A radar-optoelectronic system time-space information fusion method for sea-air targets

Abstract

This invention provides a spatiotemporal information fusion method for radar-electro-optical systems targeting sea and air targets. By applying multi-sensor fusion technology to fuse radar and electro-optical tracking equipment information, and using the azimuth and elevation information of the electro-optical tracking equipment to correct the azimuth and elevation information of the radar, more accurate target location information is obtained.

Description

Technical Field

[0001] This invention belongs to the field of information processing technology, specifically relating to a method for fusion of spatiotemporal information of radar-electro-optical systems for targeting sea and air targets. Background Technology

[0002] In radar-electro-optical systems, photoelectric tracking devices have high angle measurement accuracy. However, traditional photoelectric tracking devices rely on radar information for tracking. When the radar target is lost or the error is too large, the photoelectric tracking device will lose the target, which will have an adverse effect on the stability and accuracy of tracking.

[0003] Traditional maritime surveillance radars only target ships on the sea surface at a fixed altitude, thus eliminating the need to measure target pitch. Pitch angle errors have a relatively small impact on target position information. However, in recent years, there has been an increasing number of drones operating in coastal waters. Radar cannot distinguish between drones and ships, so altitude significantly affects azimuth, pitch, and range. Adding pitch angle measurement capabilities to radar is prohibitively expensive. Therefore, it is necessary to fuse information from radar and electro-optical tracking equipment to obtain accurate target position information. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a spatiotemporal information fusion method for radar-electro-optical systems targeting sea and air targets. By applying multi-sensor fusion technology to fuse information from radar and electro-optical tracking devices, and utilizing the azimuth and elevation information of the electro-optical tracking devices to correct the azimuth and elevation information of the radar, more accurate target location information is obtained.

[0005] A method for spatiotemporal information fusion of radar-electro-optical systems targeting sea and air targets, characterized by the following steps:

[0006] Step 1: After the radar detects the target, obtain the initial slant range r and initial azimuth θ of the target relative to the radar. AZ Transform it to a Cartesian coordinate system to obtain the target's two-dimensional coordinates (x, y) relative to the radar. The transformation formula is:

[0007]

[0008] Step 2: Perform coordinate transformation on the target's two-dimensional coordinates (x, y) relative to the radar to obtain the target's azimuth θ relative to the photoelectric tracking device. AZ-opt1 The conversion formula is:

[0009]

[0010] Where R represents the distance between the radar and the photoelectric tracking device;

[0011] Step 3: Adjust the photoelectric tracking device to align its field of view and angle with the azimuth θ. AZ-opt1 And obtain the accurate azimuth θ′ of the target relative to the photoelectric tracking device. AZ-opt1 Pitch θ′ EL-opt1 ;

[0012] Step 4: Determine the accurate azimuth θ′ of the target relative to the photoelectric tracking device. AZ-opt1 Pitch θ′ EL-opt1 Perform coordinate transformation to obtain the target's accurate azimuth θ″ relative to the radar. AZ Pitch θ″ EL The specific conversion formula is as follows:

[0013]

[0014]

[0015] Where Δh is the height difference between the photoelectric tracking device and the radar;

[0016] Step 5: According to The target's accurate azimuth, elevation, and slant range information relative to the radar is converted into a Cartesian coordinate system to obtain the target's accurate three-dimensional coordinates (x′, y′, z′).

[0017] Furthermore, if the target's location is within the observable range of N electro-optical tracking devices, then all N electro-optical tracking devices operate simultaneously. In step 4, the accurate azimuth and elevation values ​​of the target relative to the N electro-optical tracking devices are transformed using coordinates to obtain N values ​​of the target's accurate azimuth and elevation relative to the radar. Then, the average value of these values ​​is taken to obtain the accurate azimuth θ′ of the target relative to the radar. A ′ Z Pitch θ′ E ′ L ,Right now:

[0018]

[0019]

[0020] Where N represents the number of photoelectric tracking devices, θ″ AZn θ″ represents the accurate azimuth of the target relative to the radar after being acquired and converted by the nth photoelectric tracking device. ELn This represents the accurate elevation of the target relative to the radar after being acquired and converted by the nth photoelectric tracking device.

[0021] The beneficial effects of this invention are: by fusing the azimuth, elevation, and radar slant range of the photoelectric tracking device, more accurate target geographic coordinates can be obtained. This invention allows radar and photoelectric tracking devices to be deployed in different spatial locations, and their spatiotemporal information can be fused through networking. Attached Figure Description

[0022] Figure 1 This is a flowchart of a spatiotemporal information fusion method for radar-electro-optical systems targeting sea and air targets according to the present invention;

[0023] Figure 2 This is a schematic diagram illustrating the working principle of a radar-electro-optical system. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments. The present invention includes, but is not limited to, the following embodiments.

[0025] Currently, maritime surveillance radar can only obtain two-dimensional information about the target: azimuth and range, with the range dimension being the slant range. Combining this with electro-optical azimuth and elevation information can yield more accurate target geographic coordinates. This invention provides a spatiotemporal information fusion method for radar-electro-optical systems targeting sea and air targets. It is applicable to multi-sensor systems equipped with radar and electro-optical tracking devices. After networking, the temporal and spatial information of the radar and electro-optical systems needs to be registered to achieve data fusion between two sensors with asynchronous sampling periods and inconsistent spatial positions. All coordinates are based on a three-dimensional Cartesian coordinate system. Figure 1 As shown, the specific implementation process of the present invention is as follows:

[0026] Step 1: After the radar detects the target, obtain the initial slant range r and initial azimuth θ of the target relative to the radar. AZ Transform it to a Cartesian coordinate system to obtain the target's two-dimensional coordinates (x, y) relative to the radar. The transformation formula is:

[0027]

[0028] Step 2: Perform coordinate transformation on the target's two-dimensional coordinates (x, y) relative to the radar to obtain the target's azimuth θ relative to the photoelectric tracking device. AZ-opt1 The conversion formula is:

[0029]

[0030] Where R represents the distance between the radar and the photoelectric tracking device.

[0031] Step 3: Obtain the target's azimuth θ relative to the photoelectric tracking device. AZ-opt1 Then, rotate the camera and adjust the field of view and angle of the photoelectric tracking device to azimuth θ. AZ-opt1This ensures that after the target is observed in the field of view, the accurate azimuth θ′ of the target relative to the photoelectric tracking device is obtained. AZ-opt1 Pitch θ′ EL-opt1 .

[0032] Step 4: Determine the accurate azimuth θ′ of the target relative to the photoelectric tracking device. AZ-opt1 Pitch θ′ EL-opt1 Perform coordinate transformation to obtain the target's accurate azimuth θ″ relative to the radar. AZ Pitch θ″ EL The specific conversion formula is as follows:

[0033]

[0034]

[0035] Where Δh is the height difference between the photoelectric tracking device and the radar.

[0036] If the target's location is within the observable range of N photoelectric tracking devices, then all N photoelectric tracking devices will operate simultaneously, such as... Figure 2 As shown, at this point, the accurate azimuth and elevation values ​​of the target relative to the N photoelectric tracking devices are transformed using coordinate transformation to obtain N values ​​of the target's accurate azimuth and elevation relative to the radar. Then, the average value of these values ​​is taken to obtain the accurate azimuth θ″ of the target relative to the radar. AZ Pitch θ″ EL ,Right now:

[0037]

[0038]

[0039] Where N represents the number of photoelectric tracking devices, θ″ Azn θ″ represents the accurate azimuth of the target relative to the radar after being acquired and converted by the nth photoelectric tracking device. ELn This represents the accurate elevation of the target relative to the radar after being acquired and converted by the nth photoelectric tracking device.

[0040] At this point, the fusion of radar and electro-optical tracking equipment information is complete. The azimuth and elevation information of the radar is corrected using the azimuth and elevation information of the electro-optical tracking equipment, and then coordinate transformation is performed to obtain more accurate target position information.

[0041] Step 5: Convert the target's accurate azimuth, elevation, and slant range information relative to the radar to a Cartesian coordinate system to obtain the target's accurate three-dimensional coordinates (x′, y′, z′). The specific conversion formula is as follows:

[0042]

[0043] This invention has three main features: The first feature is that the photoelectric tracking device can only start tracking after the system obtains the fused target and relies on the position information of the fused target, and feeds back the target information obtained during tracking and integrates it into the target information. The fusion algorithm needs to fuse based on accurate photoelectric information and radar information in order to improve the accuracy of the fused data.

[0044] The second feature is that each photoelectric tracking device can only track one target at a time until the target leaves the automatic tracking area or the tracking is manually ended. This is suitable for providing stable and accurate target coordinate information for on-duty monitoring personnel to continuously track and monitor specific targets.

[0045] The third feature is that radar and photoelectric tracking devices can be deployed in different spatial locations. Since the detection range of photoelectric tracking devices is usually relatively short, multiple photoelectric tracking devices can be deployed at any suitable location within the detection area in the system shown in this invention. After the radar obtains the initial target information, the system guides the photoelectric tracking devices at the corresponding locations to track the target based on the generated fused target information.

[0046] The second feature mentioned above requires stable tracking. If the electro-optical tracking device can still stably track the target even if the original radar track is lost, it needs to continue to maintain the track number of the fused target. If the newly generated original radar target is determined to be a target being tracked, the original radar information will be fused into the target information.

Claims

1. A radar-optoelectronic system space-time information fusion method for sea-air targets, characterized in that The steps are as follows: Step 1: After the radar detects the target, obtain the initial slant range r and initial azimuth θ of the target relative to the radar. AZ Transform it to a Cartesian coordinate system to obtain the target's two-dimensional coordinates (x, y) relative to the radar. The transformation formula is: Step 2: Coordinate transformation is performed on the two-dimensional coordinates (x, y) of the target relative to the radar to obtain the azimuth θ of the target relative to the photoelectric tracking device AZ-opt1 , and the conversion formula is: Where R represents the distance between the radar and the photoelectric tracking device; Step 3: Adjust the photoelectric tracking device to align its field of view and angle with the azimuth θ. AZ-opt1 And obtain the accurate azimuth θ′ of the target relative to the photoelectric tracking device. AZ-opt1 Pitch θ′ EL-opt1 ; Step 4: Determine the accurate azimuth θ′ of the target relative to the photoelectric tracking device. EL-opt1 Pitch θ′ EL-opt1 By performing coordinate transformation, the accurate azimuth θ″ of the target relative to the radar is obtained. AZ Pitch θ″ EL The specific conversion formula is as follows: Where Δh is the height difference between the photoelectric tracking device and the radar; Step 5: According to The target accurate azimuth, pitch and slant range information relative to the radar is converted to the rectangular coordinate system to obtain the target accurate three-dimensional coordinates (x', y', z').

2. The method for radar-optoelectronic system time-space information fusion for sea-air targets according to claim 1, characterized in that: If the target's location is within the observable range of N electro-optical tracking devices, then all N electro-optical tracking devices will operate simultaneously. In step 4, the accurate azimuth and elevation values ​​of the target relative to the N electro-optical tracking devices will be transformed using coordinates to obtain N values ​​of the target's accurate azimuth and elevation relative to the radar. Then, the average value of these values ​​will be taken to obtain the accurate azimuth θ″ of the target relative to the radar. AZ Pitch θ″ EL ,Right now: Where N represents the number of photoelectric tracking devices, θ″ AZn θ″ represents the accurate azimuth of the target relative to the radar after being acquired and converted by the nth photoelectric tracking device. ELn This represents the accurate elevation of the target relative to the radar after being acquired and converted by the nth photoelectric tracking device.

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