Data processing method for realizing target detection and tracking during radar marching

Abstract

The invention discloses a data processing method for realizing target detection and tracking during radar advancing, and belongs to the technical field of radar data processing. Firstly, data resources of a radar platform during advancing are obtained by means of positioning and orientation equipment, and calculation of a Doppler compensation value and an airspace scanning angle compensation value is achieved by means of the resources. Secondly, performing data preprocessing and spatial calibration on radar data issued by signal processing to obtain trace point data containing longitude and latitude height information; and then selecting a reference point in a geodetic coordinate system, constructing an inter-travel amplitude clutter map, and judging and marking clutters according to the clutter map to obtain a target trace point. Then, a sector where the target is located is calculated according to target trace point information, and a target track is formed through a track processing algorithm. And finally, selecting a tracking target, and carrying out beam pointing angle calculation on the selected target to complete target tracking. According to the invention, target detection and tracking during radar advancing are realized.

Description

Technical Field

[0001] The present invention relates to the field of radar moving data processing, and specifically to a data processing method for realizing target monitoring and tracking while the radar is moving. Background Art

[0002] When the radar is moving, Doppler frequency shift occurs, which affects the target speed judgment and the elimination of stationary targets, so Doppler compensation is required. At the same time, the change of the carrier's instantaneous posture affects the radar's beam pointing, thereby affecting the scanning airspace coverage range, so the radar's scanning airspace angle needs to be compensated. Secondly, the target information detected by the radar while moving is information in the radar spherical coordinate system. Since the radar position changes in real time, it is impossible to implement the data processing algorithm under static conditions using only this information. Therefore, the target needs to be spatially calibrated to ensure the implementation of the subsequent data processing algorithm.

[0003] In the prior art, the patent application with application number CN202211349764.2, "A method for suppressing clutter while radar is moving", proposes a method of constructing an amplitude and velocity composite clutter map in a moving scene based on the platform Doppler velocity and the Doppler velocity of fixed clutter points to achieve clutter suppression; the patent application with application number CN20231022491.7, "A moving detection vehicle-mounted platform for one-dimensional phased array radar", provides a method for achieving velocity compensation and beam compensation based on the motion information of the vehicle-mounted platform; the patent application with application number CN202310295783.X, "A track correlation method based on a vehicle-mounted four-sided two-dimensional phased array radar", proposes a real-time update of the track processing sector range of the array surface to ensure that the track correlation is not affected by the movement of the carrier.

[0004] The prior art with application number CN202211349764.2 does not take into account the factor that the origin of the clutter map changes due to the change in the position of the radar while the radar is moving. The prior art with application number CN20231022491.7 only provides speed compensation and beam compensation for the vehicle-mounted platform, and does not further explain the subsequent track association and data processing methods. The prior art with application number CN202310295783.X only updates the track processing sector range, and does not explain the update of the sector to which the point track belongs, which may cause the track to be lost or disconnected.

[0005] The three existing technologies only consider part of the data processing system of the radar while it is moving, and do not fully explain the overall data processing flow for realizing target detection and tracking while the radar is moving.

[0006] Therefore, a data processing method is needed to realize target detection and tracking while the radar is moving. Summary of the invention

[0007] The technical purpose of the present invention is to provide a data processing method for realizing target detection and tracking while a radar is moving.

[0008] The technical solution of the present invention is: a data processing method for realizing target detection and tracking while a radar is moving, comprising the following steps:

[0009] Step 1: Relying on the positioning and orientation equipment, the data resources M of the radar platform are obtained in real time when it is moving, where the data resources M include the platform's real-time position information P, the platform's real-time attitude information θ, and the platform's real-time speed information V.

[0010] Step 2: Calculate the velocity Doppler compensation value f based on the data resource M d and spatial scanning angle compensation value E d The Doppler compensation value is calculated based on the acquired north sky east velocity data (V n , V s , V e ) and the real-time posture information of the platform (θ r ,θ p ,θ h ), calculate and obtain the platform speed compensation value V d And the corresponding Doppler compensation value f d , the calculation formula is:

[0011]

[0012] Where V g is the platform speed, It is the angle between the beam center of the lowest elevation beam and the horizontal ground.

[0013] Calculate the spatial scanning angle compensation value E d , Where φ is the tilt angle between the radar and the radar platform.

[0014] Upload the Doppler compensation value f to the signal processing module and beam control module via PCIe d and airspace scanning E d , and upload the acquisition time T of the corresponding data resource M d .

[0015] Step 3: Compare the radar data timestamp T sent by the signal processing module f The time stamp T of the radar platform's moving data resource stored i , select timestamp as T fThe data resources are used for data preprocessing and spatial calibration. The main process of spatial calibration is to convert all point data from the radar spherical coordinate system (R, A, E) under measurement to the geodetic coordinate system (B1, L1, H1). The conversion process is:

[0016] First, convert the target coordinates from radar sphere coordinates (R, A, E) to station center rectangular coordinates (X, Y, Z).

[0017]

[0018] Among them, M is the coordinate transformation matrix, M(θ r ,θ p ,θ h ) and M(0, 0, φ) are the coordinate transformation matrices from the array rectangular coordinate system to the array platform coordinate system and from the array platform coordinate system to the station center rectangular coordinate system. The coordinate transformation matrices are:

[0019]

[0020] Then the station center rectangular coordinates (X, Y, Z) are converted into the station center spherical coordinate system (R1, A1, E1).

[0021]

[0022] Then according to T f The positioning and orientation data (B, L, H) at the moment is used to calculate the target latitude and longitude (B1, L1, H1). The calculation formula is:

[0023] temp_lat=a cos(sin L cos(R1cos E1 / Epi)+cos L sin(R1cosE1 / Epi)cos A1)

[0024] B1=B+a sin(sin(R1cos E1 / Epi)sin A1 / temp_lat)*RAD

[0025] L1=90-temp_lat*RAD

[0026] Epi is the radius of the earth Epi = 6378137.0, RAD = 180 / pi. All longitude, latitude and angle information must be converted to radians before calculation.

[0027] Finally, the current radar position is selected as the coordinate origin, which is (B0, L0, H0) in the geodetic coordinate system. The position of the target relative to the coordinate origin (R0, A0, E0) is calculated. The calculation process is:

[0028] A0=a tan 2(sin(B1-B0)cos(L1), cos L0sin L1-sin L0cos L1cos(B1-B0 ) )*RAD+360

[0029] temp_lon = sin 2 ((L1-L0) / 2)+cos L0cos L1sin 2 ((B1-B0 ) / 2)

[0030] R0=sqrt((Epi*2*a tan 2(sqrt(temp_lon),sqrt(1-temp_lon))) 2 +(Z+H-H0) 2 )

[0031] E0=a sin((Z+H-H0) / R0)*RAD

[0032] Step 4: If the clutter background intensity of the temporary clutter map TM-CMA(n) is known, the clutter background intensity of the stored clutter map TM-CMA(n) is:

[0033]

[0034] Where h is the number of time series for calculating the clutter background intensity of the stored clutter map.

[0035] The clutter background intensity of the applied clutter image AM-CMA(n) can be calculated based on the clutter background intensity of the stored clutter image TM-CMA(n). The calculation formula is:

[0036]

[0037] Among them, k i is the forgetting factor ∑k=1 of the clutter background intensity, and t is the number of time series of the clutter background intensity for calculating the applied clutter map.

[0038] The amplitude q(n) of the currently detected point trace is compared with the clutter background intensity AM-CMA(n) of the clutter block corresponding to the point trace in the applied clutter map.

[0039] If q(n)<μ*AM-CMA(n), the point track is judged as clutter, its clutter flag is changed, and it no longer enters the subsequent track processing algorithm.

[0040] Step 5: Calculate the physical sector azim_index of the target point according to its angle A0. The calculation formula is: azim_index = mod[ceil[A0 / am ]+index_num*floor[A0 / 360], index_num]

[0041] where a m is the azimuth beamwidth, index_num is the total number of sectors, mod[·] is the modulo function, ceil[·] is the upward rounding function, and floor[·] is the downward rounding function.

[0042] Step 6: Select the target to be tracked, and obtain the position of the target in the array platform coordinate system (X a , Y a , Z a ). Then it is converted into the target position in the radar ball coordinate system (R p , A p , E p ), and finally the calculated beam pointing angle is assigned to the antenna module to complete the target tracking.

[0043] Compared with the prior art, the present invention has the following significant advantages: 1) The present invention effectively improves the clutter suppression capability of the radar while it is moving, thereby improving the detection performance by realizing Doppler compensation and constructing an amplitude clutter map while it is moving. 2) The present invention avoids the problem of failure of the track processing algorithm when the carrier is moving through spatial calibration, while realizing target tracking while the radar is moving. 3) When the platform is relatively stationary, this method is consistent with the traditional radar-centric processing method, and does not increase too much computational complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A block diagram of a data processing method for realizing target detection and tracking while a radar is moving according to the present invention;

[0045] Figure 2 A schematic diagram of a clutter map implementation method for radar moving data processing according to the present invention;

[0046] Figure 3 It is a clutter unit division diagram of the present invention;

[0047] Figure 4 It is a dot trace sector division diagram for radar moving data processing of the present invention;

[0048] Figure 5 It is a schematic diagram of the radar operation while on the move of the present invention; DETAILED DESCRIPTION

[0049] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the appendix in the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0050] Example

[0051] refer to Figures 1 to 5 This embodiment provides a data processing method for realizing target detection and tracking while a radar is moving, and the method includes:

[0052] Figure 1 The data processing flow of radar to achieve target detection and tracking while moving is demonstrated.

[0053] Step 1: Relying on the positioning and orientation equipment, the data resource M of the radar platform is obtained in real time when it is moving, where the data resource M includes the real-time position information P of the platform, the real-time attitude information θ of the platform, and the real-time speed information V of the platform, where P is the longitude and latitude data (B, L, H), and θ is the three-axis angle data (θ r ,θ p ,θ h ), V is the north sky east velocity data (V n , V s , V e ).

[0054] Step 2: Calculate the velocity Doppler compensation value f based on the data resource M d and spatial scanning angle compensation value E d The Doppler compensation value is calculated based on the acquired north sky east velocity data (V n , V s , V e ), and the real-time posture information of the platform (θ r ,θ p ,θ h ), calculate and obtain the platform speed compensation value V d And the corresponding Doppler compensation value f d , the calculation formula is:

[0055]

[0056] Where V g is the platform speed, It is the angle between the beam center of the lowest elevation beam and the horizontal ground.

[0057] Calculate the spatial scanning angle compensation value E d ,

[0058] Where φ is the tilt angle between the radar and the radar platform.

[0059] Upload the Doppler compensation value f to the signal processing module and beam control module via PCIe d and airspace scanning E d , and upload the acquisition time T of the corresponding data resource M d .

[0060] Step 3: Compare the radar data timestamp T sent by the signal processing module f The time stamp T of the radar platform's moving data resource stored i , select timestamp as T f The data resources are used for data preprocessing and spatial calibration. The main process of spatial calibration is to convert all point data from the radar spherical coordinate system (R, A, E) under measurement to the geodetic coordinate system (B1, L1, H1). The conversion process is:

[0061] First, convert the target coordinates from radar sphere coordinates (R, A, E) to station center rectangular coordinates (X, Y, Z).

[0062]

[0063] Among them, M is the coordinate transformation matrix, M(θ r ,θ p ,θ h ) and M(0, 0, φ) are the coordinate transformation matrices from the array rectangular coordinate system to the array platform coordinate system and from the array platform coordinate system to the station center rectangular coordinate system. The coordinate transformation matrices are:

[0064]

[0065] Then the station center rectangular coordinates (X, Y, Z) are converted into the station center spherical coordinate system (R1, A1, E1).

[0066]

[0067] Then according to T f The positioning and orientation data (B, L, H) at the moment is used to calculate the target latitude and longitude (B1, L1, H1). The calculation formula is:

[0068] temp_lat=a cos(sin L cos(R1cos E1 / Epi)+cos L sin(R1cosE1 / Epi)cos A1)

[0069] B1=B+asin(sin(R1cos E1 / Epi)sin A1 / temp_lat)*RAD

[0070] L1=90-temp_lat*RAD

[0071] Epi is the radius of the earth Epi = 6378137.0, RAD = 180 / pi. All longitude, latitude and angle information must be converted to radians before calculation.

[0072] Finally, the current radar position is selected as the coordinate origin, which is (B0, L0, H0) in the geodetic coordinate system. The position of the target relative to the coordinate origin (R0, A0, E0) is calculated. The calculation process is:

[0073] A0=a tan 2(sin(B1-B0)cos(L1),cos L0sin L1-sin L0cos L1cos(B1-B0))*RAD+360

[0074] temp_lon = sin 2 ((L1-L0) / 2)+cos L0cos L1sin 2 ((B1-B0) / 2)

[0075] R0=sqrt((Epi*2*a tan 2(sqrt(temp_lon),sqrt(1-temp_lon))) 2 +(Z+H-H0) 2 )

[0076] E0=a sin((Z+H-H0) / R0)*RAD

[0077] Figure 2 The construction method of the radar moving amplitude clutter map is shown. In step 4, the moving amplitude clutter map based on time series is constructed based on the point trace data. If the clutter background intensity of the temporary clutter map TM-CMA(n) is known, the clutter background intensity of the stored clutter map TM-CMA(n) is:

[0078]

[0079] Where h is the number of time series for calculating the clutter background intensity of the stored clutter map.

[0080] The clutter background intensity of the applied clutter image AM-CMA(n) can be calculated based on the clutter background intensity of the stored clutter image TM-CM4(n). The calculation formula is:

[0081]

[0082] Among them, k iis the forgetting factor ∑k=1 of the clutter background intensity, and t is the number of time series of the clutter background intensity for calculating the applied clutter map.

[0083] like Figure 3 The division of clutter blocks in the clutter map is shown. The amplitude of the currently detected point track q(n) is compared with the clutter background intensity AM-CMA(n) of the corresponding clutter block in the applied clutter map. If q(n)<μ*AM-CMA(n), the point track is judged as clutter, and its clutter flag is changed, and it will no longer enter the subsequent track processing algorithm.

[0084] Figure 4 The distribution of the array sector and the physical sector when the radar is moving is shown. In step 5, according to the angle A0 of the target point, the physical sector azim_index is calculated, and the calculation formula is:

[0085] azim_index = mod[ceil[A0 / a m ]+index_num*floor[A0 / 360], index_num]

[0086] where a m is the azimuth beamwidth, index_uum is the total number of sectors, mod[·] is the remainder function, ceil[·] is the upward rounding function, and floor[·] is the downward rounding function.

[0087] Step 6: Select the target to be tracked, and obtain the position of the target in the array platform coordinate system (X a , Y a , Z a ). Then it is converted into the target position in the radar ball coordinate system (R p , A p , E p ), and finally the calculated beam pointing angle is assigned to the antenna module to complete the target tracking.

[0088] Figure 5 The schematic diagram of the radar working while moving is shown. When the radar is working while moving, the carrier speed is kept constant at 30km / h in the west direction, the radar platform is fixed on the carrier, and the radar scanning normal is consistent with the carrier axis. At this time, the radar tilt angle is 5°, the carrier's roll angle is 0.3°, the heading angle is 270°, and the pitch angle is -2°. With the help of step 2, the Doppler compensation value f can be calculated d =52.7778, Spatial scanning angle compensation value E d= -3°. The target's azimuth angle relative to the radar is detected to be 60°, the pitch angle is 3.8°, and the radial distance is 3000m. The current radar latitude and longitude information is known to be (118.8634751, 32.0255672, 12). The target's latitude and longitude information calculated by step 3 is (118.8909470, 32.0390093, 212). The sector number of the physical sector where the target is located is further calculated by step 5 as 28, thereby completing the track processing algorithm. Select the tracking target in the display and control module. Given the target latitude and longitude information (118.8709460, 32.0377093, 234) and the current radar latitude and longitude information (118.8634751, 32.0255672, 34), the target's azimuth angle relative to the radar is calculated to be 27.54°, and the pitch angle is 7.47°, thereby determining the beam pointing angle of the tracking beam and finally achieving target tracking.

[0089] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A data processing method for realizing target detection and tracking while radar is moving, characterized in that: The steps include: Step 1, relying on the positioning and orientation equipment, real-time acquisition of data resources M of the radar platform while it is moving, wherein the data resources M include the platform's real-time position information P, the platform's real-time attitude information θ, and the platform's real-time speed information V; Step 2: Calculate the velocity Doppler compensation value f based on the data resource M d and spatial scanning angle compensation value E d , and upload the compensation value to the corresponding module to achieve compensation during travel; Step 3: According to the timestamp T of the radar data sent by the signal processing module f Perform data time registration and obtain T f The data resources M of the radar platform when it is moving at the moment f , relying on data resources M f , perform data preprocessing and spatial calibration on the radar data to obtain point data containing latitude, longitude and altitude information; Step 4: According to the point trace data, a reference point in the geodetic coordinate system is selected to construct an AM-CMA map based on the time series, and the clutter is judged, marked and eliminated by the clutter map to obtain the target point trace after the clutter map; Step 5, calculate the processing sector to which the target point track belongs according to the information of the target point track, perform track processing through the radar data processing algorithm in turn, obtain the target track, and then execute step 6; Step 6: Select the target to be tracked based on the target track information, and calculate the pointing angle of the target beam in conjunction with the data resources of the radar platform during its movement to achieve target tracking.

2. The data processing method for realizing target detection and tracking while radar is moving according to claim 1, characterized in that: The specific steps of step 1 include: In step 1, the radar platform moving data resource M obtained includes the platform real-time position information P, the platform real-time attitude information θ and the platform real-time speed information V, where P is the latitude and longitude data (B, L, H), θ is the three-axis angle data (θ r ,θ p ,θ h ), V is the north sky east velocity data (V n , V s , V e ).

3. The data processing method for realizing target detection and tracking while radar is moving according to claim 1, characterized in that: The specific steps of step 2 include: In step 2, the platform velocity Doppler compensation value is calculated based on the acquired north sky east velocity data (V n , V s , V e ), and the real-time posture information of the platform (θ r ,θ p ,θ h ); Calculate and obtain the platform speed compensation value V d And the corresponding Doppler compensation value f d , the calculation formula is: Where V g is the platform speed, It is the angle between the beam center of the lowest elevation beam and the horizontal ground. Calculate the spatial scanning angle compensation value E d , the calculation formula is: Where φ is the tilt angle between the radar and the radar platform. Upload the Doppler compensation value f to the signal processing module and beam control module via PCIe d and airspace scanning E d , and upload the acquisition time T of the corresponding data resource M d .

4. The data processing method for realizing target detection and tracking while radar is moving according to claim 1, characterized in that: In step 3, by comparing the radar data timestamp T sent by the signal processing module f The time stamp T of the radar platform's moving data resource stored i , select timestamp as T f The data resources are used for data preprocessing and spatial calibration. The main process of spatial calibration is to convert all point data from the radar spherical coordinate system (R, A, E) under measurement to the geodetic coordinate system (B1, L1, H1). The conversion process is: First, convert the target coordinates from radar sphere coordinates (R, A, E) to station center rectangular coordinates (X, Y, Z). Among them, M is the coordinate transformation matrix, M(θ r ,θ p ,θ h ) and M(0, 0, φ) are the coordinate transformation matrices from the array rectangular coordinate system to the array platform coordinate system and from the array platform coordinate system to the station center rectangular coordinate system. The coordinate transformation matrices are: Then the station center rectangular coordinates (X, Y, Z) are converted into the station center spherical coordinate system (R1, A1, E1). Then according to T f The positioning and orientation data (B, L, H) at the moment is used to calculate the target latitude and longitude (B1, L1, H1). The calculation formula is: temp_lat=a cos(sin L cos(R1cos E1 / Epi)+cos L sin(R1cos E1 / Epi)cos A1) B1=B+a sin(sin(R1cos E1 / Epi)sin A1 / temp_lat)*RAD L1=90-temp_lat*RAD Epi is the radius of the earth Epi = 6378137.0, RAD = 180 / pi. All longitude, latitude and angle information must be converted to radians before calculation. Finally, the current radar position is selected as the coordinate origin, which is (B0, L0, H0) in the geodetic coordinate system. The position of the target relative to the coordinate origin (R0, A0, E0) is calculated. The calculation process is: A0=a tan 2(sin(B1-B0)cos(L1),cos L0sin L1-sin L0cos L1cos(B1-B0))*RAD+360 temp_lon=sin 2 ((L1-L0) / 2)+cos L0cos L1sin 2 ((B1-B0) / 2) R0=sqrt((Epi*2*a tan 2(sqrt(temp_lon),sqrt(1-temp_lon))) 2 +(Z+H-H0) 2 ) E0=a sin((Z+H-H0) / R0)*RAD 5. The data processing method for realizing target detection and tracking while radar is moving according to claim 1, characterized in that: The specific steps of step 4 include: The traveling amplitude clutter map based on time series is constructed by relying on the point trace data. If the clutter background intensity of the temporary clutter map TM-CMA(n) is known, the clutter background intensity of the stored clutter map TM-CMA(n) is: Where h is the number of time series for calculating the clutter background intensity of the stored clutter map. The clutter background intensity of the applied clutter image AM-CMA(n) can be calculated based on the clutter background intensity of the stored clutter image TM-CMA(n). The calculation formula is: Among them, k i is the forgetting factor ∑k=1 of the clutter background intensity, and t is the number of time series of the clutter background intensity for calculating the applied clutter map. The amplitude q(n) of the currently detected point trace is compared with the clutter background intensity AM-CMA(n) of the clutter block corresponding to the point trace in the applied clutter map. If q(n)<μ*AM-CMA(n), the point track is judged as clutter, its clutter flag is changed, and it no longer enters the subsequent track processing algorithm.

6. The data processing method for realizing target detection and tracking while radar is moving according to claim 1, characterized in that: The specific steps of step 5 include: According to the angle A0 of the target point, calculate the physical sector azim_index where it is located. The calculation formula is: azim_index=mod[ceil[A0 / a m ]+index_num*floor[A0 / 360],index_num] where a m is the azimuth beamwidth, index_num is the total number of sectors, mod[·] is the modulo function, ceil[·] is the upward rounding function, and floor[·] is the downward rounding function. Then the point tracks in the sector are sequentially input into the track processing algorithm to obtain the target track.

7. The data processing method for realizing target detection and tracking while radar is moving according to claim 1, characterized in that: The specific steps of step 6 include: Convert the target position in the geodetic coordinate system (B1, L1, H1) to the target position in the radar sphere coordinate system (R p , A p , E p The calculation process is as follows: first, the position of the target in the array platform coordinate system (X a , Y a , Z a ). Then it is converted into the target position in the radar ball coordinate system (R p , A p , E p ), and finally the calculated beam pointing angle is assigned to the antenna module to complete the target tracking.

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