JPH01213590A - Active sonar device - Google Patents

Abstract

PURPOSE:To make the distance resolution of a CRT display finer without increasing the preciseness of the display by detecting the maximum value within a certain period on the level of received signals and performing correction in accordance with the detailed position of the maximum value. CONSTITUTION:Maximum value detecting circuits 7 and 8 detect maximum values at every fixed time T (seconds) from beam-1 level signals - beam-N level signals and output beam-1 maximum value signal 58 - beam-N maximum value signal 59 to an azimuth interpolating circuit 9. At the same time, the circuits 7 and 8 output beam-1 distance correcting signal 61 - beam-N distance correcting signal 62, which indicate where the maximum values exist during the fixed time T to a storage circuit 11. A distance correcting circuit 12 inputs a distance cursor position signal 63 and adds a correcting quantity DELTAt/2c(m) to a cursor distance in the unit of DELTAR decided by the signal 63. After adding the correcting quantity, the distance correcting circuit 12 outputs the corrected cursor distance to a distance azimuth calculating circuit 13 as a corrected dis tance cursor position signal 66 and the signal 66 is displayed on a display 14.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention transmits a pulse-modulated acoustic signal underwater, detects the presence of a target from the echoes reflected by the target, and determines the location of the target. Regarding active sonar equipment that measures

[Prior Art] A conventional active sonar device has a system as shown in FIG.

The prior art will be explained below with reference to FIG.

The transmission circuit l pulse-modulates the sine wave, performs power amplification, and generates a transmission signal 5! is output to the transmission/reception conversion circuit 2. The transmission/reception conversion circuit 2 outputs the transmission signal 51 as a transducer signal 52 to the transducer 3 during the transmission period, and outputs the transducer signal 52 from the transducer 3 as the reception signal 53 during the reception period. Output to the synthesis circuit 4.

The transducer 3 converts the transducer signal 52 into sound and radiates it into the water during the transmission period, and converts the underwater sound into an electrical signal and converts it into an electric signal as the transducer signal 52 during the reception period. Output to 2.

The operation during the reception period will be explained below.

The received signal 53 output from the transmission/reception conversion circuit 2 is synthesized by a method such as delay synthesis in the directional synthesis circuit 4, and then
As shown in the figure, for the entire circumference 360' (36Q/N)
Beam l signal 54 to beam N signal 55 (see FIG. 1) are equivalent to the received signals of a receiver having N trees of directional characteristic beams arranged in @ steps.

N detection circuits 5 to 6 detect the beam l signal 54.
~ Beam N signal 55 is detected and beam Loubel signal 56 ~ Beam N level signal 57 are output to the azimuth interpolation circuit 9.

The azimuth interpolation circuit 9 interpolates the beam rubel signal 56 to the beam N level signal 57 with a period of T [seconds], which is a certain fixed time, and outputs the azimuth vs. level signal 60 with improved azimuth accuracy to the CRTR 7 display l ratio. Strengthen.

The CRTR7 display 1 ratio displays the azimuth versus level signal on the B scope as shown in FIG.

Here, when the speed of sound is C [m/sec], the distance resolution ΔR is 8R=T − C/[ml].

Note that the target echo sound A is detected as a high-luminance portion on the display as shown in FIG.

The distance/azimuth cursor control circuit 15 outputs a distance cursor position signal 63 and an azimuth cursor position signal 64 in accordance with the operation by the operator of the sawchie, and controls the position of the cursor displayed on the CRT display IO.

The distance/azimuth calculation circuit 13 converts the distance cursor position signal 63 and the azimuth cursor position signal 64 from the distance/azimuth cursor control circuit 15 into numerical values, and outputs them as a distance numerical value signal 67 and a bearing numerical value signal 68 to the distance/azimuth display 14. The distance/azimuth indicator 14 displays these numerical signals in numbers and informs the sochie operator.

Here, the numerical display of the distance cursor is in units of the distance resolution ΔR described above.

[Problems to be solved] In the conventional active sonar described above, the range resolution is ΔR as mentioned above, so in order to refine the range resolution ΔR using short pulses, a high-definition CRT display is required. There was a problem in that it had to be prepared.

The present invention was conceived in view of the above-mentioned problems, and
without increasing the resolution of the RT display.

The purpose of this invention is to provide an actitsorchie device that can achieve finer distance resolution.

[Means for Solving Problems] In order to achieve the above object, the present invention transmits a pulse-modulated acoustic signal underwater, detects the presence of a target from the reflection reflected by the target, and detects the presence of the target. In an active search device for measuring a position, a maximum value detecting means detects the maximum value of the received signal level within the period and the position where the maximum value occurs at regular intervals; a display means for displaying the received level as the reception level; a storage means for storing the position of occurrence of the maximum value; This configuration includes distance correction means for performing correction based on the position of occurrence.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a system diagram of an embodiment of the present invention.

In the figure, transmitting circuit 1. Transmission/reception conversion circuit 2. Transducer/receiver 3. Directional synthesis circuit 4. Detection circuits 5-6. Orientation interpolation circuit 9. C
RT display lO1 distance/azimuth calculation circuit 13. Distance and direction indicator 14. Distance/azimuth cursor control circuit 15. Transmission signal 51
．． Transducer/receiver signal 52, received signal 53. beam l signal 54
~Beam N signal 55. Beam level signal 56 ~ Heem N
Level signal 57. Azimuth versus level signal 60. Distance cursor position signal 63. Since the azimuth cursor position signal 64, the distance numerical value signal 67, and the azimuth numerical value signal 68 are the same as the conventional ones shown in FIG. 3, their explanation will be omitted.

The feature of this embodiment is that, as shown in Fig. 1, a distance correction value is output at fixed time intervals indicating at what point in the period the maximum value of the received signal level occurred during that period. Each beam has a maximum value detection circuit 7 to 8 for each beam, and also has a storage circuit 11 for storing a distance correction value, and a distance correction circuit 12 for correcting the distance cursor position with the distance correction value. .

This example will be described in detail below.

The N maximum value detection circuits 7 to 8 detect the beam rubel signals to
The maximum value of the beam N level signal is detected every fixed time T [seconds] and the beam l maximum value signal 58 to beam N maximum value signal 59 are output to the azimuth interpolation circuit 9, and the maximum value is fixed. A beam I distance correction value signal 61 to a beam N distance correction value signal 62 indicating the position within the time period T are output to the storage circuit 11.

Figure 2 is a diagram for explaining the function of the maximum value detection circuit, and shows whether P is the maximum value of the beam level signal during a certain period of time T [seconds] (that is, the maximum value signal), Δt or its maximum value. Indicates the position (ie, distance correction value signal).

Beam l maximum value signals 58~ from maximum value detection circuits 7~8
The beam N maximum value signal 59 is interpolated and calculated by the azimuth interpolation circuit 9 and displayed on the CRTR 7 display as in the conventional case shown in FIG.

Furthermore, the beam L distance correction value signals 61 to beam N distance correction value signals 62 from the maximum value detection circuits 7 to 8 are stored in the storage circuit 11.
is memorized.

The storage circuit 11 inputs the distance cursor position signal 63 and the direction cursor position signal 64 from the distance/azimuth cursor control circuit 15, and calculates, from among the distance correction values detected every T [seconds] of all stored beams, The distance and direction specified by the cursor are selected and output to the distance correction circuit 12 as a distance correction signal q5.

The distance correction circuit 12 inputs the distance cursor position signal 63, and corrects the cursor distance in ΔR units determined by the distance cursor position signal 63 by the distance correction value Δt of the distance correction signal 65 from the storage circuit 11. min△t/2
c [Add ml.

This is output as a corrected distance cursor position signal 66 to the distance/azimuth calculation circuit 13.

Then, the corrected distance cursor position signal 66 and the azimuth cursor position signal 64 are converted into numerical values by the distance/azimuth calculating circuit 13 and displayed numerically on the distance/azimuth display 14.

[Effects of the Invention] As described above, the present invention detects the maximum value of the received signal level within a certain period, and displays the detected value as the level within that period.

By memorizing the detailed position of the maximum value and applying correction based on the memorized detailed position of the maximum value (1) when calculating the distance of the target echo from the cursor position, the definition of the CRT display can be adjusted. The effect is that the distance resolution can be made finer without increasing the distance resolution.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of an embodiment of the present invention, Fig. 2 is an explanatory diagram showing the operation of the maximum value detection circuit, Fig. 3 is a system diagram of a conventional active sonar device, and Fig. 4 is an explanation of the receiving beam. figure,
FIG. 5 is a reference diagram showing the display of the actitsu search device. 1: Transmission circuit 2 2 Transmission/reception conversion circuit 3: Transducer/receiver 4: Directivity synthesis circuit 5-6: Detection circuit 7-8: Maximum value detection circuit 9, azimuth interpolation circuit 10
: cRT display 11: Memory circuit 12: Distance correction circuit 13: Distance/azimuth calculation circuit 14: Distance/azimuth display 15: Distance/azimuth cursor control circuit 51: Transmission signal 52: Transmission/reception wave layer signal 53: Reception signals 54-55: Beam l signal to N signal 56 to 57; Beam level signal to N level signal 58 to 59: Beam l maximum value signal "N maximum value signal 60: Direction vs. level signal 61, Beam l distance correction value signal to N distance correction value Signal 63: Distance cursor position signal 64: Direction cursor position signal 65: Distance correction signal 66: Corrected distance cursor position signal

Claims (1)

[Claims] In an active sonar device that transmits a pulse-modulated acoustic signal underwater, detects the presence of a target from the echoes reflected by the target, and measures the position of the target, the received signal within that time is measured at regular intervals. Maximum value detection means for detecting the maximum level and the position at which the maximum value occurs; display means for displaying the maximum value as the reception level within that time; and a memory for storing the position at which the maximum value occurs. and distance correction means for correcting the target distance based on the occurrence position of the maximum value stored in the storage means when calculating the target distance from the cursor on the display by the display means. .