JPH044231Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses a laser distance meter that measures the distance to the point irradiated by the projection light by comparing the phase and time of the modulated waves between the projection light and the reflected light. The measured data is transferred to the CRT of the PPI radar.
This invention relates to a PPI radar image display type laser irradiation point display device that displays on the screen.

Conventionally, this type of laser distance meter has been fixedly installed on land and used for distance measurement. However, when this type of laser distance meter is installed on a moving body such as a ship to measure distance, the target point to be measured moves every moment, making it difficult to capture the target point. Moreover, in radar, every second
Since we perform measurements on the order of 1,000 times while rotating the radar antenna, we display data on the order of several dozen times for each target point, but for targets with heights or surfaces, It was difficult to confirm which specific point in the data was measured, and it was difficult to find ways to improve the situation.

In view of the above-mentioned circumstances, the present invention is able to confirm the position of the target point measured by the laser rangefinder on the radar displaying a wide area even if the number of measurements per second is different between the radar and the laser rangefinder. The target points measured at different measurement times by the laser distance meter and radar are displayed on the same screen, and the target reflected by the laser irradiation light is displayed as a bright spot on the CRT screen of the PPI radar, overlaid with the surrounding image. It is an object of the present invention to provide a PPI radar image display type laser irradiation point display device.

An embodiment of the device of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a simplified block diagram for explaining the basic operation of the device of the present invention. In the figure, reference numeral 1 denotes a laser distance meter section, which sends a measured distance value signal indicating the distance value for each measurement to the target and an azimuth signal indicating the direction of the laser distance meter toward the target to the next stage signal conversion section 2. supply Reference numeral 3 denotes a conventionally known ship radar, which supplies a radar trigger signal and an azimuth signal to the signal converter 2, and also supplies a radar trigger signal and a video signal of a radar echo to a second indicator 4. supply In the signal conversion section 2, each signal is converted so that the measured distance value signal and the direction signal output from the laser distance meter section 1 indicate the distance and direction on the same scale as the PPI display of the radar echo. It can be done. In addition, in the second indicator, the image of the radar echo and the target point to be measured by the laser rangefinder are the same.
They are displayed on the CRT screen at the same scale, and the target point to be measured is located in the radar PPI image so that it can be distinguished by a second sweep display that is different from the echo display.

Next, the basic temporal relationships of the respective signals will be explained using simplified waveforms shown in FIG. In the figure, 20
is a radar trigger signal, and 21 is a radar sweep waveform. The rise time of this sweep waveform 21 is determined by the radar trigger signal 20, and the sweep is performed during a sweep period 22 of the sweep waveform 21. In the short range of the radar, there is a sweep pause period 23 which is sufficiently longer than the sweep period 22. This period 23
A second trigger signal 24 having a fixed delay from the radar trigger signal 20 is generated during the process, and a second sweep waveform 25 and a converted distance signal 26 are generated by this signal 24. In addition, these signals and waveforms 24, 25, 26
is not generated for each trigger of the radar trigger signal 20, but is generated a fraction of the number of times, or when the angle at which the radar antenna is pointing matches the angle at which the laser rangefinder is pointing. It is generated in correspondence with the trigger signal 20.

The converted distance signal 26 will be explained in more detail.

The target point to be measured by the laser distance meter is displayed at a position that matches the distance and direction displayed by the radar corresponding to the measured distance value. For example, in the case of basic radar, the real-time time T (μs) corresponding to 450m
is T=450×2/300=3μS, and this distance is
If you try to display it 12cm from the center of the CRT screen,
The speed of the sweep line in the radar sweep waveform 21 is 1
It becomes 0.25 μs per cm. On the other hand, with a laser rangefinder
When the measured distance is 450 m, the second trigger signal 24 generates a signal with a delay of 200 μs per 1 km of the measured distance.
This is the converted distance signal 26 shown in FIG.
Here, 450m is 90μs, so if you want to display 450m at the same 12cm as the radar, the second sweep waveform 2
If the second sweep waveform 25 is used with the speed of the sweep line 5 set at 7.5 μs per cm, the radar target at 450 m is displayed at the same distance on the same CRT screen. Regarding direction, a synchronized transmitter that generates a direction signal is installed in the laser distance meter separately from the radar, and this direction signal determines the direction of the sweep line of the second sweep when the direction signal of the radar in the first sweep is used. is the same as

Next, the apparatus of the present invention will be explained in more detail with reference to the block diagram of FIG. In the figure, 30 is a conventionally known ship radar, and the ship radar 30 generates an azimuth signal 30a, a radar echo video signal 30b, and a trigger signal 30c. 31 is a laser distance meter, and the laser distance meter 31 receives a measured distance value signal 3.
1a is generated. Reference numeral 32 denotes a rotary table on which the laser distance meter 31 is mounted and fixed, and the rotary table 32 is rotationally driven by a rotary drive mechanism 33. Reference numeral 34 denotes a synchro transmitter provided in the laser range finder 31, and the transmitter 34 generates an azimuth signal for the laser range finder 31 in accordance with the rotation of the rotary table 32. A trigger signal 30c from the radar 30 generates a second trigger signal 35a in a second trigger transmitter 35. This signal 35
a is supplied to a conversion distance signal generator 36, which converts this second trigger signal 35a into a signal with a pulse width proportional to the numerical value of the measured distance value signal 31a supplied from the laser distance meter 31. The end of this pulse width generates a sharp pulse conversion distance signal 36a. 37 is a second indicator, and the second indicator 37 receives an azimuth signal 30a, a video signal 30b and a trigger signal 30c from the ship radar 30, an azimuth signal 34a from the synchro transmitter 34, and a azimuth signal 34a from the second trigger transmitter 35. second trigger signal 35a and conversion distance signal generator 36
A converted distance signal 36a from . Therefore, in this second indicator 37, two types of PPI
A sweep is performed. The first is PPI sweep of the radar echo, and by inputting the azimuth signal 30a, video signal 30b, and trigger signal 30c from the radar 30, the image of the radar echo is generated in the same way as in conventional radars.
displayed on the CRT screen. Next, the direction signal 34a from the synchro transmitter 34, the second trigger transmitter 3
A second sweep is performed by inputting the second trigger signal 35a from the converter 5 and the converted distance signal 36a from the converted distance signal generator 36, and the converted distance signal 36a is
is a special radar echo, that is, a laser rangefinder 31
is displayed on the same CRT screen as the image of the target echo.

For example, at night, the second indicator 37
Select the target to be measured with the laser range finder 31 from among the radar echo conditions displayed on the CRT screen, place the cursor on the image of the target echo, and operate the controller 38 provided on the second indicator 37. When the setting direction signal 38 is set by the controller 38,
a is generated, and this signal 38a is input to the measurement azimuth gate signal generator 39. Also, this signal 38a
is also input to the angle comparator 40, which receives the azimuth signal 34a input from the synchro transmitter 34 and the set azimuth signal 3 from the controller 38.
8a input, and if there is a difference, the error signal 40a generated from the angle comparator 40 is supplied to the rotational drive mechanism 33, and the rotation is rotated by the rotational drive mechanism 33 until the error signal 40a becomes zero. The stand 32 or the laser distance meter 31 is driven to rotate.

On the other hand, the measurement azimuth gate signal generator 39 receives the set azimuth signal 38a from the controller 38 and the radar 30
The measuring azimuth gate signal generator 39 generates the azimuth gate signal 39a at the moment when the azimuth angles of both azimuth signals match, and this azimuth gate signal 39a is input to the angle comparator 40.
is supplied to If the azimuth gate signal 39a is input to the angle comparator 40 when its error signal 40a is zero, the angle comparator 40 generates a measurement trigger signal 40b, and this signal 40b is transmitted to the laser distance meter. 31. The measurement trigger signal 40b causes the laser distance meter 31 to start a measurement operation, and the laser distance meter 31 supplies a measured distance value signal 31a to the conversion distance signal generator 36, where the measured distance value signal 31a is converted into a conversion distance signal. 36a, that is, converted into a radar equivalent echo signal corresponding to the position of the irradiation point of the laser distance meter 31, and this signal 36a is superimposed with the radar echo signal during the second sweep in the second indicator 37 to detect the target to be measured. Displayed as a bright spot.

Furthermore, when the laser distance meter 31 captures the target and starts measurement by the measurement trigger signal 40b,
In the second indicator 37, each time the laser distance meter 31 performs distance measurement during the second sweep, the direction signal 34 of the synchro oscillator 34 or the laser distance meter 31 is generated by the second sweep, in addition to the sweep of the image display of the radar echo.
A sweep is performed in the azimuth direction a, and the converted distance signal 36a, that is, the target point to be measured by the laser distance meter 31, is displayed on the same CRT screen together with the radar echo image so that the two can be distinguished. .
Note that the target point to be measured by the laser distance meter is displayed regardless of the radar antenna.

As explained in detail above, according to the device of the present invention, the pointing direction signal of a laser distance meter installed on a moving object such as a ship and the radar equivalent echo signal corresponding to the position of the irradiation point of the distance meter are converted into a radar echo signal. To,
The radar echo image and the target point to be measured by the laser rangefinder are superimposed using separate sweeps, and are displayed on the same CRT screen of the PPI radar, which allows you to see the entire area. It is possible to instantly measure accurate distances on moving objects using a laser distance meter while selecting the necessary target on the radar's PPI screen. Therefore, problems that could not be solved conventionally,
The difficulty of distance measurement using a laser distance meter on a moving body can be completely eliminated. Furthermore, it has great practical effects, such as significantly improving the short-range distance measurement accuracy of general ship radars, which was conventionally considered to be at its limit.

[Brief explanation of the drawing]

The drawing shows one embodiment of the PPI radar image display type laser irradiation point display device according to the present invention.
The figure is a simple block diagram to explain the basic operation.
FIG. 2 is an explanatory diagram for explaining the time relationship of each signal, and FIG. 3 is a block diagram showing the configuration of the entire apparatus. 1... Laser distance meter section, 2... Signal conversion section,
3, 30... Ship radar, 4, 37... Second indicator, 20, 30c... Radar trigger signal, 21
... Radar sweep waveform, 24, 35a ... Second trigger signal, 26, 36a ... Conversion distance signal, 25
...Second sweep waveform, 31...Laser distance meter, 31
a... Measured distance value signal, 32... Turntable, 33...
... Rotation drive mechanism, 34 ... Synchro transmitter, 34
a... Orientation signal, 35... Second trigger transmitter, 3
0a... Radar azimuth signal, 30b... Video signal, 36... Conversion distance signal generator, 38... Controller, 38a... Setting azimuth signal, 39... Measurement azimuth gate signal generator, 39a... Direction gate signal,
40... Angle comparator, 40a... Error signal, 40
b...Measurement trigger signal.

Claims (1)

[Scope of Claim for Utility Model Registration] A laser rangefinder that measures the distance to a selected target and outputs a measured distance value signal, on which the laser rangefinder is placed and rotates/stops based on the pointing direction error signal. a rotary drive unit; a synchro oscillator attached to the rotary drive unit and outputting a direction signal directed by the laser rangefinder; a radar unit generating a radar trigger signal, a direction signal, and a radar echo signal; measurement of the laser rangefinder a conversion distance signal generation unit that uses a distance value signal and a trigger signal of the radar unit as input signals to convert the measured distance value signal into a radar equivalent echo signal having the same scale as the radar PPI display; the radar equivalent echo signal and the radar echo signal; an indicator unit that displays PPI and generates an azimuth signal of a target specified by a cursor on the radar echo image, and compares the azimuth signal of the designated target with the azimuth signal pointed by the laser rangefinder; A PPI radar image display type, comprising an angle comparison section that outputs an error signal of the pointing direction, and displaying the image of the radar echo and the measured target point of the laser distance meter on the same screen of the indicator section. Laser irradiation point display device.