An airborne calibration evaluation method and system for a spaceborne early warning radar

Abstract

The application relates to a kind of airborne calibration flight evaluation methods of spaceborne early warning radar, step 1: the pre-processing of calibration flight test data is carried out, the number M of detection point traces in calibration flight test is obtained, radar action distance R E,m , signal-to-clutter-plus-noise ratio margin SCNR E,m , and target actual flight point trace number N and RCS value sigma E,m Wherein, m=1, 2...M;Step 2: according to radar action distance R E,m The on-orbit detection distance R G,m of spaceborne early warning radar is calculated;Step 3: the balance conversion between detection distance and discovery probability is carried out, and the on-orbit detection distance R under the condition of specific discovery probability p is obtained.The airborne calibration flight evaluation method of spaceborne early warning radar provided by the application comprehensively considers the conversion between signal-to-clutter-plus-noise ratio margin and action distance, discovery probability and radar action distance, and fully excavates calibration flight test data information, so that the accuracy and reliability of calculation and evaluation are improved.

Description

Technical Field

[0001] This invention relates to an airborne flight calibration evaluation method and system for spaceborne early warning radar, which is used to extrapolate the performance of spaceborne early warning radar from the results of airborne flight calibration tests, and belongs to the technical field of radar detection performance evaluation. Background Technology

[0002] During the development of a spaceborne early warning radar system, equivalent flight calibration tests are required to verify the feasibility of the technical system and to extrapolate the main technical indicators of the spaceborne early warning radar from the flight calibration data. Both the verification of the technical system's feasibility and the extrapolation of the main technical indicators' compliance are best evaluated from the perspective of flight calibration detection effects. That is, the radar's effective range and target detection probability obtained from the flight calibration tests can be used to extrapolate and evaluate the feasibility of the spaceborne early warning radar's technical system and the compliance of its power-related indicators.

[0003] In flight calibration tests, radar range refers to the distance between the physical location of the radar and the physical location of the target at the moment of detection, provided the target can be detected. Two points need clarification: First, the measured radar range does not represent its true capability, because the radar may have a greater range, but due to the limitation of the physical distance between the radar and the target, it cannot demonstrate greater capability. Therefore, it is necessary to combine the range at the time of detection with the signal-to-clutter ratio margin to calculate a radar range index that truly represents its capability. Second, the radar system used for flight calibration differs from the early warning radar system in many aspects such as antenna size, transmit power, and target drone RCS. Equivalent conversion is required to deduce the effective range index of the spaceborne early warning radar.

[0004] In flight calibration tests, the target detection probability refers to the ratio of the number of target traces detected by the radar to the number of actual flight traces of the target drone. The actual flight traces of the target drone are formed by extracting the actual flight paths of the target drone within the effective test area according to the detection frame frequency. Two points need clarification: First, the detection probability index is related to the radar's operating range. Once the maximum radar operating range is determined, the number of actual flight traces of the target drone should be counted within the range of the maximum radar operating range. Second, some balancing calculations are needed between the detection probability and radar operating range indices. For example, by reducing the radar operating range index, the detection probability index can be increased, thus obtaining the radar operating range index corresponding to the converted detection probability index (e.g., 50%).

[0005] When extrapolating the results of airborne flight calibration tests to evaluate the performance of spaceborne early warning radar, traditional evaluation methods rarely consider the conversion between signal-to-clutter-to-noise ratio margin and range, and between detection probability and radar range. This results in certain shortcomings in fully utilizing flight calibration test data and accurately evaluating radar detection capabilities. Summary of the Invention

[0006] The technical problem solved by this invention is to address the inaccurate assessment of radar detection power caused by traditional evaluation methods that fail to consider factors such as the conversion relationship between signal-to-clutter ratio margin and range, and between detection probability and radar range when extrapolating the performance of spaceborne early warning radar based on airborne flight calibration test results. This invention provides an airborne flight calibration evaluation method for spaceborne early warning radar, which is suitable for high-precision extrapolation evaluation of spaceborne early warning radar performance based on airborne flight calibration test data.

[0007] The technical solution of this invention is:

[0008] An airborne flight calibration and evaluation method for a spaceborne early warning radar includes the following steps:

[0009] Step 1: Preprocess the flight calibration test data to obtain the number of detection points M and the radar range R in the flight calibration test. E,m Signal-to-noise ratio margin (SCNR) E,m The actual number of target flight points N and the RCS value σ of the target drone E,m Where m = 1, 2…M;

[0010] Step 2: Based on the radar range R E,m Calculate the on-orbit detection range R of the spaceborne early warning radar G,m ;

[0011] Step 3: Perform a balance calculation between the detection range and the detection probability to obtain the on-orbit detection range R under a specific detection probability p.

[0012] Furthermore, the radar range R corresponding to each point is... E,m This refers to the distance between the physical location of the radar and the physical location of the target drone;

[0013] The target RCS value σ corresponding to each detection point's viewpoint. E,m The target RCS dataset is obtained as follows: The target RCS dataset is obtained through testing, and its values ​​are a sequence that varies with the incident angle. During airborne flight calibration tests, the radar position, target position, and attitude corresponding to the m-th point are measured. From this, the incident angle of the radar wave with respect to the target is calculated, and the target RCS value σ corresponding to this detection is retrieved from the target RCS dataset. E,m .

[0014] Furthermore, the actual flight path of the target drone. If N is not an integer, round up; where t B t represents the flight time of the target drone's trajectory within the effective area. I The time interval between point frames is defined as the effective area, which is defined as the physical distance between the target drone and the radar ≤ max(R).E,m () the flight path section.

[0015] Furthermore, the effective distance R corresponding to all the points obtained from the airborne flight calibration test will be... E,m This translates to the on-orbit detection range R of a spaceborne early warning radar. G,m The specific conversion formula is as follows:

[0016]

[0017] Among them, P G,av P represents the average transmit power of the spaceborne early warning radar during its future on-orbit operation. E,av G represents the average transmit power of the airborne flight calibration radar. G,T For the future on-orbit transmission antenna gain of the spaceborne early warning radar, G E,T A is the transmit antenna gain of the airborne flight calibration radar. G,R A represents the receiving antenna area of ​​the spaceborne early warning radar when it is in orbit. E,R L represents the receiving antenna area of ​​the airborne flight calibration radar. G To mitigate link loss during future on-orbit operation of the spaceborne early warning radar, L E For the link loss of the airborne flight calibration radar; T G,cpi T is the coherent accumulation time for future on-orbit detection by the spaceborne early warning radar. E,cpi The coherent accumulation time during airborne calibration radar detection tests; σ G RCS of future on-orbit detection targets for spaceborne early warning radar; D G This will serve as a detection factor for future on-orbit detection by spaceborne early warning radar.

[0018] Furthermore, the on-orbit detection range R under a specific discovery probability p is obtained as follows:

[0019] Let K = pN, and round up if K is not an integer. The on-orbit detection range R of the spaceborne early warning radar is... G,m The dataset is arranged in descending order. The Kth largest value in this dataset is R, which represents the calculated on-orbit detection range R of the spaceborne early warning radar. G,m In the dataset, there are K points whose converted distances satisfy R. G,m ≥R.

[0020] Secondly, this invention also proposes an airborne flight calibration and evaluation system for a spaceborne early warning radar, comprising:

[0021] Parameter acquisition module: preprocesses the flight calibration test data to obtain the number of detection points M and radar range R in the flight calibration test. E,m Signal-to-noise ratio margin (SCNR) E,m The actual number of target flight points N and the RCS value σ of the target drone E,mWhere m = 1, 2…M;

[0022] On-orbit detection range conversion module: Based on radar range R E,m Calculate the on-orbit detection range R of the spaceborne early warning radar G,m ;

[0023] Balance Calculation Module: Performs a balance calculation between the detection range and the detection probability to obtain the on-orbit detection range R under a specific detection probability p.

[0024] The advantages of this invention compared to the prior art are:

[0025] (1) The present invention proposes an airborne flight calibration evaluation method for a spaceborne early warning radar, which comprehensively considers issues such as clutter ratio margin and range, and conversion between detection probability and radar range, and fully explores the information from the calibration test data to improve the accuracy and reliability of the calculation evaluation.

[0026] (2) The airborne flight calibration evaluation method for a spaceborne early warning radar proposed in this invention quantitatively considers the change of the target RCS with the incident angle during the flight calibration test when converting the detection range of the airborne early warning radar from the detection range of the airborne flight calibration test. That is, the incident angle of the radar wave with respect to the target is calculated for each point in the flight calibration test, and the corresponding RCS value is queried to ensure the accuracy of the RCS value used, thereby supporting a more accurate measurement of the radar power.

[0027] (3) The airborne calibration evaluation method for a spaceborne early warning radar proposed in this invention quantitatively considers the influence of the signal-to-clutter-noise ratio margin in the calibration test when converting the detection range of the airborne calibration test to the on-orbit detection range of the spaceborne early warning radar. That is, the relationship between the signal-to-clutter-noise ratio margin and the detection range is calculated quantitatively for each point in the calibration test, thereby supporting a more accurate measurement of the radar's power.

[0028] (4) The present invention proposes an airborne calibration and evaluation method for a spaceborne early warning radar. In view of the strong coupling relationship between the detection probability and the radar operating range index, it gives an equivalent conversion method between the two indexes of detection probability and radar operating range, and finally can accurately calculate the index of "detection range under specific detection probability conditions". Attached Figure Description

[0029] Figure 1 This is a flowchart of the evaluation method of the present invention. Detailed Implementation

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

[0031] This invention proposes an airborne flight calibration evaluation method for spaceborne early warning radar. First, based on the quantitative relationship between airborne calibration radar and spaceborne early warning radar in terms of system parameters, accumulation time, signal-to-clutter ratio, and target RCS, the method performs an equivalent conversion of the on-orbit detection range. Second, considering the strong coupling relationship between the detection probability and the radar's effective range, an equivalent conversion method is given, and finally, the "on-orbit detection range under specific detection probability conditions" index can be accurately calculated.

[0032] like Figure 1 As shown, this evaluation method specifically includes the following steps:

[0033] Step 1: Preprocessing of flight calibration test data.

[0034] By processing the airborne flight calibration radar echoes, the following parameters were obtained: the number of detection points M actually obtained during the flight calibration test, and the radar operating range R corresponding to each detection point (the distance between the radar's physical location and the target drone's physical location). E,m (m=1,2…M), the signal-to-clutter ratio margin corresponding to each point trace

[0035] SCNR E,m (m=1,2…M), the target RCS (radar cross section) σ corresponding to each detection point's viewing angle. E,m (m=1,2…M), the actual number of flight points of the target drone N.

[0036] The target RCS dataset can be obtained through testing or analysis, and its values ​​are a sequence that varies with the incident angle. In airborne flight calibration tests, the radar position, target position, and attitude corresponding to the m-th point can be measured. From this, the incident angle of the radar wave with respect to the target can be calculated, and the target RCS value σ corresponding to that detection can be retrieved from the target RCS dataset. E,m .

[0037] Actual flight traces of the target drone (If N is not an integer, round up)

[0038] Among them, t B For the target drone's trajectory to be within the effective area (the physical distance between the target drone and the radar ≤ max(R) E,m The flight duration within the track segment (t) I This represents the time interval between point frames.

[0039] Step 2: Calculation of on-orbit detection range of spaceborne early warning radar.

[0040] The effective distance R corresponding to all the points obtained in the airborne flight test E,m (m=1,2…M), all can be converted into the on-orbit detection range R of the spaceborne early warning radar.G,m (m=1,2…M). The conversion approach involves comprehensively considering and quantitatively comparing factors in the radar equations that affect the effective range, such as system parameters, accumulation time, signal-to-clutter ratio / detection factor, and target RCS. The specific conversion formula is as follows:

[0041]

[0042] Among them, P G,av P represents the average transmit power of the spaceborne early warning radar during its future on-orbit operation. E,av G represents the average transmit power of the airborne flight calibration radar. G,T For the future on-orbit transmission antenna gain of the spaceborne early warning radar, G E,T A is the transmit antenna gain of the airborne flight calibration radar. G,R A represents the receiving antenna area of ​​the spaceborne early warning radar when it is in orbit. E,R L represents the receiving antenna area of ​​the airborne flight calibration radar. G To mitigate link loss during future on-orbit operation of the spaceborne early warning radar, L E For the link loss of the airborne flight calibration radar; T G,cpi T is the coherent accumulation time for future on-orbit detection by the spaceborne early warning radar. E,cpi The coherent accumulation time during airborne calibration radar detection tests; σ G RCS of future on-orbit detection targets for spaceborne early warning radar; D G These are the detection factors for future on-orbit detection by spaceborne early warning radar. All of the above parameters can be obtained from the design scheme of the spaceborne early warning radar or the parameters of airborne flight calibration tests.

[0043] The method described above for estimating the on-orbit detection range of a spaceborne early warning radar based on airborne flight test results has two characteristics:

[0044] (1) Given that the RCS of the target drone varies with the incident angle, selecting accurate RCS data is the basis for accurately measuring the radar's power. This patented method calculates the incident angle of the radar wave with respect to the target drone for each point in the flight calibration test, and then looks up the corresponding RCS value σ. E,m (m=1,2…M) to ensure the accuracy of the RCS values ​​used.

[0045] (2) Considering the limitation of the physical distance between the radar and the target drone, the radar's effective range measured during calibration flight may not necessarily represent its true power. In order to more accurately measure the radar's power, this patented method considers the relationship between the measured effective range and the signal-to-clutter-noise ratio (SCNR) margin for each point in the calibration flight test, that is, by quantitatively calculating the SCNR margin. E,m The influence of (m=1,2…M) is used to ensure the accuracy of the method in this patent.

[0046] Step 3: Balancing the detection distance with the probability of discovery.

[0047] In the actual evaluation or measurement of radar system effectiveness, the effective range index under a specific detection probability (e.g., 50%) is usually used. However, in actual flight calibration tests, the measured detection probability is often not a specific value. It is necessary to perform some balancing and conversion between the detection probability and the radar effective range index to obtain the radar effective range index corresponding to the specific detection probability index.

[0048] The on-orbit detection range R under a specific discovery probability p can be obtained using this method: Let

[0049] K = pN (round up if K is not an integer), representing the dataset R. G,m Arranged in descending order (m=1,2…M), the Kth largest value in this dataset is R. In other words, in the converted dataset R of the on-orbit detection range of the spaceborne early warning radar... G,m In (m=1,2…M), there are K points whose corresponding converted distances satisfy R G,m ≥R.

[0050] Example:

[0051] This embodiment presents the following specific steps of an airborne flight calibration and evaluation method for a spaceborne early warning radar:

[0052] Step 1: Preprocessing of flight calibration test data.

[0053] By processing the airborne flight calibration radar echoes, the following parameters were obtained: the number of detection points M actually obtained during the flight calibration test, and the radar operating range R corresponding to each detection point (the distance between the radar's physical location and the target drone's physical location). E,m (m=1,2…M), the signal-to-clutter ratio margin corresponding to each point trace

[0054] SCNR E,m (m=1,2…M), the target RCS (radar cross section) σ corresponding to each detection point's viewing angle. E,m (m=1,2…M), the actual number of flight points of the target drone N.

[0055] The target RCS dataset can be obtained through testing or analysis, and its values ​​are a sequence that varies with the incident angle. In airborne flight calibration tests, the radar position, target position, and attitude corresponding to the m-th point can be measured. From this, the incident angle of the radar wave with respect to the target can be calculated, and the target RCS value σ corresponding to that detection can be retrieved from the target RCS dataset. E,m .

[0056] Actual flight traces of the target drone (If N is not an integer, round up)

[0057] Among them, t B For the target drone's trajectory to be within the effective area (the physical distance between the target drone and the radar ≤ max(R) E,m The flight duration within the track segment (t) I This represents the time interval between point frames.

[0058] In a specific embodiment, the flight time of the target drone within the effective area is t. B =100min, the time interval between point frames is t I =10s, the actual number of flight traces of the target drone is N=600, the actual number of traces detected in the calibration flight test is M=500, and the detection distance corresponding to each trace is...

[0059] R E,m (m=1,2…500) Between 100km and 200km, the signal-to-noise ratio margin (SCNR) E,m (m=1,2…500) Between 13dB and 20dB, the target RCS (radar cross section) of the target drone corresponding to each detection angle is σ. E,m (m = 1, 2…500) at 10m 2 up to 50m 2 between.

[0060] Step 2: Calculation of on-orbit detection range of spaceborne early warning radar.

[0061] The effective distance R corresponding to all the points obtained in the airborne flight test E,m (m=1,2…M), all can be converted into the on-orbit detection range R of the spaceborne early warning radar. G,m (m=1,2…M). The conversion approach involves comprehensively considering and quantitatively comparing factors in the radar equations that affect the effective range, such as system parameters, accumulation time, signal-to-clutter ratio / detection factor, and target RCS. The specific conversion formula is as follows:

[0062]

[0063] In a specific embodiment, the RCS of the target detected by the spaceborne early warning radar in orbit is σ. G =25m 2 The detection factor for spaceborne early warning radar during on-orbit detection is D. G =11dB, the converted on-orbit detection range R G,m (m=1,2…500) is between 1500km and 2500km.

[0064] Step 3: Balancing the detection distance with the probability of discovery.

[0065] The "on-orbit detection distance R under a specific discovery probability p" can be obtained as follows: Let K = pN (round up if K is not an integer), and then... G,m Arranged in descending order (m=1,2…M), the Kth largest value in this dataset is R. In other words, in the converted dataset R of the on-orbit detection range of the spaceborne early warning radar... G,m In (m=1,2…M), there are K points whose corresponding converted distances satisfy R G,m ≥R.

[0066] In a specific embodiment, the spaceborne early warning radar needs to assess the on-orbit detection range under a specific detection probability p = 50%, where the RCS of the on-orbit detection target is σ. G =25m 2 The detection factor for spaceborne early warning radar during on-orbit detection is D. G =11dB, the converted on-orbit detection range dataset R G,m Arranged from largest to smallest, (m=1,2…500) have K=300 values ​​greater than or equal to 2000km. Therefore, it can be concluded that the on-orbit detection range of the spaceborne early warning radar under a detection probability p=50% is R=2000km. Parts not described in detail in this invention are common knowledge to those skilled in the art.

Claims

1. A method for airborne flight calibration and evaluation of a spaceborne early warning radar, characterized in that, include: Preprocess the flight calibration test data to obtain the number of detection points in the flight calibration test. Radar range Signal-to-noise ratio margin and the actual number of flight traces of the target drone and RCS value ,in, ; According to radar range Calculate the on-orbit detection range of spaceborne early warning radar ; A balance calculation is performed between detection range and detection probability to obtain a specific detection probability. On-orbit detection range under certain conditions ; Actual flight traces of the target drone ,like If the result is not an integer, round it up to the nearest integer; where, The flight time of the target drone within the effective area. The time interval between point frames refers to the time interval between the target drone and the radar; the effective area refers to the physical distance between the target drone and the radar. The flight path segment; The effective distance corresponding to all the points obtained from the airborne flight calibration test This translates to the on-orbit detection range of a spaceborne early warning radar. The specific conversion formula is as follows: ； in, This represents the average transmit power of the spaceborne early warning radar while it is in orbit. This represents the average transmit power of the airborne flight calibration radar. This is for the transmit antenna gain of the spaceborne early warning radar when it is in orbit. The gain of the transmitting antenna for the airborne flight calibration radar; This represents the receiving antenna area of ​​the spaceborne early warning radar when it is in orbit. The receiving antenna area of ​​the airborne flight calibration radar; To account for link loss during the future on-orbit operation of the spaceborne early warning radar, For the link loss of the airborne flight calibration radar; This is to allow for the coherent accumulation time of the spaceborne early warning radar during future on-orbit detection. The coherent accumulation time for airborne calibration radar detection tests; The RCS of future on-orbit detection targets for spaceborne early warning radar; This will serve as a detection factor for future on-orbit detection by spaceborne early warning radar. Specific discovery probability On-orbit detection range under certain conditions Obtain it using the following method: make , If the value is not an integer, round it up to the nearest integer. This will determine the on-orbit detection range of the spaceborne early warning radar. The dataset is arranged in descending order, and the first [item] in this dataset is [number]. The larger value is That is, the calculated on-orbit detection range of the spaceborne early warning radar. In the dataset, there are The converted distances corresponding to each point satisfy the following conditions: .

2. The airborne flight calibration and evaluation method for a spaceborne early warning radar according to claim 1, characterized in that: The radar range corresponding to each point This refers to the distance between the physical location of the radar and the physical location of the target drone; The target RCS value corresponding to each detection point's viewpoint. The target RCS dataset was obtained through testing, and its values ​​are a sequence of changes with the incident angle. In airborne flight calibration tests, the [dataset name missing]... The radar position, target position, and attitude corresponding to each point are obtained through measurement. From this, the incident angle of the radar wave with respect to the target is calculated, and then the target RCS value corresponding to this detection is obtained from the target target RCS dataset. .

3. An airborne flight calibration and evaluation system for a spaceborne early warning radar, characterized in that, include: Parameter acquisition module: preprocesses the flight calibration test data and obtains the number of detection points in the flight calibration test. Radar range Signal-to-noise ratio margin and the actual number of flight traces of the target drone and RCS value ,in, ; On-orbit detection range conversion module: based on radar range Calculate the on-orbit detection range of spaceborne early warning radar ; Balanced conversion module: Performs a balanced conversion between detection range and detection probability to obtain a specific detection probability. On-orbit detection range under certain conditions ; Actual flight traces of the target drone ,like If the result is not an integer, round it up to the nearest integer; where, The flight time of the target drone within the effective area. The time interval between point frames refers to the time interval between the target drone and the radar; the effective area refers to the physical distance between the target drone and the radar. The flight path segment; The effective distance corresponding to all the points obtained from the airborne flight calibration test This translates to the on-orbit detection range of a spaceborne early warning radar. The specific conversion formula is as follows: ； in, This represents the average transmit power of the spaceborne early warning radar while it is in orbit. This represents the average transmit power of the airborne flight calibration radar. This is for the transmit antenna gain of the spaceborne early warning radar when it is in orbit. The gain of the transmitting antenna for the airborne flight calibration radar; This represents the receiving antenna area of ​​the spaceborne early warning radar when it is in orbit. The receiving antenna area of ​​the airborne flight calibration radar; To account for link loss during the future on-orbit operation of the spaceborne early warning radar, For the link loss of the airborne flight calibration radar; This is to allow for the coherent accumulation time of the spaceborne early warning radar during future on-orbit detection. The coherent accumulation time for airborne calibration radar detection tests; The RCS of future on-orbit detection targets for spaceborne early warning radar; This will serve as a detection factor for future on-orbit detection by spaceborne early warning radar. Specific discovery probability On-orbit detection range under certain conditions Obtain it using the following method: make , If the value is not an integer, round it up to the nearest integer. This will determine the on-orbit detection range of the spaceborne early warning radar. The dataset is arranged in descending order, and the first [item] in this dataset is [number]. The larger value is That is, the calculated on-orbit detection range of the spaceborne early warning radar. In the dataset, there are The converted distances corresponding to each point satisfy the following conditions: .

4. The airborne flight calibration and evaluation system for a spaceborne early warning radar according to claim 3, characterized in that: The radar range corresponding to each point This refers to the distance between the physical location of the radar and the physical location of the target drone; The target RCS value corresponding to each detection point's viewpoint. The target RCS dataset was obtained through testing, and its values ​​are a sequence of changes with the incident angle. In airborne flight calibration tests, the [dataset name missing]... The radar position, target position, and attitude corresponding to each point are obtained through measurement. From this, the incident angle of the radar wave with respect to the target is calculated, and then the target RCS value corresponding to this detection is obtained from the target target RCS dataset. .

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