A method and system for improving SAR azimuth resolution or detection capability by splitting aperture

Abstract

The present application provides a method and system for improving the azimuth resolution or detection capability of SAR by dividing the aperture. The system for improving the azimuth resolution or detection capability of SAR according to an embodiment of the present invention may include: an aperture coding signal generation unit, a transmitting assembly, an antenna, a receiving assembly, a data acquisition unit, a decoding and processing unit, an imaging processor, a control unit, etc. The method and system for improving the azimuth resolution or detection capability of SAR by dividing the aperture of the present invention have the advantages that they can break through the theoretical limitation of the antenna size on the imaging resolution of traditional strip SAR, obtain strip SAR images with high azimuth resolution, or enhance the signal-to-noise ratio of strip SAR images and improve the detection performance of the SAR system, etc.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of radar, and particularly to a method and system for improving the azimuth resolution or detection ability of SAR by splitting apertures. Background Art

[0002] Synthetic Aperture Radar (SAR) can achieve high-resolution imaging of targets. SAR uses pulse compression to improve range resolution and synthetic aperture to improve azimuth resolution.

[0003] SAR has different imaging modes, including stripmap imaging, scan imaging, spotlight imaging, etc.

[0004] In the prior art, stripmap SAR imaging is the earliest and currently the most widely used SRA imaging mode. The imaging area of stripmap SAR imaging is a long strip area parallel to the moving direction of the carrier (such as an aircraft or a satellite and other carrier platforms). Usually, the radar beam is perpendicular to the flight trajectory, that is, in the side-looking mode. It can also work in the squint mode. However, during the imaging process, ideally, the angle between the radar beam and the flight track remains unchanged. The azimuth resolution of the stripmap SAR imaging mode is limited by the size of the radar antenna, that is, it cannot be lower than half of the azimuth antenna length. In the actual system design, it is impossible to infinitely reduce the azimuth antenna size limit. Therefore, improving the azimuth resolution of SAR is restricted.

[0005] Therefore, there is a need in the art for a synthetic aperture radar working method and system that can overcome the deficiency of the traditional stripmap SAR imaging in improving the azimuth resolution limit. Summary of the Invention

[0006] The purpose of the present invention is to provide a new method and system for improving the azimuth resolution or detection ability of SAR by splitting apertures, which can overcome the deficiency of the traditional stripmap SAR imaging in improving the azimuth resolution limit and meet the system performance requirements for improving the resolution.

[0007] The first aspect of the embodiments of the present disclosure provides a system for improving the azimuth resolution or detection ability of SAR by splitting apertures, which includes: a radar antenna configured to be split into multiple apertures to form N apertures, where N is a positive integer greater than 1, and different said apertures have independent radar signal transmission and reception links;

[0008] An aperture coding signal generation unit configured to generate coding signals transmitted by N apertures, and the transmitted signals of the N apertures are each independently pulse-coded and frequency-converted and / or modulated to radio frequency;

[0009] A transmitting component configured to amplify the N-channel radio frequency pulse coding signals generated by the aperture coding signal generation unit and respectively feed them into the N apertures;

[0010] A receiving component, configured to receive echo signals of N apertures, perform radio frequency amplification, frequency conversion, and / or demodulation on the corresponding N-channel echo signals, and perform intermediate frequency amplification or baseband amplification;

[0011] A data acquisition unit, configured to sample the N-channel intermediate frequency or baseband signals output by each receiving component, convert them into digital signals, and form N-channel target echo data;

[0012] A decoding and processing unit, configured to perform decoding processing on the acquired N-channel target echo data, and separate the target echo data corresponding to the transceiver channel combinations formed by different apertures;

[0013] An imaging processor, configured to perform SAR imaging processing and SAR image accumulation processing on the target echo data corresponding to different transceiver channel combinations;

[0014] A control unit, configured to control the signal generation, transceiver, acquisition, and processing of a system for improving SAR azimuth resolution or detection ability by splitting apertures.

[0015] A second aspect of the embodiments of the present disclosure provides a method for improving SAR azimuth resolution by splitting apertures, which includes:

[0016] Dividing a radar antenna into N apertures along the azimuth direction, where N is an integer greater than 1;

[0017] When the radar is working, each aperture transmits its own independent coded pulse signal, and each aperture receives the echo signal of its own transmitted coded pulse signal, and at the same time receives the echo signals of the coded pulse signals transmitted by other apertures;

[0018] Performing decoding processing on the echo signals received by each aperture to form N echo signals of different aperture transceiver combinations. For the echo signals received by N apertures, N×N echo signals can be formed;

[0019] Performing SAR imaging processing on each echo signal or combination of echo signals to obtain multiple SAR images;

[0020] Performing coherent accumulation on multiple SAR images to obtain a high-resolution SAR image.

[0021] In one embodiment, the separate coded signal is separable in time, space, or frequency of the echo signal generated by the target for the coded signal, or through decoding processing.

[0022] In one embodiment, performing SAR imaging processing on each echo signal or combination of echo signals is to perform imaging processing using the phase difference between the target echo signals of different-time coded pulses of each aperture to obtain an SAR image, or to perform imaging processing using the phase difference between the target echo signals of different-time coded pulses between different apertures to obtain an SAR image.

[0023] The second aspect of the embodiments of the present disclosure provides a method for improving SAR detection ability by splitting apertures, including:

[0024] Dividing a radar antenna into N apertures along the azimuth direction, where N is an integer greater than 1;

[0025] When the radar operates, each aperture transmits an independent coded pulse signal, and each aperture receives the echo signal of its own transmitted coded pulse signal, and at the same time receives the echo signals of the coded pulse signals transmitted by other apertures;

[0026] Performing decoding processing on the echo signals received by each aperture to form N echo signals of different aperture transceiver combinations. For the echo signals received by N apertures, N×N echo signals can be formed;

[0027] Performing SAR imaging processing on each echo signal or combination of echo signals to obtain multiple SAR images;

[0028] Performing non-coherent accumulation on multiple SAR images to obtain an SAR image with a high signal-to-noise ratio, equivalently improving the detection ability.

[0029] In one embodiment, the separate coded signals are separable in time or space or frequency of the echo signals generated by the target for the coded signals, or through decoding processing.

[0030] In one embodiment, performing SAR imaging processing on each echo signal or combination of echo signals is to perform imaging processing using the phase difference between the target echo signals of different-time coded pulses of each aperture to obtain an SAR image, or to perform imaging processing using the phase difference between the target echo signals of different-time coded pulses between different apertures to obtain an SAR image.

[0031] The radar antenna in this embodiment has N apertures. Each aperture can transmit radar signals and receive the echo signals of the radar signals transmitted by the N apertures. The decoding component processes the echo signals received by the N apertures to obtain the corresponding target synthetic aperture radar signals. Since the target synthetic aperture radar signals are obtained based on the echo signals received by multiple apertures, these target signals can be used to generate radar images with higher resolution, thereby improving the resolution of the radar images. It can break through the limitation of the antenna size on the imaging resolution of traditional strip SAR, and under the same conditions, a strip SAR image with higher azimuth resolution can be obtained. In addition, under the condition of the same azimuth resolution, the signal-to-noise ratio of the strip SAR image can be enhanced, and the detection performance of the SAR system can be improved. Description of the Drawings

[0032] Figure 1 FIG. is a schematic diagram of a radar system for improving the azimuth resolution or detection ability of SAR by dividing apertures provided by an embodiment of the present disclosure;

[0033] Figure 2 FIG. is a schematic diagram of a method for improving the azimuth resolution or detection ability of SAR by dividing apertures provided by an embodiment of the present disclosure. Detailed Embodiments

[0034] The technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings of the specification and specific embodiments.

[0035] Refer to Figure 1 , which is a schematic diagram of a radar system for improving the azimuth resolution or detection ability of SAR by dividing apertures.

[0036] According to an embodiment of the present invention, a radar system for improving the azimuth resolution or detection ability of SAR by dividing apertures includes:

[0037] A radar antenna configured to be divided into multiple apertures to form N apertures, where N is a positive integer greater than 1, and different said apertures have independent radar signal transmission and reception links;

[0038] An aperture coding signal generation unit configured to generate coding signals transmitted by the N apertures, and the N aperture transmitted signals are each independently pulse-coded and frequency-converted and / or modulated to radio frequency;

[0039] A transmitting component configured to amplify the N-channel radio frequency pulse coding signals generated by the aperture coding signal generation unit and respectively feed them into the N apertures;

[0040] A receiving component configured to receive the echo signals of the N apertures, perform radio frequency amplification, frequency conversion and / or demodulation on the corresponding N-channel echo signals, and intermediate frequency amplification or baseband amplification;

[0041] A data acquisition unit, configured to sample N intermediate frequency or baseband signals output by each receiving component, convert them into digital signals, and form N target echo data;

[0042] A decoding processing unit, configured to perform decoding processing on the acquired N target echo data, and separate the target echo data corresponding to the transceiver channel combinations formed by different apertures;

[0043] An imaging processor, configured to perform SAR imaging processing and SAR image accumulation processing on the target echo data corresponding to different transceiver channel combinations;

[0044] A control unit, configured to control the signal generation, transceiver, acquisition, and processing of a system for improving SAR azimuth resolution or detection ability by segmented apertures.

[0045] The control unit generates synchronization signals for the system operation, including signal generation synchronization signals, signal acquisition synchronization signals, and transceiver protection synchronization signals. Each aperture has independent signal generation synchronization signals, signal acquisition synchronization signals, and transceiver protection synchronization signals. A strict synchronization relationship needs to be maintained between the signal generation synchronization signals and signal acquisition synchronization signals corresponding to each aperture, and the synchronization requirement is not lower than the time synchronization requirement of SAR imaging.

[0046] Figure 2 It is a schematic diagram of a method for improving SAR azimuth resolution or detection ability by segmented apertures.

[0047] According to an embodiment of the present invention, a radar antenna is equally divided into N apertures along the azimuth direction, where N is an integer greater than 1;

[0048] When the radar operates, each aperture transmits its own different coded pulse signals, and each aperture receives the echo signals of its own transmitted coded pulse signals and the echo signals of the coded pulse signals transmitted by other apertures; the echo signals generated by different coded pulse signals at the target are separable in time or space or frequency, or through decoding processing.

[0049] Transmit a separate coded pulse signal for each aperture;

[0050] The separate coded pulse signal makes the echo signals generated by target reflection separable in time or space or frequency; or the echo signals are separable through decoding processing.

[0051] Preferably, the separate coded pulse signal is a frequency division coded pulse signal. During transmission, each aperture transmits at a different frequency to isolate the transmission channels through frequency. During reception, after each aperture receives the echo signals, the echo signals corresponding to the transmitted signals of different apertures are separated through frequency domain filtering;

[0052] Preferably, the individual coded pulse signal is a time-phase combined coded pulse signal, and the basic constraint of the coding is that each coding channel is orthogonal to each other. During transmission, each aperture transmits with a different code. During reception, after each aperture receives the echo signal, the echo signals corresponding to the transmitted signals of different apertures are separated through decoding processing;

[0053] Preferably, the individual coded pulse signal is a time-phase-frequency combined coded pulse signal, and the basic constraint of the coding is that each coding channel is orthogonal to each other, and each aperture transmits with a different code. During reception, after each aperture receives the echo signal, the echo signals corresponding to the transmitted signals of different apertures are separated through decoding processing;

[0054] When the radar is working, each aperture transmits its own coded pulse signal. Specifically, according to an individual coded pulse signal assigned to each aperture, each aperture transmits its own coded pulse signal.

[0055] Each aperture receives the echo signal of its own transmitted coded pulse signal and the echo signals of the coded pulse signals transmitted by other apertures; and through frequency isolation or codec isolation, the problem of interference between transmitted signals in different channels is solved.

[0056] Collect the echo signals received by each aperture, and perform decoding processing on the echo signals. The decoding processing includes:

[0057] For the frequency-division coded pulse signal, frequency-domain filtering is used for decoding processing;

[0058] For the time-phase combined coded pulse signal, a decoding matrix is obtained through the coding matrix, and then the echo signal is processed using the decoding matrix to complete the decoding processing;

[0059] For the time-phase-frequency combined coded pulse signal, a decoding matrix is obtained through the coding matrix, and then the echo signal is processed using the decoding matrix, and in combination with frequency filtering, the decoding processing is completed.

[0060] Perform decoding processing on the echo signals received by each aperture, and separate the echo signals received by each aperture into echo signals corresponding to N different transmitting apertures. For example, for the received echo signal of any aperture i (i is any integer from 1 to N), it includes the sum of the echo signals generated by the transmitted signals of apertures 1 to N acting on the target. Perform decoding processing on the echo signal received by aperture i to obtain the signals of aperture 1 transmitting / aperture i receiving, aperture 2 transmitting / aperture i receiving,..., aperture N transmitting / aperture i receiving, a total of N signals. For the echo signals received by N apertures, through decoding, N×N signals will be obtained.

[0061] Perform high-resolution SAR imaging processing on the above signals to obtain a high-resolution SAR image; specifically including,

[0062] First, the target echo signals of different-time coded pulses of each individual receiving aperture are utilized for imaging processing. For example, the echo signals of aperture 1 transmitting / aperture i receiving, aperture 2 transmitting / aperture i receiving, …, aperture N transmitting / aperture i receiving are used. There are a total of N receiving signals of the i-th aperture. During the SAR movement process, in the slow-time dimension in the movement direction, echo signals corresponding to different transmitting channels and receiving channels will be formed at different slow-time moments. By using the Doppler modulation process in the slow-time dimension formed by the phase differences between the N echo signals of the i-th receiving aperture at different slow-time moments, imaging processing is carried out to obtain a SAR image, which is called a SAR aperture image here.

[0063] The SAR aperture images corresponding to each aperture, that is, the 1st to Nth receiving apertures, are coherently accumulated to obtain a high-resolution SAR image, and the resolution of this image is higher than that of the SAR aperture image.

[0064] Or, the target echo signals of different-time coded pulses of each individual transmitting aperture are utilized for imaging processing. For example, the echo signals of aperture i transmitting / aperture 1 receiving, aperture i transmitting / aperture 2 receiving, …, aperture i transmitting / aperture N receiving are used. There are a total of N transmitting signals of the i-th aperture. During the SAR movement process, in the slow-time dimension in the movement direction, echo signals corresponding to different transmitting channels and receiving channels will be formed at different slow-time moments. By using the Doppler modulation process in the slow-time dimension formed by the phase differences between the N echo signals of the i-th transmitting aperture at different slow-time moments, imaging processing is carried out to obtain a SAR image, which is called a SAR aperture image here.

[0065] The SAR aperture images corresponding to each aperture, that is, the 1st to Nth transmitting apertures, are coherently accumulated to obtain a high-resolution SAR image, and the resolution of this image is higher than that of the SAR aperture image.

[0066] Or, the target echo signals corresponding to different-time coded pulses of each individual transmitting aperture and receiving aperture are utilized for imaging processing. For example, the echo signals of aperture i transmitting / aperture k receiving are used. During the SAR movement process, in the slow-time dimension in the movement direction, echo signals corresponding to different transmitting channels and receiving channels will be formed at different slow-time moments. By using the Doppler modulation process in the slow-time dimension formed by the phase differences between the echo signals corresponding to the i-th transmitting aperture and the k-th receiving aperture at different slow-time moments, imaging processing is carried out to obtain a SAR image, which is called a SAR aperture image here.

[0067] For each aperture, that is, the N×N pairs of combinations of the first to Nth transmitting apertures and the first to Nth receiving apertures, the SAR aperture images formed correspondingly will be coherently accumulated to obtain a high-resolution SAR image, and the resolution of this image is higher than that of the SAR aperture image.

[0068] Perform high signal-to-noise ratio SAR imaging processing on the above signals to obtain a high signal-to-noise ratio SAR image; specifically,

[0069] One is to use the target echo signals of different-time encoded pulses of each individual receiving aperture for imaging processing. For example, use the echo signals of aperture 1 transmitting / aperture i receiving, aperture 2 transmitting / aperture i receiving,..., aperture N transmitting / aperture i receiving. There are a total of N received signals of the i-th aperture. During the SAR movement process, in the slow time dimension in the movement direction, at different slow time moments, echo signals corresponding to different transmitting channels and receiving channels will be formed. Utilize the Doppler modulation process in the slow time dimension formed by the phase differences between the N received echo signals of the i-th receiving aperture at different slow time moments to perform multi-look imaging processing on the above echo signals. The number of looks is N, and then non-coherently accumulate each look signal to increase the signal-to-noise ratio to obtain a SAR image, which is called a multi-look SAR aperture image here.

[0070] Non-coherently accumulate the multi-look SAR aperture images formed corresponding to each aperture, that is, the first to Nth receiving apertures, to obtain a high signal-to-noise ratio SAR image, equivalently improving the detection ability.

[0071] Or use the target echo signals of different-time encoded pulses of each individual transmitting aperture for imaging processing. For example, use the echo signals of aperture i transmitting / aperture 1 receiving, aperture i transmitting / aperture 2 receiving,..., aperture i transmitting / aperture N receiving. There are a total of N transmitted signals of the i-th aperture. During the SAR movement process, in the slow time dimension in the movement direction, at different slow time moments, echo signals corresponding to different transmitting channels and receiving channels will be formed. Utilize the Doppler modulation process in the slow time dimension formed by the phase differences between the N transmitted echo signals of the i-th transmitting aperture at different slow time moments to perform multi-look imaging processing on the above echo signals. The number of looks is N, and then non-coherently accumulate each look signal to increase the signal-to-noise ratio to obtain a SAR image, which is called a multi-look SAR aperture image here.

[0072] Non-coherently accumulate the SAR aperture images formed corresponding to each aperture, that is, the first to Nth transmitting apertures, to obtain a high signal-to-noise ratio SAR image, equivalently improving the detection ability.

[0073] Alternatively, the target echo signals corresponding to the non-simultaneous coding pulses of each individual transmitting aperture and receiving aperture are used for imaging processing. For example, the echo signals of transmitting aperture i / receiving aperture k are used. During the movement of the SAR, in the slow time dimension in the movement direction, at different slow time moments, echo signals corresponding to the transmitting and receiving channels at different moments will be formed. The Doppler modulation history in the slow time dimension formed by the phase difference between the echo signals corresponding to the i-th transmitting aperture and the k-th receiving aperture at different slow time moments is used for imaging processing to obtain a SAR image, which is herein referred to as a SAR aperture image.

[0074] The SAR aperture images corresponding to the N×N pairs of combinations of each aperture, that is, the 1st to Nth transmitting apertures and the 1st to Nth receiving apertures, are non-coherently accumulated to obtain a SAR image with high signal-to-noise ratio, equivalently improving the detection ability.

[0075] It should be noted that, in order to make the embodiments of the present invention easier to understand, the above description omits some more specific technical details that are well-known to those skilled in the art and may be necessary for the implementation of the embodiments of the present invention. For example, the above description omits the general description of existing radars or radar systems and SAR imaging processing methods. It should be understood that, according to the embodiments of the present invention, in addition to the transmitting component, receiving component, and radar antenna described above, other components or assemblies existing in existing radars or radar systems may also be included. The above description is merely illustrative and not restrictive.

[0076] The specification of the present invention is provided for illustration and description, and is not intended to be exhaustive or to limit the present invention to the disclosed form. Many modifications and variations are possible for those of ordinary skill in the art.

[0077] The above-described embodiments have further detailed the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0078] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present invention, and all should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A system for improving SAR azimuth resolution or detection capability by splitting the aperture, wherein, Comprising: A radar antenna configured to be segmented into multiple apertures, forming N apertures, where N is a positive integer greater than 1, and different said apertures have independent radar signal transmitting and receiving links; An aperture coding signal generating unit configured to generate coding signals transmitted by the N apertures, with the transmitted signals of the N apertures being independently pulse-coded and frequency-converted and / or modulated to radio frequency; each said aperture transmits a different coded pulse signal; For each said aperture, a separate coded pulse signal is transmitted, and the separate coded pulse signal is a frequency-division coded pulse signal; or, the separate coded pulse signal is a time-phase combined coded pulse signal, and the basic constraint of the coding is that each coding channel is orthogonal to each other; or, the separate coded pulse signal is a time-phase-frequency combined coded pulse signal, and the basic constraint of the coding is that each coding channel is orthogonal to each other; A transmitting component configured to amplify the N radio frequency pulse coded signals generated by the aperture coding signal generating unit and feed them into the N apertures respectively; A receiving component configured to receive the echo signals of the N apertures, perform radio frequency amplification, frequency conversion and / or demodulation on the corresponding N echo signals, and perform intermediate frequency amplification or baseband amplification; A data acquisition unit configured to sample the N intermediate frequency or baseband signals output by each receiving component, convert them into digital signals, and form N target echo data; A decoding processing unit configured to perform decoding processing on the acquired N target echo data and separate the target echo data corresponding to the transceiver channel combinations formed by different apertures; An imaging processor configured to perform SAR imaging processing and SAR image accumulation processing on the target echo data corresponding to different transceiver channel combinations; A control unit configured to control the signal generation, transceiver, acquisition and processing of the system for splitting the aperture to improve the SAR azimuth resolution or detection ability; 2. A method for improving SAR azimuth resolution by splitting the aperture, wherein, Comprising: The radar antenna is segmented into N apertures along the azimuth direction, where N is an integer greater than 1; When the radar is operating, each aperture transmits an independent coded pulse signal, each aperture receives the echo signal of its own transmitted coded pulse signal, and at the same time receives the echo signals of the coded pulse signals transmitted by other apertures; each said aperture transmits a different coded pulse signal; for each said aperture, a separate coded pulse signal is transmitted, and the separate coded pulse signal is a frequency-division coded pulse signal; or, the separate coded pulse signal is a time-phase combined coded pulse signal, and the basic constraint of the coding is that each coding channel is orthogonal to each other; or, the separate coded pulse signal is a time-phase-frequency combined coded pulse signal, and the basic constraint of the coding is that each coding channel is orthogonal to each other; Decoding processing is performed on the echo signals received by each aperture to form N echo signals of different aperture transceiver combinations. For the echo signals received by the N apertures, N×N echo signals can be formed; Performing SAR imaging processing on each echo signal or combination of echo signals to obtain multiple SAR images; Performing coherent accumulation on the multiple SAR images to obtain a high-resolution SAR image.

3. The method for improving the azimuth resolution of SAR by splitting the aperture according to claim 2, wherein, the separate coded signal is separable in time or space or frequency, or by decoding processing, from the echo signal generated by the target for the coded signal.

4. The method for improving the SAR azimuth resolution by splitting the aperture according to claim 2, wherein, The SAR imaging process for each echo signal or combination of echo signals is to perform imaging processing using the phase difference between the target echo signals of different-time coded pulses of each aperture to obtain an SAR image, or to perform imaging processing using the phase difference between the target echo signals of different-time coded pulses between different apertures to obtain an SAR image.

5. A method for improving the detection capability of SAR by splitting the aperture, comprising: splitting a radar antenna into N apertures along the azimuth direction, where N is an integer greater than 1; when the radar operates, each aperture transmits its own independent coded pulse signal, and each aperture receives the echo signal of its own transmitted coded pulse signal, and at the same time receives the echo signals of the coded pulse signals transmitted by other apertures; each of the said apertures transmits different coded pulse signals; a separate coded pulse signal is transmitted for each of the said apertures, and the separate coded pulse signal is a frequency-division coded pulse signal; or, the separate coded pulse signal is a time-phase combined coded pulse signal, and the basic constraint of the coding is that each coding channel is orthogonal to each other; or, the separate coded pulse signal is a time-phase-frequency combined coded pulse signal, and the basic constraint of the coding is that each coding channel is orthogonal to each other; performing decoding processing on the echo signals received by each aperture to form N echo signals of different aperture transceiver combinations, and for the echo signals received by N apertures, N×N echo signals can be formed; performing SAR imaging processing on each echo signal or combination of echo signals to obtain multiple SAR images; performing non-coherent accumulation on the multiple SAR images to obtain an SAR image with high signal-to-noise ratio, equivalently improving the detection capability.

6. The method for improving SAR detection ability by splitting aperture according to claim 5, wherein, The separate coded signal is separable in time or space or frequency, or by decoding processing, from the echo signal generated by the target for the coded signal.

7. The method for improving SAR detection ability by splitting aperture according to claim 5, wherein, The SAR imaging process for each echo signal or combination of echo signals is to perform imaging processing using the phase difference between the target echo signals of different-time coded pulses of each aperture to obtain an SAR image, or to perform imaging processing using the phase difference between the target echo signals of different-time coded pulses between different apertures to obtain an SAR image.

Images