CN114814801A - Method for improving target resolution of fishing sonar image - Google Patents

Abstract

The invention relates to a method for improving the resolution of a fishing sonar image target, belonging to the technical field of fishing sonars, wherein the method for improving the resolution of the fishing sonar image target comprises the following steps: acquiring echo data uploaded by a sonar signal processing host, and preprocessing the data to obtain preprocessed echo data; carrying out interpolation visualization imaging on the preprocessed echo data to obtain an initial sonar image for fishing; introducing Gain to adjust the echo intensity value of the initial fishing sonar Image to obtain the adjusted echo intensity value Image data of the initial fishing sonar Image; and carrying out interpolation visualization imaging on the adjusted echo intensity value Image data to obtain an adjusted sonar Image for fishing. According to the method for improving the resolution of the target of the fishing sonar image, provided by the invention, the echo intensity value of the initial fishing sonar image is adjusted by introducing Gain, so that the loss of the signal receiver hardware to the remote echo intensity is made up, and the target display of the fishing sonar image is adjusted.

Description

A method for improving the target resolution of fishing sonar images

technical field

The invention belongs to the technical field of fishing sonar, and in particular relates to a method for improving the resolution of a fishing sonar image target.

Background technique

Fishing sonar, as one of the important fishing aids for precise detection and fishing in marine fisheries, is widely used in marine fishery production. The working principle of fishing sonar is the same as that of active sonar. It transmits sonic signals underwater through the signal processing host. The signals are transmitted when encountering fish schools and received by receivers to achieve fast tracking and positioning of fish schools. Users mainly estimate the position and density of fish by viewing sonar images in real time, so as to achieve precise fishing. Due to the sound absorption of the seawater medium itself, the expansion of the wave vibration surface in the sound propagation process, and various uneven scattering in the seawater, the propagation speed of sound waves in different sea areas is different, and the energy propagation of sound waves in water increases with the distance. Therefore, most of the sonar images obtained by fishing sonar will be distorted, and the image quality will be poor, which is not conducive to the development of marine fishery. At present, people use TVG gain in the receiver to compensate for the energy loss caused by long-distance propagation to improve the image resolution. The TVG gain compensation curve of the AD8338 chip commonly used in the prior art is shown in Figure 1. From Figure 1 It can be seen that the maximum value of the variable gain amplifier in the circuit is 80dB. When the detection distance is less than 3000m, the TVG gain has reached the maximum value. When the detection distance is greater than 3000m, the TVG gain compensation will maintain a fixed value. It can be seen that, The adjustment range of TVG gain is limited, and the larger the adjustment range, the higher the cost of the device. Therefore, this method has many restrictions in practical use, and it is difficult to popularize and apply.

SUMMARY OF THE INVENTION

Aiming at the deficiencies in the related art, the present invention provides a method for improving the target resolution of a fishing sonar image, so as to make up for the loss caused by the signal receiver hardware to the long-distance echo intensity, and improve the target resolution of the sonar image. It can change the gain in real time and display the current fish image information, which greatly improves the detection efficiency of fishing sonar and reduces the cost of its development.

The present invention provides a method for improving the resolution of a fishing sonar image target, comprising the following steps:

Step 1: Acquire the echo data uploaded by the sonar signal processing host, and preprocess the data to obtain the preprocessed echo data data;

Step 2: Interpolate and visualize the preprocessed echo data data obtained in Step 1 to obtain an initial fishing sonar image;

Step 3: Introduce Gain Gain to adjust the echo intensity value of the initial fishing sonar image in step 2 to obtain Image data of the adjusted echo intensity value of the initial fishing sonar image;

Step 4: Interpolate and visualize the image data row of the adjusted echo intensity value in step 3 to obtain an adjusted fishing sonar image.

This technical solution adjusts the echo intensity value of the initial fishing sonar image by introducing Gain, so as to make up for the loss of the long-distance echo intensity caused by the hardware of the signal receiver, and improve the resolution of the image, so as to achieve the accuracy of the fish target. Detection and efficient trapping.

In some of these embodiments, the calculation formula for adjusting the echo intensity value Image data in step 3 is:

Image data=20*lg(data)+Gain.

In some of the embodiments, the calculation formula of Gain is:

In the formula, C—digital gain is used to adjust the overall echo intensity information of the sonar image, and the value range of digital gain C is -50 to 50 dB;

R—detection range, km;

P - screen resolution;

L - the detection distance, the value range is 0~P, except the blind area;

D—gain compensation coefficient, the value of gain compensation coefficient D is an integer between 1 and 10.

In some of the embodiments, the digital gain C is valued according to the echo intensity value of the initial fishing sonar image.

In some of the embodiments, in step 1, the echo data uploaded by the host is processed according to the sonar signal to obtain the maximum real-time echo intensity max_data, by comparing the real-time maximum echo intensity max_data with the preset echo intensity mid_data To judge the echo intensity value of the initial fishing sonar image; the digital gain C presets the initial value C ₀ , when the maximum real-time echo intensity max_data is greater than the preset echo intensity mid_data, the initial value C ₀ is reduced 3dB is used as the digital gain C. When the real-time maximum echo strength max_data is smaller than the preset echo strength mid_data, the initial value C ₀ is increased by 3dB as the digital gain C.

In some of the embodiments, the gain compensation coefficient D takes a value according to the value of the detection range R.

In some of these embodiments, when the value of the detection range R is below 1000m, the value of the gain compensation coefficient D is ≥8; when the value of the detection range R is between 1000m and 2000m, the value of the gain compensation coefficient D is 6 to 8; When the R value of the detection range is 2000m~4000m, the value of the gain compensation coefficient D is 4~6; when the value of the detection range R is above 4000m, the value of the gain compensation coefficient D is ≤4.

Based on the above technical solution, a method for improving the target resolution of a fishing sonar image in the embodiment of the present invention improves the resolution of the image by making up for the loss caused by the signal receiver hardware to the long-distance echo strength, and not only improves the fishing use The detection efficiency of the sonar also reduces the cost of its development; and it does not need to change the signal processing host (ie, the lower computer), which is simple and easy to operate.

Description of drawings

The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

Fig. 1 is the TVG gain compensation curve of AD8338 chip in the prior art;

2 is an embodiment of the method for improving the target resolution of a fishing sonar image according to the present invention, the curve of the gain compensation coefficient D when the measurement range R is 2000m;

3 is an embodiment of the method for improving the target resolution of a fishing sonar image according to the present invention, the gain compensation coefficient D curve when the measurement range R is 4000m;

4 is a work flow diagram of an embodiment of the method for improving the target resolution of a fishing sonar image according to the present invention;

FIG. 5 is a working principle diagram of an embodiment of the method for improving the target resolution of a fishing sonar image according to the present invention.

Detailed ways

The technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

In an exemplary embodiment of the method for improving the resolution of a fishing sonar image target of the present invention, the method for increasing the resolution of a fishing sonar image target includes the following steps:

Step 1: Acquire the echo data uploaded by the sonar signal processing host, and preprocess the data to obtain the preprocessed echo data data;

Step 2: Interpolate and visualize the preprocessed echo data data obtained in Step 1 to obtain an initial fishing sonar image;

Step 3: Introduce Gain Gain to adjust the echo intensity value of the initial fishing sonar image in step 2 to obtain Image data of the adjusted echo intensity value of the initial fishing sonar image;

Step 4: Interpolate and visualize the image data row of the adjusted echo intensity value in step 3 to obtain an adjusted fishing sonar image.

It should be noted that, in the above exemplary embodiment, the preprocessed echo data data in step 1 includes the echo intensity value of the initial fishing sonar image in step 2. It should also be noted that, in step 4, the adjusted fishing sonar image is the final fishing sonar image, and the resolution of the adjusted fishing sonar image is much higher than the initial fishing sonar image.

In the above-mentioned exemplary embodiment, the calculation formula for adjusting the echo intensity value Image data in step 3 is:

Image data=20*lg(data)+Gain.

In the above-mentioned exemplary embodiment, the calculation formula of Gain is:

In the formula, C—digital gain is used to adjust the overall echo intensity information of the sonar image, and the value range of digital gain C is -50 to 50 dB;

R—detection range, km;

P - screen resolution;

L - the detection distance, the value range is 0~P, except the blind area;

D—gain compensation coefficient, the value of gain compensation coefficient D is an integer between 1 and 10.

Among them, the digital gain C is valued according to the echo intensity value of the initial fishing sonar image.

The gain compensation coefficient D is selected according to the value of the detection range R. When the value of the detection range R is below 1000m, the value of the gain compensation coefficient D is ≥8; when the value of the detection range R is between 1000m and 2000m, the gain compensation coefficient D When the detection range R value is 2000m~4000m, the gain compensation coefficient D value is 4~6; when the detection range R value is above 4000m, the gain compensation coefficient D value is ≤4.

It should be noted that the above exemplary embodiment is adjusted based on the display and control system of the fishing sonar. As shown in Figures 4 and 5, the working principle of the fishing sonar is: the multi-beam fishing sonar receives the echo of the lower computer. Wave data, through UDP communication, the original data is transmitted to the display and control system; the display and control system first undergoes data preprocessing, and then uses the algorithms and programs of the existing technology to visualize the image; the user chooses whether to carry out Gain adjustment, if gain adjustment is not required, the image displayed on the display and control system screen is the final fishing sonar image; if gain adjustment is required, the display and control system has set manual adjustment mode and automatic adjustment mode, the user can Choose any one of the modes to adjust. The adjustment process of the manual adjustment mode and the automatic adjustment mode will be specifically described below by way of embodiments.

Example 1

In manual mode, the sonar echo intensity value can be judged by observing the image information displayed on the screen of the display and control system. The specific adjustment process is as follows:

If the sonar echo intensity is small, the sonar image target will not be displayed clearly, and some fish targets will be filtered out. At this time, the value of the digital gain C needs to be increased to make the fish targets clearly visible. The adjustment process needs to be carried out. Multiple times, each adjustment in increments of +3dB, until the fish target is clearly visible. If the echo intensity is too large, the sonar image target is too prominent or the noise is too large, so that the target cannot be distinguished. At this time, it is necessary to reduce the value of the digital gain C to reduce the intensity of noise and reverberation, and highlight the target intensity. Adjustment process It needs to be done several times, and the amplitude of each adjustment is -3dB until the target information of the fish school can be accurately identified.

In addition, the value of the gain compensation coefficient D needs to be adjusted according to the detection range R. When detecting a long-distance underwater target (that is, the detection range R is large), due to the loss of sound wave energy and the influence of noise and reverberation, the remote target is difficult to distinguish, and the target close to the ship (that is, the detection range R When it is smaller), the loss of acoustic energy is smaller, and the image resolution of sonar detection is higher. When the R value of the detection range is below 1000m, the value of the gain compensation coefficient D is ≥8; when the R value of the detection range is 1000m～2000m, the value of the gain compensation coefficient D is 6～8; when the R value of the detection range is 2000m～ At 4000m, the value of the gain compensation coefficient D is 4 to 6; when the value of the detection range R is above 4000m, the value of the gain compensation coefficient D is ≤4. Figure 2 and Figure 3 are the gain compensation curves of the detection range R at 2000m and 4000m respectively, and the appropriate gain compensation coefficient D is selected.

It should be noted that, in order to control a single variable to quickly obtain an image with higher resolution, the adjustment processes of the digital gain C and the gain compensation coefficient D are usually independent of each other.

Embodiment 2

In the automatic selection mode, the echo intensity value of the initial fishing sonar image is judged by comparing the real-time maximum echo intensity max_data with the preset echo intensity mid_data. The specific adjustment process is as follows:

In step 1, the echo data uploaded by the host is processed according to the sonar signal to obtain the maximum real-time echo intensity max_data, and the digital gain C is preset to an initial value C ₀ . When the real-time maximum echo intensity max_data is greater than the preset echo When the wave intensity is mid_data, the initial value C ₀ is reduced by 6dB as the digital gain C. When the real-time maximum echo intensity max_data is less than the preset echo intensity mid_data, the initial value C ₀ is increased by 6dB as the digital gain C.

When the R value of the detection range is below 1000m, the value of the gain compensation coefficient D is 8; when the value of the detection range R is between 1000m and 2000m, the value of the gain compensation coefficient D is 6; when the value of the detection range R is between 2000m and 4000m, the value of the gain compensation coefficient D is 6. The value of the gain compensation coefficient D is 4.

It should be noted that when the automatic selection mode is selected, the parameters can also be modified and adjusted manually to achieve the optimal display of the fishing sonar image.

In the above exemplary embodiment, the method for improving the target resolution of the fishing sonar image can adjust the echo intensity value of the initial fishing sonar image by introducing the gain Gain without changing the signal processing host (ie, the lower computer). In order to make up for the loss of long-distance echo strength caused by the signal receiver hardware, improve the resolution of the image, so as to achieve accurate detection and efficient gathering of fish targets, which not only improves the detection efficiency of fishing sonar, but also reduces the the cost of its development.

Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments may be referred to each other.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the specific embodiments of the present invention can still be carried out. Modification or equivalent replacement of some technical features; without departing from the spirit of the technical solution of the present invention, all of them should be included in the scope of the technical solution claimed in the present invention.

Claims (7)

1. A method for improving the resolution of a fishing sonar image target is characterized by comprising the following steps:

step 1: acquiring echo data uploaded by a sonar signal processing host, and preprocessing the data to obtain preprocessed echo data;

step 2: carrying out interpolation visualization imaging on the preprocessed echo data obtained in the step 1 to obtain an initial sonar image for fishing;

and step 3: introducing Gain to adjust the echo intensity value of the initial fishing sonar Image in the step 2 to obtain an adjusted echo intensity value Image data of the initial fishing sonar Image;

and 4, step 4: and (4) carrying out interpolation visualization imaging on the adjusted echo intensity value Imdata in the step (3) to obtain an adjusted sonar Image for fishing.

2. The method for improving the resolution of the object in the sonar Image for fishing according to claim 1, wherein the calculation formula for adjusting the echo intensity value Image data in step 3 is as follows:

Image data＝20*lg(data)+Gain。

3. the method for improving the resolution of the objects in the sonar images for fishing according to claim 2, wherein the Gain is calculated by the formula:

in the formula, C is a digital gain and is used for adjusting the integral echo intensity information of the sonar image, and the value range of the digital gain C is-50 dB;

r-detection range, km;

p is the screen resolution;

l is the detected distance, the numerical range is 0 to P, and the blind area is removed;

d, a gain compensation coefficient, wherein the value of the gain compensation coefficient D is an integer between 1 and 10.

4. The method for improving the resolution of the objects in the fish sonar image according to claim 3, wherein the digital gain C is derived from the echo intensity values of the initial fish sonar image.

5. The method for improving the target resolution of the fishing sonar image according to claim 4, wherein in the step 1, the echo data uploaded by a host computer is processed according to sonar signals to obtain a real-time echo intensity maximum value max _ data, and the echo intensity value of the initial fishing sonar image is judged by comparing the real-time echo intensity maximum value max _ data with a preset echo intensity mid _ data; the digital gain C is preset with an initial value C ₀ When the maximum value max _ data of the real-time echo intensity is larger than the preset echo intensity mid _ data, the initial value C is set ₀ Reducing the real-time echo intensity maximum value max _ data to 3dB as the digital gain C, and when the real-time echo intensity maximum value max _ data is smaller than the preset echo intensity mid _ data, reducing the initial value C ₀ The digital gain C is increased by 3 dB.

6. The method for improving the resolution of the objects in the sonar images for fishing according to claim 3, wherein the gain compensation coefficient D is a value according to the value of the detection range R.

7. The method for improving the resolution of the objects in the sonar images for fishing according to claim 6, wherein when the value of the detection range R is below 1000m, the value of the gain compensation coefficient D is not less than 8; when the value of the detection range R is 1000-2000 m, the value of the gain compensation coefficient D is 6-8; when the value of the detection range R is 2000-4000 m, the value of the gain compensation coefficient D is 4-6; when the value of the detection range R is more than 4000m, the value of the gain compensation coefficient D is less than or equal to 4.

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