Method for identifying true target and ghost target and radar device

Abstract

A method for identifying real targets and false targets, performed by a radar device, includes the following steps: (A) obtaining range spectrum data related to multiple objects based on multiple echo signals reflected from multiple objects, and performing calculations on the range spectrum data to generate range-velocity spectrum data; (B) for each echo signal intensity value, using a target detection algorithm to determine whether the object corresponding to the echo signal intensity value is a detected object; (C) for each detected object, calculating a path loss theoretical value based on a detection distance corresponding to the detected object; and (D) for each detected object, determining whether the detected object is a real target or a false target based on a detection peak value corresponding to the detected object and the path loss theoretical value.

Claims

1. A method for distinguishing between real targets and false targets, performed by a radar device that transmits multiple transmission signals and receives multiple echo signals reflected from multiple objects, the method comprising the steps of: (A) obtaining range spectrum data related to the objects based on the echo signals, and performing calculations on the range spectrum data to generate range-velocity spectrum data, wherein, The distance-velocity spectrum data includes multiple echo signal intensity values ​​corresponding to the same object, multiple distances corresponding to the same echo signal intensity values, and multiple velocities corresponding to the same echo signal intensity values; (B) For each echo signal intensity value, a target detection algorithm is used to determine whether the echo signal intensity value is greater than a detection threshold representing the degree of environmental interference in its vicinity. If it is greater than the detection threshold, the object corresponding to the echo signal intensity value is defined as a detection object, and the distance corresponding to the echo signal intensity value is a detection distance, and the echo signal intensity value is a detection peak value; (C) For each detection object, a path loss theoretical value for evaluating the degree of echo signal attenuation is calculated based on the detection distance; and (D) For each detection object, the detection peak value and the path loss theoretical value corresponding to the detection object are used to determine whether the detection object is a real target or a false target.

2. The method for identifying real targets and false targets as described in claim 1, wherein, In step (C), the theoretical path loss value of each detected object is obtained using the Friis free space path loss model, as shown in the following formula: , where d is the detection distance, is the reference distance, is the preset path loss value at the reference distance, and n is the path loss exponent.

3. The method for identifying real targets and false targets as described in claim 1, step (D) includes the following sub-steps: (D-1) determining whether the theoretical value of the path loss minus the detection peak is greater than or equal to a threshold; (D-2) when it is determined that the theoretical value of the path loss minus the detection peak is greater than or equal to the threshold, determining that the detected object is the false target; and (D-3) when it is determined that the theoretical value of the path loss minus the detection peak is less than the threshold, determining that the detected object is the real target.

4. The method for identifying real targets and false targets as described in claim 1, further comprising the following steps after step (B): (E) For each detected object, a subspace analysis is performed using an angle estimation algorithm based on the distance or velocity corresponding to the echo signal intensity value of the detected object, so as to obtain the arrival direction angle information of the corresponding detected object.

5. The method for identifying real targets and false targets as described in claim 4, further comprising the following steps after step (D): (F) selecting multiple real objects from multiple detection objects determined to be real targets, and comparing each of the detection objects determined to be false targets with the real objects based on the detection distance and arrival direction angle information corresponding to the real objects, so as to determine whether the detection objects determined to be false targets belong to the same group of the same energy source as the real objects.

6. The method for identifying real targets and false targets as described in claim 5, wherein step (F) includes the following sub-steps: (F-1) selecting a first real object and a second real object related to the first real object from the detected objects determined to be real targets; (F-2) obtaining a plurality of theoretical distances of false targets based on the detection distance and arrival direction angle information corresponding to the first real object and the second real object, wherein each theoretical distance of a false target is the theoretical distance corresponding to a false target formed by the mutual reflection of the echo signals through the first real object and the second real object; and (F-3) determining whether the detected object belongs to the same group of the same energy source as the first real object and the second real object based on the detection distance corresponding to each of the detected objects determined to be false targets and the theoretical distances of the false targets.

7. The method for identifying real targets and false targets as described in claim 6, wherein, In step (F-2), the theoretical distances of these false targets include: a first theoretical distance where the radar device, via the second real object, reflects off the first real object and then returns to the radar device; a second theoretical distance where the radar device, via the first real object, reflects off the second real object and then returns to the radar device; a third theoretical distance where the radar device, via the second real object, reflects off the first real object and then reflects off the second real object and finally returns to the radar device; and a fourth theoretical distance where the radar device, via the first real object, reflects off the second real object and then reflects off the first real object and finally returns to the radar device.

8. The method for identifying real targets and false targets as described in claim 7, wherein, In step (F-2), the arrival direction angle information corresponding to the first real object includes a first horizontal direction angle and a first vertical direction angle, and the arrival direction angle information corresponding to the second real object includes a second horizontal direction angle and a second vertical direction angle. The first theoretical distance, the second theoretical distance, the third theoretical distance, and the fourth theoretical distance of the false target are given by the following formula: , , , , where is the detection distance corresponding to the first real object, is the detection distance corresponding to the second real object, is the first horizontal direction angle, is the first vertical direction angle, is the second horizontal direction angle, and is the second vertical direction angle.

9. The method for identifying real targets and false targets as described in claim 6, wherein, In step (F-3), for each detected object identified as a false target, it is determined whether the absolute value of the difference between the detection distance corresponding to the detected object and the theoretical distance of the false target is less than a threshold value, so as to determine whether the detected object belongs to the same group of the same energy source as the first real object and the second real object. When it is determined that the absolute value of the difference between the detection distance corresponding to the detected object and the theoretical distance of the false target is less than the threshold value, it is determined that the detected object belongs to the same group of the same energy source as the first real object and the second real object. When it is determined that the absolute value of the difference between the detection distance corresponding to the detected object and the theoretical distance of the false target is greater than or equal to the threshold value, it is determined that the detected object does not belong to the same group of the same energy source as the first real object and the second real object.

10. A radar device comprising: a plurality of transmitting antennas, each transmitting antenna transmitting a transmitted signal; a plurality of receiving antennas, each receiving antenna receiving a plurality of echo signals reflected from a plurality of objects, each object being one of a real target and a false target; and a signal processing unit electrically connected to the transmitting antennas and the receiving antennas, and configured to perform the method of identifying a real target and a false target according to any one of claims 1 to 9.

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