Method and device for improving radar target detection precision

Abstract

The invention discloses a method and a device for improving radar target detection precision. The method comprises the following steps: firstly, acquiring data, and receiving and storing atmospheric waveguide height, radar original video, AIS dynamic information and radar track; evaluating a target track and an echo, and generating a strategy for synthesizing output power; and finally, controlling the output power of the power synthesis. The device comprises a data acquisition unit; the data evaluation unit is used for evaluating the target track or echo and generating a synthetic transmitter output power strategy; the control unit is used for controlling the output power of the power amplifier unit; the power amplifier unit comprises a plurality of final-stage power amplifier assemblies and a power synthesis module, and generates high-power output. According to the method, the track or the echo of the radar target is evaluated, the transmitting power of the radar is properly adjusted, and the detection precision and the tracking stability of the radar target can be improved when the height of the atmospheric waveguide is high.

Description

Technical Field

[0001] This invention belongs to the field of radar target tracking technology, and in particular relates to a method and apparatus for improving the accuracy of radar target detection. Background Technology

[0002] The phenomenon of atmospheric waveguide propagation not only causes electromagnetic waves to deviate from their original propagation direction, but also enables them to propagate along the waveguide to great distances with minimal attenuation, allowing radar to detect targets at sea surface beyond visual range. Atmospheric waveguides close to the sea surface are called evaporation waveguides.

[0003] Under the combined influence of various factors such as temperature, humidity, and pressure in the sea surface atmosphere, the height of the evaporation waveguide varies, and the propagation attenuation of electromagnetic waves within the sea surface atmospheric waveguide is time-varying. The change in target echo power caused by variations in evaporation waveguide height can range from 30 to 40 dB. Traditional radars generally use a fixed output power. When the evaporation waveguide is strong, target echo saturation frequently occurs, leading to a decrease in radar target detection accuracy. Generally, radar operators can judge whether the target echo is saturated based on their experience, and if so, select a lower output power or use STC (Special Controlled Transmission) processing to reduce the target echo power. This is because excessively low output power also reduces radar detection capability and the target echo signal-to-noise ratio. When the evaporation waveguide weakens, radar operators can select a higher output power based on their experience, or disable STC processing to increase the target echo power. This places high demands on operator training, usage, and experience summarization. Summary of the Invention

[0004] The purpose of this invention is to solve the problems mentioned in the background art and to propose a method and device for improving the accuracy of radar target detection. By appropriately adjusting the radar's transmission power, the accuracy and stability of radar target tracking can be improved, which has important application value.

[0005] To achieve the objective of this invention, a method for improving radar target detection accuracy is disclosed, comprising the following steps:

[0006] S1. Data acquisition: Receive and store atmospheric waveguide height, raw radar video, AIS dynamic information, and radar track.

[0007] S2. A strategy for evaluating target tracks and echoes to generate composite output power;

[0008] S3, control the output power of power synthesis; according to the strategy of power synthesis, make the power amplifier unit produce the corresponding power output.

[0009] Furthermore, in step S1, the atmospheric waveguide height is divided into N+1 atmospheric waveguide levels from 0 to N, with level 0 being the lowest level and level N being the highest level; the original radar video must contain at least time, azimuth, and amplitude information on each sampling unit; the AIS dynamic information must contain at least MMSI number, longitude, latitude, speed, and time information; the radar track must contain at least batch number, time, distance, azimuth, longitude, latitude, and MMSI number associated with the AIS.

[0010] Further, step S2 includes the following steps:

[0011] S21. Define the i-th waypoint of the target of interest and its associated AIS;

[0012] S22. Perform linear interpolation of AIS in a rectangular coordinate system and convert it to polar coordinates;

[0013] S23. Calculate the azimuth and range accuracy. If the conditions are met, proceed to S24; otherwise, keep the transmission power unchanged.

[0014] S24. Define the sampling distance and offset of the radar video, and extract the amplitude array;

[0015] S25. Take the amplitude vector at the preset distance from the center in the amplitude array and calculate its consistency with the antenna pattern curve; if the consistency is less than the specified nominal value, proceed to S26; otherwise, keep the transmit power unchanged.

[0016] S26. After sorting the amplitude array, take the average value of the amplitude values ​​of the largest part. If the atmospheric waveguide level is greater than the preset level threshold and the average value is greater than the specified nominal value, reduce the transmission power; otherwise, increase the transmission power.

[0017] Furthermore, S21 specifically defines the i-th waypoint of the target of interest as {t}. i ,θ i ,ρ i}, where i = 1, 2, ..., n, t i Represents time, t1 <t2<…<t n θ i Indicates direction, ρ i Represents distance; the AIS associated with the track of the target of interest is {t' j ,θ j ,ρ j ,x j ,y j}, where j = 1, 2, ..., m, t' j Representing time, t′1<t′2<…<t′ m θ j and ρ jx represents the azimuth and range calculated using the Vicente formula with the radar as the coordinate origin. j and y j These are the corresponding x and y coordinates;

[0018] S22 specifically refers to: at time t1 <t2<…<t n The AIS values ​​in the rectangular coordinate system are respectively set to {t' j ,x j},{t' j ,y j Linear interpolation is used to obtain time t. i Cartesian coordinates of interpolation Then convert to polar coordinates

[0019] S23 specifically refers to: according to the formula Calculate azimuth accuracy S θ According to the formula Calculation distance accuracy S ρ ; such as S θ >U θ And S ρ >U ρ Then proceed to step S24, where U θ and U ρ The specified nominal value shall be used; otherwise, the transmission power shall remain unchanged.

[0020] Furthermore, S24 specifically defines the sampling distance of the radar video as D. The corresponding distance offset is In radar video Extract the amplitude array {A} centered on the center pq}, where p = 1, 2, ..., P, q = 1, 2, ..., Q, and Q is an odd number; the horizontal axis of the amplitude array represents the azimuth, and the azimuth width should not be less than 1.5 times the azimuth width of the large ship echo when the atmospheric waveguide is of class N; the vertical axis of the amplitude array represents the distance, and the distance width should not be less than 1.5 times the distance width of the large ship echo when the atmospheric waveguide is of class N.

[0021] Furthermore, S25 specifically refers to: the amplitude array at a distance from the center The magnitude vector at point A is {A} pω}; Define the antenna radiation pattern curve obtained from laboratory testing as Consistency based on formula calculation in and They represent The mean and standard deviation, μ Aω and σ Aω They represent {A} pω The mean and standard deviation of}; if C < UC Then proceed to step S26, where U C The specified nominal value shall be used; otherwise, the transmission power shall remain unchanged.

[0022] Furthermore, S26 specifically refers to: for the amplitude array {A pq Sort the values ​​from largest to smallest, and average the amplitude values ​​of the first c×P×Q to obtain M, where c is a coefficient between 0 and 1; if the atmospheric waveguide level is greater than the preset level threshold and M > U M The transmission power needs to be reduced; otherwise, the transmission power needs to be increased, where U M The specified nominal value.

[0023] Furthermore, in step S3, the control unit controls the output power of the power amplifier unit by turning on or off the operating voltage of the power amplifier tubes in some of the final stage power amplifier components according to the strategy of combining the output power of the transmitter; the power amplifier unit includes multiple final stage power amplifier components and a power combining module to generate the corresponding power output.

[0024] To achieve the objectives of this invention, the present invention also discloses a device for improving the accuracy of radar target detection, comprising:

[0025] The data acquisition unit receives and stores atmospheric waveguide altitude, raw radar video, AIS dynamic information, and radar track.

[0026] The data evaluation unit evaluates the target trajectory or echo and generates a strategy for synthesizing the output power of the transmitter.

[0027] The control unit controls the output power of the power amplifier unit by turning on or off the operating voltage of the power amplifier tubes in some of the final stage power amplifier components, according to the strategy of the output power of the synthesized transmitter.

[0028] The power amplifier unit includes multiple final stage power amplifier components and a power combining module to generate the corresponding power output.

[0029] Furthermore, the control unit turns the final stage power amplifier components on or off according to the first-in-first-out rule; if it is necessary to reduce the transmission power, the number of final stage power amplifier components in the on state is reduced by half; if it is necessary to increase the transmission power, the number of final stage power amplifier components in the on state is doubled.

[0030] The power amplifier unit includes multiple final-stage power amplifier components and a power combining module; the final-stage power amplifier components are connected in parallel; the final-stage power amplifier components can be controlled to be in two states, on or off, by turning on or off the operating voltage of the power amplifier tubes; when in the on state, the input power and output power of each final-stage power amplifier component are the same; when in the off state, the input power and output power of each final-stage power amplifier component are both 0; the power combining module combines the output power of multiple final-stage power amplifier components into a single output.

[0031] Compared with the prior art, the significant advancement of the present invention lies in the fact that by evaluating the trajectory or echo of the radar target and appropriately adjusting the radar's transmission power, the present invention can improve the detection accuracy and tracking stability of the radar target when the atmospheric waveguide level is high.

[0032] To more clearly illustrate the functional characteristics and structural parameters of the present invention, further explanation is provided below in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0034] Figure 1 This is a flowchart illustrating a method for improving radar target detection accuracy.

[0035] Figure 2 This is a block diagram illustrating the principle of a device for improving the accuracy of radar target detection. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example

[0038] like Figure 1 As shown, a method for improving radar target detection accuracy includes:

[0039] S1, Data Acquisition

[0040] Numerous experiments have shown that the intensity of sea surface evaporation waveguides corresponds to their height, which generally does not exceed 50 meters. Atmospheric waveguide heights are divided into six levels, from 0 to 5, with level 0 being the lowest and level 5 being the highest.

[0041] The original radar video contains at least information such as time, azimuth, and amplitude at each sampling unit.

[0042] AIS dynamic information includes at least MMSI number, longitude, latitude, speed, and time.

[0043] Radar tracks must include at least the batch number, time, distance, azimuth, longitude, latitude, amplitude, and the MMSI number associated with AIS.

[0044] S2, Data Evaluation

[0045] The positioning accuracy of the Automatic Identification System (AIS) for ships, obtained from dynamic information via GPS / DGPS, typically ranges from 5 to 30 meters, and this accuracy remains constant regardless of distance or the target's motion. Compared to radar track accuracy, the positioning accuracy obtained from AIS's longitude and latitude information increases with greater distance.

[0046] (1) Estimating track accuracy

[0047] S21, define the i-th waypoint of the target of interest as {t} i ,θ i ,ρ i}, where i = 1, 2, ..., n, t i Representing time, t1 < t2 < ... < t n θ i Indicates direction, ρ i Represents distance; the AIS associated with the track of the target of interest is {t' j ,θ j ,ρ j ,x j ,y j}, where j = 1, 2, ..., m, t' j Indicates time, t1' < t'2 < ... < t' m θ j and ρ j x represents the azimuth and range calculated using the Vicente formula with the radar as the coordinate origin. j and y j For the corresponding x and y coordinates; the number of target track points should generally be no less than 32 and no more than 64.

[0048] S22, at times t1 < t2 < ... < t n The AIS values ​​in the rectangular coordinate system are respectively set to {t' j ,x j},{t' j ,y j Linear interpolation is used to obtain time t. i Cartesian coordinates of interpolation Then convert to polar coordinates

[0049] S23, according to formula Calculate azimuth accuracy S θ According to the formula Calculation distance accuracy S ρ ; such as S θ >U θ And S ρ >U ρ Then proceed to (B.2), where U θ and U ρ The specified nominal value shall be used; otherwise, the transmission power shall remain unchanged.

[0050] (2) Assess the shape of the target echo

[0051] S24, define the sampling distance of the radar video as D. The corresponding distance offset is In radar video Extract the amplitude array {A} centered on the center pq}, where p = 1, 2, ..., P, q = 1, 2, ..., Q, and Q is an odd number; the horizontal axis of the amplitude array represents the azimuth, and the azimuth width should not be less than 1.5 times the azimuth width of the large ship echo when the atmospheric waveguide is of level 5; the vertical axis of the amplitude array represents the distance, and the distance width should not be less than 1.5 times the distance width of the large ship echo when the atmospheric waveguide is of level 5.

[0052] S25, in the amplitude array at a distance from the center The magnitude vector at point A is {A} pω}; Define the antenna radiation pattern curve obtained from laboratory testing as Consistency based on formula calculation in and They represent The mean and standard deviation, μ Aω and σ Aω They represent {A} pω The mean and standard deviation of}; if C < U C Then proceed to step S26, where U C The specified nominal value shall be used; otherwise, the transmission power shall remain unchanged.

[0053] (3) Determine if the target echo is saturated

[0054] S26, regarding the amplitude array {A} pq Sort the values ​​from largest to smallest, and average the first c×P×Q values ​​to obtain M, where c is a coefficient between 0 and 1; if the atmospheric waveguide level is high and M>U MThe transmit power needs to be reduced by 6dB; otherwise, the transmit power needs to be increased by 6dB, where U M The nominal value is specified; generally, c = 0.1 can be set.

[0055] like Figure 2 As shown, this embodiment also provides a device for improving radar target detection accuracy, including:

[0056] The data acquisition unit receives and stores atmospheric waveguide levels, raw radar video, AIS dynamic information, and radar tracks.

[0057] The data evaluation unit evaluates the target trajectory or echo and generates a strategy for synthesizing the output power of the transmitter.

[0058] The control unit controls the output power of the power amplifier unit by turning on or off the operating voltage of the power amplifier tubes in some of the final stage power amplifier components, according to the strategy of the output power of the synthesized transmitter.

[0059] The power amplifier unit includes multiple final stage power amplifier components and a power combining module to produce high-power output.

[0060] The control unit controls the output power of the power amplifier unit by turning on or off the operating voltage of some of the power amplifier tubes in the final stage power amplifier assembly.

[0061] The final stage power amplifier component is turned on or off according to the first-in-first-out rule;

[0062] To reduce the transmit power by 6dB, the number of final stage power amplifier components that are in the on state is reduced by half; at least one final stage power amplifier component is in the on state.

[0063] To increase the transmit power by 6dB, double the number of the final stage power amplifier components that are in the ON state; the number of the final stage power amplifier components that are in the ON state shall not exceed the total number of the final stage power amplifier components.

[0064] The control unit has a built-in first-in-first-out queue that stores the IDs of the final stage power amplifier components that are in the off state. When the power is on, all final stage power amplifier components are in the off state. Starting from the head of the queue, odd-numbered IDs are stored sequentially, followed by even-numbered IDs. When turning on a final stage power amplifier component, the ID of the final stage power amplifier component is retrieved from the head of the queue, and then the corresponding final stage power amplifier component is turned on. When turning off a final stage power amplifier component, the final stage power amplifier component is turned off first, and then the corresponding ID is placed at the tail of the queue. The advantage of this method is that by using a rotation method, the service life of the final stage power amplifier module can be improved.

[0065] The power amplifier unit includes multiple final stage power amplifier components and a power combining module;

[0066] The final stage power amplifier components are connected in parallel; each final stage power amplifier component is assigned a unique ID according to the order of arrangement.

[0067] The final stage power amplifier assembly typically uses GaN power transistors to achieve power amplification.

[0068] The final stage power amplifier assembly can be controlled to be in two states: on or off, by turning on or off the operating voltage of the power amplifier tubes. When in the on state, the input power of each final stage power amplifier assembly is the same; the output power of each final stage power amplifier assembly is the same; when in the off state, both the input power and output power of each final stage power amplifier assembly are 0.

[0069] The power combining module combines the output power of multiple final stage power amplifier components into a single output.

[0070] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0071] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for improving the accuracy of radar target detection, characterized in that, Includes the following steps: S1. Data acquisition: Receive and store atmospheric waveguide height, raw radar video, AIS dynamic information, and radar track. S2. A strategy for evaluating target tracks and echoes to generate composite output power; S3, control the output power of power synthesis; according to the strategy of power synthesis, make the power amplifier unit produce the corresponding power output.

2. The method for improving radar target detection accuracy according to claim 1, characterized in that, In step S1, the atmospheric waveguide height is divided into N+1 atmospheric waveguide levels from 0 to N, with level 0 being the lowest and level N being the highest. The original radar video must include at least time, azimuth, and amplitude information for each sampling unit. The AIS dynamic information must include at least MMSI number, longitude, latitude, speed, and time information. The radar track must include at least batch number, time, distance, azimuth, longitude, latitude, and the MMSI number associated with the AIS.

3. The method for improving radar target detection accuracy according to claim 1, characterized in that, Step S2 includes the following steps: S21. Define the i-th waypoint of the target of interest and its associated AIS; S22. Perform linear interpolation of AIS in a rectangular coordinate system and convert it to polar coordinates; S23. Calculate the azimuth and range accuracy. If the conditions are met, proceed to S24; otherwise, keep the transmission power unchanged. S24. Define the sampling distance and offset of the radar video, and extract the amplitude array; S25. Take the amplitude vector at the preset distance from the center in the amplitude array and calculate its consistency with the antenna pattern curve; if the consistency is less than the specified nominal value, proceed to S26; otherwise, keep the transmit power unchanged. S26. After sorting the amplitude array, take the average value of the amplitude values ​​of the largest part. If the atmospheric waveguide level is greater than the preset level threshold and the average value is greater than the specified nominal value, reduce the transmission power; otherwise, increase the transmission power.

4. The method for improving radar target detection accuracy according to claim 3, characterized in that, S21 specifically defines the i-th track point of the target of interest as {t}. i ,θ i ,ρ i }, where i = 1, 2, ..., n, t i Represents time, t1 <t2<…<t n θ i Indicates direction, ρ i Represents distance; the AIS associated with the track of the target of interest is {t' j ,θ j ,ρ j ,x j ,y j }, where j = 1, 2, ..., m, t' j Indicates time, t1' <t'2<…<t' m θ j and ρ j x represents the azimuth and range calculated using the Vicente formula with the radar as the coordinate origin. j and y j These are the corresponding x and y coordinates; S22 specifically refers to: at time t1 <t2<…<t n The AIS values ​​in the rectangular coordinate system are respectively set to {t' j ,x j },{t' j ,y j Linear interpolation is used to obtain time t. i Cartesian coordinates of interpolation Then convert to polar coordinates S23 specifically refers to: according to the formula Calculate azimuth accuracy S θ According to the formula Calculation distance accuracy S ρ ; such as S θ >U θ And S ρ >U ρ Then proceed to step S24, where U θ and U ρ The specified nominal value shall be used; otherwise, the transmission power shall remain unchanged.

5. The method for improving radar target detection accuracy according to claim 4, characterized in that, S24 specifically defines the sampling distance of the radar video as D. The corresponding distance offset is In radar video Extract the amplitude array {A} centered pq }, where p = 1, 2, ..., P, q = 1, 2, ..., Q, and Q is an odd number; the horizontal axis of the amplitude array represents the azimuth, and the azimuth width should not be less than 1.5 times the azimuth width of the large ship echo when the atmospheric waveguide is of class N; the vertical axis of the amplitude array represents the distance, and the distance width should not be less than 1.5 times the distance width of the large ship echo when the atmospheric waveguide is of class N.

6. The method for improving radar target detection accuracy according to claim 5, characterized in that, S25 specifically refers to: the amplitude array at a distance from the center. The magnitude vector at point A is {A} pω }; Define the antenna radiation pattern curve obtained from laboratory testing as Consistency based on formula calculation in and They represent The mean and standard deviation, μ Aω and σ Aω They represent {A} pω The mean and standard deviation of}; if C C Then proceed to step S26, where U C The specified nominal value shall be used; otherwise, the transmission power shall remain unchanged.​ 7. The method for improving radar target detection accuracy according to claim 6, characterized in that, S26 specifically refers to: For the amplitude array {A} pq Sort the values ​​from largest to smallest, and average the amplitude values ​​of the first c×P×Q to obtain M, where c is a coefficient between 0 and 1; if the atmospheric waveguide level is greater than the preset level threshold and M>U M The transmission power needs to be reduced; otherwise, the transmission power needs to be increased, where U M The specified nominal value.

8. The method for improving radar target detection accuracy according to claim 1, characterized in that, In step S3, the control unit controls the output power of the power amplifier unit by turning on or off the operating voltage of the power amplifier tubes in some of the final stage power amplifier components according to the strategy of combining the output power of the transmitter. The power amplifier unit includes multiple final stage power amplifier components and a power combining module to generate the corresponding power output.

9. An apparatus for improving radar target detection accuracy, said apparatus being based on a method for improving radar target detection accuracy according to any one of claims 1-8, characterized in that, include: The data acquisition unit receives and stores atmospheric waveguide altitude, raw radar video, AIS dynamic information, and radar track. The data evaluation unit evaluates the target trajectory or echo and generates a strategy for synthesizing the output power of the transmitter. The control unit controls the output power of the power amplifier unit by turning on or off the operating voltage of the power amplifier tubes in some of the final stage power amplifier components, according to the strategy of the output power of the synthesized transmitter. The power amplifier unit includes multiple final stage power amplifier components and a power combining module to generate the corresponding power output.

10. The device for improving radar target detection accuracy according to claim 9, characterized in that, The control unit turns the final stage power amplifier components on or off according to the first-in-first-out rule; if it is necessary to reduce the transmission power, the number of final stage power amplifier components in the on state is reduced by half; if it is necessary to increase the transmission power, the number of final stage power amplifier components in the on state is doubled. The power amplifier unit includes multiple final-stage power amplifier components and a power combining module; the final-stage power amplifier components are connected in parallel; the final-stage power amplifier components can be controlled to be in two states, on or off, by turning on or off the operating voltage of the power amplifier tubes; the input power and output power of each final-stage power amplifier component in the on state are the same; the input power and output power of each final-stage power amplifier component in the off state are both 0; the power combining module combines the output power of multiple final-stage power amplifier components into a single output.

Images