JP2002257931A - Radar apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radar apparatus of which ability to detect targets from complex backgrounds can be improved and which can efficiently classify targets by use of polarization data having different characteristics adapted to different kinds of backgrounds. SOLUTION: The radar apparatus is made to have such a constitution that both a clutter suppressing process and a target classifying process are carried out using polarization information about all of HH, HV and VV, and processing loads can be reduced, and classification of targets in a state where they are mutually at standstill, is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar device mounted on an aircraft or the like used as an anti-ground defense device for detecting target information, in particular, detecting a stationary target and classifying the target. The present invention relates to a radar apparatus capable of greatly improving cost-effectiveness.

[0002]

2. Description of the Related Art FIG. 6 is a diagram showing the configuration of a conventional radar device used for target classification and the like. The conventional radar device is roughly divided into a pre-processing unit 2, a clutter suppression processing unit 4, and an image processing unit 20. Conventionally, based on Doppler information, a radar device that detects and targets a moving target, or detects a target by moving its own device,
A radar apparatus for imaging is general, and a person classifies a target based on target information for imaging output to a display or the like.

Next, the operation of the conventional radar apparatus shown in FIG. 6 will be described. The preprocessing unit 2 receives radio waves from the background and the target to be imaged, and the preprocessing unit 2 and the clutter suppression processing unit 4 convert the electric signal to a required level from the target data whose electric signal has been amplified to a necessary level. The target is detected and tracked using the Doppler effect generated by the relative motion with the target. While continuing this tracking, usually
While SAR moves the radar and combines the aperture surface with the stationary target, terrain, etc., ISAR combines the aperture surface using the movement of the target and obtains the amplitude detection data to obtain a high-resolution image. Is output to the image processing unit 20. The image processing unit 20 receives the amplitude detection data, outputs image data, and performs classification of a target through human eyes.

[0004]

A conventional radar device is:
Imaging is performed based on the Doppler signal generated when either the target or the own aircraft moves, and the imaging performance is significantly poor when both are stationary, such as a helicopter anti-tank. Or, there was a big problem that a target could not be detected. Also, as one of the target classification processing,
Although a method of performing data correlation processing and the like has been proposed, conventionally, a huge amount of reference data must be retained, and a large amount of signal processing is required. It was connected.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned technical problems. In order to improve the ability to find a stationary target from a complicated background, polarization data having different characteristics adapted for each type of background has been developed. It is an object of the present invention to obtain a radar device that can improve the ability to detect a target from a complicated background and can efficiently perform target classification.

[0006]

SUMMARY OF THE INVENTION A radar apparatus according to the present invention receives a radio wave reflected from a background and a target to be imaged, inputs target data in which power and phase with respect to polarization are detected, and outputs the target data. A pre-processing unit that creates a range profile for each polarization; and a data processing unit that processes the range profile of each polarization created by the pre-processing unit to suppress clutter and to extract the target polarization within an area only for the area where the target exists. A clutter suppression processing unit that outputs wave data, a dictionary data storage unit that stores dictionary data of various objects, a target polarization data extracted in the area from the clutter suppression processing unit, and dictionary data from the dictionary data storage unit A target attitude angle calculation unit that calculates a target attitude angle by performing a correlation process based on the target polarization data extracted from the clutter suppression processing unit. And those in which a target classification processor to classify process target based on the target posture angle from the target posture angle calculating portion.

The clutter suppression processing unit suppresses clutter from the range profile from the preprocessing unit, extracts target detection data, extracts a region where a target exists from the target detection data, and detects only a region within the region. The method is characterized in that the polarization data is output as region extraction target polarization data.

[0008] Further, the target classification processing section includes a Diplane An
A first processing unit that performs global data processing using gle, and a Di that decomposes the electric field strength from polarization data into three basic components
a second processing unit that locally performs data processing on feature points of a target using plane, Helix, and Trihedral contribution data.

[0009] A self-positioning device for calculating a self-position, and a type of background in an imaging target range is determined based on self-position data from the self-positioning device and target distance data from the preprocessing section. A digital map that outputs background polarization data, wherein the clutter suppression processing unit subtracts background polarization data output from the digital map from a range profile output from the preprocessing unit to generate clutter. It is characterized by suppressing and extracting target detection data.

Further, a dictionary polarization data storage unit for storing object polarization data as dictionary data, target classification data from the target classification processing unit, dictionary data from the dictionary data storage unit, and dictionary polarization data. An enemy / friend identification processing unit for performing a correlation process based on the object polarization data from the storage unit and identifying the enemy or the ally is further provided.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of a radar apparatus according to Embodiment 1 of the present invention. Figure 1
The radar device shown in FIG. 1 receives radio waves reflected from a background and a target to be imaged, inputs target data 1 in which power and phase with respect to polarization are detected, and converts a range profile 3 of each polarization from the target data 1. Preprocessing unit 2 to be created
Data processing is performed on the range profile 3 of each polarization created by the pre-processing unit 2 to suppress clutter and to extract the target polarization data 5 within the region only for the region where the target exists.
And a clutter suppression processing unit 4 for outputting RC
S: Correlation processing based on the dictionary data storage unit 6 for storing the shape data 7 as dictionary data, the target polarization data 5 extracted from the area from the clutter suppression processing unit 4 and the dictionary data 7 from the dictionary data storage unit 6 Target angle calculation unit 8 for calculating target posture angle data 9 by performing the above operation, and clutter suppression processing unit 4
And a target classification processing unit 10 that classifies targets based on the target polarization data 5 extracted from the target and the target posture angle data 9 from the target posture angle calculation unit 8.

Next, the operation of the first embodiment according to the above configuration will be described. The radar device searches the range to be imaged, receives radio waves reflected from the background and the target, and detects power and phase as target data 1. In order to detect and classify a stationary target, the polarization characteristics of the background and the target are used. Therefore, target data 1
Is the power and phase for all polarizations of HH, VV, including the cross polarization of HV.

When the target data 1 is input to the pre-processing unit 2, the pre-processing unit 2 calculates a range profile 3 for all polarizations of HH, HV and VV. Preprocessing unit 2
The clutter suppression processing unit 4 detects the target, extracts the range profile of the region where the target exists, and converts the extracted target polarization data 5 within the region into the target attitude angle based on the range profile 3 output from Output to the calculation unit 8 and the target classification processing unit 10.

For example, as shown in the conceptual diagram of FIG. 2, in order to classify the target as a stationary target, the target data 1 is directly input to, for example, a signal processing unit as shown in the conceptual diagram of FIG. I have to do it. Since the cross-polarization information is weak, clutter is suppressed using the polarization information to detect a target. However, information processed through a filter cannot be used for target classification processing.

Therefore, clutter is suppressed from the range profile 3 and target detection data is extracted. The region where the target exists is extracted from the target detection data, and the polarization data only in the region is output as the region extraction target polarization data 5.

On the other hand, the target attitude angle calculation section 8 outputs the extracted target polarization data 5 in the area output from the clutter suppression processing section 4.
From the dictionary data storage unit 6 based on the
S, the shape data 7 is extracted, correlation processing is performed, and the target attitude angle data 9 is calculated and output to the target classification processing unit 10.

The target classification processing unit 10 determines, for example, whether a wheeled vehicle or a tracked vehicle based on the extracted target polarization data 5 and the target attitude angle data 9 output from the clutter suppression processing unit 4. Perform target categorization.

For example, as shown in the conceptual diagram of FIG. 3, when classifying a wheeled vehicle or a tracked vehicle, the process is roughly divided into two. That is, the target classification processing unit 10
The first processing unit 10a that performs data processing globally using Angle, and the characteristic points of the target object are determined using the contribution data of Diplane and Helix and Trihedral obtained by decomposing the electric field strength into three basic components from the polarization data. Second local data processing
And a processing unit 10b.

The target classification processing unit 10 receives as input the in-region extracted target polarization data 5 output from the clutter suppression processing unit 4, and first performs global data processing, for example, Diplan.
Focusing on the change rate of e Angle, we classify wheeled vehicles or tracked vehicles based on polarization data whose characteristics such as polarization characteristics and permittivity are significantly different. Since the polarization information is greatly affected by the shape of the object, the angle dependence is high, and in order to improve the target classification probability, for example, data correlation processing is performed on a local portion where the characteristics of the tracked vehicle appear in the polarization data. And output the target classification result.

Embodiment 2 FIG. 4 is a configuration diagram showing a second embodiment of the present invention. In the configuration shown in FIG.
In contrast to the first embodiment shown in FIG. 1, a self-positioning unit 12 for calculating a self-position, an imaging target range based on self-position data 13 from the self-positioning unit 12 and target distance data 11 from the preprocessing unit 2. And a digital map 14 for determining the type of the background and outputting background polarization data 15. The clutter suppression processing unit 4 outputs the range profile 3 output from the preprocessing unit 2 to the digital map 14. The background polarization data 15 is subtracted to suppress clutter and extract target detection data.

Next, the operation of the second embodiment will be described. Self position data 1 output from self position locator 12
3 and the target distance data 11 output from the preprocessing unit 2, by comparing the terrain and background information with a digital map 14 having digital information,
The type of background in the range to be imaged is determined. And the digital map 14 is based on the result of the determination.
And it outputs the background polarization data 15 to accommodate the type of background clutter suppression processing section 4.

As in the first embodiment, for example, as shown in the conceptual diagram of FIG. 2, in order to classify the target as a stationary target, the target data 1 is converted into a signal processing unit as shown in the conceptual diagram of FIG. Must be directly input to the data processing. Since the cross-polarization information is weak, clutter suppression is performed using the polarization information to detect a target. However, information processed through a filter cannot be used for target classification processing.

Accordingly, the clutter suppression processing unit 4 suppresses the clutter by subtracting the background polarization data 15 of the target background outputted from the digital map 14 from the range profile 3 and extracts the target detection data. I do. The region where the target exists is extracted from the target detection data, and the polarization data only in the region is output as the region extraction target polarization data 5.

On the other hand, the target attitude angle calculation unit 8 extracts the target polarization data 5 extracted from the clutter suppression processing unit 4.
From the dictionary data storage unit 6 based on the
S, the shape data 7 is extracted, correlation processing is performed, and the target attitude angle data 9 is calculated and output to the target classification processing unit 10.

The target classification processing section 10 is based on the extracted target polarization data 5 output from the clutter suppression processing section 4 and the target attitude angle data 9 output from the target attitude angle calculation section 8. For example, a target classification of a wheeled vehicle or a tracked vehicle is performed.

Further, as in the first embodiment, the target classification processing section 10 divides the target vehicle into two parts, as shown in the conceptual diagram of FIG. I do. It comprises a first processing unit 10a and a second processing unit 10b. With the extracted target polarization data 5 extracted from the clutter suppression processing unit 4 as an input, first, as global data processing, for example, focusing on the change rate of Diplane Angle,
Based on polarization data whose characteristics such as polarization characteristics and permittivity are significantly different, wheeled vehicles or tracked vehicles are classified. Since the polarization information is greatly affected by the shape of the object and is highly dependent on the angle, in order to improve the probability of target classification, for example, data correlation processing is performed on local parts where the characteristics of tracked vehicles appear in the polarization data. And output the target classification result.

Embodiment 3 FIG. 5 is a configuration diagram showing a third embodiment of the present invention. In the configuration shown in FIG.
A dictionary polarization data storage unit 17 that stores object polarization data 18 as dictionary data with respect to the first embodiment shown in FIG.
Based on the target classification data 16 from the target classification processing unit 10 and the dictionary data 7 from the dictionary data storage unit 6 and the object polarization data 18 from the dictionary polarization data storage unit 17, perform a correlation process to determine whether it is an enemy or an ally. And an enemy / friend identification processing unit 19 for performing identification processing.

Next, the operation of the third embodiment will be described.
In the third embodiment, as in the first embodiment, based on the outputs of the clutter suppression processing unit 4 and the target posture angle calculation unit 8,
The target classification processing section 10 outputs target classification data 16.

On the other hand, in Japan, it is difficult to obtain in advance the polarization data of an enemy country, for example, a tracked vehicle, but those owned by Japan obtain polarization data in advance and use it as dictionary data. Can be stored. Therefore, the enemy / friend identification processing unit 19 retrieves the object polarization data 18 from the dictionary polarization data storage unit 17 and performs a correlation process to determine whether it is an enemy or a friend, and for example, is output from the target classification processing unit 10. Together with the target classification data 16, it is used as a deciding factor for selecting a weapon and determining whether or not to attack.

[0030]

Therefore, according to the present invention, in addition to the conventional function of detecting a target from a moving target and classifying the target, polarization data having different characteristics adapted for each type of background is used, and a stationary target can be obtained from under a complex background. Can be detected and the target can be classified, so that the target classification can be efficiently performed based on the target detection capability and the target classification capability.

Further, clutter is suppressed from the range profile, target detection data is extracted, a region where the target exists is extracted from the target detection data, and only the polarization data within the region is extracted using the target polarization data extracted within the region. Since a stationary target can be detected from a complicated background and the target can be classified, the target classification can be efficiently performed based on the target detection capability and the target classification capability.

The stationary target can be classified using the polarization information, and by dividing the processing section into two, the load required for the target classification processing can be reduced, and the cost can be reduced. .

Also, by adding the self-locating device and the digital map, the type of background can be determined, and clutter can be suppressed based on polarization data adapted for each type of background. I'm firing. This improvement also affects the improvement of target classification processing capacity.

Further, since it is difficult to acquire the polarization data of the enemy target and hold it as dictionary data, data processing is performed using the polarization data of the object held in Japan as dictionary data to distinguish the enemy from the viewpoint. It can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a radar apparatus according to the present invention.

FIG. 2 is a diagram illustrating a concept of a clutter suppression processing unit according to the present invention.

FIG. 3 is a diagram showing a concept of a target classification processing unit according to the present invention.

FIG. 4 is a diagram showing a second embodiment of the radar apparatus according to the present invention;

FIG. 5 is a diagram showing a third embodiment of the radar device according to the present invention;

FIG. 6 is a diagram showing a conventional radar device.

[Explanation of symbols]

1 target data, 2 pre-processing section, 3 range profile, 4 clutter suppression processing section, 5 extracted target polarization data in area, 6 dictionary data storage section, 7 RCS, shape data, 8 target attitude angle calculation section, 9 target attitude Angle data, 1
0 Target classification processing section, 10a First processing section, 10b
2nd processing unit, 11 target distance data, 12 self-location unit, 13 self-location data, 14 digital map, 15 background polarization data, 16 target classification data, 17
Dictionary polarization data storage unit, 18 object polarization data, 19
Enemy / friend identification processing unit.

Claims (5)

[The claims] 1. A pre-process for receiving radio waves reflected from a background and a target to be imaged, inputting target data in which power and phase with respect to polarization are detected, and creating a range profile of each polarization from the target data. And a clutter suppression processing unit that performs data processing on the range profile of each polarization created by the preprocessing unit, suppresses clutter, and outputs extracted target polarization data within the region only for the region where the target exists. A dictionary data storage unit for storing dictionary data of various objects, and a correlation process based on target polarization data extracted from the area from the clutter suppression processing unit and dictionary data from the dictionary data storage unit, and a target attitude angle And a target attitude angle from the clutter suppression processing unit and a target attitude angle from the target attitude angle calculation unit. Radar apparatus provided with a target classification processor to classify processing target based on. 2. The radar apparatus according to claim 1, wherein the clutter suppression processing unit suppresses clutter from a range profile from the preprocessing unit, extracts target detection data, and detects a target from the target detection data. A region to be extracted, and outputs polarization data only in the region as target region polarization data extracted in the region. 3. The radar device according to claim 1, wherein the target classification processing unit performs a data processing globally using a Diplane Angle, and a target processing unit that calculates an electric field intensity from polarization data. Diplane, Helix and Tr broken down into three basic components
A radar apparatus comprising: a second processing unit that locally performs data processing on feature points of a target object using ihedral contribution data. 4. The radar device according to claim 1, wherein a self-locator for calculating a self-position, self-position data from the self-locator, and a target distance from the preprocessing unit. A digital map that determines the type of background in the imaging target range based on the data, and outputs background polarization data, wherein the clutter suppression processing unit performs the digital processing based on the range profile output from the preprocessing unit. A radar apparatus comprising: subtracting background polarization data output from a map to suppress clutter and extracting target detection data. 5. The radar apparatus according to claim 1, wherein: a dictionary polarization data storage unit for storing the object polarization data as dictionary data; and target classification data from the target classification processing unit. An enemy / friend identification processing unit that performs a correlation process based on the dictionary data from the dictionary data storage unit and the object polarization data from the dictionary polarization data storage unit to identify an enemy or an ally; A radar device characterized by the above-mentioned.