JPH0693019B2 - Radar equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application> The present invention receives an echo signal returning from each direction by emitting radar detection signals in different directions sequentially while rotating an antenna, and this echo signal is received. This is related to a radar device that once writes and stores in the image memory, then reads it out and supplies it to the display device, and displays the surrounding condition of the radar antenna on its display surface, especially a scan for removing unnecessary waves such as sea surface reflection. The present invention relates to a product improved so that the correlation processing can be performed correctly.

<Prior Art> A conventional radar device will be described with reference to FIG. That is, the receiver 1 receives and amplifies the detection of the one-beam echo signal that returns from each direction due to the detection pulse signals that are sequentially emitted in different directions by the rotation of the radar antenna (not shown). The received signal of one beam from this receiver 1 is
A / D conversion is performed by the A / D conversion unit 2 and is temporarily stored in the buffer memory 3 in time series. The received signal (echo data) supplied from the buffer memory 3 is converted into image display data by the write data creation unit 4.

The write data creation unit 4 performs a process called scan correlation on the echo signal captured by the radar antenna in order to remove unnecessary reflected waves such as sea surface reflection. This scan correlation process is a process for creating data for one round using received signals for ten rounds of antenna rotation, as disclosed in, for example, Japanese Patent Application Laid-Open No. 62-223681. To explain, first, the received signal of the first round and the received signal of the second round are compared, comparison result data is created according to a predetermined rule, and then the comparison result data and the third round are created. By comparing with the received signal of the eye, new comparison result data is created, and thereafter, the same processing as described above is sequentially repeated to remove the image due to unnecessary waves such as sea surface reflection. That is, in order to perform this scan correlation, the current reception signal given from the buffer memory 3 and the past reception signal already written in the frame memory 6 are used.

The output data from the write data generator 4 is written in the frame memory 6 at the write address generated by the write address generator 5. The data written in the frame memory 6 is read based on the read address generated by the read address generation unit 7 according to the raster scan method. The read data is displayed as an image on a display device such as a CRT (not shown).

The write address generator 5 generates a write address composed of Cartesian coordinates (X, Y) based on the antenna direction, the course of the ship and the designated display mode.
Perform polar coordinate-rectangular coordinate transformation. This conversion is performed based on the following equation.

X = Xc + Rsinθ Y = Yc + Rcosθ (However, in the case of HU display, θ = θ _A , in the case of NU display, θ =
θ _A + θ _G , and in the case of CU display, θ = θ _A + θ _G −θ _C. ) Xc, Yc is the ship's position address on the frame memory, R is the distance from the ship's position, θ is the angle in the sweep direction from the Y axis (frame memory), and θ _A is the antenna relative angle with reference to the bow direction. , Θ _G is the course of the ship, and θ _C is the set course.

In the above radar device, the write address generator 5 is configured to perform coordinate conversion from polar coordinates to Cartesian coordinates when the readout for display on the display is performed by the raster scan method. When doing so, it is not necessary to perform the above-mentioned coordinate conversion in the write address generator 5.

In the conventional radar device described above, the mode setting unit (not shown) controls the north-up mode (hereinafter abbreviated as NU mode), the head-up mode (hereinafter abbreviated as HU mode), and the course-up mode (hereinafter abbreviated as HU mode). , CU mode) can be selected.

In NU mode, as shown in Fig. 4, it always points north just above the display screen. In this case, the image of a fixed target such as a fixed buoy is always displayed in a fixed direction regardless of the direction of the bow, but when the direction of the bow is north, the bow line is in the direction indicated by the solid arrow, and If you change the direction to the east, the bow line will be displayed in the direction indicated by the dashed arrow.

In HU mode, as shown in Fig. 5, the area directly above the display screen always points to the bow. In this case, the bow line is always displayed right above the display screen regardless of the direction of the bow.
When the bow direction is north, fixed images such as fixed buoys are displayed as A ₁
Direction, and turning the bow east, the static image is displayed in the A ₂ direction.

In the CU mode, as shown in FIG. 6, the area directly above the display screen always indicates the preset course of the ship that has been preset. In this case, the image of a fixed target such as a fixed buoy is always displayed in a fixed direction regardless of the direction of the bow, but when the bow is set to the north, the bow line is in the direction indicated by the phantom line, and If you change the direction to the east, the bow line will be displayed in the direction indicated by the dashed arrow.

In this way, in NU mode and CU mode, the fixed target is displayed in the fixed direction on the display screen and the bow line is displayed in different directions on the display screen depending on the direction.In HU mode, the bow line is displayed. The fixed target is displayed on the display screen in a fixed direction, and the fixed target is displayed in different directions on the display screen depending on the direction of the bow.

By the way, in the above (1) to (4), it is assumed that the movement amount can be ignored even if the own ship is stopped or moving, but in the situation where the own ship is moving, the own ship position is specified. The fixed target is displayed at a position (for example, the center of the drawing), and the fixed target is displayed so as to move relative to the movement of the ship. Such a display is called a relative motion mode (hereinafter abbreviated as RM mode). Of these, the RM / HU mode is relatively frequently used because the actual view seen by the operator matches the display screen, and the view of the operator is displayed on the screen.

<Problems to be Solved by the Invention> By the way, the scan correlation processing uses the current received signal given from the buffer memory 3 and the past received signal already written in the frame memory 6, so that RM.
Although it can be correctly performed in the NU mode and RM / CU mode, it cannot be correctly performed in the RM / HU mode which is relatively frequently used.

In other words, in the RM / NU mode and RM / CU mode, the writing data for one rotation of the antenna in the frame memory 6 is generated by constantly changing the bow line direction when displaying when the own ship is stopped. The data indicating the fixed target is always written in the same position on the frame memory 6 even if is updated every moment, so the display position of the fixed target is fixed on the screen, and fixed targets such as islands and buoys are fixed. Can be distinguished from the sea surface reflected wave.

However, in the RM / HU mode, when the ship's own ship is stopped and the direction of the bow line constantly fluctuates due to the turning of the ship, when the echo signal captured by the antenna is written in the frame memory 6, the fixed target is changed. Even the signal shown is changed and written to a different position on the frame memory 6 for each rotation of the antenna, so that the display position of the fixed target changes from moment to moment on the screen, and the fixed target such as an island or a buoy changes. It will not be possible to distinguish it from reflected waves on the sea surface.

For this reason, scan correlation processing can be performed correctly in RM / HU mode and RM / CU mode, but RM
-In HU mode, scan correlation processing cannot be performed correctly.

The present invention was devised in view of such circumstances, and a main object thereof is to enable correct scan correlation processing in all display modes, even in a situation where the bow line constantly changes.

Another object of the present invention is to perform scan correlation processing correctly in all display modes, for example, in a situation where the bow line is constantly changing, with a relatively simple structure.

<Means for Solving the Problems> The present invention has the following configuration in order to achieve such an object.

The radar device of the present invention is installed in a moving object, sequentially emits detection signals in different directions, receives an echo signal resulting from the detection signals, and displays an ambient condition in a wide range direction on a display. A receiver for receiving signals,
A first memory that stores a signal output from the following correlating unit in a storage element that is designated by an address that is determined based on a predetermined azimuth, a current reception signal that is output from the receiving unit, and a signal that is read from the first memory. Correlation means that obtains a signal for image display by removing unnecessary waves such as reflected waves from the sea surface by performing correlation processing with received signals that have been received, and the signal output from this correlation means in the set display mode. The present invention is characterized in that it is provided with a second memory which is stored in a storage element designated by a fixed address, and a display device which displays a signal read from the second memory.

The radar device of the present invention is installed in a moving object, sequentially emits detection signals in different directions, receives an echo signal resulting from the detection signals, and displays an ambient condition in a wide range direction on a display. A receiver for receiving signals,
A buffer memory for temporarily storing a received signal sent from the receiving section; a first memory for respectively storing a signal output from the following correlating means in a storage element designated by an address determined with reference to a predetermined direction; By correlating the present received signal output from the memory and the past received signal read from the first memory,
Correlation means for obtaining a signal for image display from which unnecessary waves such as sea surface reflected waves are removed, and a signal output from this correlation means are
The present invention is characterized in that it is provided with a second memory for storing in a storage element designated by an address determined by the set display mode, and a display for displaying a signal read from the second memory.

The radar device of the present invention is mounted on a moving object, sequentially emits detection signals in different directions, receives echo signals resulting from the detection signals, and displays an ambient condition in a wide range on a display. A compass, an antenna azimuth detecting unit, a display mode setting unit that specifies a head-up mode, a receiving unit that receives an echo signal for one beam for each antenna azimuth by the antenna circuit, and a predetermined azimuth output from the receiving unit. By correlating the present reception signal output from the buffer memory and the past reception signal read from the processing memory below, the buffer memory that temporarily stores the reception signal for one beam A light data creation unit that creates a signal for image display with waves removed, and a frame that stores the signal created by the light data creation unit. Memory and, separately provided and this frame memory, a processing memory for storing signals generated by the write data generator, the gyrocompass,
A first write address generation unit that generates a write address that is determined in the display mode for the frame memory based on signals from the antenna azimuth detection unit and the display mode setting unit, and the gyro compass and the antenna azimuth detection unit. A second write address generator that generates a write address that is determined on the basis of a signal based on a signal based on a predetermined direction; a read address generator that gives a read address to the frame memory; And a display for displaying the read signal as an image.

The first memory can be stored in a storage element designated by an address determined in the relative movement / north up mode or the relative movement / coarse up mode. Further, the second memory can be stored in a storage element designated by an address determined in the relative movement / head-up mode.

<Operation> In the radar device of the present invention, since the signal output from the correlating means is stored in the first memory at an address determined based on a predetermined direction, for example, north, the influence is exerted even if the course is changed (turning). Without receiving the data, the data representing the fixed target in the current reception signal output from the receiving unit or the buffer memory and the past reception signal output from the first memory is written to the corresponding address. Therefore, even if data indicating the fixed target exists in the past signal from the first memory, data corresponding to the data indicating the fixed target exists in the current signal from the receiving unit or the buffer memory. Have to,
The data indicating the fixed target in the first memory is considered to be an unnecessary wave due to sea surface reflection or the like. Therefore, by performing correlation processing on both received signals by the correlating means, it becomes possible to obtain the data of only the necessary reflected wave from which the unnecessary wave data has been removed.

The signal output from the correlation means is stored in the second memory,
Since the data is written in the address position determined by the designated display mode, the display in the designated display mode is performed by the signal output from the second memory. To put it simply, the data to be written to the second memory is different from the data to be written to the first memory in the direction but has the same content but simply rotated.

Further, in the radar device of the present invention, the output data from the receiving unit or the buffer memory is a write address which is always determined with reference to a predetermined azimuth, such as RM / NU mode or RM / NU.
It is written to the processing memory at the write address according to the CU mode. Apart from that, the data written in the processing memory is appropriately written in the frame memory at the write address generated by the second write address generation unit based on the designated display mode, antenna direction, and course. To put it simply, the data to be written to the frame memory has a different direction from the data to be written to the processing memory, but has the same content but simply rotated.

Therefore, if RM / HU mode is specified as the display mode, the processing memory is RM / NU mode or RM mode.
-While the data determined in CU mode is written, the data is written to the frame memory at the write address determined in RM / HU mode. Therefore, if the scan correlation processing is performed using the past reception signal written in the processing memory and the current reception signal given from the buffer memory, the scan correlation processing can be correctly performed even in the RM / HU mode. Moreover, as compared with the conventional example, the configuration in which the processing memory and the second write address generating section are increased is sufficient.

<Examples> The details of the present invention will be described below with reference to the examples shown in FIGS. 1 to 3.

1 to 3 relate to an embodiment of the present invention. FIG. 1 is a block diagram of a radar device, FIG. 2 is a data map of a processing memory, and FIG. 3 is a data map of a frame memory. . In these figures, the same reference numerals as those shown in FIG. 7 of the conventional example refer to the same parts and portions.

Since the receiver 1, the A / D converter 2, and the buffer memory 3 are almost the same as those described in the conventional example, detailed description thereof will be omitted.

The write data creation unit 4 (corresponding to the correlating means described in the claims) reads the current received signal given from the buffer memory 3 and the processing memory 8 (corresponding to the first memory described in the claims). Scan correlation processing is performed by using the received signal in the past, and converted into data for image display.

The output data from the write data creation unit 4 is written into the processing memory 8 at the write address generated by the second write address generation unit 9 and also the first write address generation unit 5 (the write address of the conventional example shown in FIG. 7). It is written in the frame memory 6 (corresponding to the second memory described in the claims) with the write address generated by the generating unit). The data written in the frame memory 6 is read based on the read address generated by the read address generation unit 7 according to the raster scan method. The read data is displayed as an image on a display device such as a CRT (not shown).

The first write address generator 5 generates a write address composed of Cartesian coordinates (X, Y) based on the antenna direction, the course of the ship, and the designated display mode. Coordinates are exchanged and an address signal is given to the frame memory 6.

The processing memory 8 outputs the output signal of the write data creation unit 4 to
Based on the write address signal supplied from the second write address generator 9, the data is always written in the storage element designated by the address determined in the RM / NU mode or the RM / CU mode.
On the other hand, the frame memory 6 is a storage element in which the output signal of the write data creation unit 4 is designated by an address determined by the display mode set at that time based on the write address signal given from the first write address generation unit 5. Write in.

That is, the second write address generator 9 for the processing memory 8 is configured to always generate the write address determined in the display mode of the RM / NU mode or the RM / CU mode. The first write address generator 5 for one of the frame memories 6 is the same as the write address generator of the conventional example, and is different from the second write address generator 9 described above in that the designated display mode (RM.NU. Mode, RM / HU
Mode, or RM / CU mode), which is configured to generate a write address that is determined.

Specifically, for example, the course θ _G = 90 °, the antenna direction θ _A =
When the RM / HU mode is designated as the display mode at 90 °, the data map of the processing memory 8 is as shown in FIG. 2 and the data map of the frame memory 6 is as shown in FIG. That is, for example, RM /
In HU mode, the angle θ written in the frame memory 6
Is the angle written in the processing memory 8 minus the course θ _G. The write start address of the processing memory 8 changes on the memory as the ship moves, but the write start address of the frame memory 6 is fixed. Except for this point, the data to be written in the processing memory 8 is exactly the same as the data to be written in the frame memory 6, and only the contents of the processing memory 8 are rotated and written in the frame memory 6 when writing.

When the RM / NU mode or the RM / CU mode is set, the processing memory 8 is written in the storage element corresponding to the address determined by the north or the direction in which the ship is traveling, respectively. Alternatively, the echo signal may be written in the storage element that is determined with reference to this direction.

Next, the operation will be described.

In the write data creation unit 4, the image display data created by performing the scan correlation processing with the current received signal given from the buffer memory 3 and the past received signal of the processing memory 8 are sequentially stored in the processing memory 8 as the first data. 2 RM / NU mode or RM / CU generated from the write address generator 9
Write at the write address determined by the mode.

Then, the write address determined by the specified display mode (either RM / NU mode, RM / HU mode, RM / CU mode) generated from the first write address generation unit 5 for the data written in the processing memory 8 With frame memory 6
Write in. The data written in the frame memory 6 is read according to the read address generated by the read address generator 7, and then displayed as an image on a display (not shown). The image of the data map of the frame memory 6 is displayed on the screen of this display.

In other words, when the RM / HU mode is specified as the display mode, the RM / NU mode or the processing memory 8 is always displayed.
Since the data is written at the write address determined in the RM / CU mode, even if the bow line constantly changes, the correspondence between the past signal of the processing memory 8 and the current signal of the buffer memory 3 can be accurately obtained, and the scan correlation processing can be performed. Can be done correctly. By the way, except when the moving speed of a moving target such as another ship is fast or the detection range is extremely small, the old and new echo data representing the moving target have overlapping portions, whereas the sea surface reflection Unwanted waves such as appear and appear at unrelated positions every time the antenna makes one revolution (for example, every 2 to 3 seconds), so that the probability that new and old echo data of undesired waves overlap is low, so move in scan correlation processing. The moving target that is present and the unwanted waves such as sea surface reflection can be properly discriminated, and the moving target is not removed by the scan correlation processing.

In the above-described embodiment, the readout for display on the display is performed by the raster scan method, and both the first write address generation unit and the second write address generation unit can perform coordinate conversion from polar coordinates to rectangular coordinates. Although the example in which the address signal is given to the frame memory and the processing memory is given, the reading for displaying on the display can be carried out by the spiral scan method. Even if this spiral scan method is used, the second
It is not necessary to generate polar coordinate address signals in the write address generation unit and neither the first write address generation unit nor the second write address generation unit should perform coordinate conversion from polar coordinates to rectangular coordinates.

<Effects of the Invention> As described above, in the radar device of the present invention, the RM / HU
In all display modes of mode, RM / NU mode, RM / CU mode, even if the bow line is constantly changing,
Scan correlation processing can be performed correctly, and unnecessary waves such as sea surface reflections can be accurately removed and a clear ambient image can be displayed.

In addition, in the radar device of the present invention, in addition to the configuration of the conventional example, a simple configuration in which a processing memory and a second write address generation unit for the processing memory are provided is used.
In all display modes of NU mode, RM / CU mode,
Even in situations where the bow line is constantly changing, scan correlation processing can be performed correctly, and unnecessary waves such as sea surface reflections can be accurately removed and a clear ambient image can be displayed.

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention. FIG. 1 is a block diagram of a radar device, FIG. 2 is a data map diagram of a processing memory, and FIG. 3 is a data map diagram of a frame memory. is there. 4 to 7 relate to the conventional example, and FIG. 4 shows NU.
FIG. 5 is a schematic diagram showing a display image in HU mode, FIG. 5 is a schematic diagram showing a display image in HU mode, FIG. 6 is a schematic diagram showing a display image in CU mode, and FIG. Is. 1 ... Receiver, 2 ... A / D conversion section, 3 ... buffer memory, 4 ... write data creation section (correlation means), 5 ... first write address generation section, 6 ... frame memory (first section) Two
Memory), 7 ... read address generation unit, 8 ... processing memory (first memory), 9 ... second write address generation unit.

Claims (5)

[Claims] 1. A radar device, which is mounted on a moving object, sequentially emits detection signals in different directions, receives echo signals resulting from the detection signals, and displays ambient conditions in a wide range on a display. A first memory for respectively storing a signal output from the following correlating means in a storage element designated by an address determined with reference to a predetermined azimuth; and a current received signal output from the receiving unit. And a past reception signal read from the first memory by performing correlation processing to obtain a signal for image display from which unnecessary waves such as sea surface reflected waves are removed, and a signal output from the correlation means. , A second memory to be stored in a storage element designated by an address determined by the set display mode, and a table for displaying signals read from the second memory Comprising a vessel, the radar apparatus characterized by. 2. A radar device, which is mounted on a moving object, sequentially emits detection signals in different directions, receives an echo signal resulting from the detection signals, and displays an ambient condition in a wide range on a display device. And a buffer memory for temporarily storing a received signal sent from the receiving unit, and a signal output from the following correlating means is stored in a storage element designated by an address determined with reference to a predetermined direction. By correlating the present reception signal output from the first memory and the buffer memory with the past reception signal read from the first memory, an image display for removing unnecessary waves such as sea surface reflected waves is displayed. The correlating means for obtaining a signal and the signal output from the correlating means are respectively stored in the storage element designated by the address determined by the set display mode. A second memory for 憶, and a display device for displaying the signal read from the second memory, that the radar apparatus according to claim. 3. The first memory according to claim 1, wherein the first memory stores in a storage element designated by an address determined in a relative motion / north up mode or a relative motion / coarse up mode, respectively. The radar device according to 1. 4. The radar device according to claim 1, wherein the second memory stores in a storage element designated by an address determined in a relative motion / head-up mode. 5. A gyro compass equipped with a moving object, which sequentially emits detection signals in different directions, receives echo signals resulting from the detection signals, and displays an ambient condition in a wide range on a display. , An antenna azimuth detection unit, a display mode setting unit that specifies a relative motion / head-up mode, a reception unit that receives an echo signal for one beam for each antenna azimuth due to antenna rotation, and a predetermined output from the reception unit. By receiving correlation processing between the buffer memory that temporarily stores the received signal for one beam in the azimuth and the current received signal output from the buffer memory and the past received signal read from the processing memory below, sea surface reflected waves, etc. The write data creation part that creates the signal for image display with the unnecessary wave of the signal removed and the signal created by the write data creation part is stored A frame memory, a processing memory provided separately from the frame memory for storing the signal created by the write data creating section, and a signal from the gyro compass, the antenna azimuth detecting section and the display mode setting section. Based on the output signals from the first write address generation unit that generates a write address determined by the display mode for the frame memory, and the gyro compass and the antenna direction detection unit, a predetermined direction for the processing memory A second write address generation unit that generates a write address that is determined based on the above, a read address generation unit that gives a read address to the frame memory, and a display that displays an image of the signal read from the frame memory. A radar device, comprising: