CN117805854B - MIMO-based laser SAL wide-field imaging device and method - Google Patents
MIMO-based laser SAL wide-field imaging device and method Download PDFInfo
- Publication number
- CN117805854B CN117805854B CN202410236266.XA CN202410236266A CN117805854B CN 117805854 B CN117805854 B CN 117805854B CN 202410236266 A CN202410236266 A CN 202410236266A CN 117805854 B CN117805854 B CN 117805854B
- Authority
- CN
- China
- Prior art keywords
- array
- transmitting
- field
- mimo
- laser
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000003384 imaging method Methods 0.000 title claims abstract description 35
- 238000000034 method Methods 0.000 title claims abstract description 10
- 238000001514 detection method Methods 0.000 claims abstract description 19
- 239000013307 optical fiber Substances 0.000 claims description 16
- 238000003491 array Methods 0.000 claims description 7
- 230000002194 synthesizing effect Effects 0.000 claims description 3
- 238000013507 mapping Methods 0.000 description 13
- 239000000835 fiber Substances 0.000 description 8
- 238000012545 processing Methods 0.000 description 7
- 238000004088 simulation Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 3
- 238000002592 echocardiography Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 230000003044 adaptive effect Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004422 calculation algorithm Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 230000035800 maturation Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Landscapes
- Optical Radar Systems And Details Thereof (AREA)
- Variable-Direction Aerials And Aerial Arrays (AREA)
Abstract
The invention provides a laser SAL wide-view-field imaging device and method based on MIMO, which belong to the field of wide-view-field imaging of synthetic aperture laser radar, and solve the problems of wide-view-field and long-distance detection of laser by using a microwave multi-input multi-output synthetic aperture radar SAR technology. The invention adopts the MIMO array synthetic aperture laser radar technology, and a plurality of channels simultaneously transmit and receive mutually separable transmitting waveforms to finish the imaging of the synthetic aperture laser radar.
Description
Technical Field
The invention belongs to the field of wide-field imaging of synthetic aperture laser radar (SYNTHETIC APERTURE LADAR, SAL), and particularly relates to a laser SAL wide-field imaging device and method based on Multiple-Input-Multiple-output (MIMO).
Background
In 2000, with the maturation of laser technology and synthetic aperture technology, the trend of research on synthetic aperture lidar imaging has been raised both at home and abroad. At present, the research on the laser SAL is mainly a single-shot SAL system, and as an ideal mode of long-distance high-resolution observation, the laser SAL technology is developed towards the directions of higher resolution, longer acting distance and larger mapping breadth.
In the traditional single-shot SAL system, the laser divergence angle commonly used in long-distance detection is smaller, and the contradiction between the distance mapping bandwidth and the azimuth resolution is unavoidable, so that the application of the laser SAL technology is limited. There are two main reasons for the narrowing of the distance to the swath:
The first, the laser wavelength is short, the wave beam is narrow, the distance of the laser SAL is influenced by the system distance to the wave beam width, increasing the wave beam width can increase the width of the surveying and mapping band, and meanwhile, the detection distance can be reduced, namely, the contradiction between the divergence angle and the detection distance exists, and the long-distance wide surveying and mapping band is difficult to realize;
second, the contradiction between range-wise mapping bandwidth and azimuth resolution arises from their different requirements on the system pulse repetition frequency (pulse repeat frequency, PRF). When the single-shot laser SAL system is used for observing in the azimuth direction with high resolution, the distance direction mapping bandwidth can be limited to a certain range.
In order to solve the first problem, a multiple optical fiber array is used as a light source in a transmitting and receiving antenna, and the number of array elements in a distance direction is increased, for example, the problem group Tang Yu of the electronic technology university of western security adopts the distance direction multiple receiving and multiple transmitting to realize a distance direction wide mapping zone. For the second reason, the Tang Yu subject group adopts azimuth multiple-input multiple-output to increase azimuth divergence angle, and realizes high azimuth resolution imaging of the synthetic aperture laser radar, and the two schemes theoretically solve the problems of azimuth high resolution and range width, but consider that the diameter of an outgoing fiber core of a common light source is 10 μm, the diameter of a cladding is 127 μm, the minimum interval of an optical fiber array is 127 μm, the filling factor between array elements is 10/127, the filling factor is defined as the ratio of the diameter of the array elements to the spacing of the array elements, and for the range multiple SAL, the array light source is imaged into a plurality of separated imaging areas in a far field, and the continuous expansion of a mapping band is difficult to realize. For the above-mentioned azimuth multiple-input multiple-output synthetic aperture laser radar, the azimuth array light source is imaged into a plurality of separated imaging areas in the far field, and it is difficult to continuously increase the azimuth beam width.
Disclosure of Invention
Aiming at the problems, the invention provides a laser SAL wide-field imaging device and method based on MIMO, which are used for solving the contradiction between divergence angle and detection distance by referring to microwave MIMO SAR technology, providing a multi-receiving array laser SAL, constructing an optical small-caliber micro-lens array, realizing a wide field through a small caliber, increasing the energy of a light field in the field by adopting the micro-lens array on the basis of the wide field, improving the detection distance, forming equivalent phase center signals at different positions by utilizing the combination of different receiving and transmitting channels, and meeting the application requirements of laser SAL imaging of a high-resolution wide mapping band.
In order to achieve the above purpose, the invention adopts the following technical scheme:
A laser SAL wide-field imaging device based on MIMO comprises 16 array transceiver devices with azimuth direction of 4 columns and distance direction of 4 rows, a MIMO mode is formed among the array transceiver devices, and the array transceiver devices comprise a transmitting system and a receiving system; the emission system comprises a laser source, a modulation module, an optical amplification module, an emission optical fiber array and a micro lens array; the receiving system comprises an array detection unit and an array acquisition imaging processing unit; the transmitting optical fiber array and the micro lens array form a transmitting array, and the array detection unit forms a receiving array; each emission optical fiber array is used for emitting laser beams, and the emitted laser beams are collimated and irradiated to a far field through the micro lens array so as to obtain larger mapping bandwidth; the echo signals enter the array detection unit and then enter the array acquisition imaging processing unit to carry out array acquisition imaging processing.
The invention also provides a laser SAL wide-field imaging method based on MIMO, which comprises the following steps:
step 1), designing the azimuth and the range divergence angle of an emitted light beam according to the requirements of resolution and breadth in laser SAL application;
step 2) determining the number of the multi-transmission multi-reception arrays in the azimuth direction and the distance direction based on a radar equation according to the detection distance requirement, and designing a micro lens array corresponding to the transmitting optical fiber array to form the multi-transmission multi-reception array;
Step 3) assuming a multi-transmitting and multi-receiving array with a micro lens array to be a two-dimensional array, wherein each transmitting optical fiber of a transmitting system and a corresponding micro lens are one transmitting array element, and synthesizing the transmitting array elements through the micro lens array to obtain near-field light beam amplitude;
step 4) regarding the far-field light intensity distribution as Fourier transform of an output light field of the micro-lens array, thereby obtaining field distribution formed by emergent light of the multiple-input multiple-output array in a far field;
And 5) when different arrangement modes are calculated, obtaining the optimal arrangement modes of the transmitting position and the receiving position of the multiple-input multiple-output array according to the field distribution formed by the emergent light of the multiple-input multiple-output array in the far field and the far field facula energy distribution.
The beneficial effects are that:
(1) The invention realizes a large imaging view field by using a small caliber distribution mode of azimuth and distance direction arrays.
(2) Based on the small-caliber lens, the beam combination mode of the array transmitting unit is utilized to improve the energy distribution in the field of view, and the long-distance wide detection is realized.
(3) The invention utilizes a plurality of arrays to transmit and receive waveforms which are mutually separable, and simulates and designs an array transmitting system according to the arrangement technology of the existing micro lens array to generate an imaging transmitting and receiving device with high main lobe energy.
Drawings
FIG. 1 is a schematic diagram of a laser SAL wide field imaging device based on MIMO according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an emission fiber and corresponding microlens arrangement;
FIG. 3 is a graph showing a distribution of laser SAL two-dimensional 4×4 emission array and far-field flare;
FIG. 4a is a graph of the far field beam profile of an equally spaced multiple-input multiple-output array;
FIG. 4b is a graph showing the intensity distribution of the far field beam of the equally spaced multiple-input multiple-output array;
FIG. 5a is a diagram of a far field spot profile of an optimized MIMO sparse array;
Fig. 5b is a graph of the intensity distribution of the far field light spots of the optimized MIMO sparse array.
Detailed Description
The invention adopts a two-dimensional array multi-transmission and multi-reception mode to realize laser SAL high-resolution wide-view field imaging, and simultaneously utilizes an optimization algorithm to design multi-transmission and multi-reception array element arrangement so as to realize high main lobe energy and low side lobe energy; and each receiving detector receives echo data at the same time, adopts a corresponding waveform separation method (such as a matched filtering method when transmitting the same-frequency orthogonal waveforms) according to different transmitting waveforms, separates the echoes of different transmitting waveforms to obtain echoes of different transceiving combinations, and then carries out coherent imaging processing on the echoes of all the transceiving combinations. Meanwhile, the invention adopts a theoretical simulation method to verify the effectiveness of the device.
The present invention will be described in further detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
According to an embodiment of the present invention, as shown in fig. 1, there is provided a MIMO-based laser SAL wide field imaging apparatus, including a transmitting system and a receiving system, wherein the transmitting system includes a laser source, a modulating module, an optical amplifying module, a transmitting fiber array, a microlens array, and the like. The echo signals enter a receiving system and are optically coupled with the intrinsic light, and the receiving system comprises an array detection unit, an array acquisition imaging processing unit and the like. The transmitting optical fiber array and the micro lens array form a transmitting array, and the receiving array comprises an array detection unit. The emitting fiber array is collimated by the micro lens array and irradiates to the far field. Each emission optical fiber array is used for emitting laser beams, and the emitted laser beams are collimated and irradiated to a far field through the micro lens array so as to obtain a large mapping bandwidth; the echo signals enter an array detection unit, and the detection output signals are subjected to array acquisition imaging processing.
According to the requirements of high resolution and breadth of the laser SAL azimuth, the azimuth and the distance divergence angle of the transmitting array are designed, and the number of the azimuth and the distance multi-transmitting multi-receiving array is determined. The laser SAL wide-field imaging method based on MIMO comprises the following steps:
step 1) based on the current requirement of laser SAL on the width, setting the width to be 56.7m when 3km, calculating to obtain the divergence angle of 0.0189rad emitted by the system, selecting the fiber core diameter of a single output light source to be 10 mu m according to the fiber parameters of a common laser, and adopting an emitting fiber array to output laser beams to form a multi-emission multi-reception MIMO emission array, wherein the numerical aperture NA of the fiber is=0.12.
Step 2) determining the multi-transmission array arrangement mode of azimuth direction (route direction) and distance direction (oblique distance direction) based on radar equation and the divergence angle of the array emission light beams according to the requirement of 3km detection distance, wherein the multi-transmission array arrangement mode is as followsFor the above emitting optical fiber array, a microlens array corresponding to the emitting array is designed, the diameter of the microlens is 127 μm, the focal length is 529 μm, and the distance is 254 μm, as shown in fig. 2, the emitting optical fiber array is placed at the focal plane position of the microlens array in a one-to-one correspondence, and is fixed, the emitting optical fiber and the microlens corresponding to the front face thereof are one emitting array element, and the divergence angle θ Single sheet of a single emitting array element after passing through the microlens array is 0.0189rad, wherein/>F is the focal length of the microlens and d is the aperture diameter of the transmitting array element. Adopting an inter-array beam combining mode of MIMO, wherein the divergence angle of the multi-transmission and multi-reception array beam combining laser SAL is/>。
On the basis of large divergence angle of single aperture, the beam combining mode between arrays can improve the energy in the field of view, increase the detection distance and the mapping breadth, and improve the resolution of the azimuth direction of the array laser SAL. In order to make the azimuth direction not have Doppler blurring, the pulse repetition frequency PRF of the single-shot single-received laser SAL satisfies the inequality/>，/>Is the speed at which the imaging device is operated in the azimuth direction. In order to prevent the range ambiguity during imaging, the echo signals in the swath need to be received by the antenna in the same pulse repetition period, i.e. the range mapping bandwidth/>C is the speed of light.
Step 3) as shown in FIG. 3, it is assumed that the emission system with microlens array is a two-dimensional array with array elements of the numberM is the number of azimuth arrays, N is the number of distance arrays, the coordinates of the (M, N) th array element are (x m,yn), and the initial phase of each array element is/>The axial amplitude of the array element is/>Beam propagation direction angle/>, for coordinates of far-field planeTo show that each array element is approximately a gaussian beam, and the near-field beam amplitude U (x, y) obtained by synthesizing the array of microlenses is:
（1）
Where i is an imaginary number, ω=63.5 μm is a spot radius of each transmitting array element after passing through the microlens array, exp () is an exponential operation, and (x, y) represents coordinates of the transmitting array element.
Step 4) based on the theory of multiple emission and multiple reception, the far-field light intensity distribution can be regarded as Fourier transform of the light field output by the micro-lens array, and the field distribution formed by the emergent light of the multiple emission and multiple reception array in the far fieldExpressed as:
（2）
Far field light intensity distribution Can be expressed as:
（3）
the above is simplified to formula (4):
（4）
Wherein, Is referred to as proportional,/>, />, />Wherein/>Representing the (m, n) th transmitting array element initial phase in the x direction component,/>Indicating that the initial phase of the (m, n) th transmitting array element is in the y-direction component.
And (4) calculating far-field light spot energy distribution according to the formula (4).
And 5) calculating far-field light spot energy distribution, total far-field light field energy distribution I Total (S) , main lobe energy distribution I Main unit and side lobe energy distribution I Side by side in different arrangement modes.
In order to achieve the maximum energy concentration of the far-field main lobe after beam combination and inhibit grating lobes, an evaluation function is set；
Wherein the main lobe energy concentration of the array beamWherein/>The light field intensity representation in the polar coordinate system is (r, z, theta) the coordinate representation in the corresponding polar coordinate system, and omega is the light spot radius.
Contrast of grating lobe characteristics; Wherein I max is the ratio of the energy of the far-field main lobe to the total energy, and k 1 is the weighted value of the main lobe characteristics; c max is the contrast of the main lobe and the maximum grating lobe, i.e. the energy of the far-field main lobe minus the energy of the maximum grating lobe to the energy of the main lobe, and k 2 is the weighted value of grating lobe suppression. And optimizing the array element spacing by taking the inhibition grating lobes as an adaptive function based on an evaluation function k 1=0,k2 =1 to obtain a position arrangement method of the array transmitting device.
In a uniform linear array, the intervals between adjacent array elements are the same, the same position difference can generate the same phase difference, and grating lobes can be generated in an equidistant array mode. Based on this, a sparse MIMO system is proposed, whereby the maximum radar effective aperture is obtained. The following is the process and results of simulation verification of the transmit array.
According to the requirement of the current application, the laser SAL is designed to have the azimuth resolution of millimeter and the breadth of 56.7m when imaging at the detection distance of 3 km. Consider a single array with a divergence angle of 0.0189rad, a spot diameter of 127 μm after microlens collimation, and an array element pitch of 254 μm. According to the parameter, according to the azimuth resolution calculation formulaThe azimuth resolution ρ=0.041 mm of a single array element, calculated according to PRF equation/>，/>Is the running speed. Prf= 1219.5KHz at this point, the swath was 56.7m at 3km probe distance.
Under the condition of not increasing pulse repetition frequency PRF, 4 array units are arranged in the azimuth direction under the condition of array MIMO beam combination; the light field energy of the imaging region is improved under the condition that 4 array units are arranged in the distance direction, the azimuth divergence angle is kept to be 18.9mrad, and the imaging breadth is kept to be 56.7 m. According to this requirement, simulations were performed using the parameters in table 1.
TABLE 1
，
Then, the distribution of the far-field light spots of the multi-transmission multi-reception array is simulated, the used parameters are the azimuth direction 4 array elements, the distance is 4 array elements, the wavelength lambda=1.550 mu m, and the radius of the light spots of the array after collimation is 63.5 mu m. The simulation results are shown in fig. 4a and fig. 4b, fig. 4a shows the two-dimensional light field energy distribution of the far field, fig. 4b shows the light intensity distribution of one dimension, then the optimized sparse array is adopted, the position intervals of the two-dimensional array elements are (127 μm, 254 μm, 190 μm), the simulation results show that the two-dimensional light field and the light intensity distribution are as shown in fig. 5a and fig. 5b, and the simulation results show that after optimization, the central main lobe energy concentration is enhanced, and the grating lobe peak energy is suppressed.
The MIMO simultaneously emits mutually separable light beams, after the emitted light beams irradiate a target, the echo signals of multiple channels are respectively received by adopting an array receiving mode, signal energy superposition and imaging processing are carried out, and different receiving and transmitting channels are combined to form equivalent phase centers at different positions, so that the imaging of the synthetic aperture laser radar is completed.
It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (2)
1. The laser SAL wide-field imaging method based on MIMO is characterized by comprising the following steps:
step 1), designing the azimuth and the range divergence angle of an emitted light beam according to the requirements of resolution and breadth in laser SAL application;
Step 2) determining the number of the azimuth and distance multi-transmission multi-reception arrays based on a radar equation according to SAL detection distance requirements, and designing a micro lens array corresponding to the transmitting optical fiber array to form the multi-transmission multi-reception array;
Assuming that the number of the MIMO array in the azimuth direction is M and the number of the MIMO array in the distance direction is N, the number of the MIMO array in the azimuth direction is M N, the diameter of the light spot output by the emitting optical fiber is 10 μm, and the numerical aperture na=0.12; the diameter of the micro lens is 127 mu M, the focal length is 529 mu M, and the arrangement mode of the micro lens array is M/>N array, M/>N transmitting optical fibers are arranged in M/>, correspondinglyThe focal plane positions of the N microlenses are fixed, and the numerical values of M and N are calculated according to a radar equation;
Step 3) assuming a multi-transmitting and multi-receiving array with a micro lens array to be a two-dimensional array, wherein each transmitting optical fiber of a transmitting system and a corresponding micro lens are one transmitting array element, and synthesizing the transmitting array elements through the micro lens array to obtain near-field light beam amplitude;
the number of the transmitting array elements is M The coordinates of the (m, N) th transmitting array element are (x m,yn), and the initial phase of the (m, N) th transmitting array element is/>The axial amplitude of the transmitting array element is A mn, and the coordinate of the far-field plane is the propagation direction angle/>, of the light beamTo show that each transmitting array element is approximately a gaussian beam, and the amplitude of the near-field beam synthesized by the microlens array is denoted as U (x, y), which is expressed as:
（1）
Wherein (m, n) is the coordinate of the m-th array element in the x-axis direction and the n-th array element in the y-axis direction, i is an imaginary number, ω=63.5 μm is the spot radius of each transmitting array element after passing through the microlens array, exp () is an exponential operation, and (x, y) represents the coordinate of the transmitting array element;
Step 4) regarding the far-field light intensity distribution as Fourier transform of the light field output by the micro-lens array, thereby obtaining field distribution formed by emergent light of the multiple-input multiple-output array in a far field;
The field distribution formed by the light emitted by the multiple-input multiple-output array in the far field is recorded as Expressed as:
（2）
where (x, y, z) is the coordinates of the coordinate system of the initial plane, (x ', y ', z ') is the coordinates of the coordinate system of the far field viewing surface, And/>Is the spatial frequency; k=2pi/λ is the wave vector, λ is the laser wavelength, dx, dy represents the integral of the initial plane; θ x represents an x-axis directional tangential distribution, and θ y represents a y-axis directional tangential distribution;
the far field light intensity distribution I (θ x,θy) is expressed as:
（3）
Wherein, The initial phase of the (m, n) th array element is represented, and the above formula is simplified as formula (4):
（4）
wherein, the ratio is proportional to the ratio, ，/>，/>Wherein/>Representing the (m, n) th transmitting array element initial phase in the x direction component,/>Representing the component of the initial phase of the (m, n) th transmitting array element in the y direction;
And 5) when different arrangement modes are calculated, obtaining the optimal arrangement modes of the transmitting position and the receiving position of the multiple-input multiple-output array according to the field distribution formed by the emergent light of the multiple-input multiple-output array in the far field and the far field facula energy distribution.
2. The method according to claim 1, wherein in the step 5), the far-field main lobe energy in the equidistant MIMO array mode and the sparse MIMO array mode is compared to obtain an optimal arrangement mode of the transmitting position and the receiving position of the multiple-input multiple-output array.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410236266.XA CN117805854B (en) | 2024-03-01 | 2024-03-01 | MIMO-based laser SAL wide-field imaging device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410236266.XA CN117805854B (en) | 2024-03-01 | 2024-03-01 | MIMO-based laser SAL wide-field imaging device and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117805854A CN117805854A (en) | 2024-04-02 |
| CN117805854B true CN117805854B (en) | 2024-05-07 |
Family
ID=90422048
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410236266.XA Active CN117805854B (en) | 2024-03-01 | 2024-03-01 | MIMO-based laser SAL wide-field imaging device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117805854B (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8629975B1 (en) * | 2010-08-18 | 2014-01-14 | The United States Of America As Represented By The Secretary Of The Air Force | Apparatus and method for a multiple aperture coherent ladar |
| CN104898127A (en) * | 2015-06-17 | 2015-09-09 | 西安电子科技大学 | Multiple-input multiple-output synthetic aperture ladar system and system design method thereof |
| WO2016196543A1 (en) * | 2015-06-02 | 2016-12-08 | Exciting Technology, Llc | System, method and apparatus for detecting and characterizing ground motion |
| CN107728130A (en) * | 2017-09-14 | 2018-02-23 | 中国科学院上海光学精密机械研究所 | Multi-channel wide Amplitude Composition aperture laser imaging radar receive-transmit system |
| CN110645886A (en) * | 2019-09-30 | 2020-01-03 | 重庆大学 | Ground-based interference virtual aperture deformation monitoring radar system and working method |
| CN112577446A (en) * | 2020-12-23 | 2021-03-30 | 中国科学院西安光学精密机械研究所 | In-place surface shape splicing measuring device and method for large-caliber planar optical element |
| CN113917461A (en) * | 2021-10-21 | 2022-01-11 | 苏州威陌电子信息科技有限公司 | MIMO radar imaging method and system |
-
2024
- 2024-03-01 CN CN202410236266.XA patent/CN117805854B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8629975B1 (en) * | 2010-08-18 | 2014-01-14 | The United States Of America As Represented By The Secretary Of The Air Force | Apparatus and method for a multiple aperture coherent ladar |
| WO2016196543A1 (en) * | 2015-06-02 | 2016-12-08 | Exciting Technology, Llc | System, method and apparatus for detecting and characterizing ground motion |
| CN104898127A (en) * | 2015-06-17 | 2015-09-09 | 西安电子科技大学 | Multiple-input multiple-output synthetic aperture ladar system and system design method thereof |
| CN107728130A (en) * | 2017-09-14 | 2018-02-23 | 中国科学院上海光学精密机械研究所 | Multi-channel wide Amplitude Composition aperture laser imaging radar receive-transmit system |
| CN110645886A (en) * | 2019-09-30 | 2020-01-03 | 重庆大学 | Ground-based interference virtual aperture deformation monitoring radar system and working method |
| CN112577446A (en) * | 2020-12-23 | 2021-03-30 | 中国科学院西安光学精密机械研究所 | In-place surface shape splicing measuring device and method for large-caliber planar optical element |
| CN113917461A (en) * | 2021-10-21 | 2022-01-11 | 苏州威陌电子信息科技有限公司 | MIMO radar imaging method and system |
Non-Patent Citations (3)
| Title |
|---|
| 合成孔径激光雷达光学系统和作用距离分析;李道京 等;雷达学报;20180404(第02期);全文 * |
| 城区地表形变差分TomoSAR监测方法;王爱春;向茂生;汪丙南;;测绘学报;20161215(第12期);全文 * |
| 多通道宽幅度合成孔径激光成像雷达收发装置优化研究;张波;周煜;孙建锋;张国;李光远;许蒙蒙;贺红雨;劳陈哲;;光学学报;20180110(第05期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117805854A (en) | 2024-04-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20190319368A1 (en) | Electromagnetic Phased Array Antenna with Isotropic and Non-Isotropic Radiating Elements | |
| US10838059B2 (en) | Acoustic phased array antenna with isotropic and non-isotropic radiating elements | |
| CN112511209B (en) | Beam control method, system and controller of array antenna based on frequency diversity | |
| US11411324B2 (en) | Phased array antenna with isotropic and non-isotropic radiating and omnidirectional and non-omnidirectional receiving elements | |
| RU2298267C1 (en) | Multibeam active phased antenna array | |
| CN110058218B (en) | Radio frequency stealth emission beam forming method and system based on four-dimensional antenna array | |
| Gao et al. | Impact of frequency increment errors on frequency diverse array MIMO in adaptive beamforming and target localization | |
| US11749909B2 (en) | Phased array antenna with isotropic and non-isotropic radiating and omnidirectional and non-omnidirectional receiving elements | |
| Gao et al. | Study on distributed aperture coherence-synthesizing radar with several experiment results | |
| CN108363058A (en) | Frequency controls the signal parameter design method of battle array imaging radar | |
| CN101329397B (en) | Method and apparatus for rapidly detecting multi-wave beam | |
| CN109061654B (en) | Single-circular-ring-array active three-dimensional positioning method in deep sea environment | |
| CN113656913B (en) | Distributed forward-looking radar geometric configuration optimization design method | |
| CN117805854B (en) | MIMO-based laser SAL wide-field imaging device and method | |
| Tan et al. | Adaptive beamforming using frequency diverse MIMO radar with nonlinear frequency offset | |
| CN110988835B (en) | Distributed coherent radar angle measurement method | |
| CN113064169A (en) | Three-dimensional imaging method for multi-input multi-output frequency diversity array synthetic aperture radar | |
| CN110320499A (en) | MIMO radar beam transmitting beam pattern method based on Subarray partition | |
| CN113820665B (en) | Airspace coverage area enhancement method based on time diversity array subarray division | |
| Khan et al. | Transmit/received beamforming for MIMO log-frequency diverse array radar | |
| CN111352127A (en) | Composite speckle field coherent imaging method and device for inhibiting atmospheric turbulence effect | |
| Youssef et al. | A Simple Method for Equivalent Transmit Beamforming using the Frequency Diverse Array | |
| Vincent et al. | Optimization of gain and return loss of a 2× 6 planar coaxial cavity horn antenna array for MELISSA | |
| CN115877346B (en) | Unmanned aerial vehicle-mounted off-target vector detection method based on two-dimensional phased array radar | |
| US20240142623A1 (en) | Doppler processing in coherent lidar |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |