CN112698324B - Sum and difference single pulse angle measurement method of frequency modulation stepping radar - Google Patents
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Abstract
The invention discloses a sum and difference single pulse angle measurement method of a frequency modulation stepping radar, which comprises the following steps: 1) Acquiring an angle sensitivity function of a frequency modulation stepping radar and a difference single pulse angle measurement; 2) Measuring angles of a plurality of strong scattering centers which are large in amplitude and far away from each other and not interfering with each other in a target range profile; 3) And carrying out weighted average on the angle measurement values of the strong scattering centers to obtain a final target angle. An angle-sensitive function calculation formula of the frequency modulation stepping radar and the difference monopulse angle measurement is established; after the function of single pulse angle measurement is added and subtracted, the frequency modulation stepping radar can accurately measure the azimuth angle and the pitch angle of a target; the high-precision angle measurement improves the tracking performance of the radar on moving targets.
Description
Technical Field
The invention relates to an angle measurement method of a frequency modulation stepping radar, in particular to a sum and difference single pulse angle measurement method of the frequency modulation stepping radar.
Background
Range-high resolution is the basis for achieving radar target imaging, classification recognition, etc., which generally requires an increase in the bandwidth of the radar signal according to pulse compression theory. The frequency modulation step signal is a wideband radar signal capable of realizing high resolution, and is composed of a series of coherent narrow-band pulses with carrier frequency linearly hopped, and each pulse is narrow-band, so that the instantaneous bandwidth of a receiver and the sampling rate requirement of an analog-to-digital converter are reduced, and the frequency modulation step signal is a wideband radar signal form which is widely focused.
Angle measurement is one of the basic functions of modern radars, and sum and difference monopulse angle measurement is an angle measurement mode commonly used in radars, but no in-depth research on the frequency-modulated step radars and the difference monopulse angle measurement problem is currently seen.
Disclosure of Invention
The invention aims to provide a sum and difference single pulse angle measurement method of a frequency modulation stepping radar, which establishes an angle sensitivity function calculation formula of the sum and difference single pulse angle measurement of the frequency modulation stepping radar; after the function of single pulse angle measurement is added and subtracted, the frequency modulation stepping radar can accurately measure the azimuth angle and the pitch angle of a target; the high-precision angle measurement improves the tracking performance of the radar on moving targets.
In order to achieve the above object, according to one aspect of the present invention, the following technical solutions are provided:
a sum and difference single pulse angle measurement method of a frequency modulation stepping radar comprises the following steps:
1) Acquiring an angle sensitivity function of a frequency modulation stepping radar and a difference single pulse angle measurement;
2) Measuring angles of a plurality of strong scattering centers which are large in amplitude and far away from each other and not interfering with each other in a target range profile;
3) And carrying out weighted average on the angle measurement values of the strong scattering centers to obtain a final target angle.
The invention is further provided with: the step 1) obtains the angle-sensitive function of the frequency modulation step radar and the differential monopulse angle measurement, specifically,
1-1) a frequency-modulated stepping radar is arranged to emit a frequency-stepped chirped coherent pulse train consisting of K pulses, i.e. a frequency-stepped LFM coherent pulse train, with a pulse width of T and a pulse repetition period of T r The carrier frequency of the 1 st pulse, i.e. the initial carrier frequency is f 0 The carrier frequency difference, i.e. the frequency step amount deltaf,
setting frequency steps of radar emissionLFM coherent pulse train signal s t (t) is the number of the components,
wherein: t is time, a t For the amplitude of the transmitted signal, rect (.cndot.) is a rectangular function, when-1/2 is less than or equal to t is less than or equal to 1/2, rect (t) =1, otherwise rect (t) =0, u (.cndot.) is LFM pulse signal, u (t) =exp (jpi gamma t) 2 ) T/2 is less than or equal to T is less than or equal to T/2, gamma=B/T is the frequency modulation slope of the LFM pulse signal, B is the bandwidth of the LFM pulse signal, j is an imaginary unit, j 2 ＝-1；
1-2) an antenna array provided with a frequency modulation stepping radar is a uniform linear array composed of N array elements, the distance between two adjacent array elements is d, if the distance is R 0 Angle theta t A stationary point target is arranged, an echo signal is generated when a radar emission signal meets the stationary point target in the propagation process, the echo signal is received by a radar antenna array, and then an echo signal s 'received by an nth array element' rn (t) is the number of the components,
wherein: a, a r Is the amplitude of the echo signal, t 0 ＝2R 0 And c is the double-pass time delay of the echo signal received by the reference array element, c is the speed of light, tau n ＝ndsinθ t And/c is the delay of the echo signal received by the nth element relative to the reference element, n=0, 1,..,
let element 0 be the reference element, τ 0 ＝0，
For echo signal s' rn (t) mixing to obtain zero intermediate frequency signal s rn (t)，
For array aperture transit time τ N-1 ＝(N-1)dsinθ t And/c, when the condition B < 1/τ is satisfied N-1 When formula (3) is used, it can be expressed as,
wherein: lambda (lambda) k Lambda is the wavelength of the kth pulse k ＝c/(f 0 +kΔf)，k＝0,1,...,K-1，
Synthesizing echo signals on N array elements to obtain a target echo signal vector s r (t)，
Wherein:φ tk ＝(2π/λ k )dsinθ t superscript T denotes a transpose;
1-3) setting the target echo signal vector s r (t) steering vector a for sum beamforming Σk Steering vector a for differential beamforming Δk In order to achieve this, the first and second,
a Σk ＝a 0k ⊙ω Σ ,a Δk ＝a 0k ⊙ω Δ (6)
wherein:φ 0k ＝(2π/λ k )dsinθ 0 ，θ 0 for sum beam forming pointing, ω Σ Window function, ω, for sum beamforming Δ For the window function of the difference beamforming, +.,
for the target echo signal vector s of (5) r (t) performing sum beam forming to obtain a sum beam signal s Σ (t) is the number of the components,
wherein: the superscript H denotes that the conjugate transpose is taken,
for the target echo signal vector s of (5) r (t) performing differential beam forming to obtain a differential beam signal s Δ (t) is the number of the components,
1-4) summing the beam signals s of equation (7) Σ (t) transforming to the frequency domain to obtain a first spectral signal S Σ (f)，
Wherein: f is the frequency at which the frequency of the signal is,for the frequency spectrum of the LFM signal,
the difference beam signal s of the formula (8) Δ (t) transforming to the frequency domain to obtain a second spectrum signal S Δ (f)，
Wherein:
according to the theory of the matched filter, the frequency response function of the matched filter of the echo signal is U * (f) The superscript indicates that the first spectrum signal of formula (9) is output as S 'after passing through the matched filter' Σ (f)，
Wherein: a' r ＝a r The/gamma is the amplitude of the matched filter output signal,
the second spectrum signal of the (10) is output as S 'after passing through the matched filter' Δ (f)，
Performing inverse Fourier transform on the formula (11) to obtain a first signal s 'with a resolution of c/(2B) for coarse distance resolution' Σ (t)，
Performing inverse Fourier transform on the formula (12) to obtain a second signal s 'with a resolution of c/(2B) for coarse distance resolution' Δ (t)，
1-5) to achieve a high-resolution range with resolution c/(2kΔf), an inverse Fourier transform is performed on each range coarse resolution element of formula (13) to obtain a sum-beam high-resolution range profile of the element where the target is located
Wherein: θ=θ t -θ 0 For a target angle theta t Relative to the array and beam direction theta 0 Is used for the deviation of (a),
performing inverse Fourier transform on each distance coarse resolution unit of the (14) to obtain a difference beam high-resolution range profile of the unit where the target is located
1-6) high resolution range profile for sum beam in equation (15)And the difference beam high-resolution range profile in equation (16)>Calculating the ratio of the two to obtain an angle-sensitive function χ (θ),
the invention is further provided with: the step 2) measuring the sum beam high-resolution range profile of the targetThe angles of a plurality of strong scattering centers which have large medium amplitude and are far away from each other and are not interfered with each other, specifically,
2-1) performing coarse distance resolution and high resolution processing, wherein the frequency modulation step radar obtains high resolution range images of the target on two channels of a sum beam and a difference beam, and then performs target detection on the high resolution range images of the sum beam channel to obtain a plurality of strong scattering centers of the target;
2-2) at a plurality of strong scattering centers, respectively calculating the ratio of the difference beam to the sum beam, comparing them with an angle-sensitive function, and measuring the deviation of the azimuth angle or pitch angle of the target relative to the direction of the sum beam, which is recorded as { θ }, based on the relationship between the angle-sensitive function and the angle 1 ,θ 2 ,...,θ L Where L is the number of strongly scattering centers.
The invention is further provided with: and 3) carrying out weighted average on the angle measurement value of the strong scattering center to obtain a final target angle, specifically,
angle deviation value { θ } 1 ,θ 2 ,...,θ L Weighted average and sum beam pointing θ 0 Adding to obtain the angle of the target
Wherein:as the weighted value, a l For the echo amplitude at the first strong scattering center, l=1, 2,..l.
Compared with the prior art, the invention has the following advantages: (1) An angle-sensitive function calculation formula of the frequency modulation stepping radar and the difference monopulse angle measurement is established; (2) After the function of single pulse angle measurement is added and subtracted, the frequency modulation stepping radar can accurately measure the azimuth angle and the pitch angle of a target; (3) The high-precision angle measurement improves the tracking performance of the radar on moving targets.
Drawings
FIG. 1 is a flow chart of a sum and difference monopulse angle measurement method of a frequency modulated step radar of the present invention;
FIG. 2 is a high resolution range profile of the sum and difference beam outputs of a sum and difference monopulse angle measurement method of the frequency modulation stepping radar of the present invention;
FIG. 3 is a graph showing the relationship between the angle-sensitive function of the sum and difference monopulse angle measurement method of the frequency modulation stepping radar of the present invention and the target angle.
Detailed Description
The invention will be further described with reference to the drawings.
The invention provides a sum and difference single pulse angle measurement method of a frequency modulation stepping radar, which establishes an angle sensitivity function calculation formula of the sum and difference single pulse angle measurement of the frequency modulation stepping radar; after the function of single pulse angle measurement is added and subtracted, the frequency modulation stepping radar can accurately measure the azimuth angle and the pitch angle of a target; the high-precision angle measurement improves the tracking performance of the radar on moving targets.
A sum and difference single pulse angle measurement method of a frequency modulation stepping radar comprises the following steps:
1) Acquiring an angle sensitivity function of a frequency modulation stepping radar and a difference single pulse angle measurement;
in particular to a special-shaped ceramic tile,
1-1) a frequency-modulated stepping radar is arranged to emit a frequency-stepped chirped coherent pulse train consisting of K pulses, i.e. a frequency-stepped LFM coherent pulse train, with a pulse width of T and a pulse repetition period of T r The carrier frequency of the 1 st pulse, i.e. the initial carrier frequency is f 0 The carrier frequency difference, i.e. the frequency step amount deltaf,
let radar transmitted frequency step LFM coherent pulse train signal s t (t) is the number of the components,
wherein: t is time, a t For the amplitude of the transmitted signal, rect (.cndot.) is a rectangular function, when-1/2 is less than or equal to t is less than or equal to 1/2, rect (t) =1, otherwise rect (t) =0, u (.cndot.) is LFM pulse signal, u (t) =exp (jpi gamma t) 2 ) T/2 is less than or equal to T is less than or equal to T/2, gamma=B/T is the frequency modulation slope of the LFM pulse signal, B is the bandwidth of the LFM pulse signal, j is an imaginary unit, j 2 ＝-1；
1-2) an antenna array provided with a frequency modulation stepping radar is a uniform linear array composed of N array elements, the distance between two adjacent array elements is d, if the distance is R 0 Angle theta t A stationary point target is arranged, an echo signal is generated when a radar emission signal meets the stationary point target in the propagation process, the echo signal is received by a radar antenna array, and then an echo signal s 'received by an nth array element' rn (t) is the number of the components,
wherein: a, a r Is an echo signalAmplitude t of (t) 0 ＝2R 0 And c is the double-pass time delay of the echo signal received by the reference array element, c is the speed of light, tau n ＝ndsinθ t And/c is the delay of the echo signal received by the nth element relative to the reference element, n=0, 1,..,
let element 0 be the reference element, τ 0 ＝0，
For echo signal s r ′ n (t) mixing to obtain zero intermediate frequency signal s rn (t)，
For array aperture transit time τ N-1 ＝(N-1)dsinθ t And/c, when the condition B < 1/τ is satisfied N-1 When formula (3) is used, it can be expressed as,
wherein: lambda (lambda) k Lambda is the wavelength of the kth pulse k ＝c/(f 0 +kΔf)，k＝0,1,...,K-1，
Synthesizing echo signals on N array elements to obtain a target echo signal vector s r (t)，
Wherein:φ tk ＝(2π/λ k )dsinθ t superscript T denotes a transpose;
1-3) setting the target echo signal vector s r (t) steering vector a for sum beamforming Σk Steering vector a for differential beamforming Δk In order to achieve this, the first and second,
a Σk ＝a 0k ⊙ω Σ ,a Δk ＝a 0k ⊙ω Δ (6)
wherein:φ 0k ＝(2π/λ k )dsinθ 0 ，θ 0 for sum beam forming pointing, ω Σ Window function, ω, for sum beamforming Δ For the window function of the difference beamforming, +.,
for the target echo signal vector s of (5) r (t) performing sum beam forming to obtain a sum beam signal s Σ (t) is the number of the components,
wherein: the superscript H denotes that the conjugate transpose is taken,
for the target echo signal vector s of (5) r (t) performing differential beam forming to obtain a differential beam signal s Δ (t) is the number of the components,
1-4) summing the beam signals s of equation (7) Σ (t) transforming to the frequency domain to obtain a first spectral signal S Σ (f)，
Wherein: f is the frequency at which the frequency of the signal is,for the frequency spectrum of the LFM signal,
the difference beam signal s of the formula (8) Δ (t) transforming to the frequency domain to obtain a second spectrum signal S Δ (f)，
Wherein:
according to the theory of the matched filter, the frequency response function of the matched filter of the echo signal is U * (f) The superscript indicates that the first spectrum signal of formula (9) is output as S 'after passing through the matched filter' Σ (f)，
Wherein: a' r ＝a r The/gamma is the amplitude of the matched filter output signal,
the second spectrum signal of the (10) is output as S 'after passing through the matched filter' Δ (f)，
Performing inverse Fourier transform on the formula (11) to obtain a first signal s 'with a resolution of c/(2B) for coarse distance resolution' Σ (t)，
Performing inverse Fourier transform on the formula (12) to obtain a second signal s 'with a resolution of c/(2B) for coarse distance resolution' Δ (t)，
1-5) to achieve a high range resolution of resolution c/(2 K.DELTA.f), an inverse Fourier transform is performed on each range coarse resolution element of formula (13) to obtain the sum beam high fraction of the element where the target is locatedDistance-identifying image
Wherein: θ=θ t -θ 0 For a target angle theta t Relative to the array and beam direction theta 0 Is used for the deviation of (a),
performing inverse Fourier transform on each distance coarse resolution unit of the (14) to obtain a difference beam high-resolution range profile of the unit where the target is located
1-6) high resolution range profile for sum beam in equation (15)And the difference beam high-resolution range profile in equation (16)>Calculating the ratio of the two to obtain an angle-sensitive function χ (θ),
2) Measuring angles of a plurality of strong scattering centers which are large in amplitude and far away from each other and not interfering with each other in a target range profile;
in particular to a special-shaped ceramic tile,
2-1) performing coarse distance resolution and high resolution processing, wherein the frequency modulation step radar obtains high resolution range images of the target on two channels of a sum beam and a difference beam, and then performs target detection on the high resolution range images of the sum beam channel to obtain a plurality of strong scattering centers of the target;
2-2) at a plurality of strong scattering centers, respectively calculating the ratio of the difference beam to the sum beam, comparing them with an angle-sensitive function, and measuring the deviation of the azimuth angle or pitch angle of the target relative to the direction of the sum beam, which is recorded as { θ }, based on the relationship between the angle-sensitive function and the angle 1 ,θ 2 ,...,θ L Where L is the number of strongly scattering centers.
3) Carrying out weighted average on angle measurement values of the strong scattering centers to obtain a final target angle;
in particular to a special-shaped ceramic tile,
angle deviation value { θ } 1 ,θ 2 ,...,θ L Weighted average and sum beam pointing θ 0 Adding to obtain the angle of the target
Wherein:as the weighted value, a l For the echo amplitude at the first strong scattering center, l=1, 2,..l.
Since the angular sensitivity function of equation (17) is derived for a single scattering center, for a plurality of scattering centers in the target range profile, strong scattering centers with large amplitude and far distance should be selected to avoid mutual interference, azimuth or pitch angles thereof are measured, and weighted average is performed.
The sum and difference single pulse angle measurement method of the frequency modulation stepping radar is adopted for simulation, and the performance of the angle measurement method is verified through a simulation example.
The antenna array provided with the radar is a uniform linear array consisting of 50 array elements, the array element distance is half of the wavelength corresponding to the frequency modulation stepping center frequency point, the beam direction is the array normal direction, and the sum and difference beam forming respectively adopts a Taylor window and a Beris window of-35 dB. The frequency stepping coherent pulse train comprises 32 LFM pulses, the time width of the LFM pulses is 10 mu s, the bandwidth is 25MHz, the frequency stepping amount between the pulses is 25MHz, and the initial carrier frequency of the radar is 1GHz. Assuming a stationary range expansion target comprising 3 scattering center points, the amplitudes are all 1, the distances are 1000-0.75m,1000 +0.75m, respectively, the target direction is offset from the beam pointing 1 °.
Firstly, forming sum and difference wave beams of a simulation echo pulse train, then, carrying out conventional matched filtering pulse pressure on each LFM pulse to realize coarse distance resolution, and finally, carrying out inverse Fourier transform on a coarse resolution unit where a target is located to obtain a high-resolution range profile of the target, wherein the range profiles of the sum and difference wave beams are basically the same as shown in fig. 2, and only 3 peak values of the difference wave beams are lower. Taking these 3 peak points, the ratio of the difference beam to the sum beam is calculated, respectively, as indicated by the circles in fig. 3. The solid line in fig. 3 shows the relationship of the angle-sensitive function to the target angle.
From fig. 3, the angles of the 3 scattering center points can be obtained respectively, and then they are subjected to an angle weighted average treatment according to the formula (18), so that the target angle is 1.02 °, which is close to the true angle 1 °, i.e. the measurement error is not large, and the result shows that: (1) the theoretically derived angle-sensitive function in the present invention is correct; (2) in order to avoid mutual interference, strong scattering centers with large amplitude and far distance in the target range profile should be actually selected for angle measurement.
The foregoing has outlined and described the basic principles, features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention, which is defined in the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (2)
1. The sum and difference single pulse angle measurement method of the frequency modulation stepping radar is characterized by comprising the following steps of:
1) Acquiring an angle-sensitive function of a frequency modulation stepping radar and a difference monopulse angle measurement, specifically,
1-1) a frequency-modulated stepping radar is arranged to emit a frequency-stepped chirped coherent pulse train consisting of K pulses, i.e. a frequency-stepped LFM coherent pulse train, with a pulse width of T and a pulse repetition period of T r The carrier frequency of the 1 st pulse, i.e. the initial carrier frequency is f 0 The carrier frequency difference, i.e. the frequency step amount deltaf,
let radar transmitted frequency step LFM coherent pulse train signal s t (t) is the number of the components,
wherein: t is time, a t For the amplitude of the transmitted signal, rect (.cndot.) is a rectangular function, when-1/2 is less than or equal to t is less than or equal to 1/2, rect (t) =1, otherwise rect (t) =0, u (.cndot.) is LFM pulse signal, u (t) =exp (jpi gamma t) 2 ) T/2 is less than or equal to T is less than or equal to T/2, gamma=B/T is the frequency modulation slope of the LFM pulse signal, B is the bandwidth of the LFM pulse signal, j is an imaginary unit, j 2 ＝-1；
1-2) an antenna array provided with a frequency modulation stepping radar is a uniform linear array composed of N array elements, the distance between two adjacent array elements is d, if the distance is R 0 Angle theta t A stationary point target is arranged, an echo signal is generated when a radar emission signal meets the stationary point target in the propagation process, the echo signal is received by a radar antenna array, and then an echo signal s 'received by an nth array element' rn (t) is the number of the components,
wherein: a, a r Is the amplitude of the echo signal, t 0 ＝2R 0 And c is the double-pass time delay of the echo signal received by the reference array element, c is the speed of light, tau n ＝nd sinθ t And/c is the delay of the echo signal received by the nth element relative to the reference element, n=0, 1,..,
let element 0 be the reference element, τ 0 ＝0，
For echo signal s' rn (t) mixing to obtain zero intermediate frequency signal s rn (t)，
For array aperture transit time τ N-1 ＝(N-1)dsinθ t And/c, when the condition B < 1/τ is satisfied N-1 When formula (3) is used, it can be expressed as,
wherein: lambda (lambda) k Lambda is the wavelength of the kth pulse k ＝c/(f 0 +kΔf)，k＝0,1,...,K-1，
Synthesizing echo signals on N array elements to obtain a target echo signal vector s r (t)，
Wherein:φ tk ＝(2π/λ k )d sinθ t superscript T denotes a transpose;
1-3) setting the target echo signal vector s r (t) steering vector a for sum beamforming Σk Steering vector a for differential beamforming Δk In order to achieve this, the first and second,
a Σk ＝a 0k ⊙ω Σ ,a Δk ＝a 0k ⊙ω Δ (6)
wherein:φ 0k ＝(2π/λ k )d sinθ 0 ，θ 0 for sum beam forming pointing, ω Σ Window function, ω, for sum beamforming Δ For the window function of the difference beamforming, +.,
for the target echo signal vector s of (5) r (t) performing sum beam forming to obtain a sum beam signal s Σ (t) is the number of the components,
wherein: the superscript H denotes that the conjugate transpose is taken,
for the target echo signal vector s of (5) r (t) performing differential beam forming to obtain a differential beam signal s Δ (t) is the number of the components,
1-4) summing the beam signals s of equation (7) Σ (t) transforming to the frequency domain to obtain a first spectral signal S Σ (f)，
Wherein: f is the frequency at which the frequency of the signal is,for the frequency spectrum of the LFM signal,
the difference beam signal s of the formula (8) Δ (t) transforming to the frequency domain to obtain a second spectrum signal S Δ (f)，
Wherein:
according to the theory of the matched filter, the frequency response function of the matched filter of the echo signal is U * (f) The superscript indicates that the first spectrum signal of formula (9) is output as S 'after passing through the matched filter' Σ (f)，
Wherein: a' r ＝a r The/gamma is the amplitude of the matched filter output signal,
the second spectrum signal of the (10) is output as S 'after passing through the matched filter' Δ (f)，
Performing inverse Fourier transform on the formula (11) to obtain a first signal s 'with a resolution of c/(2B) for coarse distance resolution' Σ (t)，
Performing inverse Fourier transform on the formula (12) to obtain a second signal s 'with a resolution of c/(2B) for coarse distance resolution' Δ (t)，
1-5) in order to achieve a high resolution of the distance with a resolution of c/(2 K.DELTA.f), on each distance coarse resolution element of formula (13) respectivelyPerforming inverse Fourier transform to obtain a sum beam high-resolution range profile of the unit where the target is located
Wherein: θ=θ t -θ 0 For a target angle theta t Relative to the array and beam direction theta 0 Is used for the deviation of (a),
performing inverse Fourier transform on each distance coarse resolution unit of the (14) to obtain a difference beam high-resolution range profile of the unit where the target is located
1-6) high resolution range profile for sum beam in equation (15)And (16) a difference beam high resolution range profileCalculating the ratio of the two to obtain an angle-sensitive function χ (θ),
2) The angles of a plurality of strong scattering centers which are large in amplitude and far away from each other and not interfering with each other in the target range profile are measured, specifically,
2-1) performing coarse distance resolution and high resolution processing, wherein the frequency modulation step radar obtains high resolution range images of the target on two channels of a sum beam and a difference beam, and then performs target detection on the high resolution range images of the sum beam channel to obtain a plurality of strong scattering centers of the target;
2-2) at a plurality of strong scattering centers, respectively calculating the ratio of the difference beam to the sum beam, comparing them with an angle-sensitive function, and measuring the deviation of the azimuth angle or pitch angle of the target relative to the direction of the sum beam, which is recorded as { θ }, based on the relationship between the angle-sensitive function and the angle 1 ,θ 2 ,...,θ L Wherein L is the number of strongly scattering centers;
3) And carrying out weighted average on the angle measurement values of the strong scattering centers to obtain a final target angle.
2. The method for measuring the angle of the sum and difference monopulses of the frequency modulation stepping radar according to claim 1, wherein the method comprises the following steps: and 3) carrying out weighted average on the angle measurement value of the strong scattering center to obtain a final target angle, specifically,
angle deviation value { θ } 1 ,θ 2 ,...,θ L Weighted average and sum beam pointing θ 0 Adding to obtain the angle of the target
Wherein:as the weighted value, a l For the echo amplitude at the first strong scattering center, l=1, 2,..l.
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