JPS62105071A - Radar equipment for marine vessel - Google Patents

Abstract

PURPOSE:To eliminate a pseudo image formed in a radar screen owing to a structure on a vessel and to improve a radar function by storing pieces of received information from a tranmsitter-receives corresponding to the 1st and the 2nd antenna systems separately and outputting them at a specific timing. CONSTITUTION:The 1st antenna 10A is mounted at the bow part of the vessel and put in charge of target detection for the 1st azimuth range in front of the bow, the 2nd antenna mechanism 10B is mounted on the stern part and put in charge of target detection for the 2nd azimuth range behind the stern, and the transmitter receivers are provided separately corresponding to those mechanisms. A memory mechanism 20 is stored with the pieces of received information outputted by the transmitters-receivers 12A and 12B separately and outputs them at the predetermined timing. The composite image of the 1st and the 2nd azimuth ranges is displayed on an image display mechanism 21 based on the output information from the memory mechanism 20.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a marine radar device, and particularly to a marine radar device equipped with two antenna mechanisms for target object detection.

[Conventional technology]

Generally, in a marine radar system, a support such as a radar mast is installed at a predetermined position on the ship's hull (for example, at the stern).
Many systems are used in which an antenna mechanism comprising a radar antenna and an antenna drive unit that moves the radar antenna is installed at a predetermined height of the support.

In this method, while the antenna is rotated at a predetermined speed by an antenna drive unit, radar radio waves are transmitted and received by a separately equipped transceiver through the antenna, and the target object is detected on a display device such as a cathode ray tube. It is designed to display images.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional technology, the vertical beam width of the radar transmission wave is set relatively wide (for example, 25 degrees) in consideration of the ship's rolling, etc., so a part of the transmission wave is The waves are reflected by structures (such as tanker tanks, cranes, bridges, etc.) in a direction unrelated to the measurement detection direction, and this reflected wave detects a target in a direction that is not originally the detection target, making it appear as if the measurement detection The target is displayed as if it exists in the direction.

Since a so-called false image is displayed on the display, it has often been pointed out that the reliability of the radar image is significantly reduced, such as when an operator misidentifies the false image as a real target.

In addition, to solve the above-mentioned disadvantages, it is possible to install the antenna mechanism higher, but in this case, it will be difficult to secure visibility to the close range of the ship, so the height of the antenna mechanism should be set at a specified height. There was a situation where it was limited.

Furthermore, to address the above-mentioned disadvantages, a method has been proposed in which a radio wave absorber is pasted on structures to prevent reflection and scattering of radar waves, but in this method, the radio wave absorber itself is expensive. Therefore, large ships with the above-mentioned disadvantages are particularly expensive, and absorption efficiency for radio waves other than those incident vertically decreases significantly, making it impractical.

[Purpose of the invention]

The present invention improves the disadvantages of the prior art and, in particular, almost completely eliminates false images on radar images caused by structures on board the ship, thereby improving radar functionality. The purpose is to provide a marine radar device that can.

[Means for solving problems]

Therefore, in the present invention, a first antenna mechanism is installed at the bow portion and is responsible for detecting a target object in a first azimuth range in front of the bow, and a first antenna mechanism is installed at the stern portion and responsible for detecting a target object in a second azimuth angle range behind the stern. Equipped with a second antenna mechanism responsible for detection and a transmitter/receiver separately equipped corresponding to each of these antenna mechanisms,
a memory mechanism that separately stores the received information output from each transmitter/receiver and outputs it at a predetermined timing; The present invention attempts to achieve the above object by adopting a configuration including a single image display mechanism that displays a composite image with two azimuth angle ranges.

[For production]

1st. The transmitter/receiver separately installed in the second antenna mechanism transmits and receives radar radio waves via each antenna mechanism, and outputs each received information to the memory mechanism. In the memory mechanism, the first
The received information in the azimuth range of the azimuth range and the received information in the second azimuth range behind the stern by the second antenna mechanism are stored separately, and each received information is sent to the image display mechanism at a predetermined timing. Output. This image display mechanism displays a composite image of the first azimuth angle range and the second azimuth angle range based on the sent information. In this case, each of the first and second azimuth angle ranges is set in an appropriate manner so that the radar radio waves are not reflected by a structure on the ship located between the first antenna mechanism and the second antenna mechanism. By setting this value to a value, it is possible to eliminate false images caused by the structure from the radar image and increase the reliability of the radar image.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

First, in FIG. 1, IOA indicates the first antenna mechanism, 1' OB indicates the second antenna mechanism, and 12
A and 12B indicate first and second transceivers respectively installed in each of the antenna mechanisms 10A and IOB. Among these, the first antenna mechanism 10A is installed at a predetermined position on the bow part as shown in FIG. It is responsible for detecting targets (180°).
In addition, the second antenna mechanism 10B is installed at a predetermined position on the stern portion and is responsible for detecting targets in a second azimuth angle range θB (180° in this embodiment) in the stern direction while rotating 360°. ing.

The main parts of the first antenna mechanism 10A include a first radar antenna 14A for transmitting and receiving radio waves, a first motor 16A that rotates the first radar antenna 14A at a constant speed, and a first radar antenna 14A that rotates the first radar antenna 14A at a constant speed. The rotation angle of the antenna 14A is constantly detected electrically and an analog angle signal RA is generated.
(hereinafter referred to as "analog angle signal")
It is equipped with a synchro oscillator 18A. Further, the second antenna mechanism 10B is similarly configured by a second radar antenna 14B, a second motor 16B, and a second synchro oscillator 18B.

and each of the first and second radar antennas 14A,
14B are designed to perform a detection operation using radio waves of the same frequency while rotating at a predetermined rate asynchronously with each other (in this embodiment, the rotational speeds are the same).

Here, different radio wave frequencies may be used for the radar antennas 14A and 14B.

For this reason, each of the transceivers 12A, 12B (these are
The pulsed radio waves generated in the transmitting section (which has the same configuration here) are transmitted to each of the first and second radar antennas 14A, 14 via a transmitting/receiving switching section (not shown).
B and radiates into the atmosphere. Then, the reflected waves from the target object are received by the radar antennas 14A and 14B, and outputted to the receiving section via the transmission/reception switching section, subjected to predetermined processing, and sent to an intermediate frequency amplifier (not shown) as an analog image signal ( (hereinafter referred to as "analog image signal") VD, ,VD
B is obtained and sent to the next stage memory mechanism 20. In addition, each of these transceivers 12A,
12B is configured to form predetermined transmission trigger signals T P A and T P 11 in synchronization with the transmission wave and output them to the memory mechanism 20 as well.

Further, the first synchro oscillator 18A in the first antenna mechanism 10A has a corresponding first antenna 14A.
It is configured to output one pulse-like rotation signal RT each time it rotates, and also outputs it to the memory mechanism 20.

And, as mentioned above, the analog angle signal RA.

The memo IJ a structure 20 that inputs each of RB, analog image signals VDA, VD, transmission trigger signals TPA, TPIl, and rotation signal RT extracts predetermined target object information from each of these signals and processes it. Each of the antenna mechanisms 10
It is configured to separately store received information corresponding to A and 10B, and to output this to the next stage image display mechanism 21 as necessary. As described later, this image display mechanism 21 synthesizes the received information of each of the first and second azimuth angle ranges θ, , θ, and synthesizes the received information of the entire range (360
') is configured to form a target object detection image.

Here, the memory mechanism 20 and image display mechanism 21 will be explained in more detail.

First, an example of the memory mechanism 20 is shown in FIGS. 3 and 4.

In these figures, the memory mechanism 20 has a first .
Second image signal processing means 22A.

22B, and 1st. Second angle signal processing means 32A, 3
2B, and each of the angle signal processing means 32A, 32B includes the first .2B of the input information to be stored. Second azimuth angle range θ4. A reference angle signal generator 42 for setting θ8 is also provided.

Further, the digital image signals VD,', VD,', which have been A/D converted and processed in each of the image signal processing means 22A, 22B as will be described later, are sent to the memory means 50,
On the other hand, the angle signals R and II are processed by the angle signal processing means 32A and 32B.

RB'' is sent to first and second write control means 44A and 44B provided correspondingly, and these first and second write control means 44A and 44B receive the respective angle signals RA''.
, RB'' are sent to the memory means 50, and the digital image signals VDA', VD,' are written into the memory means 50. The digital image signals VDA' and VD8' in the memory means 50 are read out at a predetermined timing by the action of the readout control means 58 and the mode setting means 52, and are output to the image display mechanism 21. Reference numeral 23 denotes a dot clock generator that outputs a reference clock signal CP, which is the basis of the overall operation of the memory mechanism 20 and the image display mechanism 21.

To explain this in more detail along the signal flow, first, the first. The transmission trigger signals TPA, TP and analog image signals VDA, vDI+ respectively output from the second transceivers 12A, 12B are sent to the first and second image signal processing means 22A, 22B in the memory mechanism 20, respectively. Output.

As shown in FIG. 4, the first image signal processing means 22A includes a buffer memory 26 as a main part, and is provided with a quantization section 24 at its input stage. Write address generator 2
8 and a read address generation section 30 are provided together.

The analog image signal VDA input to the first image processing means 22A is first sent to the quantization section 24. This quantization unit 24 transmits a transmission trigger signal TPA.
The analog image signal vDA is quantized for each sweep (IPPIPP-P) based on a predetermined sampling clock synchronized with the , and is outputted to the next-stage backup memory 26 as a quantized image signal, that is, a digital image signal VDA'. It has the function of In this buffer memory 26, the digital image signal vDA' is temporarily stored in a predetermined memory cell in accordance with a write address signal from a write address generation section 28 which operates and outputs in synchronization with the transmission trigger signal TPA. It is now possible to do so. Further, the digital image signal DA' in the buffer memory 26 is read out at a predetermined timing by a read address generation section 30 that generates a read address signal based on the reference clock signal CP, and is outputted to the memory means 50. It looks like this.

The second image signal processing means 22B is similarly constructed and functions in the same manner.

In addition, analog angle signals RA, R, (r, θ; polar coordinate data) from the first and second antenna mechanisms 10A
are configured to be sent separately to the first and second angle signal processing means 32A and 32B in the memory mechanism 20, as described above.

Of these, in this embodiment, the first angle signal processing means 32A includes a comparison section 38 and a coordinate transformation section 4, as shown in FIG.
Further, an A/D converter 34 is provided at the input stage of the coordinate converter 40 via a launch circuit 36.

The analog angle signal RA inputted to the first angle signal processing means 32A is transmitted to the above-mentioned A/D converter 34.
is converted into a digital angle signal RA'(r, θ) and sent to the launch circuit section 36 at the next stage. A part of the above-mentioned transmission trigger signal TPA is sent to this launch circuit section 36. The launch circuit section 36 latches the digital angle signal RA' at the falling timing of the transmission trigger signal TPA, temporarily stores it, and then immediately outputs it to the comparison section 38 and the coordinate conversion section 40, respectively. It has the function to

On the other hand, the memory mechanism 20 includes the first. Azimuth angle range θ4. which each second antenna 14A, 14B is responsible for. A reference angle signal generator 42 for determining θ8 is provided (see FIG. 3).

Here, the digital reference signals (θ5.~θ,2), (θ21~θ2□
) (see Figure 2 (2)) in 1st. It is possible to output the signal to each comparing section 38 of the second angle signal processing means 32A, 32B.

Therefore, the comparator 38 of the first angle signal processing means 32A uses the digital reference angle signal (θ1. to θ1□
) is compared with the above-mentioned digital angle signal RA', and as a result, the comparing section 38 is configured to send an enable signal WE to the next-stage first write control means 44A.

In this embodiment, this enable signal WEA is a digital reference angle signal (θ, ~θ1□), a digital angle signal R,
If they match (that is, RA' is within θ^), the level is set to a predetermined "low" level, and if they do not match (Rt+'
is outside θ), it is set in advance to be at a “high” level.

Furthermore, in the coordinate conversion section 40, the digital angle signal RA
'(r, θ polar coordinate data) is x=rsinθ
, according to the formula y=rcosθ, orthogonal coordinate data (
x, y) into a digital angle signal RA'', which is output to the next stage first write control means 44A. ROM (Read) that stores conversion data
0nly Memory) is used.

The second angle signal processing means 32B is also constructed in substantially the same manner and functions in the same manner.

And the above-mentioned 1. Second angle signal processing means 32A, 3
A predetermined signal WEA output from 2B.

RA', WEB, R,'' are sent to first and second writing means 44A and 44B provided correspondingly, respectively.

In this embodiment, the first writing means 44A is composed of a write address generation section 46 and an off-center setting section 48, as shown in FIG.

Of these, the write address generator 46 operates in synchronization with the reference clock signal CP, and when the enable signal WEA sent thereto is at a "low" level, the write address generator 46 generates a write address signal WRA based on the digital angle signal RA''. On the other hand, when the enable signal WEA is at a "high" level, no write address signal WRA is output.

In addition, the off-center setting device 48 detects the positional deviation between the installation positions of the first antenna mechanism 10A and the second antenna mechanism 10B and the installation position of the image display mechanism 22 (see FIG. 2).
This is to correct SA and SI+ in 1). In other words, ignoring this positional shift, the azimuth range θ
, , θ6, when images are combined, a step (shift) occurs in the image corresponding to the positional shift, so this is to eliminate this. For this reason, the off-center generator 4
Reference numeral 8 is configured to apply a correction signal corresponding to the interval of the positional deviation to the write address generation section 46 in advance to generate a write address signal WRA with the positional deviation corrected.

The second write control means 44B is also constructed in the same manner as described above and functions in the same manner.

Here, the second antenna mechanism 10 installed at the stern
Regarding the information received from B, as mentioned above,
A second image signal processing means 22B, a second angle signal processing means 32B, and a second write control means 44B are provided within the memory mechanism 20. In this case, from the reference angle signal generator 42 to the comparison section 3 of the second angle signal processing means 32A.
8 (not shown), a digital reference angle signal (θ21 to θ2□) corresponding to the azimuth angle range θ8, which is the responsible By area of the second antenna 14B, is provided.

The memory means 50 forming the main part of the memory mechanism 20 includes:
In this embodiment, four RAMs (Ra
ndom Access Memory) 5
0 A+, 5 0 B+.

It is composed of 50Az and 508z.

Of these, the RAMs 50A and 50A2 are supplied with digital image signals VD,' from the first image signal processing means 22A, and are supplied with a write address signal WRA from the first write control means 44A. As described later, the digital image signal DA' can be written into either RAM 50A or 50Az which is in the write mode. Further, the RAMs 50B+ and 50B2 are supplied with the digital image signal VDB' from the second image signal processing means 22B and the write address signal WRB from the second write control means 44B. As described later, the digital image signal VDB' can be written into either RAM 50B+ or 508z which is in write mode.

In this write operation, the first radar antenna 14A
The radio wave emission direction is within the first azimuth angle range θ.

or when the radio wave emission direction of the second radar antenna 14B is outside the second azimuth angle range θ, the respective recessed address signals are WRA and WRIl will not be output, and in this case, the digital image signal VDA'.

Even if VDs' is given, it is not written in the end because there is no address specification.

Further, the memory means 50 described above includes the memory means 50.
The above-mentioned mode setting means 52 is provided to determine whether each of the RAMs 50A, 50B+, 50A2, and 50B2 is in the read mode or the write mode. In this embodiment, the mode setting means 52 includes a mode control section 54 and an inverter 56.

To explain this in more detail, the mode control section 54 in the mode setting means 52 receives the reference clock signal CP from the don't clock generator 23 and the first antenna mechanism 10.
A rotation signal RT is given from A. Therefore, the mode control unit 54 operates in synchronization with the reference clock signal CP, and each time the rotation signal RT is detected once (the antenna rotates once), a predetermined logic "high" or "low" level is read. Write control signal (hereinafter referred to as "rR/W control signal")
The square wave-like operation of outputting and holding it until the next rotation signal is detected is repeated. This R/W control signal is applied as it is to the RAM 50A2.5082, and is also applied to the RAM 50A via the inverter 56.
1.5 The configuration is also given to QB. As a result, in this embodiment, the R/W control signal becomes "high".
When the level is "low", the RAMs 50A2 and 5082 are in the write mode and the RAMs 50A+ and 50B are in the continuous output mode, and when the level is "low", the mode is set to be the opposite.

Further, in order to control reading from the memory means 50, a read control means 58 is provided as shown in FIG. In this embodiment, the read control means 58 includes a read address generator 60 and a read changeover switch 62.

To explain this in detail, the read address generation section 60 has a function of generating a read address signal RD for one image screen (one frame) at a predetermined timing in synchronization with the reference clock signal CP.

Further, this read address signal RD is transmitted to the RAMs 50A+, 50B1 . or 50A2, 5082.

Further, the switching operation of the readout changeover switch 62 is performed in the third mode.
As shown in the figure, the mode control operation is performed in synchronization with the mode control operation by the mode control section 54 of the mode setting means 52. Specifically, when the R/w control signal is "high"
In the case of level, contact a- of readout switch 62
Conductive between c (state shown in Figure 3) and R in read mode
The read address signal R is applied to AM50Az and 50B+.
It is configured to output D. Therefore, in this state, the RAM 50A corresponding to the successive address signal RD, .
50B, digital image signals VDA' and VD+! ′
is read out and sent to an image display mechanism 21, which will be described later. In addition, when the R/W control signal is at the "low" level, on the contrary, the contacts b and c become conductive, and as a result, the digital image signals VDA' and VD,' in the RAM50A2.50BZ which are in the read mode are It is read out and sent to the image display mechanism 21 as well.

In this embodiment, the image display mechanism 21 includes a CR7 display section 68, a CRT control section 70 that controls the CR7 display section 68, and an OR It is composed of a circuit 64 and a D/A converter 66 (see FIG. 1). Then, as described above, the digital image signal VDA'VD! is read out from the memory mechanism 20! +' are each input to an OR circuit 64 (4-man power), and the output signal is converted to an analog image signal again by a D/A converter 66 and sent to the next stage CR7 display unit 68. There is.

Further, the CRT control section 70 has a function of outputting a predetermined control signal when energized by the reference clock signal CP from the don't clock generator 23. And this C
A control signal from the RT control section 70 is given to the D/A conversion section 66 and the CR7 display section 68, so that these are controlled respectively. Therefore, the CR7 display section 68
On the screen, a composite image of the area of the first azimuth angle range θ and the area of the second azimuth angle range θ is displayed on the own ship's CRT display section 6.
The screen is configured to be displayed using a rask scan method with the installation position No. 8 as the origin.

Next, the overall operation of this embodiment will be explained according to the timing chart of FIG.

First, when the device is powered on, the dot clock generator 2
3 is activated and the reference clock signal CP is output to each part (
(See Figure 5 ■), the control operations of each part described later are controlled by this signal C.
This is done in synchronization with P.

It is also assumed that the mode control section 54 in the mode setting means 52 outputs an R/W control signal of a logic "high" level as its initial value (see FIG. 5 (2)). As a result, as mentioned above, the RAM 50A+ in the memory means 50
, 50B, becomes successive output mode and RAM50Az, 50
Bz becomes write mode. At the same time, the readout changeover switch 62 in the readout control means 58 is electrically connected between the contacts a and c (the state shown in FIG.
It becomes possible to output to M50A, 50B+ (see Figure 5@).

As the entire apparatus operates, the memory mechanism 20 performs writing and reading of received information, and the image display mechanism 21 performs a composite image display operation.

Here, first, the writing operation of received information will be explained sequentially starting from the receiving system of the first antenna mechanism 10A.

First, in conjunction with the target object detection operation of the first antenna 14A, the first transceiver 12A outputs the transmission trigger signal TPA to the memory mechanism 20 for each sweep as described above (see FIG. 5). , the analog angle signal RA is output from the first antenna mechanism 14A to the memory mechanism 20 (see ``■'' in the figure). Furthermore, when the first transmitter/receiver 12A outputs the transmission trigger signal TPA, the first transmitter/receiver 12A responds with a
An analog image signal VDA for one sweep is obtained (Fig.
Reference (actually a complex shaped signal) is also provided to the memory mechanism 20.

Of these, the analog angle signal RA (in polar coordinates) is converted into a digital angle signal R8'Cr, θ) by the action of the first angle signal processing means 32A (see Fig. 5), as described above, and the latch After the operation, it is output to the first writing control means 44A as a digital angle signal RA'' (x, y) converted into orthogonal coordinates (see Fig. 5). Also, this first angle signal processing In the means 32A, the first azimuth angle range θ from the reference angle signal generator 42 is
A comparison is also made with reference signals (θ1. to θ, 2) corresponding to , and as a result, an enable signal WEA is output to the first write control means 44A (see FIG. 5 (2)). That is, the received digital angle signal RA' is the reference signal (θ,
~θ,2), the enable signal WE
A becomes a predetermined "low" level, and the first write control means 44A outputs the write address signal WRA to the RAM 50A2 (write mode) of the memory means 50 (R
AM50A is in read mode as described above (see Figure 5). However, the digital angle signal RA' is the reference signal (θ
11 to θ+z), the write address signal WRA is not output as described above.

On the other hand, the analog image signal ■ output to the memory mechanism 20
DA is converted into a digital image signal VDA' by the action of the first image signal processing means 22A (see FIG. 5 [phase]), and after being temporarily stored for each sweep, it enters the write mode at a predetermined timing. The data is sent to the RAM 50 Az.

Therefore, in the RAM 50A2 in the write mode state, the content D1 of the digital image signal VDA' is stored in the address A10, for example, according to the write address signal WRA.
゜ is written. This write operation is continuously performed for each transmission trigger signal TPA.

Here, the above-mentioned write operation is performed in the same way in the system of the second antenna mechanism 10B, which has the same rotation speed but performs target object detection while rotating asynchronously, and in this case, it is in the write mode. Information is written to RAM 5082 (RAM 50B).

is continuous mode) (see Figure 5 ■).

As a result, RAM 50 A z has the first azimuth angle range θ when the first seven antennas 14A rotate once.

The second azimuth range 08 when the second antenna 14B makes one rotation is stored in the RAM 50B2.
The received information for each period is written and stored. During this write operation, the RAMs 50A, 50B mentioned above
, is read out and displayed as described below.

These write and read operations are performed while being alternately inverted in synchronization with the rotation signal RT from the first antenna 14A.

In this case, the rotation signal RT may be synchronized with the second antenna 14B.

Next, the read operation will be explained using the above example.

That is, when the RAMs 50Az and 50Bz are in the write mode, the RAMs 50A+ and 50B+ are in the read mode, so the read address signal RD from the read address generator 60 of the read control means 58 is in the RAM 50A+
, 50B+. This allows R.A.
All the data of the digital image signals VD, ', VD,' written in M50A+ and 50B+ during the write mode (see Fig. 5 [Phase] ■) are read out at a high-speed predetermined timing, and the next stage image is read out. It is sent to the display mechanism 21.

Then, the image display mechanism 21 combines the digital image signals VDA' and VD8' output from the two RAMs, and displays the combined image on the CRT 68 using a rask scan method. That is, the half image A (see FIG. 6 (11)) of the azimuth angle range θA (here, 180°) shared by the first antenna 14A and the azimuth range θ shared by the second antenna 14B, (here, 180°) half image B (see (2) in the same figure) is combined, and the own ship's CRT display unit 68
A composite image C (see (3) in the same figure) centered on the set position (that is, the position of the image display mechanism 21) will be displayed. In this case, as described above, the first and second antennas 14A and 14B are each rotated by 360 degrees, but their received information does not contribute to the composite image C outside the assigned range.

Furthermore, each time the first antenna 14A completes one rotation (that is, the second antenna 14B also completes one rotation), the R/W control signal is inverted by being energized by the rotation signal RT. New received information is read out from the existing RAM, and the composite image C is updated.

In this way, in the two embodiments, the number is 360 for own ship.

The azimuth angle range is within a predetermined range θ1. Since the detection will be divided into θ8 parts, the structure within own ship ¥yJ
By setting θ and θ8 to avoid reflection caused by Unnecessary false images caused by the object 72 are not displayed, and it is possible to prevent misidentification with a real target. In addition, when radar radio waves detect a structure on the own ship, if the structure is relatively large, there is often a blind spot in the direction of its shadow, where detection is impossible. There is an advantage that this blind spot can also be eliminated. Therefore, the radar device is easy to see for the operator and has excellent detection ability, which contributes to the safety of navigation.

In addition, in this embodiment, since the write operation and the read operation for the memory means 50 can be controlled independently, in the case of reading, the antenna rotation, that is, high-speed reading can be performed without being affected by the writing speed. There is also an advantage that the visibility of the CRT display section 68 is improved.

In the above embodiment, the first and second azimuth angle ranges θ8.
Although θ3 is set to 1806 for each, the present invention is not necessarily limited to this, and depending on the structural circumstances of the ship, the reference signal of the reference angle signal generator 42 may be changed to assign a different azimuth angle (for example, θ, = 280°, θ8 = 80°), or a configuration may be adopted in which this adjustment can be easily performed from the outside. Furthermore, in the embodiment described above, each RAM of the memory means 50 has a capacity corresponding to one screen (one rotation of the antenna), but may have a capacity corresponding to the above-mentioned azimuth division.

Further, the scanning method of the CRT display section 68 is not necessarily limited to the Rask scan, but may be a PP■ scan method.

On the other hand, in the embodiment, the first and second antennas 14A
, 14B are installed at the bow and stern portions of the ship, but they may be installed at other appropriate positions, and a configuration using, for example, three antennas is also possible.

Furthermore, the above-mentioned embodiment is applicable not only to ships but also to land-based applications such as port radars. It is assumed that a false image is generated due to reflection, and in this case, the present invention is applied by determining two predetermined locations via this bridge, and the land radar detects a ship passing under this bridge. It is expected that this method will be effective in transmitting images and obtaining radar images without false images on board the ship.

〔Effect of the invention〕

Since the present invention is configured and functions as described above, according to this, even if there is a structure on the ship that reflects radar radio waves with a predetermined vertical beam width between the bow and the stern, By appropriately determining the first and second azimuth angle ranges to avoid the structure, it is possible to almost completely prevent false image detection caused by the structure, which is not originally included in the radar image. This is an excellent marine radar system that improves the reliability of the target object, thereby eliminating unnecessary trouble for the operator or giving the operator no chance of misidentifying it as a real target, and thus further enhancing the radar's original functions. can be provided.

[Brief explanation of drawings]

FIG. 1 is an overall block diagram showing an embodiment of the present invention, FIG. 2 (1) is an explanatory diagram showing the positional relationship between the first and second antenna mechanisms, and FIG. 2 (2) is an explanatory diagram showing the positional relationship between the first and second antenna mechanisms. An explanatory diagram explaining the second azimuth angle range, FIG. 3 is a block diagram showing details of the memory mechanism in FIG. 1, and FIG. 4 shows the first image signal processing means and angle signal processing in FIG. 3. FIG. 5 is a block diagram showing details of the means and write control means; FIG. 5 is a timing chart showing the operation centered on the first antenna mechanism of the embodiment shown in FIG. 1; FIG. are explanatory diagrams each explaining a composite screen. 10A...First antenna mechanism, IOB...
...Second antenna mechanism, 12A, 12B...
・First as a transmitter/receiver. second transceiver, 20...
...Memory mechanism, 21... Image display mechanism. Patent applicant: Tokyo Co., Ltd. Keiki No. 2/” θB1 Fig. 6(f) -A'tn-

Claims (1)

[Claims] (1) A first antenna mechanism is installed at the bow and is responsible for detecting targets in a first azimuth range forward of the bow, and a first antenna mechanism is installed at the stern and is responsible for detecting targets in a second azimuth range behind the stern. The second antenna mechanism is equipped with a second antenna mechanism, and a transmitter/receiver is equipped separately corresponding to each of these antenna mechanisms, and the received information output from each of the transmitter/receivers is stored separately and transmitted at a predetermined timing. and a single image display mechanism that displays a composite image of the first azimuth angle range and the second azimuth angle range based on the output information from the memory mechanism. A marine radar device characterized by: