A phased array radar search method and system

Abstract

The application provides a phased array radar search method and system, comprising the following steps: step one, determining a search area; step two, converting the search area into a sine space; step three, determining wave position arrangement; step four, determining an initial position of the search; step five, starting simultaneously with step six, storing the initial position of the search into a database; step six, determining a plurality of search wave positions according to a search sequence and the wave position arrangement, and searching the search area according to the search wave positions; step seven, after the search is completed, determining an initial position of the next search in combination with the latest recorded initial position of the search in the search database; step eight, placing the new initial position in the database, and simultaneously performing step nine; step nine, starting the search according to the new initial position, and cyclically performing steps six-nine. The application does not increase the search time, is suitable for various fast search wave position arrangement methods, reduces the fluctuation of the discovery probability space, and improves the discovery probability of part of the space.

Description

Technical Field

[0001] This invention belongs to the field of radar technology and relates to a phased array radar search method and system. Background Technology

[0002] Phased array radar uses phase shifters for phase control, which provides flexible beam agility and efficient resource management. This gives it an advantage over conventional mechanically scanned radar in terms of time, space, frequency, and energy management. As a result, phased array radar has great potential in rationally allocating resources for optimal search.

[0003] Unlike conventional mechanically rotating radars, phased array radars have discrete wavefront arrangement characteristics, allowing the antenna beam to transition seamlessly from one wavefront to another. Currently, researching wavefront arrangement can improve the resource utilization efficiency of phased array radars.

[0004] When a phased array radar performs a search scan, if the wave positions are arranged too tightly, it will inevitably lead to an excessively long search time, wasting radar time resources. If the wave positions are arranged too sparsely, there will be significant waveform loss between adjacent wave positions, thereby reducing the radar's detection probability. Therefore, in the design of phased array radar, the arrangement of search wave positions is an important fundamental task, and the quality of the wave position arrangement plays an indispensable role in optimizing phased array radar resources and improving search performance.

[0005] Common phased array radar wavefront arrangement methods include: rectangular arrangement (wavefronts are arranged with horizontal and vertical rectangles overlapping by 3dB); triangular arrangement (wavefronts are arranged with triangles overlapping by 3dB); and overlapping arrangement (wavefronts are denser than in the triangular arrangement, ensuring that waveform loss at all points in space is less than 3dB). Due to waveform loss, regardless of the arrangement method, the probability of detection in space fluctuates, resulting in a low probability of detection at certain angles. All three arrangement methods involve increasingly longer search times and smaller probability fluctuations.

[0006] The technical solution described in Chinese patent "CN105487051A Scanning Method for Radar Angle Search" has limited application scenarios and is difficult to apply to common one-dimensional search areas. Although this technical solution can save search time for overlapping arrangements, it still requires a longer search time than rectangular or triangular arrangements. In addition, during the implementation of this technical solution, there is still a problem of uneven spatial distribution of the detection probability angle, resulting in a lower detection probability in some areas. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a phased array radar search method, comprising the following steps:

[0008] Step 1: Determine the search area;

[0009] Step 2: Convert the search region into a sinusoidal space;

[0010] Step 3: Determine the wave position arrangement;

[0011] Step 4: Determine the initial search location;

[0012] Step 5: This step begins simultaneously with Step 6, storing the initial search position in the database;

[0013] Step 6: Determine several search wave positions according to the search order and wave position arrangement, and search the search area according to the search wave positions;

[0014] Step 7: After the search is completed, determine the initial position of the next search by combining the initial position of the latest record in the search database;

[0015] Step 8: Place the new initial position in the database and proceed to Step 9 simultaneously;

[0016] Step 9: Start the search from the new initial position and repeat steps 6, 7, 8, and 9 until a stop search command is received.

[0017] Furthermore, the method for determining the initial position for the next search is specifically as follows:

[0018] In the previous search, select any two consecutive search wave positions, and connect the first search wave position to the second search wave position to generate vector p;

[0019] A new initial position can be obtained by multiplying the vector p by the search coefficient ρ and adding it to the initial position of the previous search; the search coefficient ρ is determined according to the change of the target in the angular space.

[0020] Furthermore, the specific method for determining the search coefficient ρ based on the change of the target in the angular space is as follows:

[0021] For fixed targets or distant targets, the search coefficient ρ ranges from 0 to 1 / 4; the fixed targets are those with a speed of less than or equal to 5 km / s, and the distant targets are those within 60 km, excluding fixed targets.

[0022] For near-field targets, the search coefficient ρ is 1 / 2. The near-field targets are those within 0-60km, excluding fixed targets.

[0023] For targets other than distant targets, near targets, or fixed targets, the search coefficient ρ is randomly selected from a number in the range of 0 to 1 / 2.

[0024] Furthermore, the wave position arrangement is determined based on the size of the search area and the search time requirements.

[0025] Furthermore, after the wave position arrangement is determined, the initial search position is determined according to the search sequence.

[0026] The present invention also provides a phased array radar search system, which is based on the above-described phased array radar search method.

[0027] Compared with existing technologies, this invention can adapt to various fast search wave position arrangement methods without increasing search time, reduce spatial fluctuations in the discovery probability, and significantly improve the discovery probability in some spaces. Attached Figure Description

[0028] Figure 1 This is a flowchart of Example 1.

[0029] Figure 2 A comparison chart showing the fluctuations in the probability of discovery under different methods. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the embodiments and the accompanying drawings.

[0031] Example

[0032] The working principle of this embodiment is as follows:

[0033] For conventional search methods that search from a fixed initial position, due to waveform loss, the probability of a phased array radar detecting a target in the angular space is not constant but unevenly distributed. Some areas have a high probability of detection, while others have a low probability, which makes it difficult to detect targets in some angular spaces.

[0034] Considering the search method with a step-initial position, the problem of uneven spatial distribution can be compensated for without increasing the search time per search. That is, using a search method with a fixed initial position, regardless of the wave position arrangement method, assuming the search time is 'a', the target detection probability distribution is uneven in each search. However, using the method of this embodiment, the search time is also 'a', but for a certain angle, a search may be in a low detection probability area, while the next search will be in a high detection probability area due to the change in the initial position. This will improve the overall performance of the radar.

[0035] The initial step position and step length are crucial, primarily depending on the target's correlation time in the angular space. For near-field targets, the search correlation time in the angular space domain is shorter, allowing for fewer search attempts, thus necessitating a larger step length. For stationary or far-field targets, the search correlation time in the angular space domain is longer, allowing for extended search accumulation, thus enabling the selection of a smaller step length to further optimize the discovery probability distribution.

[0036] Figure 1 This is a flowchart of this embodiment, combined with... Figure 1 The phased array radar search method proposed in this embodiment specifically includes the following steps:

[0037] Step 1: Specify the search area. Users need to specify the area to be searched based on the actual combat target and objective.

[0038] Step 2: Convert the search area to sinusoidal space. In sinusoidal space, the beam will not change as the search beam position deviates from the normal, thus simplifying the beam position arrangement process.

[0039] Step 3: Waveform Arrangement. Based on the size of the search area and the required search time, waveforms are arranged. Common waveform arrangement methods in existing technologies include rectangular and triangular arrangements.

[0040] Step 4: Determine the initial search position. After determining the wavelet arrangement, determine the initial search position according to the search order. For example, if you choose to search from left to right, the leftmost wavelet is the initial search position; if you choose to search from top to bottom, the topmost wavelet is the initial search position.

[0041] Step 5: This step begins simultaneously with Step 6, storing the initial search position in the database.

[0042] Step 6: Determine several search wave positions according to the search order and wave position arrangement, and search the search area according to the search wave positions.

[0043] Step 7: After the search is completed, determine the initial position of the next search by combining the initial position of the latest record in the search database; the method for determining the initial position of the next search is as follows:

[0044] 1. In the previous search, select any two consecutive search wave positions, and connect the first search wave position to the second search wave position to generate vector p;

[0045] 2. Multiply vector p by a search coefficient (denoted as ρ, ρ≤1, generally ρ≤1 / 2, common search coefficients are 1 / 2, 1 / 3, 1 / 4, etc.). The choice of this coefficient is related to the target's variation in angular space, and can be selected based on the following characteristics of the target to be searched:

[0046] (1) For fixed targets (the fixed targets are those with a speed of less than or equal to 5 km / s) or distant targets (the distant targets are those within 60 km, excluding fixed targets), a smaller search coefficient can be selected (0-1 / 4 in this embodiment) to reduce fluctuations in the probability of discovery.

[0047] (2) For near-field targets (targets within 0-60km, excluding fixed targets), the search coefficient should be a number close to 1 / 2.

[0048] (3) If there is no knowledge of the target situation, a search coefficient in the range of 0 to 1 / 2 can be randomly selected.

[0049] 3. Multiply vector p by ρ to get ρp. Add this vector ρp to the initial position of the previous search to get a new initial position.

[0050] Step 8: Place the new initial position in the database and proceed with Step 9 simultaneously.

[0051] Step 9: Start the search from the new initial position and repeat steps 6, 7, 8, and 9 until the user issues a command to stop the search.

[0052] Example

[0053] This embodiment provides a phased array radar search system, which includes at least one processing module and at least one database. The processing module and the database are used to implement the search method described in Embodiment 1.

[0054] Compared with existing technologies, this invention does not increase search time, adapts to various fast search wave position arrangement methods, reduces spatial fluctuations in the discovery probability, and improves the discovery probability in some spaces.

[0055] A search simulation was performed in a one-dimensional region (±45°) with the antenna pattern set as follows: A single search used a 3dB overlap method. Where θ is the azimuth angle of the antenna. This represents the maximum value of the directional pattern.

[0056] When the maximum beam value is pointed at the target, the probability of target detection is 0.9, and the probability of false alarm is 10⁻⁶.

[0057] Simulation results are as follows Figure 2 As shown:

[0058] When using a fixed initial position for searching, the probability of finding the target space fluctuates greatly, with the probability of finding the target space dropping to 0.48 in some areas.

[0059] When using the 1 / 2 step search method (ρ=1 / 2), the fluctuation of the discovery probability is improved, and the discovery probability throughout the space is greater than 0.69.

[0060] When using the 1 / 3 step search method (ρ=1 / 3), the fluctuation of the discovery probability is further improved, and the discovery probability throughout the space is greater than 0.73.

[0061] Simulation results show that the method of this invention can reduce fluctuations in the probability space of discovery and increase the discovery probability in some areas.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A phased array radar search method, characterized in that, Includes the following steps: Step 1: Determine the search area; Step 2: Convert the search region into a sinusoidal space; Step 3: Determine the wave position arrangement; Step 4: Determine the initial search location; Step 5: This step begins simultaneously with Step 6, storing the initial search position in the database; Step 6: Determine several search wave positions according to the search order and wave position arrangement, and search the search area according to the search wave positions; Step 7: After the search is completed, determine the initial position of the next search by combining the initial position of the latest record in the search database; Step 8: Place the new initial position in the database and proceed to Step 9 simultaneously; Step 9: Start the search from the new initial position and repeat steps 6, 7, 8, and 9 until a stop search command is received; The method for determining the initial position for the next search is as follows: In the previous search, select any two consecutive search wave positions, and connect the first search wave position to the second search wave position to generate vector p; A new initial position is obtained by multiplying vector p by the search coefficient ρ and adding it to the initial position of the previous search; the search coefficient ρ is determined based on the change of the target in the angle space. The specific method for determining the search coefficient ρ based on the change of the target in the angular space is as follows: For fixed targets or distant targets, the search coefficient ρ ranges from 0 to 1 / 4; the fixed targets are those with a speed of less than or equal to 5 km / s, and the distant targets are those within 60 km, excluding fixed targets. For near-field targets, the search coefficient ρ is 1 / 2. The near-field targets are those within 0-60km, excluding fixed targets. For targets other than distant targets, near targets, or fixed targets, the search coefficient ρ is randomly selected from a number in the range of 0 to 1 / 2.

2. The phased array radar search method according to claim 1, characterized in that, The wave position arrangement is determined based on the size of the search area and the search time requirements.

3. The phased array radar search method according to claim 2, characterized in that, After the wave position arrangement is determined, the initial search position is determined according to the search order.

4. A phased array radar search system, characterized in that, The search system is based on the phased array radar search method described in any one of claims 1-3.

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