Airborne flight correction evaluation method and system for satellite-borne early warning radar

Abstract

The invention relates to an airborne flight correction evaluation method for a satellite-borne early warning radar, and the method comprises the steps: 1, carrying out the preprocessing of flight correction test data, obtaining the detection trace point number M, the radar operating distance RE, m, the signal-clutter-noise ratio margin SCNRE, m, the actual flight trace point number N of a target aircraft, and the RCS value sigma E, m, and m = 1, 2,... M in a flight correction test, and obtaining the detection trace point number M, the radar operating distance RE, m, the signal-clutter-noise ratio margin SCNRE, m, the actual flight trace point number N of the target aircraft, and the RCS value sigma E, m; 2, calculating the on-orbit detection distance RG, m of the satellite-borne early warning radar according to the radar operating distance RE, m; and step 3, carrying out balance conversion between the detection distance and the discovery probability to obtain an on-orbit detection distance R under the condition of a specific discovery probability p. According to the airborne flight correction evaluation method for the satellite-borne early warning radar, the problems of conversion between the clutter-noise ratio margin and the operating distance and between the discovery probability and the radar operating distance are comprehensively considered, flight correction test data information is fully mined, and the accuracy and credibility of calculation evaluation are improved.

Description

TECHNICAL FIELD

[0001] The application relates to an airborne calibration evaluation method and system of a spaceborne early warning radar, which is used for extrapolating and evaluating the performance of the spaceborne early warning radar from the results of the airborne calibration test and belongs to the technical field of radar detection performance evaluation. BACKGROUND

[0002] During the development of the spaceborne early warning radar system, equivalent calibration tests need to be carried out to verify whether the technical system of the spaceborne early warning radar is feasible and whether the main technical indexes of the spaceborne early warning radar calculated from the calibration data meet the requirements. Whether the technical system feasibility verification or the main technical index compliance calculation is suitable for evaluation from the dimension of the calibration detection effect, that is, the radar action distance and the target discovery probability obtained from the calibration test are used to calculate and evaluate the technical system feasibility and the power index compliance of the spaceborne early warning radar.

[0003] In the calibration test, the radar action distance refers to the distance between the radar physical position and the target physical position at the detection time under the premise that the target can be detected. Two points need to be explained here. First, the actually measured radar action distance does not represent the real power because the radar can have a longer action distance, but is limited by the physical distance between the radar and the target, and cannot show the longer power performance, so the radar action distance index that can truly represent the power needs to be calculated in combination with the action distance and the signal-to-clutter noise ratio margin at the detection time. Second, the radar system used for calibration and the early warning radar system are inconsistent in terms of antenna size, transmitting power, target RCS and many other aspects, so equivalent conversion is needed to calculate the action distance index of the spaceborne early warning radar.

[0004] In the calibration test, the target discovery probability refers to the ratio of the number of target tracks detected by the radar to the actual flight track number of the target. The actual flight track of the target is formed by extracting the actual flight track of the target in the test effective area according to the detection frame frequency. Two points need to be explained here. First, the discovery probability index is related to the radar action distance. When the maximum action distance of the radar is determined, the actual flight track number of the target should be counted within the range of the maximum action distance of the radar. Second, the discovery probability and the radar action distance need to be balanced and converted. For example, the discovery probability index can be adjusted and increased by adjusting and reducing the radar action distance index, so as to obtain the radar action distance index corresponding to the discovery probability index converted to a standard value (for example, 50%).

[0005] When the performance of the spaceborne early warning radar is extrapolated and evaluated from the results of the airborne calibration test, the traditional evaluation method rarely considers the conversion problem between the signal-to-clutter noise ratio margin and the action distance, the discovery probability and the radar action distance. There are certain deficiencies in the full use of the calibration test data and the accurate evaluation of the radar detection power. SUMMARY

[0006] The technical solution of the present application is: to solve the problem of inaccurate radar detection power evaluation caused by the fact that the traditional evaluation method does not consider the conversion relationship between the signal-to-clutter noise ratio margin and the action distance, the discovery probability and the radar action distance when extrapolating the performance of the spaceborne early warning radar from the airborne calibration flight test results, the present application provides an airborne calibration flight evaluation method for a spaceborne early warning radar, which is suitable for high-precision extrapolation evaluation of the performance of the spaceborne early warning radar based on airborne calibration flight test data.

[0007] The technical solution of the present application is:

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

[0009] Step 1: preprocessing the calibration flight test data to obtain the number of detection point traces M, the radar action distance R E,m , the signal-to-clutter noise ratio margin SCNR E,m , the actual flight point trace number N of the target and the RCS value σ E,m of the target in the calibration flight test, wherein m=1, 2…M.

[0010] Step 2: calculating the on-orbit detection distance R E,m of the spaceborne early warning radar according to the radar action distance R G,m .

[0011] Step 3: balancing and converting between the detection distance and the discovery probability to obtain the on-orbit detection distance R under a specific discovery probability p.

[0012] Further, the radar action distance R E,m corresponding to each point trace is the distance between the physical position of the radar and the physical position of the target.

[0013] The RCS value σ E,m of the target corresponding to each point trace detection angle is obtained in the following way: the target RCS data set is obtained through testing, and the value is a sequence varying with the incident angle; in the airborne calibration flight test, the radar position, the target position and the attitude corresponding to the mth point trace are obtained by measurement, the incident angle of the radar wave with respect to the target is calculated, and then the target RCS value σ E,m corresponding to this detection is found from the target RCS data set.

[0014] Further, the actual flight point trace number N of the target is If N is not an integer, it is rounded up; wherein t B is the flight time of the target track in the effective area, t I is the time interval between point traces, and the effective area refers to the physical distance between the target and the radar ≤max(RE,m ) of the track section.

[0015] Further, the action distance R E,m of all point tracks obtained by the airborne calibration test is converted into the on-orbit detection distance R G,m of the spaceborne early warning radar, and the specific conversion formula is:

[0016]

[0017] wherein, P G,av is the average transmitting power of the spaceborne early warning radar in the future on-orbit, P E,av is the average transmitting power of the airborne calibration radar; G G,T is the transmitting antenna gain of the spaceborne early warning radar in the future on-orbit, G E,T is the transmitting antenna gain of the airborne calibration radar; A G,R is the receiving antenna area of the spaceborne early warning radar in the future on-orbit, A E,R is the receiving antenna area of the airborne calibration radar; L G is the link loss of the spaceborne early warning radar in the future on-orbit, L E is the link loss of the airborne calibration radar; T G,cpi is the coherent accumulation time of the spaceborne early warning radar in the future on-orbit detection, T E,cpi is the coherent accumulation time of the airborne calibration radar in the detection test; σ G is the RCS of the object to be detected by the spaceborne early warning radar in the future on-orbit detection; D G is the detection factor of the spaceborne early warning radar in the future on-orbit detection.

[0018] Further, the on-orbit detection distance R under the condition of a specific discovery probability p is obtained by the following method:

[0019] Let K = pN, and if K is not an integer, then take the integer part, and the on-orbit detection distance R G,m of the spaceborne early warning radar is obtained by the following method: G,m The data set is arranged in descending order, and the Kth largest value in the data set is R, i.e. the on-orbit detection distance R G,m of the spaceborne early warning radar is obtained by the following method:

[0020] In the second aspect, the application further provides an airborne calibration evaluation system for a spaceborne early warning radar, comprising:

[0021] A parameter acquisition module: pre-processes the calibration test data, and obtains the number of detection point tracks M, the radar action distance R E,m , the signal-to-clutter-and-noise ratio margin SCNR E,m , the actual flight point track number N of the target aircraft, and the RCS value σ E,mWherein, m = 1, 2…M;

[0022] In-orbit detection distance conversion module: according to the radar action distance R E,m The in-orbit detection distance R of the spaceborne early warning radar is calculated G,m

[0023] Balancing conversion module: balancing conversion between the detection distance and the discovery probability, and obtaining the in-orbit detection distance R under the condition of a specific discovery probability p.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] (1) The airborne calibration flight evaluation method of the spaceborne early warning radar provided by the present application comprehensively considers the conversion between the residual signal-to-clutter ratio and the action distance, the conversion between the discovery probability and the radar action distance, and fully excavates the calibration flight test data information, thereby improving the accuracy and reliability of the calculation and evaluation.

[0026] (2) In the airborne calibration flight evaluation method of the spaceborne early warning radar provided by the present application, when the in-orbit detection distance of the spaceborne early warning radar is converted from the detection distance of the airborne calibration flight test, the change of the target RCS with the incident angle in the calibration flight test is quantitatively considered, that is, the incident angle of the radar wave with respect to the target in each point of the calibration flight test is calculated, and the corresponding RCS value is queried from the incident angle, so as to ensure the accuracy of the used RCS value, and further support more accurate measurement of the radar power.

[0027] (3) In the airborne calibration flight evaluation method of the spaceborne early warning radar provided by the present application, when the in-orbit detection distance of the spaceborne early warning radar is converted from the detection distance of the airborne calibration flight test, the influence of the signal-to-clutter ratio residual is quantitatively considered, that is, the relationship between the signal-to-clutter ratio residual and the detection distance is quantitatively calculated for each point of the calibration flight test, and further support more accurate measurement of the radar power.

[0028] (4) In the airborne calibration flight evaluation method of the spaceborne early warning radar provided by the present application, an equivalent conversion method between the discovery probability and the radar action distance is given for the strong coupling relationship between the discovery probability and the radar action distance, and finally the detection distance under the condition of a specific discovery probability can be accurately calculated. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The evaluation method flowchart of the present application. DETAILED DESCRIPTION

[0030] The specific embodiments of the present application will be further described in detail below 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 idea is to comprehensively consider and quantitatively compare the system parameters, accumulation time, signal-to-clutter-noise ratio / detection factor, target RCS, and other factors in the radar equation that affect the action distance. The specific conversion formula is:

[0041]

[0042] where P G,av is the average transmit power of the spaceborne early warning radar in the future on-orbit, P E,av is the average transmit power of the airborne school flying radar; G G,T is the transmit antenna gain of the spaceborne early warning radar in the future on-orbit, G E,T is the transmit antenna gain of the airborne school flying radar; A G,R is the receive antenna area of the spaceborne early warning radar in the future on-orbit, A E,R is the receive antenna area of the airborne school flying radar; L G is the link loss of the spaceborne early warning radar in the future on-orbit, L E is the link loss of the airborne school flying radar; T G,cpi is the coherent accumulation time of the spaceborne early warning radar in the future on-orbit detection, T E,cpi is the coherent accumulation time of the airborne school flying radar in the test; σ G is the RCS of the spaceborne early warning radar in the future on-orbit detection object; D G is the detection factor of the spaceborne early warning radar in the future on-orbit detection. The above parameters can be obtained from the spaceborne early warning radar design scheme or the airborne school flying test parameters.

[0043] The above method of calculating the on-orbit detection distance of the spaceborne early warning radar from the airborne school flying test results has two characteristics:

[0044] (1) Since the RCS of the target aircraft changes with the incident angle, selecting accurate RCS data is the basis for accurately measuring the radar power. The present patent method calculates the incident angle of the radar wave on the target aircraft for each point in the school flying test, and queries the corresponding RCS value σ E,m (m = 1, 2…M) to ensure the accuracy of the RCS value used.

[0045] (2) Considering the physical distance limitation between the radar and the target aircraft, the measured radar action distance in the school flying test does not necessarily represent its real power. In order to more accurately measure the radar power, the present patent method considers the relationship between the measured action distance and the signal-to-clutter-noise ratio margin for each point in the school flying test, i.e. by quantitatively calculating the influence of the signal-to-clutter-noise ratio margin SCNR E,m (m = 1, 2…M) to ensure the accuracy of the present patent method.

[0046] Step 3: Balance conversion between detection distance and discovery probability.

[0047] In the actual evaluation or measurement of radar system power, the effective distance index under a certain discovery probability (for example, 50%) is usually used. However, in the actual calibration flight test, the measured discovery probability is often not a specific value, and some balance conversion needs to be done on the discovery probability and radar effective distance to obtain the radar effective distance index corresponding to the specific discovery probability index.

[0048] The "in-orbit detection distance R under a certain discovery probability p" can be obtained by the following method: let

[0049] K = pN (if K is not an integer, round up), and arrange the data set R G,m (m = 1, 2…M) in descending order, and the Kth largest value in this data set is R. In other words, in the converted in-orbit detection distance data set R G,m (m = 1, 2…M) of the space-based early warning radar, the converted distances of K track points satisfy R G,m ≥ R.

[0050] Embodiment:

[0051] The specific steps of the airborne calibration evaluation method of the space-based early warning radar are as follows:

[0052] Step 1: Calibration test data preprocessing.

[0053] Through processing of the radar echo of the airborne calibration, the following parameters are obtained: the number of track points M actually detected in the calibration test, the radar effective distance (the distance between the radar physical position and the target physical position) R E,m (m = 1, 2…M) corresponding to each track point, the signal-to-clutter noise ratio margin SCNR

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

[0055] The target RCS data set can be obtained by testing or analysis calculation, and its value is a sequence varying with the incident angle. In the airborne calibration test, the radar position, target position and attitude corresponding to the mth track point can be measured, and thus the incident angle of the radar wave to the target can be calculated, and the target RCS value σ E,m corresponding to this detection can be found in the target RCS data set.

[0056] The actual flight track number N of the target (If N is not an integer, round up)

[0057] where t B is the flight time of the target track within the effective area (the track section of the target and the physical distance of the radar ≤ max(R E,m ), t I is the time interval between point traces.

[0058] In specific embodiments, the flight time of the target object within the effective area is t B = 100 min, the time interval between point traces is t I = 10 s, the actual flight point trace number of the target object is N = 600, the actual point trace number obtained by detection in the calibration flight test is M = 500, and the detection distance of each point trace is R

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

[0060] Step 2: On-orbit detection distance calculation of the spaceborne early warning radar.

[0061] The effective distance R E,m (m = 1, 2…M) corresponding to all point traces obtained by the airborne calibration flight test can be converted into the on-orbit detection distance R G,m (m = 1, 2…M) of the spaceborne early warning radar. The conversion idea is to comprehensively consider and quantitatively compare the system parameters, accumulation time, signal-to-noise ratio / detection factor, target RCS, and other factors in the radar equation that affect the effective distance. The specific conversion formula is:

[0062]

[0063] In specific embodiments, the RCS of the on-orbit detection object of the spaceborne early warning radar is σ G = 25 m 2 , the detection factor of the spaceborne early warning radar during on-orbit detection is D G = 11 dB, and the converted on-orbit detection distance R G,m (m = 1, 2…500) is between 1500 km and 2500 km.

[0064] Step 3: Balance conversion between detection distance and discovery probability.

[0065] The on-orbit detection distance R under the condition of a specific discovery probability p can be obtained in this way: let K = pN (if K is not an integer, round up), and arrange the data set R G,m (m = 1, 2…M) in descending order, and the Kth largest value in this data set is R. In other words, in the converted on-orbit detection distance data set R G,m (m = 1, 2…M), the converted distances of K track pairs satisfy R G,m ≥ R.

[0066] In a specific embodiment, the on-orbit detection distance of the spaceborne early warning radar under the condition of a specific discovery probability p = 50% needs to be evaluated, the RCS of the on-orbit detection object is σ G = 25 m 2 , the detection factor of the spaceborne early warning radar during on-orbit detection is D G = 11 dB, and after conversion, the on-orbit detection distance data set R G,m (m = 1, 2…500) is arranged in descending order, and there are K = 300 values greater than or equal to 2000 km. Therefore, it can be concluded that the on-orbit detection distance of the spaceborne early warning radar under the condition of a discovery probability p = 50% is R = 2000 km. The part of the present application not described in detail is common knowledge to those skilled in the art.

Claims

1. An airborne boresight evaluation method for a spaceborne early warning radar, characterized in that Comprising: The pre-processing is performed on the calibration flight test data to obtain the number of detection point traces M, the radar action distance R E,m , the signal-to-clutter noise ratio margin SCNR E,m , the actual flight point trace number N of the target aircraft, and the RCS value σ E,m of the target aircraft, wherein m = 1, 2, …, M. According to the radar action distance R E,m The on-orbit detection distance R of the spaceborne early warning radar is calculated G,m ; Balancing conversion between detection distance and discovery probability is performed to obtain the in-orbit detection distance R under a specific discovery probability p.

2. The method of claim 1, wherein the method is used for airborne calibration of a spaceborne early warning radar. The radar action distance R corresponding to each track E,m That is, the distance between the radar physical position and the target physical position. The target RCS value σ corresponding to each track detection angle of view E,m The target RCS value σ corresponding to each track detection angle of view is obtained by the following method: the target RCS data set is obtained by testing, and the value is a sequence varying with the incident angle; in the airborne calibration flight test, the radar position, the target position and the attitude corresponding to the mth track are obtained by measurement, the incident angle of the radar wave to the target is calculated, and then the target RCS value σ corresponding to this detection is found from the target RCS data set E,m .

3. The method of claim 1, wherein the method further comprises: determining a first angle of the first satellite relative to the first ground station; determining a second angle of the second satellite relative to the first ground station; and determining a third angle of the third satellite relative to the first ground station. Target actual flight track number If N is not an integer, then rounding up; wherein, t B is the flight time length of the target track in the effective area, t I is the time interval between track frames, and the effective area refers to a track section in which the physical distance between the target and the radar is ≤ max(R E,m ).

4. The method of claim 1, wherein the method further comprises: determining a first angle of the first satellite relative to the first ground station; determining a second angle of the second satellite relative to the first ground station; and determining a third angle of the third satellite relative to the first ground station. The action distance R corresponding to all the point traces obtained in the airborne calibration flight test E,m , converted into the on-orbit detection distance R of the spaceborne early warning radar G,m , and the specific conversion formula is: wherein P G,av is the average transmit power of the spaceborne early warning radar in the future on-orbit, P E,av is the average transmit power of the airborne calibration radar; G G,T is the transmit antenna gain of the spaceborne early warning radar in the future on-orbit, G E,T is the transmit antenna gain of the airborne calibration radar; A G,R is the receive antenna area of the spaceborne early warning radar in the future on-orbit, A E,R is the receive antenna area of the airborne calibration radar; L G is the link loss of the spaceborne early warning radar in the future on-orbit, L E is the link loss of the airborne calibration radar; T G,cpi is the coherent integration time of the spaceborne early warning radar in the future on-orbit detection, T E,cpi is the coherent integration time of the airborne calibration radar in the detection test; σ G is the RCS of the object detected by the spaceborne early warning radar in the future on-orbit; D G is the detection factor of the spaceborne early warning radar in the future on-orbit detection.

5. The method of claim 4, wherein the method further comprises: determining a first angle of the first satellite relative to the first ground station; determining a second angle of the second satellite relative to the first ground station; and determining a third angle of the third satellite relative to the first ground station. The in-orbit detection distance R under the specific discovery probability p is obtained by the following method: Let K = pN, K is rounded up if not an integer, the on-orbit detection range R of the spaceborne early warning radar G,m The data set is arranged in descending order, and the Kth largest value in the data set is R, i.e. the on-orbit detection range R of the spaceborne early warning radar converted G,m In the data set, the converted distances corresponding to K point tracks satisfy R G,m ≥ R.

6. An airborne boresight evaluation system for a space-based early warning radar, characterized by Comprising: Parameter acquisition module: pre-process the calibration flight test data, obtain the number of detection point traces M, radar action distance R in the calibration flight test E,m , signal-to-clutter-and-noise ratio margin SCNR E,m , and the actual flight point trace number N and RCS value σ of the target aircraft E,m , wherein m = 1, 2, …, M. In-orbit detection distance conversion module: according to the radar action distance R E,m Calculate the in-orbit detection distance R of the spaceborne early warning radar G,m ; A balancing conversion module: balancing conversion between detection distance and discovery probability is performed to obtain the in-orbit detection distance R under a specific discovery probability p.

7. The airborne calibration evaluation system for a spaceborne early warning radar of claim 6, wherein: The radar action distance R corresponding to each track E,m That is, the distance between the radar physical position and the target physical position. The target RCS value σ corresponding to each track detection view angle E,m The target RCS value σ corresponding to each track detection view angle is obtained by the following method: the target RCS data set is obtained by testing, and the value is a sequence varying with the incident angle; in the airborne calibration flight test, the radar position, the target position and the attitude corresponding to the mth track are obtained by measurement, the incident angle of the radar wave to the target is calculated, and then the target RCS value σ corresponding to this detection is searched from the target RCS data set E,m .

8. The airborne calibration evaluation system for a spaceborne early warning radar of claim 6, wherein: Target actual flight track number If N is not an integer, then rounding up; wherein, t B is the flight time length of the target track in the effective area, t I is the time interval between track frames, and the effective area refers to a track section in which the physical distance between the target and the radar is ≤ max(R E,m ).

9. The airborne calibration evaluation system for a spaceborne early warning radar of claim 6, wherein: The action distance R corresponding to all the point traces obtained in the airborne calibration flight test E,m , converted into the on-orbit detection distance R of the spaceborne early warning radar G,m , and the specific conversion formula is: wherein P G,av is the average transmit power of the space-based early warning radar in the future on-orbit, P E,av is the average transmit power of the airborne calibration radar; G G,T is the transmit antenna gain of the space-based early warning radar in the future on-orbit, G E,T is the transmit antenna gain of the airborne calibration radar; A G,R is the receive antenna area of the space-based early warning radar in the future on-orbit, A E,R is the receive antenna area of the airborne calibration radar; L G is the link loss of the space-based early warning radar in the future on-orbit, L E is the link loss of the airborne calibration radar; T G,cpi is the coherent integration time of the space-based early warning radar in the future on-orbit detection, T E,cpi is the coherent integration time of the airborne calibration radar in the detection test; σ G is the RCS of the object detected by the space-based early warning radar in the future on-orbit; D G is the detection factor of the space-based early warning radar in the future on-orbit detection.

10. The airborne calibration evaluation system for a spaceborne early warning radar of claim 9, wherein: The in-orbit detection distance R under the specific discovery probability p is obtained by the following method: Let K = pN, K is rounded up if not an integer, the on-orbit detection range R of the spaceborne early warning radar G,m The data set is arranged in descending order, and the Kth largest value in the data set is R, that is, the on-orbit detection range R of the spaceborne early warning radar converted G,m In the data set, the converted distances corresponding to K point traces satisfy R G,m ≥ R.

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