ISOS-CFAR detection method based on pre-screening

Abstract

The invention discloses an ISOS-CFAR (International Standard Organization Standard-Call False Alarm Rate) detection method based on The method comprises the steps that a to-be-detected unit set is acquired, and the to-be-detected unit set comprises a plurality of to-be-detected units; performing SO-CFAR detection on each to-be-detected unit in the to-be-detected unit set, and outputting a first detection result; when the first detection result is HOS1, setting the detection mark corresponding to the unit to be detected as 1, and when the first detection result is HOS0, setting the detection mark corresponding to the unit to be detected as 0; and performing OS-CFAR detection on all the to-be-detected units with the detection marks set to be 1, and outputting a second detection result. According to the method, the technical problems of large calculation amount and long time in the detection process of the existing mean value class constant false alarm detection and ordered statistical class constant false alarm detection methods are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of radar target detection, and in particular to an ISOS-CFAR detection method based on pre-screening. Background Art

[0002] Constant False Alarm Rate (CFAR) detection can adaptively change the detection threshold according to the change of clutter level, so as to obtain the maximum detection probability under the condition of constant false alarm rate. Classic CFAR detection algorithms can be divided into two categories.

[0003] The first category is the mean level (ML) CFAR, among which the cell average constant false alarm (CA) CFAR is the best detection algorithm in a uniform environment, but there is a missed detection problem in a multi-target environment. Smallest Of (SO) CFAR is proposed to improve the missed detection problem of CA-CFAR in a multi-target environment, but its false alarm rate will increase accordingly in the high-power mutation area at the edge of the clutter.

[0004] The second type is the Order Statistics (OS) CFAR, which can suppress the target shielding phenomenon of the mean CFAR and has good robustness in the clutter edge area, but the amount of calculation is too large and the calculation time is too long. Summary of the invention

[0005] The embodiment of the present invention provides an ISOS-CFAR detection method based on pre-screening, which at least solves the technical problems of large amount of calculation and long time in the detection process of the existing mean-type constant false alarm detection method and ordered statistics-type constant false alarm detection method.

[0006] According to one aspect of an embodiment of the present invention, a pre-screening based ISOS-CFAR detection method is provided. The method may include: obtaining a set of units to be detected, wherein the set of units to be detected includes multiple units to be detected; performing an ISOS-CFAR detection on each unit to be detected in the set of units to be detected, and outputting a first detection result; when the first detection result is H OS1 When the detection result is H, the detection flag corresponding to the unit to be detected is set to 1. OS0 When , the detection mark corresponding to the unit to be detected is set to 0; OS-CFAR detection is performed on all the units to be detected whose detection marks are set to 1, and the second detection result is output.

[0007] Optionally, before acquiring the set of units to be detected, the method further includes: acquiring a number of radar echo signals; performing matched filtering and square-law detection processing on the number of radar echo signals to determine the set of units to be detected corresponding to the number of radar echo signals.

[0008] Optionally, performing SO-CFAR detection on each unit to be detected in the set of units to be detected and outputting a first detection result includes: comparing the sum of reference units on both sides of any unit to be detected and taking the minimum value in the comparison process; determining the product between the minimum value of the sum of reference units on both sides of any unit to be detected and the SO nominal factor as the SO threshold; comparing the SO threshold with any unit to be detected through a comparator, and when the SO threshold is greater than any unit to be detected, determining the first detection result of any unit to be detected as H OS1 , and set the detection flag corresponding to any unit to be detected to 1; when the SO threshold is less than or equal to any unit to be detected, determine that the first detection result of any unit to be detected is H OS0 , and set the detection mark corresponding to any unit to be detected to 0.

[0009] Optionally, performing OS-CFAR detection on all the units to be detected with all detection flags set to 1 and outputting a second detection result includes: determining the units to be detected with all detection flags set to 1 as a set of units to be detected of interest; sorting the reference units of the set of units to be detected of interest, and selecting the kth value after sorting; determining the product between the kth value and the OS nominal factor as the OS threshold; comparing the OS threshold with any unit to be detected of interest through a comparator, and when the OS threshold is less than any unit to be detected of interest, determining the third detection result of any unit to be detected of interest as H. OS1 , and set the detection flag of any interested unit to be detected to 2, where any interested unit to be detected is marked with x i Indicates; the sliding window protection algorithm takes x in the set of units to be detected i-s ~x i+s The detection flags set to 0 are set to 1, and the detection unit x to be detected i-s Start OS-CFAR detection on the unit to be detected with the detection flag set to 1, where i represents the sequence number of the unit to be detected. P represents the number of protection units on both sides of the unit to be detected, and L represents the number of reference units on both sides of the unit to be detected; when the OS threshold is greater than or equal to any unit to be detected of interest, the third detection result of any unit to be detected of interest is determined to be H OS0, and set the detection mark of any interested unit to be detected to 3, and perform OS-CFAR detection on the next unit to be detected with its detection mark set to 1; when all the units to be detected with their detection marks set to 1 have completed OS-CFAR detection, determine that the second detection result of the unit to be detected with its detection mark set to 2 is H1, and determine that the second detection result of the unit to be detected with its detection mark set to 3 is H0.

[0010] Beneficial effects of the present invention:

[0011] The present invention proposes an ISOS-CFAR detection method based on pre-screening. The set of units to be detected is input, and the ISOS-CFAR pre-screening algorithm is used for all the units to be detected. If the result is H OS1 Then mark it as 1, if the result is H OS0 , then it is marked as 0; for the unit to be detected x marked as 1 i Perform the following processing: Perform OS-CFAR detection and judgment, if the result is H OS1 , then the unit to be detected x i Set the flag to 2 and set the unit to be detected x i-s ~x i+s The flags marked as 0 are set to 1, and then i=is, where s=(L+P) / 2, L is the number of reference units, P is the number of protection units, and for the unit x marked as 1 to be detected, i Perform loop processing, if the result is H OS0 , then the unit to be detected x i The mark is set to 3, and i=i+1. For the unit x to be detected that is marked as 1, i The invention performs a loop processing, and after completing all the units to be detected marked as 1, the units to be detected marked as 2 are output as H1, and the rest are output as H0, which solves the technical problems of large amount of calculation and long time in the detection process of the existing mean type constant false alarm detection method and the ordered statistical type constant false alarm detection method, and achieves the technical effect of detecting all the units to be detected by the pre-screening ISOS-CFAR detection method, first removing the bad units to be detected by the SO-CFAR detection method, and then detecting the units to be detected retained by the SO-CFAR detection method by OS-CFAR, with small amount of calculation and short time in the detection process. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0013] Figure 1is a flow chart of an ISOS-CFAR detection method based on pre-screening according to an embodiment of the present invention;

[0014] Figure 2 is a block diagram of an ISOS-CFAR detection algorithm according to an embodiment of the present invention;

[0015] Figure 3 It is a schematic diagram of the screening / detection results of SO, OS and ISOS-CFAR under multi-target shielding echoes in a clutter mutation environment;

[0016] Figure 4 This is a schematic diagram of the change of ISOS-CFAR false alarm probability with the number of clutter segments under segmented clutter.

[0017] Figure 5 It is a schematic diagram of the change of ISOS-CFAR detection probability with target SCR under uniform clutter single target;

[0018] Figure 6 It is a schematic diagram of the change of ISOS-CFAR detection probability with target SCR under uniform clutter 6 target shielding;

[0019] Figure 7 It is a schematic diagram of the change of ISOS-CFAR detection probability with the number of targets under uniform clutter;

[0020] Figure 8 It is a schematic diagram of the change of ISOS-CFAR operation time of uniform clutter single target echo with the number of units to be detected;

[0021] Fig. 9 It is a schematic diagram of the change of ISOS-CFAR operation time of uniform clutter 50 target echo with the unit to be detected;

[0022] Fig.10 This is a schematic diagram of the change of ISOS-CFAR operation time with the number of targets under uniform clutter background;

[0023] Fig.11 is a schematic diagram of an ISOS-CFAR detection system based on pre-screening according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] Example 1

[0027] According to an embodiment of the present invention, a pre-screening based ISOS-CFAR detection method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system comprising at least one set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in an order different from that shown here.

[0028] Figure 1 is a flow chart of a pre-screening based ISOS-CFAR detection method according to an embodiment of the present invention, such as Figure 1 As shown, the method may include the following steps:

[0029] Step S101, obtaining a set of units to be detected, wherein the set of units to be detected includes a plurality of units to be detected.

[0030] In the technical solution provided in the above step S101 of the present invention, a set of units to be detected is obtained.

[0031] Step S102 , performing SO-CFAR detection on each unit to be detected in the set of units to be detected, and outputting a first detection result.

[0032] In the technical solution provided in step S102 of the present invention, each unit to be detected in the set of units to be detected is detected by SO-CFAR detection, and a first detection result is output. The first detection result includes two situations: Figure 2 is a block diagram of an ISOS-CFAR detection algorithm according to an embodiment of the present invention, Figure 2 Divided into two parts, Figure 2 The upper part is the SO-CFAR detection. Figure 2 The lower part is the OS-CFAR detection.

[0033] Step S103: When the first detection result is H OS1When the detection result is H, the detection flag corresponding to the unit to be detected is set to 1. OS0 When , the detection flag corresponding to the unit to be detected is set to 0.

[0034] In the technical solution provided in step S103 of the present invention, if the first detection result is H OS1 , then set the detection flag corresponding to the unit to be detected to 1. If the first detection result is H OS0 When , the detection flag corresponding to the unit to be detected is set to 0.

[0035] Step S104, performing OS-CFAR detection on all the cells to be detected whose detection flags are set to 1, and outputting a second detection result.

[0036] In the technical solution provided in the above step S104 of the present invention, OS-CFAR detection is performed on all the units to be detected whose detection flags are set to 1, and a second detection result is output, wherein the second detection result includes two situations, such as Figure 2 As shown in the lower part of .

[0037] The above method of this embodiment is further introduced below.

[0038] As an optional implementation manner, in step S101, before obtaining the set of units to be detected, the method further includes: obtaining a number of radar echo signals; performing matched filtering and square-law detection processing on the number of radar echo signals to determine the set of units to be detected corresponding to the number of radar echo signals.

[0039] In this embodiment, before performing ISOS-CFAR detection on multiple radar signals, matched filtering and square-law detection are performed on a number of radar echo signals to determine a set of units to be detected corresponding to the number of radar echo signals.

[0040] As an optional implementation manner, step S102, performing SO-CFAR detection on each unit to be detected in the set of units to be detected, and outputting a first detection result, includes: comparing the sum of the reference units on both sides of any unit to be detected, and taking the minimum value in the comparison process; determining the product between the minimum value of the sum of the reference units on both sides of any unit to be detected and the SO nominal factor as the SO threshold; comparing the SO threshold with any unit to be detected through a comparator, and when the SO threshold is greater than any unit to be detected, determining that the first detection result of any unit to be detected is H OS1 , and set the detection flag corresponding to any unit to be detected to 1; when the SO threshold is less than or equal to any unit to be detected, determine that the first detection result of any unit to be detected is H OS0, and set the detection mark corresponding to any unit to be detected to 0.

[0041] In this embodiment, if Figure 2 As shown, any unit to be detected (x i ) and A and B of the reference units on both sides are compared, and the minimum value in the comparison process is taken; the minimum value of the sum of the reference units on both sides of the unit to be tested is compared with the SO nominal factor (α SO ) is determined as the SO threshold (T SO ); The SO threshold is compared with the unit to be detected by a comparator. When the SO threshold is greater than the unit to be detected, the detection result of the unit to be detected in the SO-CFAR detection is determined to be H OS1 , and set the detection flag corresponding to the unit to be detected to 1; when the SO threshold is less than or equal to the unit to be detected, the detection result of the unit to be detected in the SO-CFAR detection is determined to be H OS0 , and set the detection mark corresponding to the unit to be detected to 0, and make all the units to be detected Figure 2 The detection in the upper middle part obtains the detection marks corresponding to all units to be detected.

[0042] As an optional implementation manner, step S104, performing OS-CFAR detection on all the units to be detected with detection flags set to 1, and outputting a second detection result, includes: determining the units to be detected with all detection flags set to 1 as a set of units to be detected of interest; sorting the reference units of the set of units to be detected of interest, and selecting the kth value after sorting; determining the product between the kth value and the OS nominal factor as the OS threshold; and comparing the OS threshold with any unit to be detected of interest (x i ) is compared by a comparator, and when the OS threshold is less than any unit of interest to be detected, the third detection result of any unit of interest to be detected is determined to be H OS1 , and set the detection flag of any interested unit to be detected to 2, where any interested unit to be detected is marked with x i Indicates; the sliding window protection algorithm takes x in the set of units to be detected i-s ~x i+s The detection flags set to 0 are set to 1, and the detection unit x to be detected i-s Start OS-CFAR detection on the unit to be detected with the detection flag set to 1, where i represents the sequence number of the unit to be detected. P represents the number of protection units on both sides of the unit to be detected, and L represents the number of reference units on both sides of the unit to be detected; when the OS threshold is greater than or equal to any unit to be detected of interest, the third detection result of any unit to be detected of interest is determined to be H OS0, and set the detection mark of any unit to be detected of interest to 3, and perform OS-CFAR detection on the next unit to be detected whose detection mark is set to 1; when all units to be detected whose detection marks are set to 1 complete OS-CFAR detection, determine that the second detection result of the unit to be detected whose detection mark is set to 2 is H1, and determine that the second detection result of the unit to be detected whose detection mark is set to 3 is H0. Set the detection mark of the unit to be detected of interest to 3, and determine that the detection result of the unit to be detected of interest in ISOS-CFAR detection is H0.

[0043] In this embodiment, if Figure 2 As shown, the unit to be detected with the detection flag set to 1 is determined as the unit to be detected of interest; the reference units of the unit to be detected of interest are sorted, and the kth value after sorting is selected; the kth value and the OS nominal factor (α OS ) is determined as the OS threshold (T OS ); compare the OS threshold with the unit to be detected by a comparator. When the OS threshold is less than the unit to be detected, the detection flag of the unit to be detected is set to 2, and the sliding window protection algorithm sets the unit to be detected x i-s ~x i+s The detection mark of the detection mark 0 is set to 1, and the detection unit x to be detected i-s Start OS-CFAR detection on the unit to be detected, where i represents the serial number of the unit to be detected. P represents the number of protection units, L represents the number of reference units on both sides of the unit to be detected; when the OS threshold is greater than or equal to the unit to be detected of interest, the detection flag of the unit to be detected of interest is set to 3. If the detection result of the unit to be detected with the detection flag set to 1 in the OS-CFAR detection is H OS0 , then the next unit to be detected with the detection mark set to 1 (i=i+1) is subjected to OS-CFAR detection. After all the units to be detected with the detection marks set to 1 complete the OS-CFAR detection, the second detection result of the unit to be detected with the detection mark set to 2 is determined to be H1, and the second detection result of the unit to be detected with the detection mark set to 3 is determined to be H0.

[0044] Experimental part:

[0045] To illustrate the detection effect of the present invention, an example is given below, where the number of units to be detected N=3000, the clutter is in three sections of uniform exponential distribution, and the clutter power of each section is 15, 30, and 15 dB respectively. The number of targets E=10, the target signal-to-clutter ratio (SCR) is 20 dB, and the units to be detected where the targets are located are 900, 915, 930, 945, 950, 2015, 2030, 2045, 2060, and 2075 respectively. Figure 3 This is a schematic diagram of the screening / detection results of SO, OS and ISOS-CFAR under multi-target shielding echo in a clutter mutation environment. Figure 3 It can be seen that the SO-CFAR screening algorithm has a false screening at the detection unit 1000, but through the secondary detection of OS-CFAR, ISOS-CFAR has no false alarm in the high power area of ​​clutter mutation. The SO-CFAR screening algorithm has missed screening at the detection units 915, 930, 945, 2015, 2030, 2045 and 2060, but through the sliding window protection algorithm, ISOS-CFAR has no missed detection in the detection unit where the target is located. Figure 3 It can be seen that the detection results of the ISOS-CFAR algorithm are the same as those of the OS-CFAR algorithm.

[0046] To illustrate the false alarm performance, detection performance and operation time of the present invention, the following embodiments are listed, wherein the false alarm rate PFA = 10 -6 , the number of reference units L = 30, the number of protection units P = 6, and the number of Monte Carlo experiments is 1000. The clutter in the simulation data is exponentially distributed. If there is no description, the default clutter power is 20dB, the target SCR is 20dB, and the number of units to be detected is N = 3000.

[0047] To illustrate the variation of the false alarm probability with the number of clutter segments of the present invention, an example is given below, in which the units to be detected are evenly segmented (if they cannot be evenly divided, the number of units to be detected in the last segment is increased), the clutter power of each segment is randomly distributed between 15 and 30 dB, the number of segments starts from 5, the interval is 5, and increases to 300, the target number E=0, and the simulation results are as follows Figure 4 As shown, Figure 4 It is a schematic diagram of the change of ISOS-CFAR false alarm probability with the number of clutter segments under segmented clutter. Figure 4 It can be seen that the SO-CFAR screening probability changes dramatically with the increase of the number of clutter segments, but the ISOS-CFAR false alarm probability is not affected by the SO-CFAR screening probability and completely coincides with the OS-CFAR false alarm probability curve. The simulation experiment proves that the ISOS-CFAR false alarm performance is exactly the same as that of OS-CFAR.

[0048] To illustrate the change of detection probability with target SCR of the present invention, an example is given below, where the number of targets in the first group is E=1, and the target positions are randomly distributed. The number of targets in the second group is E=6, and the target positions are 1015, 1030, 1045, 1050, 1065 and 1080. The target SCR starts from 0dB and increases to 40dB with an interval of 1dB. The simulation results are shown in Figure 5 and Figure 6 As shown, Figure 5 It is a schematic diagram of the change of ISOS-CFAR detection probability with target SCR under uniform clutter single target. Figure 6 It is a schematic diagram of the change of ISOS-CFAR detection probability with target SCR under uniform clutter 6 targets shielding.

[0049] Depend on Figure 5 and Figure 6 It can be seen that the screening probability of SO-CFAR is close to that of OS-CFAR when there is a single target, and the screening probability of SO-CFAR is seriously reduced when there is a shielding effect on the target. The detection probability curves of ISOS-CFAR in the case of a single target and when there is a target shielding effect are completely consistent with those of OS-CFAR.

[0050] To illustrate the variation of the detection probability with the number of targets in the present invention, an example is given below, where the number of targets E starts from 0, increases to 500 at an interval of 10, and the target positions are randomly distributed. The simulation results are shown in Figure 7 As shown, Figure 7 It is a schematic diagram showing the variation of ISOS-CFAR detection probability with the number of targets under uniform clutter.

[0051] Depend on Figure 7 It can be seen that the screening probability of SO-CFAR drops sharply when the number of targets increases, and the lowest is only 0.157, while the detection probability curve of ISOS-CFAR completely coincides with that of OS-CFAR. Simulation experiments prove that ISOS-CFAR can achieve the same detection performance as OS-CFAR in various situations.

[0052] To illustrate the change of the operation time of the present invention with the number of units to be detected, the following example is given, where the number of targets E is 1 and 50 respectively, the target positions are randomly distributed, and the number of units to be detected N starts from 500, with an interval of 300 and increases to 3500. The simulation results are shown in Figure 8 and Fig. 9 As shown, the time here is the superposition of 1000 Monte Carlo trials. Figure 8 This is a schematic diagram of the change in ISOS-CFAR operation time of a uniform clutter single target echo with the number of units to be detected. Fig. 9 It is a schematic diagram of the change of ISOS-CFAR operation time of uniform clutter 50 target echo with the unit to be detected.

[0053] from Figure 8 and Fig. 9 It can be seen that when the number of units to be detected N = 2900 and the number of targets is 1, the operation time of the ISOS-CFAR algorithm is improved by 97.08% compared with the OS-CFAR algorithm. When the number of units to be detected N = 2900 and the number of targets is 50, the operation time of the ISOS-CFAR algorithm is improved by 51.65% compared with the OS-CFAR algorithm.

[0054] To illustrate the change of the algorithm operation time of the present invention with the number of targets E, an example is given below, where the number of targets E starts from 0, increases to 500 at an interval of 20, and the target positions are randomly distributed. The simulation results are shown in Fig.10 As shown, Fig.10 It is a schematic diagram of the variation of ISOS-CFAR operation time with the number of targets under uniform clutter background.

[0055] from Fig.10 It can be seen that when the number of units to be detected is fixed, the operation time of the SO and OS-CFAR algorithms does not change with the number of targets. The operation time of the ISOS-CFAR algorithm will increase with the increase of the number of targets before reaching the maximum value, and will not change with the change of the number of targets after reaching the maximum value. When the number of units to be detected is N = 3000 and the number of targets is E = 320, the operation time of the ISOS-CFAR algorithm is similar to that of the OS-CFAR algorithm. When the number of targets E < 320, the operation time of the ISOS-CFAR algorithm is less than that of the OS-CFAR algorithm.

[0056] The ISOS-CFAR algorithm proposed in the present invention ensures the false alarm performance and detection performance of the OS-CFAR algorithm and greatly improves the operation efficiency of the algorithm when the number of targets E meets certain conditions.

[0057] In the embodiment of the present invention, a set of units to be detected is obtained, wherein the set of units to be detected includes a plurality of units to be detected; SO-CFAR detection is performed on each unit to be detected in the set of units to be detected, and a first detection result is output; when the first detection result is H SO1 When the detection result is H, the detection flag corresponding to the unit to be detected is set to 1. SO0 When the detection flag corresponding to the unit to be detected is set to 0; the units to be detected with all detection flags set to 1 are subjected to OS-CFAR detection, and the second detection result is output. The technical problem of large amount of calculation and long time in the existing mean type constant false alarm detection method and ordered statistical type constant false alarm detection method is solved, and the technical effect of detecting all units to be detected by the pre-screened ISOS-CFAR detection method with small amount of calculation and short time is achieved.

[0058] Example 2

[0059] According to an embodiment of the present invention, a pre-screening based ISOS-CFAR detection system is also provided. It should be noted that the pre-screening based ISOS-CFAR detection system can be used to execute the pre-screening based ISOS-CFAR detection method in Example 1.

[0060] Fig.11 Schematic diagram of an ISOS-CFAR detection system based on pre-screening according to an embodiment of the present invention. Fig.11 As shown, a pre-screening-based ISOS-CFAR detection system may include: an acquisition unit, a first detection unit, a processing unit and a second detection unit.

[0061] The acquisition unit is used to acquire a set of units to be detected, wherein the set of units to be detected includes multiple units to be detected.

[0062] The first detection unit is used to perform SO-CFAR detection on each unit to be detected in the set of units to be detected, and output a first detection result.

[0063] A processing unit is used for when the first detection result is H OS1 When the detection result is H, the detection flag corresponding to the unit to be detected is set to 1. OS0 When , the detection flag corresponding to the unit to be detected is set to 0.

[0064] The second detection unit is used to perform OS-CFAR detection on all the units to be detected whose detection flags are set to 1, and output a second detection result.

[0065] In this embodiment, an acquisition unit is used to acquire a set of units to be detected, wherein the set of units to be detected includes a plurality of units to be detected; a first detection unit performs SO-CFAR detection on each unit to be detected in the set of units to be detected, and outputs a first detection result; and a processing unit performs a processing operation when the first detection result is H. OS1 When the detection result is H, the detection flag corresponding to the unit to be detected is set to 1. OS0When the detection mark corresponding to the unit to be detected is set to 0; the second detection unit performs OS-CFAR detection on all the units to be detected with the detection marks set to 1, and outputs the second detection result, which solves the technical problems of large amount of calculation and long time in the detection process of the existing mean-type constant false alarm detection and ordered statistical constant false alarm detection methods, and achieves the technical effect of detecting all the units to be detected by the pre-screened ISOS-CFAR detection method, first removing the bad units to be detected by the SO-CFAR detection method, and then detecting the units to be detected retained by the SO-CFAR detection method by OS-CFAR, with small amount of calculation and short time in the detection process.

[0066] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0067] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0068] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0069] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0070] In addition, each functional unit in each embodiment of the present invention may be integrated into a first processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0071] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A pre-screening based ISOS-CFAR detection method, It is characterized in that ISOS-CFAR detection includes SO-CFAR detection and OS-CFAR detection, and the method includes: Acquire a set of units to be detected, wherein the set of units to be detected includes a plurality of units to be detected; Performing SO-CFAR detection on each unit to be detected in the set of units to be detected, and outputting a first detection result; When the first detection result is H OS1 When the detection result is H, the detection flag corresponding to the unit to be detected is set to 1. OS0 When , the detection mark corresponding to the unit to be detected is set to 0; OS-CFAR detection is performed on all the cells to be detected whose detection flags are set to 1, and a second detection result is output.

2. The method according to claim 1, It is characterized in that Before obtaining the set of units to be detected, the method further includes: Acquire several radar echo signals; Matched filtering and square-law detection processing are performed on a number of radar echo signals to determine a set of units to be detected corresponding to the number of radar echo signals.

3. The method according to claim 1, It is characterized in that Performing SO-CFAR detection on each unit to be detected in the set of units to be detected, and outputting a first detection result, including: Compare the sum of the reference units on both sides of any unit to be detected, and take the minimum value in the comparison process; The product of the minimum value of the sum of the reference units on both sides of any unit to be detected and the SO nominal factor is determined as the SO threshold; The SO threshold is compared with any unit to be detected through a comparator. When the SO threshold is greater than any unit to be detected, the first detection result of any unit to be detected is determined to be H. OS1 , and set the detection flag corresponding to any unit to be detected to 1; When the SO threshold is less than or equal to any unit to be detected, it is determined that the first detection result of any unit to be detected is H OS0 , and set the detection mark corresponding to any unit to be detected to 0.

4. The method according to claim 1, It is characterized in that Perform OS-CFAR detection on all units to be detected whose detection flags are set to 1, and output a second detection result, including: The units to be detected with all detection flags set to 1 are determined as a set of units to be detected of interest; Sorting the reference units of the set of units of interest to be detected, and selecting the kth value after sorting; The product of the kth value and the OS nominal factor is determined as the OS threshold; The OS threshold is compared with any unit of interest to be detected through a comparator. When the OS threshold is less than any unit of interest to be detected, the third detection result of any unit of interest to be detected is determined to be H. OS1 , and set the detection flag of any interested unit to be detected to 2, where any interested unit to be detected is marked with x i express; The sliding window protection algorithm takes the x in the set of units to be detected i-s ~x i+s The detection flags set to 0 are set to 1, and the detection unit x to be detected i-s Start OS-CFAR detection on the unit to be detected with the detection flag set to 1, where i represents the sequence number of the unit to be detected. P represents the number of protection units on both sides of the unit to be detected, and L represents the number of reference units on both sides of the unit to be detected; When the OS threshold is greater than or equal to any one of the units to be detected of interest, the third detection result of any one of the units to be detected of interest is determined to be H. OS0 , and set the detection flag of any interested unit to be detected to 3, and perform OS-CFAR detection on the next unit to be detected whose detection flag is set to 1; When all the units to be detected with detection flags set to 1 complete the OS-CFAR detection, it is determined that the second detection result of the unit to be detected with the detection flag set to 2 is H 1 , determine that the second detection result of the detection flag of the unit to be detected is set to 3 is H 0 .

5. A pre-screening based ISOS-CFAR detection system, It is characterized in that include: An acquisition unit, used for acquiring a set of units to be detected, wherein the set of units to be detected includes a plurality of units to be detected; A first detection unit, configured to perform SO-CFAR detection on each unit to be detected in the set of units to be detected, and output a first detection result; A processing unit is used for when the first detection result is H OS1 When the detection result is H, the detection flag corresponding to the unit to be detected is set to 1. OS0 When , the detection mark corresponding to the unit to be detected is set to 0; The second detection unit is used to perform OS-CFAR detection on all the units to be detected whose detection flags are set to 1, and output a second detection result.

6. A processor, It is characterized in that The processor is used to run a program, wherein the program executes the method according to any one of claims 1 to 4 when running.

7. A computer-readable storage medium, It is characterized in that The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 4.

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