Variable repetition frequency time sequence design method, system and equipment of SAR (Synthetic Aperture Radar) and imaging method

Abstract

The invention discloses a variable repetition frequency time sequence design method, a variable repetition frequency time sequence design system, variable repetition frequency time sequence equipment and an imaging method of an SAR (Synthetic Aperture Radar). The design method comprises the following steps: acquiring satellite-borne wide-width SAR system parameters in a variable repetition frequency mode; determining a pulse emission interval initial value of the arithmetic progression variable pulse emission interval sequence; determining a pulse emission interval variable quantity; determining the length of a variable pulse emission interval sequence; and judging whether all pulse emission intervals in the variable pulse emission interval sequence are within a variable pulse emission interval range or not, if so, judging whether the pulse emission intervals can ensure that azimuth sampling signals in any range gate of the wide SAR scene are not continuously lost twice or not, and if not, re-determining related parameters. Based on the method and the device, the SAR can enable a range-direction blind area not to appear at a fixed area position in the range direction any more, it is ensured that pulse signals are not continuously lost twice in the azimuth direction in any range gate in an observation scene, and lost signals are easily and effectively recovered in subsequent processing.

Description

Technical Field

[0001] The invention relates to the technical field of synthetic aperture radar pulse emission, and in particular to a variable repetition frequency timing design method, system, equipment, storage medium and imaging method for high-resolution wide-band SAR. Background Art

[0002] In high-resolution wide-width synthetic aperture radar (SAR) systems, due to the constraints and limitations of pulse repetition frequency, wide-width imaging must cross multiple range blind areas. These blind areas are caused by the inability of spaceborne SAR to receive echoes during the pulse transmission phase. The corresponding time width is the transmission pulse width T p In traditional high-resolution wide-swath SAR systems, wide-swath imaging must span multiple range blind zones, which are caused by the inability of the spaceborne SAR to receive echoes during the pulse transmission phase. The range blind zones appear as black stripes in the final SAR image, ultimately resulting in discontinuity of the wide-swath SAR image in the range direction.

[0003] Based on the existing pulse transmission timing, the blind area appears in a fixed area position in the distance upward, making it difficult to effectively recover the lost signal in subsequent processing and to achieve the integrity of the imaging area. Therefore, it is urgent to develop a variable repetition rate timing design method for high-resolution wide-band SAR imaging. Summary of the invention

[0004] In view of the problem that blind spots appear in fixed area positions in the upward direction of the distance, it is difficult to effectively recover lost signals in subsequent processing. The present invention provides a variable repetition rate timing design method, system, device and imaging method for realizing high-resolution wide-band SAR imaging.

[0005] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0006] In a first aspect, the present invention provides a variable repetition rate timing design method for implementing a high-resolution wide-band SAR, comprising:

[0007] S1. Obtaining the system parameters of the spaceborne wide-band SAR in variable repetition rate mode;

[0008] S2. Design a variable pulse emission interval sequence, wherein the variable pulse emission interval sequence is an arithmetic progression, including: S2.1. Determine the pulse emission interval starting value PRI 1 , S2.2, determine the pulse emission interval change Δ of adjacent pulse emission intervals PRI , S2.3, determine the sequence length M;

[0009] S3, determine whether all pulse emission intervals in the variable pulse emission interval sequence are in

[0010] [PRImin ,PRI max ] within the scope of the PRI min Indicates the minimum value of the variable pulse transmission interval, PRI max Indicates the maximum value of the variable pulse transmission interval; if not, return to S2.1 or return to S2.3, if so, proceed to S4;

[0011] S4. Determine whether the transmission according to the variable pulse transmission interval sequence can ensure that the azimuth sampling signal within any range gate of the wide-band SAR scene will not be lost continuously. If so, the design is completed; if not, return to S2.1 or return to S2.2.

[0012] In a preferred embodiment, S2.2 is specifically: determining parameter m according to the satellite-borne wide-band SAR system parameters in the variable repetition frequency mode, and determining the pulse transmission interval change Δ according to the satellite-borne wide-band SAR system parameters in the variable repetition frequency mode and parameter m. PRI ; The S2.3 is specifically: according to the variable repetition frequency mode of the satellite wide-band SAR system parameters, parameter m and pulse interval change Δ PRI , determine the length M of the variable pulse transmission interval sequence.

[0013] In a preferred embodiment, the variable repetition rate mode satellite-borne wide-band SAR system parameters include the near-end slant range R of the observed scene. min and the transmit pulse width T p ; S2.1 specifically includes: determining the pulse emission interval starting value PRI according to whether the variable pulse interval sequence is an increasing sequence or a decreasing sequence 1 .

[0014] In a preferred embodiment, the parameter m is specifically determined as follows: according to the near-end slant distance R of the observation scene min , Initial transmission pulse interval PRI 1 and the transmit pulse width T p Determine the parameter m; determine the pulse emission interval change Δ PRI Specifically: according to the transmission pulse width T p The pulse emission interval change Δ is determined by the parameter m PRI ; Determine the variable pulse transmission interval sequence length M specifically as follows: according to the transmission pulse width T p , parameter m and pulse interval change Δ PRI , determine the length M of the variable pulse transmission interval sequence.

[0015] In a preferred embodiment, the formula for determining the parameter m is:

[0016]

[0017] Where c represents the propagation speed of electromagnetic waves;

[0018] Determine the pulse emission interval change Δ PRI The formula is

[0019]

[0020] In a second aspect, the present invention provides a variable repetition rate timing design system for high-resolution wide-band SAR, comprising:

[0021] An acquisition module is used to obtain the system parameters of the spaceborne wide-band SAR in variable repetition rate mode;

[0022] The first determination module is used to determine the pulse transmission interval starting value PRI of the variable pulse transmission interval sequence 1 ; The variable pulse emission interval sequence is an arithmetic progression;

[0023] The second determination module is used to determine the pulse transmission interval variation Δ of the variable pulse transmission interval sequence. PRI ;

[0024] A third determination module is used to determine the length M of the variable pulse transmission interval sequence;

[0025] The first judgment module is used to judge whether all pulse transmission intervals in the variable pulse transmission interval sequence are within [PRI min ,PRI max ] within the scope of the PRI min Indicates the minimum value of the variable pulse transmission interval, PRI max Indicates the maximum value of the variable pulse transmission interval;

[0026] The second judgment module is used to determine whether all pulse transmission intervals in the pulse transmission interval sequence are within [PRI min ,PRI max ] range, determine whether transmitting pulses according to the variable pulse transmission interval sequence can ensure that the azimuth sampling signals within any range gate of the wide-band SAR scene will not be lost continuously;

[0027] The switching module is used to start the first determination module or the third determination module when the judgment result of the second determination module is no; and to start the first determination module or the second determination module when the judgment result of the second determination module is no.

[0028] In a third aspect, the present invention provides a synthetic aperture radar imaging method, comprising:

[0029] Reading a variable pulse transmission interval sequence, wherein the variable pulse transmission interval sequence is designed by using the variable repetition rate timing design method for high resolution wide bandwidth SAR described in the first aspect;

[0030] transmitting pulses according to the variable pulse transmission interval sequence;

[0031] Receive echo.

[0032] In a preferred embodiment, the step of recovering lost signals by using an interpolation method is also included after receiving the echo.

[0033] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium includes instructions, and when the instructions are executed on a computer, the computer executes a variable repetition rate timing design method for a high-resolution wide-band SAR as described in the first aspect.

[0034] In a fifth aspect, the present invention provides an electronic device, comprising: a memory; one or more processors; one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing any method in the variable repetition rate timing design method for a high-resolution wide-bandwidth SAR according to the first aspect.

[0035] The present invention determines the pulse transmission interval starting value PRI based on the spaceborne wide-band SAR system parameters of the variable repetition frequency mode 1 , Pulse emission interval change Δ PRI And the length M of the variable pulse transmission interval sequence is designed, so that the variable pulse transmission interval sequence can ensure that the azimuth sampling signal in any range gate of the wide-band SAR scene will not be lost continuously. Through this design, a new variable repetition rate timing technology is obtained, which can move the position of the transmission interference blind area, so that the range blind area no longer appears in a fixed area position in the range upward, and ensure that no two pulse signals are lost continuously in the azimuth direction in any range gate in the observation scene. The variable pulse transmission interval sequence based on this design solves the problem of being difficult to effectively recover the lost signal in subsequent processing, and is easy to recover the signal lost during pulse transmission to achieve a complete imaging area. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 Flow chart of the variable repetition rate timing design method for high-resolution wide-band SAR;

[0038] Figure 2This is a comparison diagram of the distance blind area distribution and sampling signal loss of the traditional mode and the variable repetition rate mode spaceborne SAR;

[0039] Figure 3 A specific flow chart of the variable repetition rate timing design method for high resolution wide bandwidth SAR;

[0040] Figure 4 It is a schematic diagram of the design result of the equidistant variable pulse emission interval;

[0041] Figure 5 A schematic diagram of the pulse transmission frequency corresponding to the variable pulse transmission interval;

[0042] Figure 6 It is a schematic diagram of the emission interference area in the observation scene and the azimuth sampling points of the target at different range gates within a pulse emission interval cycle;

[0043] Figure 7 The framework diagram of the variable repetition rate timing design system for high-resolution wide-band SAR;

[0044] Figure 8 A framework diagram of an electronic device;

[0045] Fig. 9 A flow chart of a synthetic aperture radar imaging method. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0047] In the high-resolution wide-band synthetic aperture radar system, the existing pulse transmission timing has a blind spot that appears in a fixed area upward from the distance, making it difficult to effectively recover the lost signal in subsequent processing.

[0048] To this end, the present invention provides a variable repetition rate timing design method, system, device and imaging method for SAR, and designs a pulse transmission timing in a variable repetition rate mode that can move the position of a transmission interference blind area, so that the range blind area no longer appears in a fixed area position in the range upward, and ensures that pulse signals will not be continuously lost in the azimuth upward within any range gate in the observation scene, thereby solving the problem of difficulty in effectively recovering the lost signal in subsequent processing.

[0049] The following embodiments of the present invention can be performed separately, and the embodiments can also be performed in combination with each other, and the embodiments of the present invention do not specifically limit this. In the embodiments of the present invention, "first", "second", etc. are used to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one component from another component. The "and / or" mentioned in the present invention refers to any and all combinations including one or more related listed items.

[0050] The following describes a variable repetition rate timing design method and an imaging method for high-resolution wide-band SAR and their technical effects.

[0051] Figure 1 FIG. 1 is a flow chart of a variable repetition rate timing design method for a high-resolution wide-bandwidth SAR according to an embodiment of the present invention. Figure 1 As shown, the method provided in this embodiment is applicable to high-resolution wide-band SAR synthetic aperture radar, and the method comprises the following steps:

[0052] S1. Obtaining the system parameters of the spaceborne wide-band SAR in variable repetition rate mode;

[0053] S2. Design an increasing or decreasing variable pulse transmission interval sequence, including:

[0054] S2.1. Determine the pulse transmission interval starting value PRI of the variable pulse transmission interval sequence 1 ; The variable pulse emission interval sequence is an arithmetic progression;

[0055] S2.2, determine the pulse transmission interval change Δ of adjacent pulse transmission intervals in the variable pulse transmission interval sequence PRI ,;

[0056] S2.3, determine the length M of the variable pulse transmission interval sequence;

[0057] S3, determine whether all pulse emission intervals in the variable pulse emission interval sequence are in

[0058] [PRI min ,PRI max ] within the scope of the PRI min Indicates the minimum value of the variable pulse transmission interval, PRI max Indicates the maximum value of the variable pulse transmission interval; if not, return to S2.1 or return to S2.3, if so, proceed to S4;

[0059] S4. Determine whether transmitting pulses according to the variable pulse transmission interval sequence can ensure that the azimuth sampling signals within any range gate of the wide-band SAR scene will not be lost continuously. If so, the design is completed; if not, return to S2.1 or return to S2.2.

[0060] It can be understood that the azimuth sampling signals in any range gate will not be lost continuously as follows: in any range gate, two sampling signals (pulse signals) will not be lost continuously, and obviously, more than or equal to two sampling signals will not be lost continuously. That is, in any range gate, the lost sampling signals are not continuous, and there are several non-lost sampling signals as intervals between the two lost sampling signals.

[0061] It can be understood that the return to S2.1 includes re-determining the pulse transmission interval starting value PRI 1 , and may also include re-determining the pulse emission interval change Δ PRI , may also include re-determining the length M of the variable pulse transmission interval sequence.

[0062] Likewise, the return S2.2 includes the re-pulsing interval change Δ PRI , may also include re-determining the length M of the variable pulse transmission interval sequence.

[0063] In a preferred embodiment, when S3 is judged as no, only the pulse transmission interval starting value PRI is re-determined. 1 And / or only redefine the length M of the variable pulse transmission interval sequence.

[0064] In a preferred embodiment, when S4 is judged as no, the pulse transmission interval starting value PRI is re-determined. 1 , Pulse emission interval change Δ PRI And the variable pulse transmission interval sequence length M.

[0065] The present invention designs a new variable repetition frequency timing technology to move the transmission interference blind area position, so that the range blind area no longer appears in the fixed area position in the range upward, and ensures that no pulse signal is lost twice in succession in the azimuth upward in any range gate in the observation scene, thereby ensuring that the lost signal can be effectively restored by using the interpolation method during ground processing, and finally making the high-frequency wide-band SAR no longer have blind area interference in the range upward, and ensuring the integrity of its imaging area.

[0066] The present invention designs a corresponding variable pulse transmission interval sequence according to the system parameters of the spaceborne wide-band SAR in the variable repetition rate mode, so as to ensure that within any distance unit in the wide-band scene, there will not be two consecutive signal losses in the azimuth direction, thereby ensuring that the lost signal can be effectively restored by subsequent interpolation processing.

[0067] Traditional spaceborne SAR operates at a fixed pulse repetition frequency. Therefore, the blind spot position in the upward direction is fixed. Figure 2 When the variable repetition frequency timing of this embodiment is used, the position of the distance blind zone also changes due to the continuous change of the pulse transmission interval, as shown in the left figure; Figure 2 As shown in the picture on the right. Figure 2 SAR images obtained in the conventional mode and the variable repetition rate timing mode of the present embodiment are illustrated, wherein the sampling signal loss situation is specifically illustrated, wherein the circle represents the sampling signal, and the black strip represents the range blind area. From the comparison of the sampling signal loss situations in the conventional mode and the present embodiment, it can be seen that the fixed repetition rate will result in the inability to receive all azimuth sampling signals within a certain range gate, while the variable repetition rate will result in partial signal loss, and two azimuth sampling signals will not be lost continuously. Therefore, the lost sampling signal can be subsequently restored by interpolation to achieve the integrity of the imaging area.

[0068] In order to realize that the change of pulse repetition interval PRI can be controlled according to the change of observation scene, and to ensure that there will be no continuous loss of two azimuth sampling signals in any range gate, the pulse transmission interval is assumed to be an arithmetic progression, called variable pulse transmission interval sequence, the sequence length is M, that is, there are M pulse transmission intervals, and the starting pulse transmission interval is PRI 1 , the pulse interval change is Δ PRI , the kth (k∈[1,M]) PRI in the sequence can be expressed as:

[0069] PRI k =PRI 1 +(k-1)Δ PRI ,k∈[1,M] (1)

[0070] If Δ PRI > 0, then within a complete pulse repetition interval, the transmitted pulse interference presents a "∧" form, such as Figure 2 As shown in the SAR image on the right; if Δ PRI <0, then within the complete pulse repetition interval, the transmitted pulse interference presents a “∨” form.

[0071] exist Figure 3 The specific process of variable repetition frequency timing design is given in the paper. The input parameters required for this design process are: 1) satellite orbit height H, 2) near-end viewing angle α of the observation scene n 3) Observation scene far-end viewing angle α f 4) PRI value upper limit PRI max 5) PRI lower limit min 6) Transmitting pulse width T p According to formula (1), the final designed variable pulse interval timing requires three parameters: 1) the starting pulse transmission interval PRI 1 ; 2) variable pulse emission interval sequence length M; 3) pulse emission interval change Δ PRI .

[0072] Based on the above parameters, proceed as follows:

[0073] According to the satellite orbit height H, and the near-end viewing angle α of the observed scene n and the far view α f , the near-end slant distance R of the observed scene can be determined min and the distal slope distance R max .

[0074] According to whether the pulse interval sequence is an increasing sequence or a decreasing sequence, the pulse emission interval starting value PRI is preliminarily determined. 1 If it is an increasing sequence, then PRI 1 In [PRI min ,PRI max ] range; if it is a decreasing sequence, then PRI 1 In [PRI min ,PRI max ]Select a larger value in the range;

[0075] Determine the parameter m. The determination of this parameter requires the use of the near-side slant distance R of the observation scene min , Initial transmission pulse interval PRI 1 , and the transmit pulse width T p ;

[0076] Determine the pulse emission interval change Δ PRI . Δ PRI The determination of the transmit pulse width T p , parameter m;

[0077] Determine the variable pulse transmission interval sequence length M. The determination of M requires the use of parameters m, transmission pulse width T p , pulse interval change Δ PRI ;

[0078] Determine the variable pulse transmission interval sequence;

[0079] Evaluate whether the variable pulse transmission interval sequence (referred to as pulse sequence) is within [PRI min ,PRI max ] within the scope of PRI min and PRI max Respectively represent the upper and lower limits of PRI values. If it exceeds this range, for example, only PRI M and PRI M-1 Not in [PRI min ,PRI max ], then only the variable pulse transmission interval sequence length M or the pulse transmission interval starting value PRI can be optimized. 1If it does not exceed this range, the variable pulse transmission interval sequence corresponding to formula (1) is obtained and the next step of evaluation is entered.

[0080] Evaluate whether the azimuth sampling requirements are met: evaluate whether all pulse emission intervals initially obtained can ensure that the azimuth sampling signal in any range gate in the wide scene will not be lost twice in succession, that is, the range blind areas of adjacent azimuth sampling do not overlap, and only then can the design result of this variable pulse emission interval timing be considered valid. If the evaluation result is yes, the design is completed; if the evaluation result is no, optimize the starting emission pulse interval PRI 1 and / or parameter m and / or variable pulse transmission interval sequence length M, usually to optimize the initial transmission pulse interval PRI 1 , parameter m and variable pulse transmission interval sequence length M.

[0081] The following example of wide-view satellite-borne SAR imaging is used to illustrate the effectiveness of the above implementation scheme in covering wide-view scenes.

[0082] Table 1 gives the system parameters of wide-band imaging spaceborne SAR.

[0083] Table 1

[0084] Serial number parameter Parameter Value 1 Satellite orbit altitude 600km 2 System center frequency 9.8GHz 3 System pulse width 25μs 4 Observation scene near-end perspective 30° 5 Observe the scene from a distance 35° 6 Observation scene near-end slant distance 704.06km 7 Slant distance at the far end of the observation scene 750.23km 8 Observation scene near ground distance 352.21km 9 Observation scene far distance 430.64km 10 Scene width 78.43km 11 <![CDATA[Initial Pulse Repetition Interval PRI 1 > 1 / 6000s 12 PRI Arithmetic Sequence Characteristics Increasing series

[0085] According to the relevant parameters in Table 1, the corresponding variable pulse interval timing design is then carried out. Here, the increasing pulse emission interval sequence is taken as an example to introduce the timing design method provided by the present invention. Assume that the initial pulse emission interval PRI 1 =1 / 6000s, assuming that the variable pulse emission interval sequence is an increasing series.

[0086] Step 1: Determine the parameter m and the pulse interval change Δ PRI ;

[0087] It can be preliminarily determined that the constraints that the parameter m needs to satisfy are

[0088]

[0089] Where c represents the propagation speed of electromagnetic waves.

[0090] Here, the parameter m is initially set to 31. PRI Constraints

[0091]

[0092] Initial setting Δ PRI =1.129μs.

[0093] Step 2, determining the length M of the variable pulse transmission interval sequence;

[0094] The value range of pulse transmission interval sequence length M is [M min ,M max ], this range can be determined based on estimation. p , parameter m and pulse interval change Δ PRI , initially set M = 50. Therefore, according to the pulse transmission interval starting value PRI 1 , Pulse emission interval change Δ PRI The entire variable pulse transmission interval sequence can be obtained by summing up the variable pulse transmission interval sequence length M.

[0095] exist Figure 4 and Figure 5 In the figure, a schematic diagram of the pulse emission frequency corresponding to the variable pulse emission interval and the emission interval is given. The horizontal axis represents the sequence number of the emission pulse, that is, the number of pulses emitted. Similarly, it can be known that Figure 6 and Figure 7 The horizontal axis of Figure 4 and Figure 5 From the simulation results, it can be seen that the minimum value of the variable pulse transmission interval is 166μs and the maximum value is 222μs; the corresponding maximum transmission frequency is 6000Hz and the minimum transmission frequency is 4504.7Hz.

[0096] Step 3: Verify the validity of the variable pulse transmission interval sequence;

[0097] Figure 6 The emission interference area in the observation scene and the azimuth sampling points of the target at different range gates within a variable pulse emission interval cycle are given. The azimuth sampling points are Figure 6 The pink point in the middle, the horizontal axis uses the transmission pulse number, from Figure 6 It can be seen that the horizontal pink dots are arranged at equal intervals; the red and blue intervals represent the range area corresponding to the transmitted pulse interference, the blue solid line represents the interference start position, and the red sequence represents the interference end position. The azimuth sampling signal between a group of blue and red lines cannot be received. Figure 6 It can be seen that for targets located at any distance gate within the observation scene range, two consecutive azimuth samplings will not be interfered, thus verifying the effectiveness of the designed pulse emission interval timing.

[0098] See also Figure 7 , provides a variable repetition rate timing design system for high-resolution wide-band SAR, the system comprising:

[0099] An acquisition module 10 is used to obtain the system parameters of the spaceborne wide-band SAR in a variable repetition rate mode;

[0100] The first determination module 20 is used to determine the pulse transmission interval starting value PRI of the variable pulse transmission interval sequence 1 ; The variable pulse emission interval sequence is an arithmetic progression;

[0101] The second determination module 30 is used to determine the pulse transmission interval variation Δ of the variable pulse transmission interval sequence. PRI ;

[0102] A third determination module 40 is used to determine the length M of the variable pulse transmission interval sequence;

[0103] The first judging module 50 is used to judge whether all pulse transmission intervals in the variable pulse transmission interval sequence are within [PRI min ,PRI max ] within the scope of the PRI min Indicates the minimum value of the variable pulse transmission interval, PRI max Indicates the maximum value of the variable pulse transmission interval;

[0104] The second judgment module 60 is used to determine whether all pulse transmission intervals in the pulse transmission interval sequence are within [PRI min ,PRI max ] range, determine whether transmitting pulses according to the variable pulse transmission interval sequence can ensure that the azimuth sampling signals within any range gate of the wide-band SAR scene will not be lost continuously;

[0105] The switching module is used to start the first determination module 20 or the third determination module 40 when the second determination module 60 determines that the result is no; and to start the first determination module 20 or the second determination module 30 when the second determination module 60 determines that the result is no.

[0106] The second determination module 30 is specifically used to determine the parameter m according to the variable repetition frequency mode satellite-borne wide-band SAR system parameters, and determine the pulse transmission interval change Δ according to the variable repetition frequency mode satellite-borne wide-band SAR system parameters and the parameter m. PRI The third determination module 40 is specifically used according to the variable repetition frequency mode of the satellite wide-band SAR system parameters, parameter m and pulse interval change Δ PRI , determine the length M of the variable pulse transmission interval sequence.

[0107] The first determining module 20 is specifically used to determine the pulse transmission interval starting value PRI according to whether the variable pulse interval sequence is an increasing sequence or a decreasing sequence. 1 .

[0108] When the variable repetition rate timing design of the high-resolution wide-band SAR is implemented, the variable repetition rate timing design can be implemented by referring to the variable repetition rate timing design method of the high-resolution wide-band SAR in any of the above embodiments, and the specific implementation embodiments will not be repeated here.

[0109] like Figure 8 As shown, according to the method of the present invention, an electronic device can be implemented, and the electronic device includes: a memory; one or more processors; one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include instructions for executing a variable repetition rate timing design method for a high-resolution wide-band SAR according to any of the above embodiments.

[0110] The present invention also provides a computer-readable storage medium, which includes instructions. When the instructions are executed on a computer, the computer executes each step of the variable repetition rate timing design method for a high-resolution wide-band SAR described in any of the above embodiments.

[0111] See also Fig. 9 The present invention also provides a synthetic aperture radar imaging method, based on a variable pulse transmission interval sequence designed by a variable repetition frequency timing design method for high-resolution wide-band SAR, the imaging method comprising:

[0112] Read the variable pulse transmission interval sequence;

[0113] transmitting pulses according to the variable pulse transmission interval sequence;

[0114] Receive the echo to obtain the sampling signal.

[0115] The SAR imaging method also includes the step of restoring the lost signal therein by using an interpolation method according to the received echo sampling signal.

[0116] It can be understood that in the SAR imaging method, after restoring the lost signal, the method further includes the step of reconstructing the target imaging according to the sampled signal and the restored signal.

[0117] The effects of the variable repetition rate timing design method, system, device and imaging method of SAR of the present invention are:

[0118] The present invention determines the pulse transmission interval starting value PRI by using the satellite-borne wide-band SAR system parameters based on the variable repetition frequency mode. 1 , Pulse emission interval change Δ PRIAnd the length M of the variable pulse transmission interval sequence is determined, so that the variable pulse transmission interval sequence can ensure that the azimuth sampling signal in any range gate of the wide-width SAR scene will not be lost twice in succession. Through this design, a new variable repetition frequency timing technology is obtained to move the transmission interference blind area position, so that the range blind area no longer appears in a fixed area position in the range upward, and ensure that the pulse signal will not be lost twice in succession in the azimuth direction in any range gate in the observation scene. The variable pulse transmission interval sequence based on this design can easily and effectively recover the signal lost during pulse transmission during ground processing, so that the wide-width SAR will no longer have blind area interference in the range upward, and the integrity of its imaging area is guaranteed.

[0119] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and for parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0120] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, devices or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0121] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices, systems, and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0122] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0123] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0124] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0125] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A variable repetition rate timing design method for high resolution wide bandwidth SAR, characterized in that: include: S1. Obtaining the system parameters of the spaceborne wide-band SAR in variable repetition rate mode; S2. Design a variable pulse emission interval sequence, wherein the variable pulse emission interval sequence is an arithmetic progression, including: S2.

1. Determine the pulse emission interval starting value PRI1, S2.

2. Determine the pulse emission interval change Δ between adjacent pulse emission intervals PRI , S2.3, determine the sequence length M; S3, determine whether all pulse emission intervals in the variable pulse emission interval sequence are in [PRI min ,PRI max ] within the scope of the PRI min Indicates the minimum value of the variable pulse transmission interval, PRI max Indicates the maximum value of the variable pulse transmission interval; if not, return to S2.1 or return to S2.3, if so, proceed to S4; S4. Determine whether transmitting pulses according to the variable pulse transmission interval sequence can ensure that the azimuth sampling signals within any range gate of the wide-band SAR scene will not be lost continuously. If so, the design is completed; if not, return to S2.1 or return to S2.

2.

2. The variable repetition rate timing design method for high resolution wide bandwidth SAR according to claim 1, characterized in that: The S2.2 is specifically: determining the parameter m according to the satellite-borne wide-band SAR system parameters in the variable repetition frequency mode, and determining the pulse transmission interval change Δ according to the satellite-borne wide-band SAR system parameters in the variable repetition frequency mode and the parameter m. PRI ; The S2.3 is specifically: according to the variable repetition frequency mode of the satellite wide-band SAR system parameters, parameter m and pulse interval change Δ PRI , determine the length M of the variable pulse transmission interval sequence.

3. The variable repetition rate timing design method for high resolution wide bandwidth SAR as claimed in claim 2, characterized in that: The system parameters of the spaceborne wide-band SAR in the variable repetition frequency mode include the near-end slant range R of the observation scene. min and the transmit pulse width T p ; The S2.1 is specifically: determining the pulse emission interval starting value PRI1 according to whether the variable pulse interval sequence is an increasing sequence or a decreasing sequence.

4. The variable repetition rate timing design method for high resolution wide bandwidth SAR as claimed in claim 3, characterized in that: The parameter m is specifically determined as follows: min , the starting transmission pulse interval PRI1 and the transmission pulse width T p Determine the parameter m; Determine the pulse emission interval change Δ PRI Specifically: according to the transmission pulse width T p The pulse emission interval change Δ is determined by the parameter m PRI ; Determine the variable pulse transmission interval sequence length M specifically as follows: according to the transmission pulse width T p , parameter m and pulse interval change Δ PRI , determine the length M of the variable pulse transmission interval sequence.

5. The variable repetition rate timing design method for high resolution wide bandwidth SAR as claimed in claim 4, characterized in that: The formula for determining the parameter m is Where c represents the propagation speed of electromagnetic waves; Determine the pulse emission interval change Δ PRI The formula is 6. A variable repetition rate timing design system for high resolution wide bandwidth SAR, characterized in that: include: An acquisition module is used to obtain the system parameters of the spaceborne wide-band SAR in variable repetition rate mode; A first determination module, used to determine a pulse transmission interval starting value PRI1 of a variable pulse transmission interval sequence; The variable pulse transmission interval sequence is an arithmetic progression; The second determination module is used to determine the pulse transmission interval variation Δ of the variable pulse transmission interval sequence. PRI ; A third determination module is used to determine the length M of the variable pulse transmission interval sequence; The first judgment module is used to judge whether all pulse transmission intervals in the variable pulse transmission interval sequence are within [PRI min ,PRI max ] within the scope of the PRI min Indicates the minimum value of the variable pulse transmission interval, PRI max Indicates the maximum value of the variable pulse transmission interval; The second judgment module is used to change the pulse transmission interval sequence so that all pulse transmission intervals are within [PRI min ,PRI max ] range, determine whether transmitting pulses according to the variable pulse transmission interval sequence can ensure that the azimuth sampling signals within any range gate of the wide-band SAR scene will not be lost continuously; A switching module, used for starting the first determination module or the third determination module when the second determination module determines that the result is negative; Used to start the first determination module or the second determination module when the second determination module determines that the result is no.

7. A synthetic aperture radar imaging method, characterized in that: include: Reading a variable pulse transmission interval sequence, wherein the variable pulse transmission interval sequence is designed by using a variable repetition rate timing design method for a high-resolution wide-band SAR according to any one of claims 1 to 5; transmitting pulses according to the variable pulse transmission interval sequence; Receive echo.

8. A synthetic aperture radar imaging method as claimed in claim 7, characterized in that: After receiving the echo, the method further includes the step of restoring the lost signal by using an interpolation method.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes instructions, and when the instructions are executed on a computer, the computer executes the variable repetition rate timing design method for a high-resolution wide-band SAR as described in any one of claims 1 to 5.

10. An electronic device, characterized in that: include: Memory; one or more processors; One or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for executing any one of the variable repetition rate timing design methods for a high-resolution wide-bandwidth SAR according to claims 1 to 5.

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