JPH0264481A - Passive sonar apparatus - Google Patents

Abstract

PURPOSE:To limit the position of a target by calculating and operating the position line and position of the target from the Doppler shift quantity of a target frequency spectrum within a real time to display both of them. CONSTITUTION:Sensors 1 are arranged so that non-directional receivers are dispersed at proper positions and the outputs of the sensors 1 are supplied to a frequency analyzing circuit 2. The frequency analyzing circuit 2 analyzes the frequency of the output of each sensor to send the analytical result to a display device 3 and the F-T display of the frequency analytical result is performed on the display device 3. An operator finds out the frequency spectrum of a target from the F-T display and uses the input function of the display device 3 to indicate the tracking frequency of the target. The indicated frequency spectrum is tracked by a frequency tracking circuit 4 to output frequency data of a real time to which Doppler shift is applied to an operation circuit 5. A display device 6 uses the center coordinates and radius of a circle obtained by the operation circuit 5 to display a circular arc as a position line and simultaneous searching is performed using three or more sensors to make it possible to determine the position of the target.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a passive sonar device, and in particular to an omnidirectional receiver that frequency-analyzes the radiation noise of a target and finds and detects a characteristic frequency spectrum of the target. The present invention relates to a distributed distribution method passive sonar device.

[Prior Art] Conventionally, as a position localization method for this type of passive sonar device, when a sensor detects, the C of the target frequency spectrum is
Focusing on the Doppler shift during PA, the target's position line during CPA was displayed.

[Problems to be Solved by the Invention] In the conventional passive sonar device described above, the sensor focuses on the Doppler shift at the time of CPA of the target frequency spectrum at the time of detection, and displays the position line of the target at the time of CPA. Therefore, even if the target is detected, the CPA
It had the disadvantage that it could only draw the target position line at a moment's notice and could not display the position line in real time.

[Means for Solving the Problems] The present invention has been made to solve the above problems, and as a means for solving the problems, the present invention provides omnidirectional distributed wave receivers, and a frequency analysis circuit that analyzes the received wave frequency; a display that displays the analysis results of the analysis circuit;
A frequency tracking circuit that tracks the target frequency spectrum during target detection, an arithmetic circuit that calculates the target position line and target position in real time from the Doppler shift amount of the target frequency spectrum, and a display that displays the target position line and target position. The configuration includes a container.

[Example] Next, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. An outline will be explained with reference to FIG.

The sensor 1 has omnidirectional receivers distributed at appropriate locations, and the sensor output is connected to a frequency analysis circuit 2.

The frequency analysis circuit 2 analyzes the frequency of each sensor output and sends the analysis results to the display 3.

The frequency analysis results are displayed in F-T (horizontal axis: frequency, vertical axis: time) on display 3. The operator finds the target frequency spectrum from the FT display and uses the input function of display 3 to display the target tracking frequency. Specify.

The frequency tracking circuit 4 tracks the frequency spectrum of the target specified above and outputs real-time frequency information subjected to Doppler to the arithmetic circuit 5.

The arithmetic circuit 5 calculates the current target frequency f when Doppler is applied and the target frequency fO when Doppler is not applied.
From this, the angle θ to the sensor relative to the target course is calculated using the following formula (see Figure 2).

However, C: sound speed V: target speed fO, V use the values obtained when the target passes through the CPA once. Furthermore, in the case of simultaneous detection by multiple sensors, for example, if two sensors, sensor A and sensor B, simultaneously detect the target, if the angle to sensor A with respect to the target's course is OA, and the angle to sensor B is 08, then the target The position line is the angle OA-θ between the azimuth lines from sensor A and sensor B.
Since B can be represented as a constant circular arc, the center and radius of the circle for calculating the position line are calculated (see FIG. 3(a)).

Similarly, when three sensors simultaneously detect, the centers and radii of the three circles are calculated (see Figure 3(b)).

Using the coordinates of the center of the circle and the penumbra obtained by the arithmetic circuit 5, the display 6 displays the arc as a position line.

If three or more sensors are used for simultaneous detection, the arcs intersect at one point, which determines the target's location and course. Furthermore, the movement of the target can be displayed in real time on the display 6 based on the circular arc data sent from the calculation circuit 5 every moment.

[Effects of the Invention] As explained above, the puffive sonar device of the present invention has the following effects:
Omnidirectional distributed receivers, a frequency analysis circuit that analyzes the received frequency of the receiver, a display that displays the analysis results of the analysis circuit, and a target frequency spectrum during target detection. , a frequency tracking circuit that tracks the target frequency spectrum, a calculation circuit that calculates the target position line and target position in real time from the Doppler shift amount of the target frequency spectrum, and a display that displays the target position line and target position. ,
By tracking the target's frequency spectrum while multiple sensors are detecting the same target, the target's position line or position and course can be displayed in real time, which has the effect of localizing the target's position.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a passive sonar device according to an embodiment of the present invention, Fig. 2 is a diagram showing the Doppler shift of the target frequency spectrum based on the positional relationship between the target course and the sensor, and Fig. 3. (a) and FIG. 3(b) are diagrams showing position lines and target positions determined in simultaneous detection by multiple sensors.

Claims (1)

[Claims] Omnidirectional distributed receivers, a frequency analysis circuit that analyzes the received frequency of the receiver, a display that displays the analysis results of the analysis circuit, and a target frequency spectrum during target detection. A frequency tracking circuit for tracking the target frequency spectrum, an arithmetic circuit for calculating the target position line and the target position in real time from the amount of Doppler shift of the target frequency spectrum, and a display for displaying the target position line and the target position. A passive sonar device.