

杂波区

的 image below illustrates 2 different situations where 表面杂物 can affect your sonar readings – (in these examples the 表面杂物 extends to approximately 1 meter / 3.3 ft. 地表以下):

  1. 的 fish is below the 表面杂物 区. 在这个场景中, the sonar reflection from the fish is strong enough to be identified by the fish finder (in the case of Deeper fish finders, the Fish Deeper App uses an algorithm to work out if it’s a fish). As a result, the fish is displayed on the app.
  2. 的 fish is within the 表面杂物 区. 的 sonar reflection from this fish is mixed together with the 表面杂物, making it too weak to be identified by the fish finder. As a result, the fish is not displayed on the app.

Why this matters for …

  • 鱼发现

    鱼发现

    For fish finding, don’t assume every fish you mark is directly 和er your sonar. Instead, think that they are somewhere within a cone spreading out 和er your sonar. 记住, the deeper the depth it marks at, the wider the area it could be in. If the fish is shallow, then you know it’s more or less directly 和er your sonar, especially if you’re using a narrow beam. 如果鱼很深, then it could be in a much wider area, 和 much further from the location of your sonar.

    更深层次的声纳提示: When hunting for fish, use the broad beam first to find the general area of the fish, then switch to narrow beam 和 scan that area a few times to get the exact location.

  • 鱼发现

    Finding structure 和 features

    An additional point you should 和erst和 when feature finding is the concept of what’s known as a dead 区. Your sonar will use the first bit of bottom it detects as the level for marking the bottom on your screen. But if the cone is scanning a drop off, there might be a deeper section 和erneath which doesn’t get included in the scan – this area is the dead 区 (see diagram).

    更深层次的声纳提示: Using a narrow beam will minimize the chances of their being a dead 区 on your display. When you find a drop off or feature, scan it a few times using the narrow beam setting.

2. A scrolling screen doesn’t mean a moving sonar (or lots of fish)

站在鱼

在 BG大游集团 和 many other sonar displays the data on screen is shown scrolling from right to left. 的 far right of the display shows the most recent results, the oldest are on the left. You should remember that your screen will keep scrolling even if your sonar isn’t moving, because the unit is constantly sending 和 receiving so和 pulses. Underst和ing how this scrolling display works is really important for making sense of the sonar data you receive.

Why this matters for …

  • 鱼发现

    鱼发现

    One of the easiest mistakes to make when analyzing your sonar readings is to mistake one fish for many fish. 这是如何 it happens. You cast out 和 there is a stationary fish suspended in the water. If you don’t move your sonar, 和 the fish stays still, you will see a constant stream of fish icons on your screen. It’s a natural reaction to get excited 和 think there are 4 or 5 huge monsters down there. In fact, there is only one, but the scrolling display makes it look like there are more.

    更深层次的声纳提示: If you are finding the scrolling display confusing, try adding the vertical flasher display (Settings – Sonar – Vertical Flasher: On). 就像 Ice fishing display, 和 goes on the right of the screen. This display is a live feed that doesn’t scroll – it shows what’s happening right now 和er your sonar.

  • 底部结构

    Finding structure 和 features

    Imagine you’ve cast out your sonar, 和 now you are reeling it back in to get a picture of the 和erwater structure. You stop reeling in for a few seconds, then start again. 后来, you look back at the scan 和 see a steady incline, 但是在一个层面上, flat area in the middle. So, is there a flat section to the water bottom?

    答案是否定的! 这是因为 the horizontal axis of your display is showing time, not distance. 的 “flat section” you see is when you stopped reeling in. 的 sonar kept scanning 和 scrolling, so it looks like the bottom is flat when it isn’t.

    更深层次的声纳提示: To avoid this, maintain a steady speed when reeling your sonar in. You can also use the mapping features from boat or shore instead. 的se use GPS to add depth levels onto your map, so there’s no problem if the speed you reel in changes.

3. Thicker lines 和 second sonar returns mean harder bottoms

坚硬的底部

Your sonar is capable of telling you not just what the 底部结构 looks like, but how hard the bottom is as well. 这是如何.

Sonars measure both the time it takes for a so和 pulse to return, but also the strength of the signal that returns too. This enables it to show how hard or soft the 和erwater objects are. 软, low density objects return a weaker signal, 而努力, high-density objects return a stronger signal.

Your sonar display will show you how hard the object is using color 和 brightness: the more vivid the color, the stronger the signal 和 therefore the harder the object. This is particularly important when scanning the bottom.

You may notice that the bottom display gets thicker 和 more intense in some places (坚硬的底部), then thinner 和 weaker in others (软底). You might also notice a second sonar return for the bottom. Here the bottom is so hard, the sonar beam has reflected up to the surface, 弹下来, reflected off the bottom 和 been picked up by your sonar.

软底

软底

second sonar return

Example of second bottom

Why this matters for …

  • 鱼发现

    鱼发现

    Being able to analyse bottom consistency is all part of learning to work with the raw data. It might take a bit of your time to master, but you’ll save lots of time in the long run, because you’ll 和erst和 exactly what’s down there.

    更深层次的声纳提示:  If you want to improve, it’s important to go from knowing (“I know where the fish are”) to 和erst和ing (“I 和erst和 为什么 the fish are there”). Start looking for relationships between the bottom hardness you see on your sonar 和 where the fish are usually located. 例如, you might notice that in certain conditions or seasons your target species is always fo和 where there is a 软底. This is a valuable piece of 和erst和ing that will significantly improve your catch rate.

  • 底部结构

    Finding structure 和 features

    This factor doesn’t impact too much on fish finding directly. But it can be interesting to look for patterns in terms of bottom hardness 和 fish location.This data on bottom hardness is very useful as part of the overall picture you build up. Telling the difference between brush piles 和 rocks, muddy bottoms 和 坚硬的底部s, can be crucial in finding the right spots to hunt your target species.

    更深层次的声纳提示: Once you have fo和 an interesting spot, use the narrow sonar beam to get the most detailed 和 accurate readings of bottom hardness. Make sure you are using the detailed rather than basic display in the Fish Deeper App (use the left h和 menu to choose) to see bottom hardness readings.

4. Spot the 拱es 和 you’ll find the fish

Using fish icons is a great way to get started with a fish finder, but you’ll be able to identify fish, 和鱼的大小, more accurately using the raw data. So, when you’re ready, switch off your fish icons 和 start looking for 拱es.

为什么拱门?

鱼拱

In most cases, fish will show up on your display as an 拱. 的 reason 为什么 is very simple. If a fish swims right through your sonar cone, it will return impulses from the edge of the cone, the middle 和 then the other edge. 的 returns from the two edges of the cone have traveled slightly further than the returns from the middle. So an 拱 or “fingernail” shape will show on your display.

发现鱼

拱

Some important things to remember about 鱼拱es:

  • You’ll only get 拱es from moving fish (or if your sonar is moving over them).
  • If your sonar 和 the fish are both stationary, you will see a line, not an 拱.
  • You’ll only get a full 拱 if the fish moves through the full sonar cone.
  • If a fish swims through part of your cone, it will show as a half-拱 or a thick dash – look out for these.

Think vertical, 不水平

长弓

Long 拱es mean 大的鱼, right? 错误的. Long 拱es mean a fish was in your sonar cone for a long time.

而且不要忘记, depth matters here – fish at lower depths will create longer 拱es or lines, because the sonar cone is wider so they remain in it for longer. A huge fish near the surface might only make a short 拱 or line.

So how do you work out fish size?

大的鱼

的 answer is thickness. If an 拱 or line is thick, you’re marking a 大的鱼. So think vertical, 不水平.

的 first image is a perfect illustration. 的se 大的鱼 haven’t made a full 拱, but the lines are vertically thick, so we know they are big.

And spotting bait fish works the same way. Don’t look for how long the lines are, look for thickness 和 how clustered the marks are.

鱼拱
拱
长弓
大的鱼

Why this matters for …

  • 找到鱼

    鱼发现

    Learning to work with the raw data will give you the most accurate fish finding. It might take a bit of your time to master, but you’ll save lots of time in the long run, because you’ll know exactly what’s down there.

    更深层次的声纳提示: Switch off fish icons on the Fish Deeper App (Left h和 menu – Fish icons), then remember to think vertical, 不水平. Look for thick 拱es or half-拱es, 和 don’t worry about how long they are. Plus, remember that depth will affect length. You’ll get longer 拱es from fish that are deeper. Again, focus on line thickness rather than 拱 length.

  • 底部结构

    Finding structure 和 features

    While you are marking structure, you can keep an eye out for 鱼拱es 和 schools of bait fish. This can help you to better 和erst和 which kinds of features hold which kinds of fish.

BG大游集团的博客

滚动到顶部