CN106093942B - A kind of High Resolution Spaceborne SAR impulse compression method for considering strabismus and influencing - Google Patents

A kind of High Resolution Spaceborne SAR impulse compression method for considering strabismus and influencing Download PDF

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Publication number
CN106093942B
CN106093942B CN201610405011.7A CN201610405011A CN106093942B CN 106093942 B CN106093942 B CN 106093942B CN 201610405011 A CN201610405011 A CN 201610405011A CN 106093942 B CN106093942 B CN 106093942B
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signal
frequency
obtains
phase compensation
matched filter
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CN106093942A (en
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金光虎
何志华
何峰
董臻
张永胜
黄海风
余安喜
孙造宇
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National University of Defense Technology
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
    • G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
    • G01S13/9021—SAR image post-processing techniques
    • G01S13/9023—SAR image post-processing techniques combined with interferometric techniques
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
    • G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
    • G01S13/904—SAR modes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
    • G01S13/90—Radar or analogous systems specially adapted for specific applications for mapping or imaging using synthetic aperture techniques, e.g. synthetic aperture radar [SAR] techniques
    • G01S13/904—SAR modes
    • G01S13/9041—Squint mode

Abstract

The present invention provides a kind of High Resolution Spaceborne SAR impulse compression method for considering strabismus and influencing, and the technical scheme comprises the following steps：The first step compensates phase：Phase compensation is carried out to echo-signal, obtains phase compensation back echo signal；Second step generates frequency domain-matched filter：According to frequency modulation rate, reference signal is generated, frequency domain is transformed to and obtains matched filter；Third walks, and carries out pulse compression：Phase compensation back echo signal is transformed into frequency domain, obtains frequency-region signal；Frequency-region signal with the conjugation of matched filter is multiplied, obtains the frequency-region signal after matched filtering, time domain is transformed to and obtains the compressed signal of pulse.The present invention can reduce to avoid resolution ratio caused by existing impulse compression method, peak sidelobe ratio raises problem, have the advantages that realize simple, fireballing.

Description

A kind of High Resolution Spaceborne SAR impulse compression method for considering strabismus and influencing
Technical field
The invention belongs to space flight and the interleaving techniques field of microwave remote sensing, more particularly to a kind of high score for considering strabismus and influencing Resolution satellite-borne SAR (Synthetic Aperture Radar, synthetic aperture radar) impulse compression method.
Background technology
Satellite-borne SAR is a kind of active sensor for being operated in microwave band, and having being capable of round-the-clock, all weather operations Feature.It obtains two-dimentional high-resolution earth surface radar image by distance to pulse compression and orientation pulse compression, It is modern earth mapping, the important means of imaging investigation.Image resolution ratio is to weigh the important finger of Spaceborne SAR System imaging capability Mark.SAR image resolution ratio includes distance resolution and azimuth resolution.Distance resolution is limited to radar signal bandwidth, signal Bandwidth it is bigger, distance resolution is higher.Azimuth resolution is limited to beam scanning angle, and beam scanning angle is bigger, azimuth discrimination Rate is higher.Modem high-resolution satellite-borne SAR improves single scattering by controlling beam position irradiated site in ground moving The beam scanning angle of point, so as to improve azimuth resolution.This working method results in most time beam position tools There is certain angle of squint, angle of squint is usually continuously increased from the scene center of imaging to edge.
(specific method is referring to document for existing impulse compression method《Synthetic aperture imaging》45-67 pages, Ian The works such as G.Cumming, Electronic Industry Press publish for 2007) do not consider the influence that strabismus is brought, it is usually used in middle low resolution In satellite-borne SAR or carried SAR signal processing.When realizing pulse compression, echo-signal is considered as the direct of radar emission signal Time delay, the pulsewidth of echo-signal, frequency modulation rate are consistent with transmitting signal, and pulse compression is made reference with transmitting signal, by with The convolution of echo obtains high-resolution one-dimensional range profile.But in High Resolution Spaceborne SAR system, beam scanning causes spaceborne Larger movement velocity existing for angle of squint possessed by SAR beam positions and satellite platform causes satellite platform and ground radar to shine Region is penetrated there are certain speed of related movement, which increases as angle of squint increases.Speed of related movement So that radar return model changes, radar return is no longer the simple time delay for emitting signal, with transmitting signal make with reference to The pulse compress mode of echo convolution is no longer applicable in.
Invention content
The object of the present invention is to propose a kind of High Resolution Spaceborne SAR impulse compression method for considering strabismus and influencing, solve Pulse compression performance declines problem under the conditions of High Resolution Spaceborne SAR strabismus.
The thinking of technical solution of the present invention is：A kind of High Resolution Spaceborne SAR impulse compression method for considering strabismus and influencing, Echo model under the conditions of being squinted according to High Resolution Spaceborne SAR compensates the additive phase brought by speed of related movement, according to Speed of related movement generation pulse reference compression signal simultaneously obtains matched filter, echo is carried out Fourier transformation frequency domain into Row matched filtering, finally returns back to time domain, so as to complete to consider the High Resolution Spaceborne SAR pulse compression that strabismus influences, obtains High-resolution one-dimensional range profile.
The technical scheme is that：
The parameter of known High Resolution Spaceborne SAR transmitting signal is：Centre frequency fc, pulsewidth T, bandwidth B, frequency modulation rate Kr, Wavelength X, propagation velocity of electromagnetic wave C.
Assuming that the corresponding parameter of satellite-borne SAR any pulse time in certain observation process is：It is defended under body-fixed coordinate system Star speed Vs, wave beam angle of squint θ, satellite-borne SAR observed object acquisition echo-signal s (t), wherein t represent sampling time, above-mentioned ginseng Number is obtained using existing method measurement.
It is characterized by comprising the following steps：
The first step compensates phase
Phase compensation is carried out to echo-signal, obtains phase compensation back echo signal s'(t), existing phase compensating method , it is preferred to use procedure below：
Calculate compensation phase h1(t)：
Phase compensation back echo signal s'(t is calculated again)：
S'(t)=s (t) h1(t)
Second step generates frequency domain-matched filter
Calculate frequency modulation rate Kr'：
Generate reference signal h2(t)：
It transforms to frequency domain and obtains matched filter H2(f)：
Third walks, and carries out pulse compression
By phase compensation back echo signal s'(t) frequency domain is transformed to, obtain frequency-region signal S'(f)：
By frequency-region signal S'(f) and matched filter H2(f) conjugation is multiplied, and obtains the letter of the frequency domain after matched filtering Number Sh'(f)：
Sh' (f)=S'(f) H2 *(f)
By Sh' (f) transform to time domain, obtain the compressed signal s of pulseh'(t)：
The beneficial effects of the invention are as follows：The present invention introduces the compensation phase under strabismus in pulse compression process, calculates The frequency modulation rate variation that strabismus is brought is considered during matched filter, can be dropped to avoid resolution ratio caused by existing impulse compression method Low, peak sidelobe ratio raises problem, wherein the transformation of time domain to frequency domain and frequency domain to time domain can with Fast Fourier Transform (FFT) come It realizes, this method has the advantages that realize simple, fireballing.
Description of the drawings
Fig. 1 is that the present invention considers the operating diagram of satellite-borne SAR pulse compression that strabismus influences；
Fig. 2 is the satellite-borne SAR parameter set in emulation；
Fig. 3 is conventional pulse compression result；
Fig. 4 is the pulse compression result of this method.
Specific embodiment
The present invention is further detailed below in conjunction with the accompanying drawings.
Fig. 1 is the process chart of the present invention.Whole flow process is divided into three big steps.The first step：Phase compensation：Compensation is due to wave The additive phase that beam strabismus is brought；Second step：Generate matched filter：According to satellite velocities and angle of squint, generation considers strabismus Matched filter；Third walks：Process of pulse-compression：Echo is fourier transformed frequency domain, in frequency domain and matched filter It is multiplied, last another mistake is fourier transformed into time domain, completes pulse compression, obtains high-resolution one-dimensional range profile.
Fig. 2~Fig. 4 is the handling result that emulation experiment is carried out using the specific embodiment of the invention.
Fig. 2 is the satellite-borne SAR parameter set in emulation, including satellite altitude, centre frequency, wavelength, pulse width, signal The parameters such as bandwidth, frequency modulation rate, center downwards angle of visibility, angle of squint.Satellite-borne SAR is operated in X-band, according to distance resolution calculation formula It is 0.15 meter to obtain distance resolution nominal value, and the peak sidelobe ratio nominal value of pulse compression is -13.26dB.
Fig. 3 is to carry out pulse compression using existing method as a result, existing impulse compression method does not consider that strabismus is brought Radial velocity influence, it is believed that receive signal be emit signal simple time delay, there is no additive phase and adjust frequency shift. In figure, abscissa is relative distance (using pulse compression peaks position as 0 point), and ordinate is that (maximum value is normalization amplitude 0dB), it is 0.1505 meter to compress the distance resolution of afterpulse, 0.0005 meter lower than nominal value, peak sidelobe ratio for- 12.74dB is higher 0.52dB than nominal value.Illustrate, the reduction of pulse compression resolution ratio, peak value occurs in existing impulse compression method Secondary lobe ratio raises problem.
Fig. 4 is to carry out pulse compression using the method for the present invention as a result, in figure, and abscissa is relative distance (with pulse pressure Contracting peak position is 0 point), ordinate is normalization amplitude (maximum value 0dB), and the distance resolution for compressing afterpulse is 0.1498 meter, 0.0002 meter higher than nominal value, peak sidelobe ratio is consistent with nominal value for -13.26dB.Illustrate, arteries and veins of the invention Preferable pulse compression result can be obtained by rushing compression method, the resolution ratio that traditional pulse method is brought can be avoided to reduce, peak Value secondary lobe ratio raises problem.
The embodiments of the present invention described above are not intended to limit the scope of the present invention, any in the present invention Modifications, equivalent substitutions and improvements made within spirit and principle etc. should be included in the claims of the present invention Within.

Claims (1)

  1. A kind of 1. High Resolution Spaceborne SAR impulse compression method for considering strabismus and influencing, it is known that High Resolution Spaceborne SAR transmitting letter Number parameter parameter corresponding with pulse time any in certain observation process, which is characterized in that include the following steps：
    The first step compensates phase：
    Phase compensation is carried out to echo-signal, obtains phase compensation back echo signal s'(t), detailed process：
    Calculate compensation phase h1(t)：
    Phase compensation back echo signal s'(t is calculated again)：
    S'(t)=s (t) h1(t)；
    Second step generates frequency domain-matched filter：
    Calculate frequency modulation rate Kr'：
    Generate reference signal h2(t)：
    Reference signal h2(t) it transforms to frequency domain and obtains matched filter H2(f)：
    Foregoing is directed to parameter include：
    High Resolution Spaceborne SAR transmitting signal parameter be：Pulsewidth is T, frequency modulation rate Kr, propagation velocity of electromagnetic wave C；
    The corresponding parameter of satellite-borne SAR any pulse time in certain observation process is：The satellite velocities V under body-fixed coordinate systems, Wave beam angle of squint θ, t represent the sampling time；
    Third walks, and carries out pulse compression：
    Phase compensation back echo signal is transformed into frequency domain, obtains frequency-region signal；
    By frequency-region signal and matched filter H2(f) conjugation is multiplied, and obtains the frequency-region signal S after matched filteringh'(f)；
    By Sh' (f) transform to time domain, obtain the compressed signal of pulse.
CN201610405011.7A 2016-06-10 2016-06-10 A kind of High Resolution Spaceborne SAR impulse compression method for considering strabismus and influencing Active CN106093942B (en)

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CN110162833B (en) * 2019-04-11 2023-07-14 上海卫星工程研究所 Method for designing space-borne SAR distance pulse pressure performance evaluation functional module
CN111157992B (en) * 2020-01-14 2021-11-30 中国人民解放军海军工程大学 Maneuvering target ISAR imaging method based on iterative phase self-focusing
CN113723225A (en) * 2021-08-13 2021-11-30 陕西航天技术应用研究院有限公司 Novel calibration signal processing method and system, electronic equipment and storage medium

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6492932B1 (en) * 2001-06-13 2002-12-10 Raytheon Company System and method for processing squint mapped synthetic aperture radar data
CN101561970A (en) * 2009-05-25 2009-10-21 中国人民解放军理工大学气象学院 Method for controlling microwave vehicle detecting radar
CN102176016A (en) * 2011-01-25 2011-09-07 北京航空航天大学 Large squint sliding spotlight SAR (synthetic aperture radar) imaging processing method
CN102323570A (en) * 2011-05-24 2012-01-18 中国人民解放军国防科学技术大学 Method for estimating magnitude-phase characteristics of radar target echo signal simulator
CN103454635A (en) * 2013-09-08 2013-12-18 西安电子科技大学 Front squint SAR imaging method based on hypersonic aircraft at level flight section
CN103901428A (en) * 2014-03-28 2014-07-02 西安电子科技大学 Missile-borne SAR sub-aperture forward squint high-order nonlinear chirp scaling imaging method
CN104865573A (en) * 2015-06-12 2015-08-26 西安电子科技大学 Method for optimizing SAR (Specific Absorption Rate) extended scene imaging on double-base forward-looking high-mobility platform
CN105093224A (en) * 2015-01-21 2015-11-25 电子科技大学 High squint synthetic aperture radar imaging processing method
CN105372657A (en) * 2015-12-10 2016-03-02 中国科学院电子学研究所 Echo data-based video synthetic aperture radar motion compensation imaging method

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6492932B1 (en) * 2001-06-13 2002-12-10 Raytheon Company System and method for processing squint mapped synthetic aperture radar data
CN101561970A (en) * 2009-05-25 2009-10-21 中国人民解放军理工大学气象学院 Method for controlling microwave vehicle detecting radar
CN102176016A (en) * 2011-01-25 2011-09-07 北京航空航天大学 Large squint sliding spotlight SAR (synthetic aperture radar) imaging processing method
CN102323570A (en) * 2011-05-24 2012-01-18 中国人民解放军国防科学技术大学 Method for estimating magnitude-phase characteristics of radar target echo signal simulator
CN103454635A (en) * 2013-09-08 2013-12-18 西安电子科技大学 Front squint SAR imaging method based on hypersonic aircraft at level flight section
CN103901428A (en) * 2014-03-28 2014-07-02 西安电子科技大学 Missile-borne SAR sub-aperture forward squint high-order nonlinear chirp scaling imaging method
CN105093224A (en) * 2015-01-21 2015-11-25 电子科技大学 High squint synthetic aperture radar imaging processing method
CN104865573A (en) * 2015-06-12 2015-08-26 西安电子科技大学 Method for optimizing SAR (Specific Absorption Rate) extended scene imaging on double-base forward-looking high-mobility platform
CN105372657A (en) * 2015-12-10 2016-03-02 中国科学院电子学研究所 Echo data-based video synthetic aperture radar motion compensation imaging method

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