110 results about "Chirp pulse" patented technology

The invention discloses an optical fiber distributed sound wave sensing device based on double chirped pulses, which relates to the technical field of distributed optical fiber sensing and comprises a laser module (1), a chirped pulse modulation module (2), a sensing optical fiber module (3) and a Rayleigh scattering signal separation and receiving module (4), laser generated by the laser module passes through the chirped pulse modulation module to obtain double chirped pulse signals with different frequency bands, excites Rayleigh scattering signals in the sensing optical fiber module and inputs the Rayleigh scattering signals to the Rayleigh scattering signal separation and receiving module for signal separation and demodulation. The sensing optical fiber is inquired through double chirped pulses of different frequency bands, two Rayleigh scattering signals are excited to achieve a wide range and high sensitivity, the advantages of the two signals are combined through an adaptive filtering algorithm, the dynamic range of distributed sound wave detection is improved by one order of magnitude, and the detection accuracy is improved. The acquisition of large chirp bandwidth Rayleigh scattering signals is realized at a low sampling rate, and a distributed sound wave sensing technology with a large dynamic range is realized.

Some non-limiting embodiments of the present disclosure relate to transmitting and / or receiving of sensing. A waveform of a hyperbolic frequency modulated (HFM) chirp pulse in a frequency range is obtained. A first signal including a plurality of HFM chirp pulses is transmitted. A second signal is received, wherein the second signal is a signal resulting from reflection of the first signal by at least one target. A subsampled first signal is obtained by sampling the first signal at a sampling frequency fS below a Nyquist rate fnyq. A subsampled second signal is obtained by sampling the second signal at the sampling frequency fS. A range of the at least one target and / or a Doppler frequency is determined by processing of the subsampled first signal and the subsampled second signal.

The invention provides a chirp pulse-based multi-parameter distributed optical fiber sensing system and method, and relates to the technical field of optical fiber sensing, and the system comprises a chirp laser source module and a sensing detection module. The chirp laser source module is used for generating chirp laser and modulating and testing a laser source; the sensing detection module is used for receiving Raman scattering signals and Rayleigh scattering signals generated after square linear chirped pulses of the laser source are injected into the optical fibers, and calculating temperature parameters and strain parameters of the optical fibers by combining the principle that Raman scattering is only sensitive to temperature. A chirped pulse is introduced into an optical fiber to serve as a system light source, and the characteristic that the frequency of the chirped pulse linearly changes along with time and the change of the optical path difference between scattering centers caused by the uniform refractive index change # imgabs0 # can be compensated through the pulse frequency change # imgabs1 # is utilized, so that rapid co-location / ectopic synchronous measurement of a plurality of parameters along the optical fiber is realized. Especially, temperature and strain measurement is realized.

Techniques for detecting an impedance-based fault on a wire carrying power in a power delivery system. The techniques involve applying power to a wire of a power delivery system and applying onto the wire a chirp pulse comprising a sequence of waveforms of a plurality of frequencies. A signal is obtained from the wire. An impedance of the signal is analyzed at two or more frequencies of the plurality of frequencies with respect to a reference impedance to determine whether there is an indication of an impedance-based fault associated on the wire, such as a human touching the wire. The power to the wire is disconnected in response to determining an indication of the impedance-based fault.

The invention discloses a broadband spectrum all-fiber femtosecond laser system based on chirped pulse amplification and an adjusting method of the broadband spectrum all-fiber femtosecond laser system. The broadband spectrum all-fiber femtosecond laser system comprises a broadband spectrum dissipative soliton mode-locked fiber laser and an all-fiber chirped pulse amplifier which are connected. The broadband spectrum dissipative soliton mode-locked fiber laser comprises a first pumping source, a first wavelength division multiplexer, a first gain fiber, a first polarization controller, a polarization dependent isolator, a second polarization controller and a coupler. The all-fiber chirped pulse amplifier comprises a first polarization independent isolator, a dispersion compensation fiber, a second wavelength division multiplexer, a second gain fiber, a third wavelength division multiplexer, a single-mode fiber, a second polarization independent isolator, a second pumping source and a third pumping source. The system realizes the wide spectrum characteristic through the optical fiber length adjusting module, the spectrum adjusting module and the fine adjusting module. The device is simple in structure, wide in application scene, not prone to pulse distortion, wide in spectrum and high in anti-interference capacity.

The invention discloses an SSVEP (Steady-State Visual Evoked Potential) recognition system and method based on linear frequency modulation visual evoked potential migration. The visual stimulation generation and presentation module generates and presents a visual stimulation signal; the electroencephalogram signal acquisition module is used for acquiring Chirp-VEP and SSVEP electroencephalogram signals; the electroencephalogram signal preprocessing module is used for preprocessing the collected electroencephalogram signals; the Chirp pulse matrix construction module is used for converting a Chirp signal to obtain a Chirp pulse matrix, the Chirp-VEP decomposition module is used for constructing a least square optimization problem to solve common model parameters of Chirp-VEP, and the common model parameters are migrated to SSVEP through the SSVEP identification module to carry out feature extraction and classification. According to the method, the system overhead is reduced, the calibration time is shortened, the training cost is minimized while the optimal performance is kept, and the practicability of the brain-computer interface based on SSVEP is improved.

The invention discloses an ultrafast coherent modulation imaging device based on chirped pulse illumination, which can collect evolution information of intensity and phase along with time change in an ultrafast dynamic scene under the condition of single exposure. The device encodes an ultrafast scene by using the spectrum-time mapping characteristic of chirped pulses, realizes phase encoding through random phase modulation, then acquires an encoded diffraction pattern through a snapshot hyperspectral camera, and finally recovers space-time complex amplitude information of the ultrafast dynamic scene through a phase retrieval algorithm. The invention provides an imaging device capable of obtaining dozens of ultrafast time resolution complex amplitude images in single exposure, and the imaging dimension and the time resolution capability are remarkably improved. The device and method provided by the invention provide a new technical path for researching the ultrafast dynamic process, and have certain scientific research application potential and engineering popularization value.

The invention belongs to the field of vibration monitoring, and particularly relates to an optical fiber vibration sensing method and system based on chirped pulse input and phi-OTDR sensing, long-distance optical fiber vibration detection can be effectively carried out by adopting a phi-OTDR technology, and particularly, extra arrangement or installation of a plurality of sensors for sensing optical fibers is not needed in a large-range area. The frequency and phase adjustment of the chirped pulse enables the signal to be transmitted farther, and the reflected signal can maintain enough strength for accurate vibration detection. By adjusting the frequency and the phase of the chirped pulse signal, the sensing signal can be more accurately controlled at different frequencies and time points, and the fine control improves the identification capability of the optical fiber vibration position, so that the vibration source in the optical fiber can be more accurately positioned, and the accuracy of the optical fiber vibration position is improved. And a relatively high spatial resolution can be maintained in a long distance.

The invention provides a mid-infrared optical frequency comb. The mid-infrared optical frequency comb comprises a near-infrared optical frequency comb seed source of a polarization-maintaining all-fiber structure; the all-fiber nonlinear amplification and pulse compression module is connected with the near-infrared optical frequency comb seed source through a polarization maintaining fiber and is used for amplifying the power of the seed light and compressing the pulse width after generating a linear chirped pulse; the all-fiber nonlinear spectrum broadening module is connected with the all-fiber nonlinear amplification and pulse compression module through a polarization maintaining fiber and is used for broadening a laser spectrum; the difference frequency module is used for receiving the laser pulse processed by the all-fiber nonlinear spectrum broadening module and generating an intermediate infrared laser pulse through intra-pulse self-difference frequency; wherein the seed source, the all-fiber nonlinear amplification and pulse compression module and the all-fiber nonlinear spectrum broadening module are connected through a polarization maintaining fiber to form an all-fiber integrated structure. By adopting the scheme, the anti-interference capability of the system can be enhanced, miniaturization and high operation reliability are realized, the debugging process is simplified, and the difference frequency efficiency is improved.

The invention relates to the technical field of digital-to-analog conversion, in particular to a large-dispersion compact chirped pulse time domain compression method, which comprises the following steps of: projecting a broadened chirped pulse to a first grating in an inclined incidence mode, and moving adjacent back and forth diffraction spots point by point in a direction parallel to a grating scribed line; the first grating and the second grating are oppositely arranged in parallel to form a double-grating group; controlling the chirped pulse to perform multiple back-and-forth diffraction between the first grating and the second grating to obtain a preset large dispersion amount; an angular dispersion steering module is arranged on a back-and-forth diffraction light path of the chirped pulse, and vertical angular dispersion introduced due to oblique incidence is turned into horizontal angular dispersion. An angular dispersion compensation module is arranged on a light path before the chirped pulse is output, and the angular dispersion accumulated by multiple back-and-forth diffraction is offset and compensated. According to the method, on one hand, the dispersion amount several times that of a traditional pulse time domain compressor can be obtained, on the other hand, the compact design of the structure of the compressor can be achieved, and the method has important engineering application value.

The invention discloses a chirped pulse Fourier transform microwave spectrometer and a detection method, and belongs to the technical field of microwave spectrums.The chirped pulse Fourier transform microwave spectrometer comprises a pulse sample introduction and reactant in-situ generation system, a segmented chirped pulse generation and radiation system, a signal detection and high-speed acquisition system, a synchronous time sequence control system and a signal processing and automatic acquisition assembly. According to the chirped pulse Fourier transform microwave spectrometer and the detection method, 18-40 GHz continuous broadband coverage is realized through a segmented chirped pulse sequence, and a pulse discharge sampling system is integrated, so that high-reaction-activity intermediates and molecular clusters thereof can be generated and directly detected in situ; the technical blank of a broadband high-sensitivity microwave spectrometer with the frequency band of 18-40 GHz is filled, and a powerful tool is provided for research on structures and reaction kinetics of key transient species in atmospheric chemistry, combustion chemistry and celestial chemistry.

A system and method for distributed temperature and strain sensing using Chirp-Pulse Coherent Optical Time-Domain Reflectometry (CP-COTDR) utilizes optical flow processing. The method involves constructing a two-dimensional (2-D) waterfall data array from collected CP-COTDR frames. Optical flow processing is applied directly to the 2-D data to estimate the local shift of features caused by external perturbations. The optical flow is preferably calculated using a weighted least squares method with an adaptive analysis window based on the local flatness of signal derivatives. This approach provides versatile and high spatial resolution, reduces accumulative errors, and enables efficient data processing compared to conventional cross-correlation techniques.

The application provides an X-ray ultrafast imaging system and method based on radiation conversion and spectral filtering, which solves the problems of poor universality, low time resolution or limited number of frames in existing X-ray ultrafast imaging technology. The system comprises an X-ray coupling module for coupling target X-ray signals to image on a semiconductor chip module, a semiconductor chip module for converting the X-ray intensity space-time distribution into the chip refractive index space-time distribution, a chirped pulse light generation module, a chirped pulse light coupling module for irradiating linear chirped pulse light generated by the chirped pulse light generation module to the semiconductor chip module and coupling the pulse light reflected by the semiconductor chip module into a phase extraction module, the phase extraction module, a spectral filtering frame reading module for imaging the linear chirped light intensity space-time distribution signal output by the phase extraction module into the data acquisition module, the data acquisition module and an image processing module for processing the image output by the data acquisition module.

Described are techniques for interleaving range and Doppler radar processing. A data cube is memory accessed differently, from one look period to the next, which allows Doppler processing for a current look period to happen in parallel with range processing for a next look period. Range processing for a first look period writes to rows of the data cube; Doppler processing reads from and empties its columns. But before Doppler processing can finish, a second look period begins. Rather than re-writing to the rows, range processing in the second look period writes to the columns just emptied by the ongoing Doppler processing. Doppler processing for the first look period is allowed to finish by executing during processing idle times in the second period, e.g., in-between chirps. With better processor utilization, Doppler processing is afforded more time to do its complex operations, while keeping look periods as short as possible.

The invention provides a single-time ultrafast multi-mode time sequence phase imaging device, and relates to the technical field of ultrafast optical imaging and computational optical imaging, and the imaging device comprises a light source system which is used for generating a linearly polarized femtosecond laser pulse; the chirp laser pulse generation system generates a chirp laser pulse based on the femtosecond laser pulse; the pulse shaping system is used for generating a time sequence multi-wavelength sub-pulse based on the chirp laser pulse; and the coherent modulation imaging system performs coherent modulation imaging based on the time sequence multi-wavelength sub-pulses, and realizes single-time ultrafast multi-modal time sequence phase imaging by using a wavelength and modulation coding combined constraint inversion algorithm. After femtosecond laser pulses are converted into chirped pulses, coaxial time sequence multi-wavelength sub-pulses with harmonious time resolution and harmonious sub-pulse number are generated by using a pulse shaping technology.

An off-axis single-grating multi-pass pulse compressor disclosed by the present invention comprises a compression module and at least one group of mirror groups, the mirror groups are used for increasing dispersion compensation of the compression module, and the compression module comprises a D-shaped reflector, a grating, a plane reflector, a first horizontal mirror and a first high-low mirror. Each group of mirror group comprises two mirrors, one mirror of each group of mirror group is located at the laser output end of the compression module, and the other mirror of each group of mirror group is located above the first high-low mirror, or the other mirror of each group of mirror group is located above the second high-low mirror. And the other mirror of each mirror group is positioned on one side of the first high-low mirror and has the same height with the horizontal plane. According to the off-axis single-grating multi-pass pulse compressor, a multi-pass single-grating compressor can be achieved, the total dispersion compensation amount is greatly increased, the advantages of low cost and small size of a transmission-type single-grating compressor can be reserved, and the compression requirement of ultra-large chirped pulses can be met.

The application discloses a kind of mid-infrared discrete time stretching spectrum method, its characteristics are as follows:1) prepare the double-color pulse light source with slightly different repetition frequency;2) the pulse of pulse light source 1 is output wavelength broadening and time stretching for the signal light of nonlinear difference frequency, and the pulse of pulse light source 2 is output power amplification, for the pump light of nonlinear difference frequency;3) the time-domain broadening spectrum optical sampling of signal light by pump light pulse, obtain the pulse sequence of mid-infrared discrete time stretching;4) mid-infrared discrete chirp pulse is measured through low bandwidth mid-infrared detector after passing through the sample to be measured, and absorption spectrum information is obtained.The application has the advantages of wide band, high speed and high resolution compared with prior art, and the measurement of mid-infrared spectrum is completed by means of low bandwidth single-point detector, without dispersion spectrometer element and mechanical scanning device, which solves the problem of lack of time and high dispersion time-domain stretching medium in mid-infrared band, and expands the application of time stretching technology in mid-infrared band.

The embodiment of the present application relates to the technical field of ultra-high-speed imaging, and discloses a framing imaging device, which comprises a chirp spreading element, a diffraction element, a first Fourier lens, a framing element and a second Fourier lens, wherein the chirp spreading element is used for spreading incident light and emitting chirp pulse light; the diffraction element is used for splitting the chirp pulse light into diffraction beams propagating in different directions; the first Fourier lens is used for emitting the incident diffraction beams into central-symmetrical array beams; the framing element is used for framing the array beams into delay beams; and the second Fourier lens is used for converging the delay beams to the same illumination area. The present application also discloses a framing imaging system. The present application solves the technical problem of how to simplify the structure of a conventional framing imaging device under the premise of the same time resolution.

The present invention provides an optical time domain reflectometry system and demodulation method based on gas absorption spectrum frequency compensation. The optical time domain reflectometry system includes: a φ-OTDR system light source, a chirped pulse signal modulation module, a first amplifier, a coupler, a gas chamber, a first detector, a circulator, an optical fiber to be tested, a second amplifier, a filter, and a second detector. The continuous laser signal of the φ-OTDR system light source is converted into a chirped modulated pulse signal by the chirped pulse signal modulation module. One signal of the chirped modulated pulse signal enters the gas chamber, and the first detector obtains the gas absorption spectrum based on the transmission signal of the gas chamber. The other signal enters the second port through the first port and enters the optical fiber to be tested. The optical fiber Rayleigh scattering signal enters the third port through the second port and is amplified by the second amplifier. The scattered signal amplified by the second amplifier is filtered by the filter and then obtained by the second detector. The present invention can solve the technical problem that the existing frequency-sweeping φ-OTDR system is affected by the frequency drift of the light source, resulting in insufficient measurement accuracy.

The invention belongs to the technical field of lasers, and particularly relates to a dynamic dispersion compensation system and method for an intermediate infrared tunable fiber laser, and the system comprises an intermediate infrared ultrashort pulse light source mechanism which is used for outputting negative chirped pulse laser with the wave band of 2.8-4.5 microns; the pulse compression module comprises a transmission grating I and a transmission grating II which are arranged in parallel, an aberration removal structure positioned between the transmission grating I and the transmission grating II, and a roof prism; the negative chirped pulse laser sequentially passes through the first transmission grating, the aberration removing structure and the second transmission grating and then enters the ridge prism, and the negative chirped pulse laser is reflected by the ridge prism to enable the light to sequentially pass through the second transmission grating, the aberration removing structure and the first transmission grating and then outputs near Fourier transform limit pulsed light. The distance between the plane where the first transmission grating is located and the plane where the second transmission grating is located is the grating distance. And the grating distance is adjusted through the distance adjusting part. According to the invention, dynamic dispersion compensation of the mid-infrared band can be realized.

The utility model discloses a chirped pulse compressor without changing the shape of an input light spot. The chirped pulse compressor comprises two diffraction gratings which are parallel to each other and a light path vertical lifter, the two diffraction gratings are respectively a diffraction grating A and a diffraction grating B; after incident light enters the diffraction grating A, the incident light is diffracted to the diffraction grating B; the diffracted light beam is diffracted by the diffraction grating B and then enters the light path vertical lifter, and the light path vertical lifter enables the emergent light of the diffraction grating B to change the height and then return in parallel to the original light path at different heights. According to the utility model, the two reflectors are utilized to form a light path vertical lifter, so that the shape and polarization of an input pulse light spot do not change at all after passing through the compressor.

The invention provides a broadband response distributed sound wave sensing method and device, and relates to the technical field of optical fiber sensing. Single-frequency continuous light beams are split, double-sideband frequency sweep modulation is performed on a first path to generate double-sideband frequency sweep light, short-pulse-width chirped pulse light and long-pulse-width chirped pulse light are obtained through frequency band selection and pulse interception, and the short-pulse-width chirped pulse light and the long-pulse-width chirped pulse light are synthesized and injected into a sensing optical fiber; backward Rayleigh scattering light signals are collected, long-pulse-width and short-pulse-width Rayleigh scattering light signals are separated through optical filtering, and spontaneous emission noise is suppressed and amplified; coherent beat frequency detection and phase demodulation are carried out on the long-pulse-width Rayleigh scattering light signal, spectrum correlation processing is carried out on the short-pulse-width Rayleigh scattering light signal to obtain time offset, disturbance information recovery is achieved, and a sound wave measurement result distributed along the sensing optical fiber is output.

The invention provides a near self-similarity amplification flat light frequency comb based on a rare earth doped gain nonlinear optical waveguide, and belongs to the technical field of light frequency combs. A pulse light source generates a light frequency comb seed light source; the pulse compression unit is used for compressing chirped pulses of the optical pulses; the pulse shaping unit is used for shaping the compressed pulse; according to the normal dispersion rare earth doped nonlinear optical waveguide amplifier, rare earth doped ions are injected / doped into a normal dispersion nonlinear optical waveguide, and the waveguide amplifier is formed under the pumping action of pumping laser with the corresponding proper wavelength. The near self-similar amplification process evolution of the light pulse is realized in the normal dispersion rare earth doped nonlinear optical waveguide amplifier based on the combined action of normal dispersion, gain, self-phase modulation and light wave splitting. The near self-similarity amplification evolution process of the light pulse in the normal dispersion rare earth doped nonlinear optical waveguide amplifier is utilized, and the performance of the output light frequency comb in the aspects of flatness and flat bandwidth can be effectively improved.

A method for performing magnetic resonance imaging is provided. The method includes providing a magnetic resonance imaging system comprising: a radio frequency receive system comprising a radio frequency receive coil, and a housing, wherein the housing comprises a permanent magnet for providing an inhomogeneous permanent gradient field, a radio frequency transmit system, and a single-sided gradient coil set. The method also includes placing the receive coil proximate a target subject; applying a sequence of chirped pulses via the transmit system; applying a multi-slice excitation along the inhomogeneous permanent gradient field; applying a plurality of gradient pulses via the gradient coil set orthogonal to the inhomogeneous permanent gradient field; acquiring a signal of the target subject via the receive system, wherein the signal comprises at least two chirped pulses; and forming a magnetic resonance image of the target subject.

The invention discloses a distributed chirped pulse dispersion regulation and control system, and the system employs the characteristic that second-order dispersion symbols of different types of dispersion regulation and control devices are different, and carries out the excessive broadening of a near Fourier transform limit pulse through second-order positive dispersion. Second-order negative dispersion is used for partially compensating the second-order dispersion of the excessively broadened seed light before pulse amplification, and then a negative dispersion compressor is used for further performing dispersion regulation and control on the amplified pulse after amplification, so that the broadening amount of the seed light can be continuously adjusted, and the requirement of accurate dispersion compensation of the system is met. According to the scheme, the broadening amount can be flexibly adjusted, meanwhile, the broadening device can be matched with the dispersion of the compressor, and a brand new technical path is provided for fully extracting medium stored energy and achieving accurate dispersion regulation and control.

The invention relates to the technical field of femtosecond pulse measurement, in particular to a dispersion scanning pulse self-measurement method based on a chirped pulse amplification laser, which comprises the following steps of: jointly using a stretcher and a compressor which are arranged in the laser as a dispersion scanning system, and adopting a dispersion scanning coordination strategy; continuously adjusting the dispersion amount of the stretcher and the dispersion amount of the compressor, synchronously collecting second harmonic spectrum signals under different dispersion distribution combinations, and constructing a second harmonic spectrum track diagram; according to the method, an adaptive dispersion coupling phase reconstruction algorithm is adopted, iteration processing is conducted on a second harmonic frequency spectrum track diagram, a high-order dispersion compensation item is introduced for optimization, the time domain intensity and phase information of laser pulses are reconstructed, the optimal dispersion compensation amount is determined, and the narrowest pulse width value is output. Therefore, the precision of pulse phase and width measurement and the convergence speed of the algorithm are improved.

The present invention belongs to the field of laser ranging, and specifically relates to an absolute distance measurement method and device based on optical frequency comb chirped pulse interferometry. The method comprises: using an optical frequency comb to generate and split pulsed lasers; using one of the beams as signal light to generate reference light and measurement light, with a time delay between the two corresponding to the absolute distance to be measured; widening the other beam as local oscillator light, which interferes with the reference light and measurement light, respectively, to generate two interference pulses; widening the two interference pulses, and using a high-speed photodetector and a high-speed oscilloscope to collect information about the widened two interference pulses in real time; wherein the pulse width of the local oscillator light satisfies that the reference light and measurement light can interfere with the local oscillator light at any position; and subtracting the spectral phases of the two sets of chirped pulse interference fringe information to calculate the absolute distance to be measured. The present invention can achieve rapid absolute distance measurement along the entire path without blind spots.

Techniques for detecting an impedance-based fault on a wire carrying power in a power delivery system. The techniques involve applying power to a wire of a power delivery system and applying onto the wire a chirp pulse comprising a sequence of waveforms of a plurality of frequencies. A signal is obtained from the wire. An impedance of the signal is analyzed at two or more frequencies of the plurality of frequencies with respect to a reference impedance to determine whether there is an indication of an impedance-based fault associated on the wire, such as a human touching the wire. The power to the wire is disconnected in response to determining an indication of the impedance-based fault.

Single-sided MRI scanners, systems, and methods are disclosed. A method can include applying a first sweeping frequency pulse defining an X axis; applying a second sweeping frequency pulse defining a Y axis; applying a third sweeping frequency pulse defining the Y axis; and applying a fourth sweeping frequency pulse defines a −X axis. The sweep rate of the fourth sweeping frequency pulse can be less than the sweep rate of the third and / or second sweeping frequency pulse. The sweeping frequency pulses can be chirp pulses. Frequency sweep DEFT pulse sequences can provide the benefits of a broader bandwidth and less sensitivity to the inhomogeneity of a single-sided MRI scanner.

The present application provides a downward-looking three-dimensional terrain imaging radar system, comprising: an array antenna, a radio frequency and beam control device, a signal processing device, and an integrated display and control device; the signal processing device generates a chirp pulse signal, the radio frequency and beam control device performs digital-to-analog conversion, filtering, phase shifting, and amplification on the signal, the array antenna performs beam synthesis on it, generates a radar signal and transmits it to the target scene; the array antenna is further used to receive the radar echo signal returned from the target scene, the radio frequency and beam control device performs filtering, amplification, phase shifting, and beam synthesis on the radar echo signal, the signal processing device performs analog-to-digital conversion, pulse compression, synthetic aperture, real aperture super-resolution, and interference processing on it, and generates a three-dimensional topographic map directly below the flight platform; the present application generates a three-dimensional topographic map directly below the radar through real aperture super-resolution processing of the radar echo signal.