MIMO-SAR inter-pulse phase optimization coding method, device, equipment and medium

Abstract

The present disclosure provides a MIMO-SAR pulse-to-pulse phase optimization coding method, comprising: modulating a first parameter of the MIMO-SAR so that the initial phase of the equivalent phase center of each receiving antenna in the MIMO-SAR satisfies a linear relationship; adjusting a second parameter of the MIMO-SAR so that the equivalent phase center of each receiving antenna in the MIMO-SAR is evenly distributed; and allowing the MIMO-SAR to transmit two signals, wherein the echo of the first signal is in the Doppler baseband, and the Doppler carrier frequency of the second signal echo is PRF e / 2,PRF e The value of is N.PRF, where N is the number of receiving antennas of MIMO-SAR. The present disclosure also provides a device, an electronic device, and a computer storage medium corresponding to the method. The method can obtain a better interference suppression capability between multi-path parallel transmission signals without increasing PRF, and is suitable for satellite-borne multi-mode imaging and high signal-to-noise ratio imaging. In addition, the entire implementation process of the method is relatively simple and does not involve complex calculations.

Description

Technical Field

[0001] The present disclosure relates to the field of radar technology, and in particular to a MIMO-SAR pulse-to-pulse phase optimization coding method, device, equipment and medium. Background Art

[0002] Synthetic Aperture Radar (SAR) is an active microwave remote sensing imaging radar that appeared in the middle of the 20th century. It has the characteristics of high resolution, all-day, all-weather, multi-band, multi-polarization, and penetrability. It has been widely used in military reconnaissance, geological exploration, topographic mapping, marine survey, agricultural and forestry exploration and other fields, and has become an irreplaceable means of human earth observation. In recent years, high signal-to-noise ratio imaging and simultaneous multi-mode imaging are becoming hot spots for SAR applications. For example, in marine rights protection, it is necessary to conduct a high-resolution detailed inspection of suspicious ships while surveying the overall distribution of ships in a large area of ​​territorial waters. However, the traditional SAR system has limited degrees of freedom and is difficult to meet application requirements. In this context, JR Ender of the German High Frequency Physics Laboratory proposed the concept of multi-input multi-output (MIMO) synthetic aperture radar at the 2007 International Radar Conference. MIMO-SAR, a new system that integrates MIMO technology and SAR system, can not only obtain equivalent observation channels far more than the actual number of antennas, but also improve the power aperture product, providing an effective technical approach to solving problems such as multi-mode imaging and high-resolution imaging.

[0003] Since the concept of MIMO-SAR was proposed, it has attracted the attention of many military powers such as the United States and Europe, and has become a research hotspot in the SAR field. However, as a new system radar, it is still in the exploratory research stage both abroad and at home. This is mainly because the co-channel interference between multiple parallel transmission signals is too high, and the deteriorated signal-to-noise ratio makes the radar image have no practical application value. Focusing on the core problem of co-channel interference suppression, domestic and foreign experts and scholars have conducted extensive research and focused on orthogonal waveform design and separation.

[0004] At present, the three potential MIMO-SAR orthogonal signals are OFDM Chirp, STSO and inter-pulse phase coding. However, OFDM Chirp and STSO signals need to be combined with digital DBF technology in the elevation direction. This requires the deployment of a large number of antenna elements in the elevation direction. Therefore, the system cost and complexity of OFDM Chirp and STSO signal schemes are very high, which is not convenient for engineering implementation. In contrast, the inter-pulse phase coding scheme proposed by CZMeng et al. in the paper "CZMeng, J.Xu, XGXia et al., "MIMO-SAR waveform separation based on inter-pulse phase modulation andrange-Doppler decouple filtering," Electron.Lett., vol.49, no.6, pp.420-422, Mar.2013." has a lower implementation difficulty. However, this scheme requires the PRF to be multiplied to isolate the co-frequency interference between multi-path transmission signals in the range Doppler dimension. The exponentially increased PRF will inevitably reduce the SAR bandwidth and azimuth resolution, thus affecting the performance of the MIMO-SAR system. Summary of the invention

[0005] In view of the above problems, the present invention provides a MIMO-SAR pulse-to-pulse phase optimization coding method, device, equipment and medium to at least partially solve the above odd number problem.

[0006] The first aspect of the present disclosure provides a MIMO-SAR pulse-to-pulse phase optimization coding method, comprising: modulating a first parameter of the MIMO-SAR so that the initial phase of the equivalent phase center of each receiving antenna in the MIMO-SAR satisfies a linear relationship; adjusting a second parameter of the MIMO-SAR so that the equivalent phase center of each receiving antenna in the MIMO-SAR is evenly distributed; and allowing the MIMO-SAR to transmit two signals, wherein the first signal is an uncoded signal, and the corresponding echo is in the Doppler baseband, and the second signal is a coded signal, and the corresponding echo Doppler carrier frequency is PRF e / 2,PRF e The value of is N·PRF, where N is the number of receiving antennas of the MIMO-SAR.

[0007] Optionally, the first parameter includes the inter-pulse coding period, antenna transmission frequency and the number of receiving antennas of the MIMO-SAR, and the first parameter of the modulated MIMO-SAR includes: adjusting the inter-pulse coding period and the antenna transmission frequency so that the inter-pulse coding period is divisible by the antenna transmission frequency and the quotient is an odd number; adjusting the inter-pulse coding period and the number of receiving antennas so that the inter-pulse coding period is 1 and the number of receiving antennas is an odd number.

[0008] Optionally, the method further includes: setting the antenna transmission frequency within the equivalent phase center interval in the MIMO-SAR to 1 so as not to increase the pulse repetition frequency.

[0009] Optionally, the second parameter includes the speed and pulse repetition interval of the MIMO-SAR, and adjusting the second parameter of the MIMO-SAR includes: adjusting the speed and the pulse repetition interval of the MIMO-SAR to satisfy the condition N·(D / (2·V·PRI)-A)=1, where D represents the antenna length of the MIMO-SAR, V represents the speed, PRI represents the pulse repetition interval, and A represents the antenna transmission frequency of the MIMO-SAR within the equivalent phase center interval.

[0010] Optionally, the encoding of the second signal includes: under the premise that the number of receiving antennas is an odd number, setting the signal transmission frequency of the second signal within the equivalent phase center interval of the MIMO-SAR to 1, the azimuth coding period to 1, and the coding initial phase to 0 and π.

[0011] Optionally, the method further includes: rearranging echoes of all receiving antennas of the MIMO-SAR; transforming the rearranged data into a range-Doppler domain to extract aliasing-free echo data of the first signal and the second signal.

[0012] The second aspect of the present disclosure provides a MIMO-SAR pulse-to-pulse phase optimization coding device, comprising: a first adjustment module, used to modulate the first parameter of the MIMO-SAR so that the initial phase of the equivalent phase center of each receiving antenna in the MIMO-SAR satisfies a linear relationship; a second adjustment module, used to adjust the second parameter of the MIMO-SAR so that the equivalent phase center of each receiving antenna in the MIMO-SAR is evenly distributed; a signal transmission module, used to enable the MIMO-SAR to transmit two signals, wherein the first signal is an uncoded signal, and the corresponding echo is in the Doppler baseband, and the second signal is a coded signal, and the corresponding echo Doppler carrier frequency is PRF e / 2,PRF e The value of is N·PRF, where N is the number of receiving antennas of the MIMO-SAR.

[0013] Optionally, the first parameter includes the inter-pulse coding period, antenna transmission frequency and the number of receiving antennas of the MIMO-SAR, and the first adjustment module includes: a first conditional subunit, used to adjust the inter-pulse coding period and the antenna transmission frequency so that the inter-pulse coding period is divisible by the antenna transmission frequency and the quotient is an odd number; a second conditional subunit, used to adjust the inter-pulse coding period and the number of receiving antennas so that the inter-pulse coding period is 1 and the number of receiving antennas is an odd number; the second parameter includes the speed and pulse repetition interval of the MIMO-SAR, and the second adjustment module includes: a third conditional subunit, used to adjust the speed and the pulse repetition interval of the MIMO-SAR to meet the condition N·(D / (2·V·PRI)-A)=1, where D represents the antenna length of the MIMO-SAR, V represents the speed, PRI represents the pulse repetition interval, and A represents the antenna transmission frequency of the MIMO-SAR.

[0014] A third aspect of the present disclosure provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, each step in the MIMO-SAR inter-pulse phase optimization coding method described in any one of the first aspects is implemented.

[0015] A fourth aspect of the present disclosure provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the computer program implements each step in any one of the MIMO-SAR inter-pulse phase optimization coding methods in the first aspects.

[0016] At least one of the above technical solutions adopted in the embodiments of the present disclosure can achieve the following beneficial effects:

[0017] Compared with the existing pulse phase encoding technology, the present invention can obtain better interference suppression capability between multi-path parallel transmission signals without increasing PRF. If the method is used to design orthogonal signals, simultaneous multi-mode or high signal-to-noise ratio imaging can be achieved without reducing the MIMO-SAR width and azimuth resolution. In addition, the implementation process of the present invention is relatively simple and does not involve complex calculations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] For a more complete understanding of the present disclosure and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, in which:

[0019] Figure 1 A schematic diagram of a MIMO-SAR pulse-to-pulse phase optimization coding method provided by an embodiment of the present disclosure is schematically shown;

[0020] Figure 2 A typical layout of transmitting and receiving antennas is schematically shown;

[0021] Figure 3 The equivalent phase center distribution diagram of the coded signal is schematically shown;

[0022] Figure 4 The range Doppler domain echo energy distribution diagram of an embodiment of the present disclosure based on the MIMO-SAR pulse-to-pulse phase optimization coding method is schematically shown;

[0023] Figure 5 A Doppler frequency distribution diagram based on a MIMO-SAR pulse-to-pulse phase optimization coding method according to an embodiment of the present disclosure is schematically shown;

[0024] Figure 6 A diagram schematically shows the SAR mode 1 imaging result based on the MIMO-SAR inter-pulse phase optimization coding method according to an embodiment of the present disclosure;

[0025] Figure 7 Schematically shows the range and azimuth slice diagram of SAR mode 1 based on the MIMO-SAR inter-pulse phase optimization coding method according to an embodiment of the present disclosure;

[0026] Figure 8 A diagram schematically shows the SAR mode 2 imaging result based on the MIMO-SAR inter-pulse phase optimization coding method according to an embodiment of the present disclosure;

[0027] Fig. 9 Schematically shows the range and azimuth slice diagram of SAR mode 2 based on the MIMO-SAR inter-pulse phase optimization coding method according to an embodiment of the present disclosure;

[0028] Fig.10 The structure block diagram of a MIMO-SAR pulse-to-pulse phase optimization encoding device provided by an embodiment of the present disclosure is schematically shown;

[0029] Fig.11 The structural block diagram of an electronic device provided by an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0031] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0032] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0033] Some block diagrams and / or flow charts are shown in the accompanying drawings. It should be understood that some blocks or combinations thereof in the block diagrams and / or flow charts may be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that these instructions, when executed by the processor, may create a device for implementing the functions / operations described in these block diagrams and / or flow charts.

[0034] Therefore, the technology of the present disclosure can be implemented in the form of hardware and / or software (including firmware, microcode, etc.). In addition, the technology of the present disclosure can take the form of a computer program product on a computer-readable medium storing instructions, which can be used by an instruction execution system or in combination with an instruction execution system. In the context of the present disclosure, a computer-readable medium can be any medium that can contain, store, transmit, propagate, or transmit instructions. For example, a computer-readable medium can include, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, device, or propagation medium. Specific examples of computer-readable media include: magnetic storage devices, such as magnetic tapes or hard disks (HDDs); optical storage devices, such as compact disks (CD-ROMs); memories, such as random access memories (RAMs) or flash memory; and / or wired / wireless communication links.

[0035] Figure 1 A schematic diagram of a MIMO-SAR inter-pulse phase optimization coding method provided by an embodiment of the present disclosure is schematically shown.

[0036] like Figure 1 As shown, a MIMO-SAR inter-pulse phase optimization coding method provided by an embodiment of the present disclosure includes operations S110 to S130.

[0037] In operation S110, a first parameter of the MIMO-SAR is modulated so that an initial phase of an equivalent phase center of each receiving antenna in the MIMO-SAR satisfies a linear relationship.

[0038] In operation S120, the second parameter of the MIMO-SAR is adjusted so that the equivalent phase centers of the receiving antennas in the MIMO-SAR are evenly distributed.

[0039] In operation S130, the MIMO-SAR transmits two signals, wherein the first signal is an uncoded signal, and the corresponding echo is in the Doppler baseband, and the second signal is a coded signal, and the corresponding echo Doppler carrier frequency is PRF e / 2,PRF e The value of is N·PRF, where N is the number of receiving antennas of MIMO-SAR.

[0040] According to the method provided by the embodiment of the present disclosure, there is no additional coding for the first signal s1(t), and the echo of the signal is always in the Doppler baseband. On the basis of the linear frequency modulation of the second transmission signal s2(t), the pulse-to-pulse phase optimization coding of s2(t) is performed, so that the Doppler carrier frequency of the multi-channel echo of s2(t) is PRF without increasing the pulse repetition frequency PRF. e / 2, so that there is no interference between the first signal and the second signal, and the ambiguity will not be increased without increasing the system PRF, and thus the range mapping width or azimuth resolution will not be reduced.

[0041] In the embodiment of the present disclosure, the pulse-to-pulse phase optimization encoding of the second signal is implemented based on operations S110 to S120, which are described in detail as follows.

[0042] Assume that the platform moves within a single PRT distance less than the equivalent phase center interval, the pulse encoding period of the transmitted LFM signal is L, and the transmitting and receiving antennas are evenly distributed. The typical transmitting and receiving antenna layout is as follows: Figure 2 As shown, within the equivalent phase center interval, the antenna transmits at a frequency of V is the platform speed, and D is the length of the sub-antenna. For the mth transmission, after rearranging the azimuth echo, the N equivalent phase center data corresponding to the closely adjacent time are defined as a data block, such as Figure 3 As shown. The circle represents the equivalent phase center with an initial phase of 0, and the square represents the equivalent phase center with an initial phase of π. At this time, the N equivalent phase centers of the mth transmission respectively represent the signal echo of the mn·Ath transmission received by the n+1th (n=0,1,…,N-1)th antenna. In order to make the Doppler carrier frequency of the s2(t) multi-channel echo PRF e / 2, need to Figure 2The initial phases of all equivalent phase centers in the data block satisfy a linear relationship. This global linear relationship can be divided into two sub-relationships: first, the initial phases of the equivalent phase centers within the data block satisfy a linear relationship; second, the initial phase of the first equivalent phase center of each data block is opposite to the initial phase of the last equivalent phase center of the previous data block.

[0043] To satisfy the first sub-relationship, in operation S110, the first parameter includes the pulse coding period of the MIMO-SAR, the antenna transmission frequency and the number of receiving antennas, and modulating the first parameter of the MIMO-SAR includes operation S111.

[0044] In operation S111, the inter-pulse coding period and the antenna transmission frequency are adjusted so that the inter-pulse coding period is evenly divisible by the antenna transmission frequency and the quotient is an odd number.

[0045] The optimization solution process of operation S111 is as follows:

[0046] Define the initial phase sign bit C. If the initial phase is 0, C takes the value of 0. If the initial phase is π, C takes the value of 1. Then for the data block located at the mth transmission position, the ath

[0047] The initial phase sign bits of (α=1,2,...,N-1) phase centers are taken as Therefore, the first sub-relationship can be mathematically expressed as follows: the initial phase sign bits of the ath and a+1th phase centers satisfy the following conditions:

[0048]

[0049] The above formula can be simplified to:

[0050]

[0051] like The above formula can be rewritten as:

[0052]

[0053] like and Then (2) can be rewritten as

[0054]

[0055] like and Then (2) can be rewritten as

[0056]

[0057] Combining equations (3), (4) and (5), we can see that the initial phase of the equivalent phase center inside the data block satisfies the linear relationship if and only if L is divisible by A and the quotient Q must be an odd number.

[0058] In order to satisfy the second sub-relationship, that is, the initial phase of the first equivalent phase center of each data block is opposite to the initial phase of the last equivalent phase center of the previous data block, L must be 1, and N is an odd number, that is, in operation S110, the first parameter also includes the inter-pulse coding period and the number of receiving antennas of the MIMO-SAR, and operation S110 also includes operation S112:

[0059] In operation S112, the inter-pulse coding period and the number of receiving antennas are adjusted so that the inter-pulse coding period is 1 and the number of receiving antennas is an odd number.

[0060] The optimization solution process of operation S112 is as follows:

[0061] For the data block at the mth transmission position, the initial phase sign bit of the last phase center is For the data block at the m+1th transmission position, the initial phase sign bit of the first phase center is Therefore, the second sub-relation can be expressed mathematically as follows: The initial phase sign bits of the two equivalent phase centers satisfy the following conditions

[0062]

[0063] The above formula can be simplified to

[0064]

[0065] like The above formula can be rewritten as

[0066]

[0067]

[0068] Combining equations (8) and (9), we can see that the second sub-relation is satisfied if and only if L is 1 and N is an odd number, that is, the initial phase of the first equivalent phase center of each data block is opposite to the initial phase of the last equivalent phase center of the previous data block.

[0069] In operation 120 , the second parameter includes a speed and a pulse repetition interval of the MIMO-SAR. Operation S120 includes operation S121 .

[0070] In operation S121, the speed and pulse repetition interval of the MIMO-SAR are adjusted to satisfy the condition N·(D / (2·V·PRI)-A)=1, where D represents the antenna length of the MIMO-SAR, V represents the speed, PRI represents the pulse repetition interval, and A represents the antenna transmission frequency of the MIMO-SAR.

[0071] The optimization solution process of operation S121 is as follows:

[0072] In order to further make the equivalent phase center evenly distributed, it is necessary to make the equivalent phase center interval within the data block equal to the interval between the first equivalent phase center of each data block and the last equivalent phase center of the previous data block. Since the equivalent phase center interval within the data block is d1 = (D / (2·V·PRI)-A)·(V·PRI), and the interval between the first equivalent phase center of each data block and the last equivalent phase center of the previous data block is d2 = (V·PRI)-(N-1)·d1, the condition for the uniform distribution of the equivalent phase center is N·(D / (2·V·PRI)-A)=1.

[0073] According to the SAR system model, if the PRF is not increased, the value of A will not be greater than 1, otherwise the moving distance of the platform in a single PRT will be less than D / 6, which will lead to an exponential increase in PRF.

[0074] Based on the above analysis, the MIMO-SAR pulse-to-pulse phase optimization coding scheme is as follows: the signal transmission frequency A within the equivalent phase center interval is 1, the number of receiving antennas N is an odd number, the azimuth coding period L is 1, and N·(D / (2·V·PRI)-1)=1.

[0075] According to the above parameter requirements, under the premise that the number of receiving antennas is an odd number N, s2(t) is pulse-to-pulse phase encoded, that is, the signal transmission frequency A within the equivalent phase center interval is 1, the azimuth encoding period L is 1, the encoding initial phase is 0 and π, and the uncoded signal s1(t) and the coded signal s2(t) are transmitted through two antennas. At this time, s1(t) and s2(t) have no interference in the Doppler domain, the PRF is almost the same as the Doppler bandwidth of a single channel, and the equivalent phase center is evenly distributed.

[0076] The first signal and the second signal transmitted based on the method provided in the present disclosure do not interfere with each other, and each signal can be used to perform imaging of one mode, thereby realizing multi-mode radar imaging at the same time.

[0077] Based on the above MIMO-SAR inter-pulse phase optimization coding method, the method may further include operations S140 to S150.

[0078] In operation S140, echoes of all receiving antennas of the MIMO-SAR are rearranged.

[0079] In operation S150 , the rearranged data is transformed into a range-Doppler domain to extract aliasing-free echo data of the first signal and the second signal.

[0080] In one of the embodiments of the present disclosure, a classic imaging algorithm is used to perform imaging processing on the aliasing-free echo data of s1(t) and s2(t). If s1(t) is used for SAR mode 1 and s2(t) is used for SAR mode 2, SAR images of two imaging modes can be obtained. The SAR modes here are classic SAR imaging modes such as beam imaging mode, strip imaging mode, H polarization mode, and V polarization mode. If s1(t) and s2(t) are the same mode and are used for high signal-to-noise ratio imaging, the two images can be added together to increase the signal-to-noise ratio by 3dB.

[0081] The application of the MIMO-SAR inter-pulse phase optimization coding provided by the present disclosure will be described below with respect to a specific embodiment.

[0082] Reference Figure 1 , the implementation steps of the embodiment of the present disclosure are as follows:

[0083] (1) Determine the simulation parameters. The specific settings of the simulation parameters are as follows:

[0084] Table 1 MIMO-SAR simulation parameters based on pulse phase coding

[0085]

[0086] (2) Based on the pulse-to-pulse phase optimization coding relationship, the number of receiving antennas N is set to 3 and the PRF is set to 5750 Hz.

[0087] (3) If the pulse phase optimization coding scheme proposed in the present invention is adopted, the PRF value is 5750 Hz. At this time, the echo energy distribution of s1(t) and s2(t) in the range Doppler domain is as follows: Figure 4 The Doppler frequency distribution of the two is shown in Figure 5 As shown. Figure 4 and Figure 5 It can be seen that the frequency interval of the echoes of s1(t) and s2(t) in the Doppler domain is 8625 Hz. Through calculation, it can be seen that the mutual interference energy of s1(t) and s2(t) is -26.3 dB.

[0088] (4) Separate the echoes s1(t) and s2(t) from the range Doppler domain, and use the classical imaging algorithm to perform imaging processing on the separated echoes. The imaging results are shown in Figure 2. Figure 6 , Figure 7 , Figure 8and Fig. 9 shown.

[0089] The above simulations show that, compared with the existing methods, the present invention does not need to multiply the PRF, thus does not reduce the bandwidth or azimuth resolution, and can obtain better interference suppression capability between multi-path parallel transmission signals.

[0090] like Fig.10 As shown, the present disclosure further provides a MIMO-SAR pulse-to-pulse phase optimization coding device 1000 , including: a first adjustment module 1010 , a second adjustment module 1020 , and a signal transmission module 1030 .

[0091] The first adjustment module 1010 is used to modulate the first parameter of the MIMO-SAR so that the initial phase of the equivalent phase center of each receiving antenna in the MIMO-SAR satisfies a linear relationship.

[0092] The second adjustment module 1020 is used to adjust the second parameter of the MIMO-SAR so that the equivalent phase centers of the receiving antennas in the MIMO-SAR are evenly distributed.

[0093] The signal transmission module 1030 is used to enable the MIMO-SAR to transmit two signals, wherein the first signal is an uncoded signal, and the corresponding echo is in the Doppler baseband, and the second signal is a coded signal, and the corresponding echo Doppler carrier frequency is PRF. e / 2,PRF e The value of is N·PRF, where N is the number of receiving antennas of MIMO-SAR.

[0094] The first parameters include the inter-pulse coding period of the MIMO-SAR, the antenna transmission frequency and the number of receiving antennas. The first adjustment module 1010 includes: a first condition subunit 1011 and a second condition subunit 1012 .

[0095] The first condition subunit 1011 is used to adjust the inter-pulse coding period and the antenna transmission frequency so that the inter-pulse coding period is divisible by the antenna transmission frequency and the quotient is an odd number.

[0096] The second condition subunit 1012 is used to adjust the inter-pulse coding period and the number of receiving antennas so that the inter-pulse coding period is 1 and the number of receiving antennas is an odd number.

[0097] The second parameter includes the speed and pulse repetition interval of the MIMO-SAR. The second adjustment module 1020 includes: a third condition subunit 1021 .

[0098] The third condition subunit 1021 is used to adjust the speed and pulse repetition interval of the MIMO-SAR to meet the condition N·(D / (2·V·PRI)-month)=1, where D represents the antenna length of the MIMO-SAR, V represents the speed, PRI represents the pulse repetition interval, and month represents the antenna transmission frequency of the MIMO-SAR.

[0099] It is understandable that the first adjustment module 1010, the second adjustment module 1020, and the signal transmission module 1030 can be combined in one module, or any one of the modules can be split into multiple modules. Alternatively, at least part of the functions of one or more of these modules can be combined with at least part of the functions of other modules and implemented in one module. According to an embodiment of the present invention, at least one of the first adjustment module 1010, the second adjustment module 1020, and the signal transmission module 1030 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented in hardware or firmware in any other reasonable way of integrating or packaging the circuit, or in a proper combination of software, hardware, and firmware. Alternatively, at least one of the first adjustment module 1010, the second adjustment module 1020, and the signal transmission module 1030 can be at least partially implemented as a computer program module, and when the program is run by a computer, the function of the corresponding module can be executed.

[0100] Fig.11 The structural block diagram of an electronic device provided by an embodiment of the present disclosure is schematically shown.

[0101] like Fig.11 As shown, the electronic device described in this embodiment includes: the electronic device 1100 includes a processor 1110 and a computer readable storage medium 1120. The electronic device 1100 can execute the above reference Figure 1 Describes the method to achieve detection of specific operations.

[0102] Specifically, the processor 1110 may include, for example, a general-purpose microprocessor, an instruction set processor and / or a related chipset and / or a dedicated microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 1110 may also include an onboard memory for cache purposes. The processor 1110 may be a processor for executing reference Figure 1 The described method flow according to the embodiment of the present disclosure may be a single processing unit or multiple processing units for different actions.

[0103] Computer readable storage medium 1120, for example, can be any medium capable of containing, storing, conveying, propagating or transmitting instructions. For example, readable storage media can include, but are not limited to, electrical, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices, devices or propagation media. Specific examples of readable storage media include: magnetic storage devices, such as magnetic tapes or hard disks (HDD); optical storage devices, such as compact disks (CD-ROMs); memory, such as random access memory (RAM) or flash memory; and / or wired / wireless communication links.

[0104] The computer readable storage medium 1120 may include a computer program 1121, which may include code / computer executable instructions, which when executed by the processor 1110 causes the processor 1110 to perform, for example, the above-mentioned Figure 1 The described method sequences and any variations thereof.

[0105] The computer program 1121 may be configured to have, for example, computer program codes including computer program modules. For example, in an exemplary embodiment, the codes in the computer program 1121 may include one or more program modules, for example, 1121A, module 1121B, ... It should be noted that the division method and number of modules are not fixed, and those skilled in the art may use appropriate program modules or program module combinations according to actual conditions. When these program module combinations are executed by the processor 1110, the processor 1110 may execute, for example, the above combination of Figure 1-2 The described method sequences and any variations thereof.

[0106] According to an embodiment of the present invention, at least one of the first adjustment module 1010, the second adjustment module 1020, and the signal transmission module 1030 can be implemented as a reference Fig.10 The computer program modules described herein, when executed by the processor 1110, can implement the corresponding operations described above.

[0107] The present disclosure also provides a computer-readable medium, which may be included in the device / apparatus / system described in the above embodiments; or may exist independently without being assembled into the device / apparatus / system. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present disclosure is implemented.

[0108] It will be appreciated by those skilled in the art that the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations and / or combinations are not explicitly described in the present disclosure. In particular, the features described in the various embodiments and / or claims of the present disclosure may be combined and / or combined in a variety of ways without departing from the spirit and teachings of the present disclosure. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0109] Although the present disclosure has been shown and described with reference to specific exemplary embodiments of the present disclosure, it should be understood by those skilled in the art that various changes in form and details may be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-mentioned embodiments, but should be determined not only by the appended claims, but also by the equivalents of the appended claims.

Claims

1. A MIMO-SAR pulse phase optimization coding method, characterized in that: include: Modulating a first parameter of the MIMO-SAR so that an initial phase of an equivalent phase center of each receiving antenna in the MIMO-SAR satisfies a linear relationship; Adjusting the second parameter of the MIMO-SAR so that the equivalent phase centers of the receiving antennas in the MIMO-SAR are evenly distributed; The MIMO-SAR transmits two signals, wherein the first signal is an uncoded signal, and the corresponding echo is in the Doppler baseband, and the second signal is a coded signal, and the corresponding echo Doppler carrier frequency is , The value of , N is the number of receiving antennas of the MIMO-SAR; The first parameter includes the pulse coding period, antenna transmission frequency and the number of receiving antennas of the MIMO-SAR, and the first parameter for modulating the MIMO-SAR includes: Adjusting the inter-pulse coding period and the antenna transmission frequency so that the inter-pulse coding period is divisible by the antenna transmission frequency and the quotient is an odd number; Adjusting the inter-pulse coding period and the number of receiving antennas so that the inter-pulse coding period is 1 and the number of receiving antennas is an odd number; The second parameter includes the speed and pulse repetition interval of the MIMO-SAR, and the second parameter of adjusting the MIMO-SAR includes: Adjust the speed of the MIMO-SAR and the pulse repetition interval to meet the condition , D represents the antenna length of the MIMO-SAR, V represents the speed, PRI represents the pulse repetition interval, and A represents the antenna transmission frequency of the MIMO-SAR within the equivalent phase center interval.

2. The method according to claim 1, characterized in that The method further comprises: The transmission frequency of the antenna in the equivalent phase center interval in the MIMO-SAR is set to 1 so as not to increase the pulse repetition frequency.

3. The method according to any one of claims 1 to 2, characterized in that: The encoding of the second signal includes: On the premise that the number of receiving antennas is an odd number, the signal transmission frequency of the second signal in the equivalent phase center interval of the MIMO-SAR is set to 1, the azimuth coding period is 1, and the coding initial phase is 0 and π.

4. The method according to claim 1, characterized in that: The method further comprises: Rearranging echoes of all receiving antennas of the MIMO-SAR; The rearranged data is transformed into a range-Doppler domain to extract aliasing-free echo data of the first signal and the second signal.

5. A MIMO-SAR pulse phase optimization coding device, characterized in that: include: A first adjustment module, used for modulating a first parameter of the MIMO-SAR so that an initial phase of an equivalent phase center of each receiving antenna in the MIMO-SAR satisfies a linear relationship; A second adjustment module, used for adjusting a second parameter of the MIMO-SAR so that the equivalent phase center of each receiving antenna in the MIMO-SAR is evenly distributed; The signal transmission module is used for MIMO-SAR to transmit two signals, wherein the first signal is an uncoded signal, and the corresponding echo is in the Doppler baseband, and the second signal is a coded signal, and the corresponding echo Doppler carrier frequency is , The value of , N is the number of receiving antennas of the MIMO-SAR; The first parameter includes the pulse coding period, antenna transmission frequency and the number of receiving antennas of the MIMO-SAR, and the first adjustment module includes: A first condition subunit is used to adjust the inter-pulse coding period and the antenna transmission frequency so that the inter-pulse coding period is divisible by the antenna transmission frequency and the quotient is an odd number; A second condition subunit is used to adjust the inter-pulse coding period and the number of receiving antennas so that the inter-pulse coding period is 1 and the number of receiving antennas is an odd number; The second parameter includes the speed and pulse repetition interval of the MIMO-SAR, and the second adjustment module includes: The third condition subunit is used to adjust the speed of the MIMO-SAR and the pulse repetition interval to meet the condition , D represents the antenna length of the MIMO-SAR, V represents the speed, PRI represents the pulse repetition interval, and A represents the antenna transmission frequency of the MIMO-SAR.

6. An electronic device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, each step of the MIMO-SAR pulse-to-pulse phase optimization coding method as claimed in any one of claims 1 to 4 is implemented.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, each step of the MIMO-SAR pulse-to-pulse phase optimization encoding method according to any one of claims 1 to 4 is implemented.

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