A Method for Implementing Secondary Radar SuperMode Inquiry Coding

Abstract

The present invention relates to the technical field of secondary radar interrogation detection, and particularly relates to a method for implementing SuperMode interrogation coding of a secondary radar, including generating a synchronization pulse signal; generating a SuperMode coding timing sequence, embedding interrogation codings of two different modes within one interrogation period, setting a time interval between the interrogation coding pulses of the two modes, and ensuring that the response signal triggered by the interrogation coding of the previous mode is located after the interrogation coding of the latter mode; generating a transmission gate for the interrogation signal and the interrogation sidelobe suppression signal, and performing the transmission of interrogation coding pulses within one interrogation period to complete the interrogation. The present invention can receive more response information within one interrogation period, solves the problems such as the decrease in recognition probability, high false alarm rate, and reduction in detection accuracy when using several different types of modes for alternating interrogation, improves the reliability and recognition efficiency of the secondary radar identification friend or foe system, and further improves the combat performance index of the secondary radar identification friend or foe system.

Description

Technical Field

[0001] The present invention relates to the technical field of secondary radar interrogation detection, and in particular to a method for implementing a secondary radar SuperMode interrogation code. Background Art

[0002] When the secondary radar identification friend or foe (IFF) system works, the interrogator transmits interrogation signals in the form of a directional beam through an interrogation antenna. After the transponder receives the interrogation signals, it transmits response signals. The IFF between the interrogator and the transponder is completed through a "one question and one answer" collaborative working mode for the target.

[0003] The information exchange between the interrogator and the transponder is achieved by pulse coding the uplink interrogation signals and the downlink response signals. Different interrogation pulse coding formats correspond to different interrogation modes. The commonly used interrogation mode types are:

[0004] a) SIF mode: M1, M2, M3 / A, MC;

[0005] b) S mode;

[0006] c) M4;

[0007] d) M5.

[0008] The traditional interrogation method is to complete one interrogation within the same interrogation period, that is, only the information of one type of target can be obtained within one interrogation period. In order to obtain the information of different types of targets, the secondary radar IFF system can adopt an alternating interrogation method using several different types of modes. The number of alternating modes is determined according to the minimum number of responses required for each beam transponder in each mode response process and the maximum interrogation repetition rate.

[0009] For alternating interrogation using several different types of modes, the prior art mainly uses the following two methods:

[0010] a) Antenna rotation period alternation;

[0011] b) Interleaved interrogation in adjacent interrogation periods. It can be seen that when performing alternating interrogation of several different modes in a secondary radar IFF system using a mechanically scanned antenna, when using the antenna rotation period alternation method, all types of targets cannot be quickly obtained within one antenna rotation period, resulting in a reduction in the identification performance and efficiency of the device. When using interleaved interrogation in adjacent interrogation periods, the number of interrogations for each mode obtained within the working beam range is greatly reduced, which will greatly reduce the detection probability of the device and even cannot ensure the effective identification of the target.

[0012] Therefore, both alternating interrogation methods have drawbacks, and a more reasonable technical solution needs to be proposed to solve the deficiencies in the prior art. Summary of the invention

[0013] In order to solve the defects of the prior art mentioned in the above content, the present invention provides a secondary radar SuperMode interrogation coding implementation method, which makes full use of the method of alternating several different types of interrogation modes in the same interrogation cycle to obtain information of different types of targets as much as possible in one interrogation cycle. By using this combined interrogation method to interrogate different targets within the working beam range of the secondary radar friend-or-foe identification system, the rapidity and effectiveness of identification can be improved, and the detection probability can be increased, thereby achieving the effect of optimizing the performance of the interrogation system and providing highly reliable interrogation monitoring.

[0014] In order to achieve the above object, the technical solution specifically adopted by the present invention is:

[0015] A method for implementing a secondary radar SuperMode interrogation coding includes the following steps:

[0016] Generate a synchronization pulse signal, the synchronization pulse signal is a TRIG pulse;

[0017] Generate SuperMode coding timing, embed any two of S mode, SIF mode, M4 and M5 into the same interrogation cycle to determine the SuperMode interrogation mode, the SuperMode interrogation mode includes S mode + SIF mode, M4 + SIF mode, M5 + M4, M5 + S mode and M5 + SIF mode, set a time interval between interrogation coding pulses of two different modes, and ensure that the response signal triggered by the interrogation coding of the former mode is located after the interrogation coding of the latter mode; the SIF mode includes one of M1, M2, M3 / A and MC;

[0018] Generate an interrogation signal transmission gate (TRANGATE pulse) and an interrogation sidelobe suppression signal transmission gate (SLSGATE pulse), and transmit an interrogation coded pulse in the same interrogation cycle to complete SuperMode interrogation;

[0019] The interrogation signal transmitting gate is a low effective TRANGATE pulse, the leading edge of the TRANGATE pulse is ahead of the leading edge of the preceding encoding pulse, and the trailing edge of the TRANGATE pulse lags behind the trailing edge of the following encoding pulse;

[0020] The inquiry sidelobe suppression signal transmission gate is a low-effective SLSGATE pulse, and the SLSGATE pulse includes a first signal segment and a second signal segment. The leading edge and trailing edge of the first signal segment respectively advance and lag behind the leading edge and trailing edge of one of the signal pulses of the previous coding pulse, and the leading edge and trailing edge of the second signal segment respectively advance and lag behind the leading edge and trailing edge of one of the signal pulses of the subsequent coding pulse.

[0021] The above-mentioned interrogation encoding implementation method realizes the precise control method of SuperMode that simultaneously interrogates two different types of modes within the same interrogation period by controlling the time interval timing between different types of modes within the same interrogation period. This method can share the reception window set after interrogation, improve the recognition timeliness, obtain information of two different types of targets within one interrogation period, and improve the detection probability, recognition performance and reliability of the secondary radar IFF system, thereby further improving the combat performance index of the secondary radar IFF system.

[0022] Furthermore, in the present invention, multiple modes can be interrogated simultaneously within one interrogation period, so as to obtain responses corresponding to multiple modes, thereby improving the detection and recognition performance. Specifically, optimizations are made here and some feasible options are given: The interrogation mode of embedding two encoding pulses within one interrogation period includes any one of S mode + SIF mode, M4 + SIF mode, M5 + M4, M5 + S mode, and M5 + SIF mode. When different interrogation modes are adopted, interrogation encoding pulse signals corresponding to different modes can be sent at different time periods within one interrogation period, and corresponding different response results can be obtained, improving the detection efficiency. When two encoding pulses are embedded within one interrogation period, the signal of the pre-encoding pulse has an inhibitory effect on the pulse signals within a certain subsequent time period, so it is necessary to space the two segments of encoding pulses. Specifically, the subsequent pulse sequence lags behind and is located after the inhibition time of the pre-vious pulse sequence.

[0023] Furthermore, in the present invention, considering the system delay, the pulse signal formed by embedding two encoding pulses within one interrogation period lags behind the synchronization pulse signal.

[0024] Furthermore, when adopting the interrogation mode composed of two encoding pulses of S mode + SIF mode, the SIF mode encoding pulse lags behind the S mode encoding pulse; and it also includes a zero-distance start pulse sequence, and the zero-distance start pulse lags behind the synchronization inversion pulse of the pre-vious encoding pulse.

[0025] Furthermore, among multiple interrogation modes, the encoding pulses adopted are different. Optimizations are made here and one specific feasible option is given: When adopting the interrogation mode composed of two encoding pulses of M4 + SIF mode, the SIF mode encoding pulse lags behind the M4 encoding pulse; and it also includes a SIF mode start trigger pulse sequence for triggering the SIF mode, the SIF mode start trigger pulse is ahead of the SIF mode encoding pulse; and a zero-distance start pulse sequence, and the zero-distance start pulse lags behind the SIF mode encoding pulse.

[0026] Furthermore, in other feasible interrogation modes, another feasible option is presented here: when using an interrogation mode composed of two coding pulses of M5 + M4, the M4 coding pulse lags behind the M5 coding pulse, and it also includes a zero-distance start pulse sequence, where the zero-distance start pulse lags behind the subsequent coding pulse.

[0027] Furthermore, in other feasible interrogation modes, another feasible option is presented here: when using an interrogation mode composed of two coding pulses of M5 + S mode, the S mode coding pulse lags behind the M5 coding pulse, and it also includes a zero-distance start pulse sequence, where the rising edge of the zero-distance start pulse lags behind the synchronous inversion pulse of the S mode.

[0028] Furthermore, in other feasible interrogation modes, another feasible option is presented here: when using an interrogation mode composed of two coding pulses of M5 + SIF mode, the SIF mode coding pulse lags behind the M5 coding pulse, and it also includes a zero-distance start pulse sequence, where the rising edge of the zero-distance start pulse lags behind the designated signal of the SIF mode coding pulse.

[0029] When the secondary radar is working, it is necessary to use a synchronous pulse signal for synchronous coding to make the whole machine work in a synchronous state. For the synchronous coding of the SIF mode, the time difference (T0) between the interrogation pulse P3 and the whole machine synchronous pulse signal TRIG is taken as a fixed value, and this value should be at least greater than the time interval between P1 and P3 of the longest interrogation mode (MC). The time interval between P1 and TRIG varies with the mode. Therefore, when using the SIF mode, the designated signal is determined as the P3 signal.

[0030] Furthermore, in the above-mentioned selectable interrogation modes, the leading and lagging of the SLSGATE pulse signal sequence are set. Among them, the leading edge and trailing edge of the first segment signal of the SLSGATE pulse lead and lag behind the leading edge and trailing edge of the interrogation sidelobe suppression signal pulse of the previous coding respectively, and the leading edge and trailing edge of the second segment signal lead and lag behind the leading edge and trailing edge of the interrogation sidelobe suppression signal pulse of the subsequent coding respectively.

[0031] Further, in the present invention, the leading and lagging times of the leading edge and trailing edge of the first segment signal, and the leading and lagging times of the leading edge and trailing edge of the second segment signal are equal and are fixed values.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] The present invention embeds two types of coded pulses in the interrogation mode of a secondary radar, and can transmit and receive detection information of different modes within one interrogation period, so that more response information can be received within one interrogation period. It solves the problems such as the decrease in recognition probability, high false alarm rate, and reduction in detection accuracy when using several different types of modes for alternating interrogation, improves the reliability and recognition efficiency of the secondary radar IFF system, and further improves the combat technology index of the secondary radar IFF system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, so it should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0035] Figure 1 It is a schematic diagram of the steps of the coding implementation method.

[0036] Figure 2 It is a schematic diagram of the composition of the signal transceiver device involved in Embodiment 1.

[0037] Figure 3 It is the SuperMode coding timing diagram of S mode + SIF mode.

[0038] Figure 4 It is the SuperMode coding timing diagram of M4 + SIF mode.

[0039] Figure 5 It is the SuperMode coding timing diagram of M5 + M4.

[0040] Figure 6 It is the SuperMode coding timing diagram of M5 + S mode.

[0041] Figure 7 It is the SuperMode coding timing diagram of M5 + SIF mode.

[0042] Figure 8 It is the time relationship between the synchronization pulse TRIG and the SIF mode. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The present invention will be further explained below in conjunction with the drawings and specific embodiments.

[0044] It should be noted here that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation on the present invention. The specific structural and functional details disclosed herein are only used to describe the exemplary embodiments of the present invention. However, the present invention can be embodied in many alternative forms and should not be construed as limited to the embodiments set forth herein.

[0045] Embodiment 1

[0046] In view of the problems of decreased recognition probability and low reliability existing in the interrogation of multiple different types of modes during the existing secondary radar detection process, this embodiment is optimized and improved to solve this technical problem.

[0047] Specifically, as Figure 1 shown, this embodiment provides a method for implementing SuperMode interrogation coding of a secondary radar, including the following processes:

[0048] S1: Generate a synchronization pulse signal, and the synchronization pulse signal is a TRIG pulse;

[0049] S2: Generate a SuperMode coding timing sequence, embed any two of the S mode, SIF mode, M4, and M5 into the same interrogation period to determine the SuperMode interrogation mode, set a time interval between the interrogation coding pulses of the two different modes, and ensure that the response signal triggered by the interrogation coding of the previous mode is located after the interrogation coding of the latter mode; in this embodiment, the SIF mode is one of M1, M2, M3 / A, and MC;

[0050] S3: Generate an interrogation signal transmission gate (TRANGATE pulse) and an interrogation sidelobe suppression signal transmission gate (SLSGATE pulse), and perform interrogation coding pulse transmission within the same interrogation period to complete the SuperMode interrogation.

[0051] Among them, the TRANGATE pulse is a low-valid pulse, the leading edge of the TRANGATE pulse is ahead of the leading edge of the previous coding pulse, and the trailing edge of the TRANGATE pulse lags behind the trailing edge of the subsequent coding pulse;

[0052] At the same time, the SLSGATE pulse is a low-valid pulse, and the SLSGATE pulse includes a first segment signal and a second segment signal. The leading edge and trailing edge of the first segment signal are respectively ahead of and lag behind the leading edge and trailing edge of one segment of the previous coding signal, and the leading edge and trailing edge of the second segment signal are respectively ahead of and lag behind the leading edge and trailing edge of one segment of the subsequent coding signal.

[0053] After determining the timing of the encoded signal, the timing of the GATE signal can be determined. By encoding according to the corresponding timing relationship, the signal fronts and backs in the first segment signal and the second segment signal can be determined, and the leading and lagging timings between the first segment signal and the second segment signal can also be determined.

[0054] As Figure 2 shown, in this embodiment, the processes S1 - S3 are implemented in the encoder. The encoder includes a synchronization timer for generating a synchronization pulse signal, a SuperMode encoder for generating SuperMode encoding, and a transmission gate control unit for controlling the emission time of the encoding pulse. The encoder is connected to a transmitter and a receiver. The transmitter is used to perform pulse modulation and power amplification on the encoded signal and then output it to the antenna for aerial transmission. The receiver is used to receive the reply signal returned by the transponder and convert it into a video signal.

[0055] The above - disclosed interrogation encoding implementation method realizes the SuperMode interrogation control method of simultaneously interrogating two different types of modes within the same interrogation period by controlling the time - interval timing between different types of modes. This method can share the reception window set after interrogation, improve the recognition efficiency, obtain information on two different types of targets within one interrogation period, and improve the detection probability, recognition performance, and reliability of the secondary radar IFF system, thereby further improving the combat - technology index of the secondary radar IFF system.

[0056] In this embodiment, multiple - mode interrogations can be performed simultaneously within one interrogation period, so as to obtain replies corresponding to multiple modes, and further improve the detection and recognition performance. Specifically, optimizations are made here and some feasible options are adopted: The interrogation mode of embedding two encoding pulses within one interrogation period includes any one of the S - mode + SIF - mode, M4 + SIF - mode, M5 + M4, M5 + S - mode, and M5 + SIF - mode. When different interrogation modes are adopted, corresponding interrogation pulse signals can be sent at different time periods within one interrogation period, and corresponding different reply results can be obtained, improving the detection efficiency. When two encoding pulses are embedded within one interrogation period, the signal of the pre - encoding pulse has an inhibitory effect on the encoding pulse signal within a certain subsequent time period. Therefore, the two segments of encoding pulses need to be spaced apart. Specifically, the post - encoding pulse sequence lags behind and is located after the inhibition time of the pre - encoding pulse sequence.

[0057] In this embodiment, considering the system delay, the pulse signal formed by embedding two encoding pulses within one interrogation period lags behind the synchronization pulse signal.

[0058] In multiple interrogation modes, the leading and lagging of the SLSGATE pulse signal sequence are set. Among them, the leading edge and trailing edge of the first segment of the SLSGATE pulse are respectively ahead of and lag behind the leading edge and trailing edge of the interrogation sidelobe suppression signal pulse encoded previously, and the leading edge and trailing edge of the second segment of the signal are respectively ahead of and lag behind the leading edge and trailing edge of the interrogation sidelobe suppression signal pulse encoded later.

[0059] Preferably, the encoding timing is determined in the previous manner, and thus the leading edge and trailing edge of each signal can be determined. When M4 is selected in the interrogation mode, P5 in M4 is used as the signal to be determined, and when M5 is selected in the interrogation mode, the I1 + I2 signal in M5 is used as the signal to be determined. The P5 signal and the I1 and I2 signals are all interrogation sidelobe suppression pulse signals.

[0060] Preferably, in this embodiment, the leading and lagging times of the leading edge and trailing edge of the first segment of the signal, and the leading and lagging times of the leading edge and trailing edge of the second segment of the signal are equal and are a fixed value of 1 us.

[0061] Here, a practical case is given to compare the interrogation encoding implementation method disclosed in this embodiment with the existing interrogation encoding method. Specifically as follows:

[0062] It is set that the SuperMode interrogation frequency is uniformly the maximum interrogation frequency of M5, which is 225 Hz, that is, the number of interrogations per second is 225 times. Assuming that the antenna rotation rate is 15 rpm, the target detection probability within a range of 200 nautical miles is 99%, and the response probability of its transponder is 0.9. At 200 nautical miles, the working beam width of an 8-meter antenna is 2.5°. Taking the alternating interrogation of M5 and M3 / A as an example, the specific data is shown in Table 1.

[0063] Case 1:

[0064] The Nth circle: Transmission mode: M5, M5, M5, M5...

[0065] The (N + 1)th circle: Transmission mode: M3 / A, M3 / A, M3 / A, M3 / A...

[0066] Case 2:

[0067] Transmission mode: M5, M3 / A, M5, M3 / A...

[0068] Case 3:

[0069] Transmission mode: (M5 + M3 / A), (M5 + M3 / A), (M5 + M3 / A)...

[0070] Table 1 Record table of alternating interrogation of M5 and M3 / A

[0071]

[0072]

[0073] As can be seen from Table 1, in Case 1, the antenna needs to rotate two circles to achieve the same effect as in Case 3. However, in Case 2, the window length is only three times, and the number of targets within the working beam range cannot meet the requirement of effectively identifying targets. The detection probability and recognition performance of the device will be greatly reduced. By using the SuperMode coding method of the present invention, the maximization of the window length within the same beam range can be achieved within a single circle, improving the recognition efficiency and detection probability of the device, enhancing the recognition performance and reliability of the secondary radar, and further improving the combat technology index of the IFF system of the secondary radar.

[0074] More specifically, the detection modes in Case 1 and Case 2 are elaborated. Case 1 is the antenna rotation period alternation scheme, and Case 2 is the interleaved interrogation of adjacent interrogation periods. Their actual detection probabilities are described as follows:

[0075] Assume that the antenna rotation rate is 15 rpm, the target detection probability within a range of 200 nautical miles is 99%, and the response probability of its transponder is 0.9. At 200 nautical miles, the working beam width of an 8-meter antenna is 2.5°. The following analysis is carried out according to the alternating interrogation of S mode and M3 / A two modes, and the average number of interrogations per second is 250 times, the maximum number of interrogations in 1 second in S mode.

[0076] 1. Antenna rotation period alternation

[0077] For the antenna rotation period alternation, that is, within one rotation of the antenna, a set of modes can be transmitted. When the antenna rotates to the next week, another set of modes can be automatically replaced for transmission. The specific data is shown in Table 2.

[0078] Transmission mode in the Nth circle: S mode, S mode, S mode......

[0079] Transmission mode in the (N + 1)th circle: M3 / A, M3 / A, M3 / A......

[0080] Table 2 Record table of antenna rotation period alternation interrogation

[0081] Number of inquiries Mode used Number of inquiries per second Window length N S mode, S mode, S mode... 250 6.94 N+1 M3 / A, M3 / A, M3 / A... 250 6.94

[0082] According to Table 2, it can be seen that by adopting the antenna rotation period alternation interrogation method, the number of interrogations of S mode and M3 / A within the working beam window meets the requirements. However, the antenna needs to rotate two circles, and the interrogation period required to achieve the target recognition of two different types of modes is relatively long.

[0083] 2. Interleaved interrogation of adjacent interrogation periods

[0084] Interleaved interrogation in adjacent interrogation periods, that is, pattern interleaved interrogation is carried out by switching one pattern in each interrogation period. The specific data is shown in Table 3.

[0085] Transmission mode: S mode, M3 / A, S mode, M3 / A...

[0086] Table 3 Record table of interleaved interrogation in adjacent interrogation periods

[0087]

[0088] According to Table 3, it can be seen that when using interleaved interrogation in adjacent interrogation periods, the number of interrogations of S mode and M3 / A in the working beam window is directly reduced by half compared with Table 2, and the number of targets within the working beam range cannot reach the requirement of the number of targets for effective identification, which cannot meet the requirement of system performance and seriously affects the detection probability and identification ability of targets.

[0089] The detection probability is a core index in the system technical regime and even in the entire system design and equipment design process. The detection probability of a target depends on the response probability of the transponder and the minimum number of response signals required to determine the existence of the target. These parameters can be expressed by the following equations:

[0090]

[0091] Among them, P d is the target detection probability, n is the sliding window length, t is the minimum response threshold, and p is the probability of a single response signal.

[0092] If a sliding window chart extractor is used, usually the required number of response signal pulses is at least 6, so that better real targets can be obtained. Table 4 shows the probabilities of obtaining 6 response signals for a given sliding window length under three different response probabilities of the transponder.

[0093] Table 4 Target detection probability of sliding window processing method

[0094]

[0095]

[0096] For the single-pulse processing method, usually only 2 response signals are required to detect the target. Table 5 shows the probabilities of obtaining 2 response signals for a given sliding window length under three different response probabilities of the transponder.

[0097] Table 5 Target detection probability of single-pulse processing method

[0098]

[0099] Obviously, the existing identification technology methods of IFF systems have good performance. However, when several different modes of alternate interrogation are performed in a secondary radar IFF system using a mechanically scanned antenna, by adopting the antenna rotation period alternate method, all types of targets cannot be quickly acquired within one antenna rotation period, resulting in a reduction in the identification performance and efficiency of the equipment. When adopting adjacent interrogation period staggered interrogation, the number of interrogations for obtaining the S mode and M3 / A within the working beam range is greatly reduced, which will greatly reduce the detection probability of the equipment and even cannot ensure the effective identification of targets. Both alternate interrogation methods have drawbacks.

[0100] Embodiment 2

[0101] This embodiment provides a method for implementing SuperMode interrogation coding of a secondary radar. Specifically, in the pulse signal of the interrogation mode, the S mode + SIF mode is adopted, which can quickly acquire the S mode and SIF mode response information of different targets within the working beam range, efficiently complete the identification of targets, and maximize the window length of each mode.

[0102] Specifically, as Figure 3 shown, when using an interrogation mode composed of two coding pulses of the S mode + SIF mode, the SIF mode coding pulse lags behind the S mode coding pulse; and it also includes a zero-range start pulse sequence, and the zero-range start pulse lags behind the synchronous inverted pulse of the previous coding pulse.

[0103] In this embodiment, the following timing relationships are available:

[0104] a) T1 is the delay between the coding timing and the system synchronization signal, which is 10 us in this embodiment;

[0105] b) When the SIF interrogation is embedded in the S mode interrogation, since the suppression time of the P1 - P2 pulses of the S mode on the SIF mode is 35 us ± 10 us, the SIF mode coding is at least 45 us after the S mode; at the same time, in order to prevent interfering with the S mode response when transmitting the SIF mode, the SIF mode coding needs to be before the response triggered by the S mode (128 us after the SPR of the S mode). Therefore, T2 in this embodiment is set to 125 us to ensure that the zero-range start positions of the S mode and SIF mode responses are the same, and the same GTC / STC curve can be used for receiving the two modes;

[0106] c) TRANGATE is low-valid, and the falling edge (front edge) of TRANGATE is 2 us ahead of the rising edge (front edge) of P1 of the S mode. Therefore, T3 is set to 2 us, and the rising edge (trailing edge) of TRANGATE is 2 us away from the falling edge (trailing edge) of P3 of the SIF mode, that is, T4 is 2 us;

[0107] d) SLSGATE is active low, and T5 to T8 are all set to 1 us, which is used to ensure that the falling edge (front edge) of the first pulse of SLSGATE is 1 us ahead of the front edge of the P5 pulse in S mode, and the rising edge (trailing edge) lags behind the trailing edge of the P5 pulse in S mode by 1 us. The falling edge (front edge) of the second pulse of SLSGATE is 1 us ahead of the front edge of the P2 pulse in SIF mode, and the rising edge (trailing edge) lags behind the trailing edge of the P2 pulse in SIF mode by 1 us;

[0108] e) The zero-distance start pulse is fixed delayed by 128 us after the synchronous inversion (SPR) of the P6 pulse in S mode.

[0109] According to Figure 3 the timing relationship, when conducting combined interrogation of S mode and SIF mode in the same interrogation period, when the SIF mode transponder receives this combined interrogation, it will only respond to the SIF mode interrogation of this combined interrogation, and when the S mode transponder receives this combined interrogation, the S mode transponder only responds to the S mode of this combined interrogation. Thus, the responses of the S mode transponder and the SIF mode transponder can be quickly obtained within the working beam range.

[0110] Embodiment 3

[0111] This embodiment provides a method for implementing the SuperMode interrogation coding of a secondary radar. Specifically, in the pulse signal of the interrogation mode, the M4 + SIF mode is adopted, which can quickly obtain the M4 and SIF mode response information of different targets within the working beam range, efficiently complete the identification of the targets, and maximize the window length of each mode.

[0112] Specifically, as Figure 4 shown, when adopting the interrogation mode composed of two coding pulses of M4 + SIF mode, the SIF mode coding pulse lags behind the M4 coding pulse; and it also includes a SIF mode start trigger pulse sequence for triggering the SIF mode, the SIF mode start trigger pulse is ahead of the SIF mode coding pulse; and a zero-distance start pulse sequence, the zero-distance start pulse lags behind the SIF mode coding pulse.

[0113] In this embodiment, the following timing relationship exists:

[0114] a) T1 is the delay between the coding timing and the system synchronization signal, which is 10 us in the present invention;

[0115] b) When embedding the SIF mode interrogation in the M4 interrogation, when the M4 interrogation sync header meets the M4 decoding requirements of the transponder, the response suppression for the SIF mode is 80 us ± 5 us. Therefore, the SIF mode should be after 85 us after the rising edge of the P4 pulse of M4;

[0116] c) The rising edge of the zero-distance start pulse is 202 us of fixed delay from the rising edge of the P4 pulse of M4. In order to achieve the same GTC / STC curve for receiving the responses of M4 and SIF modes and the same receiving zero-distance point, T2 is 199 us.

[0117] d) In this invention, the M4 encoding module will send out the SIF mode start trigger pulse simultaneously. This pulse is before the trigger of M4 GTC (the M4 zero-distance response moment), that is, T9 is 25 us and T10 is 1 us.

[0118] e) TRANGATE is active low. The falling edge (front edge) of TRANGATE is 2 us ahead of the rising edge (front edge) of P1 of M4, so T3 is set to 2 us. The rising edge (trailing edge) of TRANGATE is 2 us from the falling edge (trailing edge) of P3 of SIF mode, so T4 is 2 us.

[0119] f) SLSGATE is active low. T5 to T8 are all set to 1 us, which is used to ensure that the falling edge (front edge) of the first pulse of SLSGATE is 1 us ahead of the front edge of the P5 pulse of M4, and the rising edge (trailing edge) lags 1 us behind the trailing edge of the P5 pulse of M4. The falling edge (front edge) of the second pulse of SLSGATE is 1 us ahead of the front edge of the P2 pulse of SIF mode, and the rising edge (trailing edge) lags 1 us behind the trailing edge of the P2 pulse of SIF mode.

[0120] According to Figure 4 the timing relationship, the encoding of M4 and SIF modes is carried out. The transponder with M4 function within the working beam width only responds to M4 interrogation and no longer responds to SIF interrogation; for the transponder only with SIF function, it does not respond to M4 interrogation and only responds to SIF interrogation, realizing the acquisition of M4 and SIF mode information of different targets within the same interrogation period.

[0121] Embodiment 4

[0122] This embodiment provides a method for realizing the SuperMode interrogation encoding of secondary radar. Specifically, as Figure 5 shown, by using M5 + M4 in the pulse signal of the interrogation mode, it is possible to quickly obtain the M5 and M4 response information of different targets within the working beam range, efficiently complete the target identification, and maximize the window length of each mode. Since the M5 reception and processing do not use the GTC / STC curve, the embedded M4 encoding is at a time period position between the M5 interrogation and the zero-distance fixed delay.

[0123] When using the interrogation mode composed of two encoding pulses of M5 + M4, the M4 encoding pulse lags behind the M5 encoding pulse, and it also includes a zero-distance start pulse sequence, and the zero-distance start pulse lags behind the post-encoding pulse.

[0124] In this embodiment, the following timing relationships are available:

[0125] a) T1 is the delay between the encoding timing and the system synchronization signal, which is 10 us in the present invention;

[0126] b) When M4 inquiry is embedded in M5 inquiry, since the decoding suppression time of M5 for M4 is 250 us ± 1.2 us, in order to prevent the decoding of M4 from being suppressed by M5 and at the same time make the encoding of M4 not exceed the response triggered by M5 (480 us after the P4 pulse of M5), so T2 is set to 300 us;

[0127] c) TRANGATE is active low, and the falling edge (front edge) of TRANGATE is 6 us earlier than the falling edge (rear edge) of the P1 of M5, so T3 is set to 6 us, and the width of TRANGATE is 417 us;

[0128] d) SLSGATE is active low, and T5 to T8 are all set to 1 us, which is used to ensure that the falling edge (front edge) of the first pulse of SLSGATE is 1 us earlier than the front edge of the I1 pulse in the M5 mode, and the rising edge (rear edge) lags behind the rear edge of the I2 pulse of M5 by 1 us. The falling edge (front edge) of the second pulse of SLSGATE is 1 us earlier than the front edge of the P5 pulse of M4, and the rising edge (rear edge) lags behind the rear edge of the P5 pulse of M4 by 1 us;

[0129] e) The zero-distance start pulse of M4 is a fixed delay of 202 us from the front edge of the P4 pulse of M4.

[0130] According to Figure 5 the timing relationship for encoding M5 and M4, it is possible to obtain the M5 and M4 response information of different targets simultaneously within the working beam width in the same inquiry cycle.

[0131] Embodiment 5

[0132] This embodiment provides a method for implementing the secondary radar SuperMode inquiry encoding. Specifically, as Figure 6 shown, in the pulse signal of the inquiry mode, the M5 + S mode is adopted, which can quickly obtain the M5 and S mode response information of different targets within the working beam range, efficiently complete the target recognition, and maximize the window length of each mode. Since the M5 reception and processing do not use the GTC / STC curve, the embedded S mode encoding is located at a time period position between the M5 inquiry and the zero-distance fixed delay.

[0133] When using the inquiry mode composed of two encoding pulses of the M5 + S mode, the S mode encoding pulse lags behind the M5 encoding pulse, and it also includes a zero-distance start pulse sequence. The rising edge of the zero-distance start pulse lags behind the synchronous inversion pulse of the S mode.

[0134] In this embodiment, the following timing relationships are as follows:

[0135] a) T1 is the delay between the encoding timing and the system synchronization signal, which is 10 us in the present invention;

[0136] b) When the S-mode interrogation is embedded in the M5 interrogation, since the decoding inhibition time of the S mode by M5 is 250 us ± 1.2 us, in order to prevent the S-mode decoding from being inhibited by M5 and at the same time make the S-mode encoding not exceed the response triggered by M5 (480 us after the P4 pulse of M5), so T2 is set to 300 us;

[0137] c) TRANGATE is low-valid. The falling edge (front edge) of TRANGATE is 6 us earlier than the falling edge (rear edge) of the P1 of M5. Therefore, T3 is set to 6 us. The width of TRANGATE is related to the length of the P6 information pulse of the S mode. When the S mode makes a full call (UF11) or a short roll call (UF format less than 16), the P6 information pulse is 56 bits. At this time, the width of TRANGATE is set to 364 us. When the S mode makes a long roll call (UF format greater than or equal to 16), the information pulse is 112 bits. At this time, the width of TRANGATE is set to 378 us;

[0138] d) SLSGATE is low-valid. T5 to T8 are all set to 1 us, which is used to ensure that the falling edge (front edge) of the first pulse of SLSGATE is 1 us earlier than the front edge of the I1 pulse of M5, and the rising edge (rear edge) lags 1 us behind the rear edge of the I2 pulse of M5. The falling edge (front edge) of the second pulse of SLSGATE is 1 us earlier than the front edge of the P5 pulse of the S mode, and the rising edge (rear edge) lags 1 us behind the rear edge of the P5 pulse of the S mode;

[0139] e) The rising edge of the S-mode zero-range start pulse is a fixed delay of 128 us after the S-mode P6 pulse synchronous inversion (SPR).

[0140] According to Figure 6 the timing relationship for encoding M5 and the S mode, it is possible to obtain the M5 and S-mode response information of different targets simultaneously within the working beam width in the same interrogation period.

[0141] Embodiment 6

[0142] This embodiment provides a method for implementing the SuperMode interrogation encoding of a secondary radar. Specifically, as Figure 7As shown, in the pulse signal of the interrogation mode, the M5+SIF mode is adopted, which can quickly obtain the M5 and SIF mode response information of different targets within the working beam range, efficiently complete the target recognition, and maximize the window length of each mode. Since the M5 reception and processing do not use the GTC / STC curve, the embedded SIF mode coding is located at a time period position between the M5 interrogation and the zero-range fixed delay.

[0143] When the interrogation mode is composed of two coded pulses of the M5+SIF mode, the SIF mode coded pulse lags behind the M5 coded pulse, and it also includes a zero-range start pulse sequence. The rising edge of the zero-range start pulse lags behind the specified signal of the SIF mode coded pulse.

[0144] When the secondary radar is working, a synchronous pulse signal is required for synchronous coding to make the whole machine work in a synchronous state. For the synchronous coding of the SIF mode, the time difference (T0) between the interrogation pulse P3 and the whole machine synchronous pulse TRIG is taken as a fixed value, and this value should be at least greater than the time interval between P1 and P3 of the longest interrogation mode (MC). The time interval between P1 and TRIG varies with the mode. Therefore, when the SIF mode is adopted, the specified signal is determined as the P3 signal. For details, please refer to Figure 8 the time relationship content shown.

[0145] In this embodiment, the following timing relationships are available:

[0146] a) T1 is the delay between the coding timing and the system synchronous signal, which is 10us in the present invention;

[0147] b) When the SIF mode interrogation is embedded in the M5 interrogation, since the decoding suppression time of the SIF mode by M5 is 360us±1.2us, in order to prevent the SIF mode decoding from being suppressed by M5 and at the same time make the SIF mode coding not exceed the response triggered by M5 (480us after the P4 pulse of the M5 mode), T2 is set to 400us;

[0148] c) TRANGATE is low-valid. The falling edge (front edge) of TRANGATE is 6us earlier than the falling edge (rear edge) of P1 of M5. Therefore, T3 is set to 6us, and the width of TRANGATE is 450us;

[0149] d) SLSGATE is low-valid. T5~T8 are all set to 1us to ensure that the falling edge (front edge) of the first pulse of SLSGATE is 1us earlier than the front edge of the I1 pulse of M5, and the rising edge (rear edge) lags behind the rear edge of the I2 pulse of M5 by 1us. The falling edge (front edge) of the second pulse of SLSGATE is 1us earlier than the front edge of the P2 pulse of the SIF mode, and the rising edge (rear edge) lags behind the rear edge of the P2 pulse of the SIF mode by 1us;

[0150] e) The rising edge of the zero-distance start pulse in the SIF mode is at a fixed delay of 3 μs from the rising edge of the P3 pulse in the SIF mode.

[0151] According to Figure 7 the timing relationship, the encoding of the M5 and SIF modes can be carried out, and the M5 and SIF mode response information of different targets can be obtained simultaneously within the working beam width in the same interrogation period.

[0152] The above are the implementation manners listed in this embodiment, but this embodiment is not limited to the above optional implementation manners. Those skilled in the art can obtain many other implementation manners by arbitrarily combining the above manners. Anyone can obtain other various forms of implementation manners under the inspiration of this embodiment. The above specific implementation manners should not be construed as limiting the protection scope of this embodiment. The protection scope of this embodiment shall be defined by the claims, and the specification can be used to interpret the claims.

Claims

1. A method for implementing a secondary radar SuperMode interrogation code, characterized in that, The process includes the following steps: Generate a synchronization pulse signal, which is a TRIG pulse; Generate a SuperMode encoding timing sequence, embed any two of S mode, SIF mode, M4, and M5 into the same interrogation period to determine the SuperMode interrogation mode, set a time interval between the interrogation encoding pulses of the two different modes, and the response signal triggered by the interrogation encoding of the previous mode is located after the interrogation encoding of the latter mode; The SIF mode includes one of M1, M2, M3 / A, and MC; Generate an interrogation signal emission gate and an interrogation sidelobe suppression signal emission gate, and perform interrogation encoding pulse emission within the same interrogation period to complete the SuperMode interrogation; The interrogation signal emission gate is a low-effective TRANGATE pulse, the leading edge of the TRANGATE pulse is ahead of the leading edge of the previous encoding pulse, and the trailing edge of the TRANGATE pulse lags behind the trailing edge of the subsequent encoding pulse; The interrogation sidelobe suppression signal emission gate is a low-effective SLSGATE pulse, the SLSGATE pulse includes a first segment signal and a second segment signal, the leading edge and the trailing edge of the first segment signal are ahead of and lag behind the leading edge and the trailing edge of one segment signal pulse of the previous encoding pulse respectively, and the leading edge and the trailing edge of the second segment signal are ahead of and lag behind the leading edge and the trailing edge of one segment signal pulse of the subsequent encoding pulse respectively; The interrogation mode with two encoding pulses embedded in one interrogation period includes any one of S mode + SIF mode, M4 + SIF mode, M5 + M4, M5 + S mode, and M5 + SIF mode.

2. The implementation method of the secondary radar SuperMode interrogation code according to claim 1, characterized in that: The pulse signal formed by embedding two encoding pulses in one interrogation period lags behind the synchronization pulse signal.

3. The implementation method of the secondary radar SuperMode interrogation coding according to claim 1, characterized in that: When using the interrogation mode composed of two encoding pulses of S mode + SIF mode, the SIF mode encoding pulse lags behind the S mode encoding pulse; and it also includes a zero-distance start pulse sequence, and the zero-distance start pulse lags behind the synchronization inversion pulse of the previous encoding pulse.

4. The implementation method of the secondary radar SuperMode interrogation coding according to claim 1, characterized in that: When using the interrogation mode composed of two encoding pulses of M4 + SIF mode, the SIF mode encoding pulse lags behind the M4 encoding pulse; and it also includes a SIF mode start trigger pulse sequence for triggering the SIF mode, the SIF mode start trigger pulse is ahead of the SIF mode encoding pulse; and a zero-distance start pulse sequence, the zero-distance start pulse lags behind the SIF mode encoding pulse.

5. The implementation method of the secondary radar SuperMode interrogation code according to claim 1, characterized in that: When using the interrogation mode composed of two encoding pulses of M5 + M4, the M4 encoding pulse lags behind the M5 encoding pulse, and it also includes a zero-distance start pulse sequence, and the zero-distance start pulse lags behind the subsequent encoding pulse.

6. The method for implementing the secondary radar SuperMode interrogation coding according to claim 1, wherein: When using the interrogation mode composed of two encoding pulses of M5 + S mode, the S mode encoding pulse lags behind the M5 encoding pulse, and it also includes a zero-distance start pulse sequence, and the rising edge of the zero-distance start pulse lags behind the synchronization inversion pulse of the S mode.

7. The implementation method of the secondary radar SuperMode interrogation coding according to claim 1, characterized in that: When using the interrogation mode composed of two encoding pulses of M5 + SIF mode, the SIF mode encoding pulse lags behind the M5 encoding pulse, and it also includes a zero-distance start pulse sequence, and the rising edge of the zero-distance start pulse lags behind the specified signal of the SIF mode encoding pulse.

8. The implementation method of the secondary radar SuperMode interrogation coding according to claim 1, characterized in that: The leading edge and trailing edge of the first segment signal of the SLSGATE pulse respectively lead and lag behind the leading edge and trailing edge of the interrogation sidelobe suppression signal pulse encoded earlier. The leading edge and trailing edge of the second segment signal respectively lead and lag behind the leading edge and trailing edge of the interrogation sidelobe suppression signal pulse encoded later.

9. The implementation method of the secondary radar SuperMode interrogation coding according to claim 1 or 8, characterized in that: The leading and lagging times of the leading edge and trailing edge of the first segment signal, and the leading and lagging times of the leading edge and trailing edge of the second segment signal are equal and are fixed values.

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