CN110308445B - Imaging method based on vehicle-mounted digital array frequency modulation continuous wave radar - Google Patents
Imaging method based on vehicle-mounted digital array frequency modulation continuous wave radar Download PDFInfo
- Publication number
- CN110308445B CN110308445B CN201910650565.7A CN201910650565A CN110308445B CN 110308445 B CN110308445 B CN 110308445B CN 201910650565 A CN201910650565 A CN 201910650565A CN 110308445 B CN110308445 B CN 110308445B
- Authority
- CN
- China
- Prior art keywords
- echo
- pixel point
- pixel
- mixing
- distance
- 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
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/93—Radar or analogous systems specially adapted for specific applications for anti-collision purposes
- G01S13/931—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of land vehicles
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
Abstract
The invention relates to the field of radar signal processing, and discloses an imaging method based on a vehicle-mounted digital array frequency modulation continuous wave radar, which comprises the steps of dividing an imaging area of a measured object, and dividing a plurality of pixel points in the area; carrying out frequency mixing processing on echo signals received by a receiving antenna and local oscillation signals transmitted by a transmitting antenna, and carrying out analog-digital conversion on the obtained echo frequency mixing signals; windowing the echo mixing signal; performing range compression on the echo mixing signals; calculating pixel point coordinates of the imaging area, extracting distance direction mixing signals corresponding to the coordinates, and performing azimuth direction compression to obtain energy information of each pixel point; and superposing the energy information of each pixel point, outputting the energy information of the pixel point and forming an image. And the phase is replaced by time delay, so that the method is irrelevant to frequency, and Fresnel approximation is avoided.
Description
Technical Field
The invention relates to the field of radar signal processing, in particular to an imaging method based on a vehicle-mounted digital array frequency modulation continuous wave radar.
Background
The imaging technology of the vehicle-mounted frequency modulation continuous wave radar is a key technology of unmanned driving, the imaging algorithm of the frequency modulation continuous wave radar is mature, and the most commonly used method is to perform distance compression in the distance direction through Fourier transform and then perform Digital Beam Forming (DBF) in the azimuth direction. When the frequency modulation continuous wave radar is a broadband signal, a wide wave beam and an imaging area is a near field, fresnel approximation is no longer true, and Doppler frequency changes in a nonlinear mode, so that the method is no longer applicable.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: aiming at the existing problems, the imaging method based on the vehicle-mounted digital array frequency modulation continuous wave radar is provided, an imaging area is divided into a plurality of pixels, the two-way time delay from each pixel in the area to an antenna array element in the aperture length is calculated, echo signals corresponding to the delay time are extracted for coherent accumulation, and therefore the energy value of each pixel point is obtained, and imaging processing is completed.
The technical scheme adopted by the invention is as follows: an imaging method based on a vehicle-mounted digital array frequency modulation continuous wave radar comprises the following steps:
step 1: dividing an imaging area of a measured object, dividing a plurality of pixel points in the area, and setting pixel point intervals;
and 2, step: to echo signals S received by a receiving antenna k (t) and the local oscillation signal P (t) transmitted by the transmitting antenna are subjected to frequency mixing processing, and the obtained echo frequency mixing signal S bk (t) performing an analog-to-digital conversion;
and step 3: mixing the echo signals S bk (t) performing windowing;
and 4, step 4: mixing the echo signals S bk (t) performing a distance-wise compression;
and 5: calculating pixel point coordinates of the imaging area, extracting distance direction mixing signals corresponding to the coordinates, and performing azimuth direction compression to obtain energy information of each pixel point;
step 6: and superposing the energy information of each pixel point, outputting the energy information of the pixel point and forming an image.
Further, the distance between the pixels in the step 1 is as follows:
where x represents the distance direction, y represents the azimuth direction, c represents the speed of light, and B represents the swept bandwidth.
Further, in step 2, the echo signal and the local oscillator signal are convolved to implement frequency mixing processing, and when the radar uses T, the radar uses T p When the repetition period of (a) continuously transmits the chirp signal, the nth modulation period echo mixing signal model:
wherein R is s Representing the radial distance, R, of the transmitting antenna to the pixel point k Representing the radial distance, f, of a pixel to each receiving antenna s The sampling rate of the analog-to-digital converter is represented, λ represents the wavelength, and v represents the radial velocity of the radar relative to the pixel.
Further, the window function in step 3 is a hamming window, and the length of the window is the number of points sampled in a single continuous wave modulation period.
Further, the step 4 includes:
step 41: carrying out zero filling and interpolation on the windowed echo mixing signals, wherein the zero filling length is an integral multiple of the sampling point;
step 42: and performing Fast Fourier Transform (FFT) on the echo mixing signals after interpolation to realize range direction compression.
Further, the step 5 specifically includes:
step 51: calculating the distance R from the transmitting antenna to the pixel point s And the distance R between the pixel point and each receiving antenna k The distance between R and s +R k ；
step 52: obtaining a Fast Fourier Transform (FFT) data position l corresponding to the pixel point according to the distance and calculation;
step 53: reading FFT data corresponding to the receiving antenna according to the position l;
step 54: performing phase compensation on the read FFT data by the compensation factor of
Step 55: and carrying out coherent superposition on the data compensated by each receiving antenna to obtain the energy information of the pixel point.
Further, the step 5 of the imaging method further includes: for the case of n modulation periods, the signal needs to be Doppler compensated by a compensation factor of
And superposing the compensated signals to obtain the information of the pixel points.
Compared with the prior art, the beneficial effects of adopting the technical scheme are as follows: the concept of phase is replaced by time delay, and the method is irrelevant to frequency, avoids Fresnel approximation and is suitable for vehicle-mounted radar motion imaging.
Drawings
FIG. 1 is a block diagram of a flow chart of an imaging algorithm of the present invention
FIG. 2 is a scene view of the imaging system of the present invention
FIG. 3 is a pixel point division diagram of an imaging region of the present invention
FIG. 4 (a) is a target imaging energy diagram of a conventional DBF algorithm
FIG. 4 (b) is an image energy map of the target for the algorithm of the present invention
FIG. 5 (a) is an imaging diagram of a conventional DBF algorithm
FIG. 5 (b) is an imaging diagram of the algorithm of the present invention
Detailed Description
The invention is further described below with reference to the accompanying drawings.
As shown in fig. 1, an imaging method based on a vehicle-mounted digital array frequency modulated continuous wave radar includes:
step 1: dividing an imaging area of a measured object, dividing a plurality of pixel points in the area, and setting pixel point intervals;
as shown in fig. 2, the transmitting antenna at (0, 0) transmits a local oscillator signal p (t), the number of receiving antenna elements is K, and the kth antenna element is at (0, u) k ) (k =0,1,2.. Said.), a spacing u between adjacent antennas, an imaging area divided into a plurality of pixels t j (x m ,y n ) (j =1,2.. Was.), as shown in fig. 3, the pixel pitch is
Where x represents the distance direction, y represents the azimuth direction, c represents the speed of light, and B represents the swept bandwidth.
Step 2: echo signal S received by receiving antenna k (t) and the local oscillation signal P (t) transmitted by the transmitting antenna are subjected to frequency mixing processing, and the obtained echo frequency mixing signal S bk (t) performing an analog-to-digital conversion;
the local oscillator signal P (t) transmitted by the transmitting antenna is
p(t)＝exp(2πj(f 0 t+μt 2 /2))0＜t＜T p
Wherein, the sweep frequency bandwidth is B, and the modulation period is T p Modulation slope of μ = B/T p Target t j The echo signal arriving at the kth receiving antenna is s k (t)。s k (t) is represented by
s k (t)＝exp(2πj(f 0 (t-τ k (t))+μ(t-τ k (t)) 2 /2))0＜t＜T p
Wherein, tau k (t) delay of echo signal received by kth receiving antenna, and setting pixel t reached by transmitting antenna j Has a radial distance R s Pixel point t j The radial distance between the antenna and the kth receiving array element is R k The radial velocity of the radar relative to the pixel point is v, the velocity is known, the speed of light is c, and the approximation result is obtained
Then the local oscillation signal P (t) and the echo signal s k (t) mixing to obtain
Then can obtain
It can be seen that the mixed signal is still a chirp signal with a start frequency f bk Frequency modulation slope of mu bk 。
When the radar is at T p When the repetition period of the first modulation period continuously transmits the linear frequency modulation signal, the echo frequency mixing signal of the nth modulation period is
Wherein f is s λ represents the wavelength for the sampling rate of the analog-to-digital converter.
And 3, step 3: and windowing the echo signals after frequency mixing, wherein the window function is a Hamming window, and the length of the window is the number of points sampled in a single continuous wave modulation period.
And 4, step 4: compressing the distance direction;
(1) Zero filling and interpolation are carried out on the windowed echo mixing signals, the purpose of zero filling is to more accurately obtain amplitude phase information on the distance of a pixel point, and the length of zero filling is integral multiple of the number of sampling points;
(2) Performing Fast Fourier Transform (FFT) on the interpolated signal to realize distance direction compression;
wherein, f' s M = f 'for interpolated sampling rate' s ×T p And l denotes the corresponding data location.
And 5: azimuthal compression
(1) Calculating the distance R from the transmitting antenna to the pixel point s And the distance R between the pixel point and each receiving antenna k The distance between R and s +R k ；
(2) Obtaining a corresponding FFT data position l according to the distance sum;
(3) Reading FFT data corresponding to the receiving antenna according to the position l;
(4) Performing phase compensation on the read FFT data by the compensation factor of
(5) Carrying out coherent superposition on the data compensated by each receiving antenna to obtain the energy information of the pixel point, carrying out Doppler compensation on the signals aiming at the condition of a plurality of modulation periodic signals, wherein the compensation factor is
And overlapping the compensated data to obtain the energy information of the pixel points.
Step 6: and superposing the energy information of each pixel point, outputting the energy information of the pixel point and forming an image.
As shown in fig. 4 (a), 4 (b), 5 (a), 5 (b), the algorithm of the present invention is compared with the conventional Digital Beam Forming (DBF) algorithm.
Testing parameters: the transmitting signal is a chirp signal, the carrier frequency is 37.5HGz, the signal bandwidth is 500MHz, the modulation period tau =1ms, and the modulation period number is 16. The distance from the radar center to the center of an imaging area is 6 meters, the size of the imaging area is 40 meters long and 6 meters wide, the pixel intervals of the image distance direction and the azimuth direction are both 0.3 meter, the number of receiving antennas is 16 array elements, and the array element interval is 0.004 meter.
When the coordinates of the target are (6.52, -1.53) meters, the test results of the conventional digital beam forming algorithm and the algorithm of the present invention are shown in fig. 4 (a) and 4 (b).
From the comparative tests of fig. 5 (a) and 5 (b), the target imaging coordinates based on the DBF algorithm are (6.58, -2.46) meters, while the target imaging coordinates based on the algorithm of the present invention are (6.49, -1.51) meters. Therefore, the target position measured by the DBF algorithm is seriously distorted, the reason is that Fresnel approximation is no longer true under the near-field condition, and the accurate target position can be obtained by the algorithm.
In order to further analyze and compare the two algorithms, the imaging effects under different target coordinates are respectively tested, and the test results are expressed as follows:
TABLE 1 comparison of imaging results
Therefore, the algorithm of the invention can well realize the digital array radar imaging by calculating the two-way time delay between the pixel point and the antenna array element and extracting the echo mixing signals corresponding to the delay time for coherent accumulation.
The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed. Those skilled in the art to which the invention pertains will appreciate that insubstantial changes or modifications can be made without departing from the spirit of the invention as defined by the appended claims.
Claims (3)
1. An imaging method based on a vehicle-mounted digital array frequency modulation continuous wave radar is characterized by comprising the following steps:
step 1: dividing an imaging area of a measured object, dividing a plurality of pixel points in the area, and setting pixel point intervals;
step 2: echo signal S received by receiving antenna k (t) and the local oscillation signal P (t) transmitted by the transmitting antenna are subjected to frequency mixing processing, and the obtained echo frequency mixing signal S bk (t) performing an analog-to-digital conversion;
the echo signal and the local oscillator signal are convoluted to realize frequency mixing processing, and when the radar uses T p When the repetition period of (a) continuously transmits the chirp signal, the nth modulation period echo mixing signal model:
wherein R is s Indicating the radial distance, R, of the transmitting antenna to the pixel k Representing the radial distance, f, of a pixel to each receiving antenna s Expressing the sampling rate of the analog-digital converter, expressing the wavelength by lambda and expressing the radial speed of the radar relative to the pixel points by v;
and step 3: mixing the analog-to-digital converted echo signals S bk (t) performing windowing;
and 4, step 4: to the echo frequency mixing signal S after the windowing bk (t) performing range compression; the method comprises the following steps:
zero padding and interpolation are carried out on the echo mixing signals after windowing, and the zero padding length is integral multiple of sampling points;
and performing Fast Fourier Transform (FFT) on the echo mixing signals after interpolation to realize distance compression:
wherein f is s ' interpolated sampling rate, M = f s '×T p And l represents the corresponding data location;
and 5: calculating pixel point coordinates of an imaging area, extracting distance direction mixing signals corresponding to the coordinates, and performing azimuth direction compression to obtain energy information of each pixel point; the method comprises the following steps:
calculating the distance R from the transmitting antenna to the pixel point s And the distance R between the pixel point and each receiving antenna k The distance between R and s +R k ；
and obtaining a corresponding FFT data position l according to the distance sum:
and reading FFT data corresponding to the receiving antenna according to the position l:
performing phase compensation on the read FFT data by the compensation factor of
Carrying out coherent superposition on the compensated data of each receiving antenna to obtain the energy information of the pixel point, and carrying out Doppler compensation and compensation on signals according to the condition of a plurality of modulation period signalsFactor is
And superposing the compensated data to obtain the energy information of the pixel points:
step 6: and superposing the energy information of each pixel point, and outputting the energy information of the pixel to form an image.
2. The imaging method based on the vehicle-mounted digital array frequency modulation continuous wave radar as claimed in claim 1, wherein the pixel pitch in the step 1 is as follows:
where x represents the distance direction, y represents the azimuth direction, c represents the speed of light, and B represents the swept bandwidth.
3. The imaging method based on the vehicle-mounted digital array frequency modulation continuous wave radar as claimed in claim 1, wherein the window function in the step 3 is a hamming window, and the length of the window is the number of points sampled by a single continuous wave modulation period.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910650565.7A CN110308445B (en) | 2019-07-18 | 2019-07-18 | Imaging method based on vehicle-mounted digital array frequency modulation continuous wave radar |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910650565.7A CN110308445B (en) | 2019-07-18 | 2019-07-18 | Imaging method based on vehicle-mounted digital array frequency modulation continuous wave radar |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110308445A CN110308445A (en) | 2019-10-08 |
| CN110308445B true CN110308445B (en) | 2022-10-04 |
Family
ID=68080280
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910650565.7A Active CN110308445B (en) | 2019-07-18 | 2019-07-18 | Imaging method based on vehicle-mounted digital array frequency modulation continuous wave radar |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110308445B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111025407B (en) * | 2019-12-26 | 2022-03-04 | 北京遥测技术研究所 | Non-sensing high-flux millimeter wave radar security inspection device and method |
| CN112526458B (en) * | 2020-11-27 | 2022-11-11 | 河海大学 | Broadband NLFM (non-line-of-sight) emission beam forming method based on parameter fraction time delay extraction |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006017651A (en) * | 2004-07-05 | 2006-01-19 | Japan Radio Co Ltd | Fmcw distance measurement apparatus |
| US7170440B1 (en) * | 2005-12-10 | 2007-01-30 | Landray Technology, Inc. | Linear FM radar |
| CN103529444A (en) * | 2013-09-27 | 2014-01-22 | 安徽师范大学 | Vehicle-mounted millimeter-wave radar moving target recognizer and recognition method |
| CN104297730A (en) * | 2014-10-17 | 2015-01-21 | 中国电子科技集团公司第二十九研究所 | Method for obtaining radar clutter image |
| CN106526588A (en) * | 2016-12-02 | 2017-03-22 | 上海无线电设备研究所 | Terahertz active imaging radar system phase compensation method |
| CN109917340A (en) * | 2019-04-25 | 2019-06-21 | 浙江力邦合信智能制动系统股份有限公司 | A kind of MIMO radar waveform modulation-demo-demodulation method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8144052B2 (en) * | 2008-10-15 | 2012-03-27 | California Institute Of Technology | Multi-pixel high-resolution three-dimensional imaging radar |
| US8207887B2 (en) * | 2009-06-19 | 2012-06-26 | The United States Of America As Represented By The Secretary Of The Army | Computationally efficent radar processing method and sytem for SAR and GMTI on a slow moving platform |
-
2019
- 2019-07-18 CN CN201910650565.7A patent/CN110308445B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006017651A (en) * | 2004-07-05 | 2006-01-19 | Japan Radio Co Ltd | Fmcw distance measurement apparatus |
| US7170440B1 (en) * | 2005-12-10 | 2007-01-30 | Landray Technology, Inc. | Linear FM radar |
| CN103529444A (en) * | 2013-09-27 | 2014-01-22 | 安徽师范大学 | Vehicle-mounted millimeter-wave radar moving target recognizer and recognition method |
| CN104297730A (en) * | 2014-10-17 | 2015-01-21 | 中国电子科技集团公司第二十九研究所 | Method for obtaining radar clutter image |
| CN106526588A (en) * | 2016-12-02 | 2017-03-22 | 上海无线电设备研究所 | Terahertz active imaging radar system phase compensation method |
| CN109917340A (en) * | 2019-04-25 | 2019-06-21 | 浙江力邦合信智能制动系统股份有限公司 | A kind of MIMO radar waveform modulation-demo-demodulation method |
Non-Patent Citations (7)
| Title |
|---|
| Radar Target Signal Detection Technology Research;Cheng Jinfeng 等;《2015 INTERNATIONAL CONFERENCE ON COMPUTATIONAL SCIENCE AND ENGINEERING APPLICATIONS》;20151231;全文 * |
| Radar Waveform Recognition based on Deep Residual Network;Yuan Rufang 等;《2015 12th IEEE International Conference on Electronic Measurement & Instruments》;20160620;全文 * |
| Randomized Switched Antenna Array FMCW Radar for Automotive Applications;Chenxi Hu 等;《IEEE Transactions on Vehicular Technology》;20140227;第63卷(第08期);全文 * |
| UWB雷达抗多普勒模糊技术研究;陈国斌 等;《现代电子技术》;20150131;第38卷(第01期);全文 * |
| Wideband 120 GHz to 140 GHz MIMO Radar: System Design and Imaging Results;Spreng Thomas 等;《2015 45TH EUROPEAN MICROWAVE CONFERENCE》;20151231;全文 * |
| 一种多频外辐射源雷达信号相参处理方法;李军 等;《电子学报》;20120330;第39卷(第12期);全文 * |
| 超宽带FMCW雷达高分辨成像技术研究;靳科 等;《中国优秀硕士学位论文全文数据库信息科技辑》;20180615;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110308445A (en) | 2019-10-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108107431B (en) | Rapid implementation method for cylindrical scanning SAR three-dimensional imaging | |
| CN100365429C (en) | Motive target imaging method of synthetic aperture radar | |
| CN101825707B (en) | Monopulse angular measurement method based on Keystone transformation and coherent integration | |
| US7532150B1 (en) | Restoration of signal to noise and spatial aperture in squint angles range migration algorithm for SAR | |
| CN109738894B (en) | High squint multi-angle imaging method for large-field-of-view synthetic aperture radar | |
| CN110927723B (en) | Intelligent monitoring and early warning system and method for millimeter wave radar debris flow | |
| JPWO2007020704A1 (en) | Target detection method and target detection apparatus | |
| CN102707269B (en) | Range walk correction method for airborne radar | |
| CN110187347B (en) | Large-width imaging method of geosynchronous orbit satellite-machine bistatic synthetic aperture radar | |
| CN109581362B (en) | Signal processing method of synthetic aperture radar altimeter in variable pulse cluster mode | |
| CN106093932A (en) | A kind of high-resolution radar scatterometer of scanning beam | |
| CN110308445B (en) | Imaging method based on vehicle-mounted digital array frequency modulation continuous wave radar | |
| US9075142B2 (en) | Device and method for selecting signal, and radar apparatus | |
| CN110879391B (en) | Radar image data set manufacturing method based on electromagnetic simulation and missile-borne echo simulation | |
| CN115128608B (en) | Time domain imaging method for vehicle-mounted Doppler diversity MIMO synthetic aperture radar | |
| CN114545411A (en) | Polar coordinate format multimode high-resolution SAR imaging method based on engineering realization | |
| CN105180852B (en) | GB SAR deformation monitoring methods based on triple steppings | |
| JP2012122743A (en) | Radar device | |
| CN109061648A (en) | Speed based on frequency diversity/range ambiguity resolving radar waveform design method | |
| Meta et al. | Correction of the effects induced by the continuous motion in airborne FMCW SAR | |
| CN109738893A (en) | A kind of biradical synthetic aperture radar echo data generation method and device | |
| CN116500626B (en) | Multi-receiving array element data receiving-transmitting combination conversion method | |
| CN110927724B (en) | Intelligent monitoring system and method for millimeter wave radar debris flow | |
| JP7224292B2 (en) | Radar device and automobile equipped with it | |
| Winarko et al. | Mitigation methods of sawtooth modulations effect on FMCW radar INDERA MX-4 |
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 |