CN106646536A - Method for extracting multipath information of electric wave based on simulation - Google Patents
Method for extracting multipath information of electric wave based on simulation Download PDFInfo
- Publication number
- CN106646536A CN106646536A CN201611178525.XA CN201611178525A CN106646536A CN 106646536 A CN106646536 A CN 106646536A CN 201611178525 A CN201611178525 A CN 201611178525A CN 106646536 A CN106646536 A CN 106646536A
- Authority
- CN
- China
- Prior art keywords
- frequency
- electric field
- multipath
- scattering object
- represent
- 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.)
- Granted
Links
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
- G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
- G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
- G01S19/13—Receivers
- G01S19/22—Multipath-related issues
Landscapes
- Engineering & Computer Science (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Monitoring And Testing Of Transmission In General (AREA)
Abstract
The invention discloses a method for extracting the multipath information of an electric wave based on simulation, and belongs to the field of multipath analysis and electromagnetic simulation. The method comprises the specific steps: firstly simulating the electric field information at two adjacent frequency points f1 and f2 in one electromagnetic environment according a generated multipath scatterer source after a scatterer is removed, and simulating the electric field information when the scatterer exists; secondly calculating the vector difference of the simulation information of the two electric fields, obtaining the amplitudes, directions and phases of multipath signals at the two adjacent frequency points f1 and f2, inputting the amplitudes, directions and phases to a multi-frequency fitting method, and obtaining the time delay of multiple paths relative to a main path; finally extracting the obtained amplitudes and phases of the multipath signals and the time delay of the multiple paths relative to the main path, and calculating a navigation error causes by multiple paths. The multipath signals are calculated through a numerical method, and multiple paths generated by the scatterer in a complex shape can be directly calculated.
Description
Technical field
The invention belongs to multipath analysis and Electromagnetic Simulation field, are related to the processing method of Electric Field Simulation, it is specifically a kind of
Extracting method based on the electric wave multi-path information of emulation.
Background technology
GPS (GNSS) is developed rapidly through semicentennial, it has also become can not be replaced in measurement and navigation
The information source in generation, its range of application has been extended to each corner of human being's production life.The application of GNSS is to satellite navigation system
The performance of system proposes various requirement, wherein the further demand to precision, it is desirable to which we go to inquire into satellite navigation deeper into ground
The impact that the various error sources of system are brought.
Most of common error in satellite ranging such as orbit error, satellite clock error, ionosphere and tropospheric delay etc.
Can substantially eliminate or by model correction, and noise and interference can be reduced using spread spectrum, so, multipath become position and
Topmost error source in tachometric survey.
Because the impact of multipath is depending on receiver environment residing in real time, multipath error is cannot effectively to be disappeared using difference
Remove.As shown in figure 1, due to there is scattering object around antenna, the electric wave that these scattering objects meeting reflecting antennas send forms electricity
Ripple multipath.But often shape is complex for the scattering object of these generation multipaths, it is difficult to carry out electromagnetism calculating by analytic method, therefore
Also it is difficult to find that the real source of multipath.Therefore the method based on emulation is particularly significant for the extraction of multi-path information；And it is current
Business software also rarely has the emulation technology for multipath.
The content of the invention
A kind of blank in order to make up multipath simulation technical field of the invention, it is proposed that electric wave multi-path information based on emulation
Extracting method, comprise the following steps that：
Step one, in two adjacent frequency f of certain electromagnetic environment1With f2, according to the scattering object source for producing multipath, emulation
Electric field information after scattering object is removed；
In two adjacent frequency f1With f2It is interior, f1<f2, removing the electric field information after scattering object includes electric field amplitude and electric field
Phase place.
f1Frequency removes the electric field amplitude after scattering objectFor：
Wherein,Represent in f1Electric field amplitude size and direction after scattering object, θ are removed under frequency00Represent electric field in f1
The phase place after scattering object is removed under frequency,Represent in f1The time-harmonic factor of electric wave under frequency.
f2Frequency removes the electric field amplitude after scattering objectFor：
Wherein,Represent in f2Electric field amplitude size and direction after scattering object, θ are removed under frequency01Represent electric field in f2
The phase place after scattering object is removed under frequency,Represent in f2The time-harmonic factor of electric wave under frequency.
Step 2, emulate two adjacent frequency f1With f2In, the electric field information when there is scattering object；
In two adjacent frequency f1With f2Interior, electric field information when there is scattering object includes the amplitude of electric field and the phase of electric field
Position.
f1There is electric field amplitude during scattering object in frequencyFor：
Wherein,Represent in f1Electric field amplitude size and direction when there is scattering object under frequency, θ0Represent electric field in f1Frequently
There is phase place during scattering object under point；
f2There is electric field amplitude during scattering object in frequencyIt is calculated as follows：
Wherein,Represent in f2Electric field amplitude size and direction when there is scattering object under frequency, θ1Represent electric field in f2Frequently
There is phase place during scattering object under point.
Step 3, according to Electric Field Simulation information when there is scattering object and there is no scattering object, by calculating phasor difference,
Obtain two adjacent frequency f1With f2Multipath signal amplitude and phase place.
f1The phasor difference of two electric field amplitudes under frequencyFor：
Represent electric field in f1The amplitude size and Orientation of multipath signal under frequency；θ10Represent electric field in f1Multipath under frequency
The phase place of signal；
f2The phasor difference of two electric field amplitudes under frequencyFor：
Represent electric field in f2The amplitude size and Orientation of multipath signal under frequency；θ11Represent electric field in f2Multipath under frequency
The phase place of signal；
Step 4, by two frequency bins f1With f2Multipath signal amplitude size and Orientation, and phase place is used as input, profit
The method being fitted with multifrequency obtains time delay of the multipath relative to main footpath.
Specifically it is calculated as follows：
Step 401, by f1Frequency and f2The phase theta of two multipath signals under frequency10And θ11, multipath is calculated relative to master
Phase-delay difference Δ θ of the footpath under two frequency bins1With Δ θ2；
The phase place of multipath is made the difference respectively with the phase place of main footpath signal, f is obtained1The phase-delay difference Δ θ of frequency1With f2Frequently
The phase-delay difference Δ θ of point2, it is as follows：
Δθ1=θ00-θ10
Δθ2=θ01-θ11
Step 402, using the phase-delay difference Δ θ under two frequency bins1With Δ θ2, and corresponding wavelength under two frequency bins
λ1With λ2, the complete cycle issue n of phase difference is calculated respectively1And n2；
According to Δ θ2λ2-Δθ1λ1Relation with 0, calculates respectively f1The complete cycle issue n of phase difference under frequency1, and f2Frequently
The complete cycle issue n of the lower phase difference of point2；
Specially：
As Δ θ2λ2-Δθ1λ1When >=0,
λ1For f1The corresponding wavelength of frequency, λ2For f2The corresponding wavelength of frequency；
As Δ θ2λ2-Δθ1λ1During ＜ 0, now：
Δθ′2=Δ θ2+2π；
Step 403, using the complete cycle issue n of phase difference1And the phase information of multipath signal calculates multipath apart from d；
2 π d=2 π n1λ1+Δθ1λ1；
Step 404, using multipath apart from d divided by the light velocity obtain multipath relative to main footpath time delay.
Step 5 is by the amplitude and phase place of the multipath signal for obtaining, and multipath is relative to the time delay in main footpath, extracts
And the navigation error that calculating is caused due to multipath.
Advantages of the present invention is with good effect：
(1) a kind of extracting method of the electric wave multi-path information based on emulation, by numerical calculations multipath signal, can be with
Directly calculate the multipath that complex-shaped scattering object is produced.
(2) a kind of extracting method of the electric wave multi-path information based on emulation, can instruct Department of Electronics at the beginning of system design
The design of system, so as to quantitative impact of the multipath to system at the beginning of design, so as to instruct the carrying out of electronic system design.
Description of the drawings
Fig. 1 is the formation schematic diagram of multipath in actual environment of the present invention；
Fig. 2 is schematic diagram of the present invention based on the extracting method of the electric wave multi-path information of emulation；
Fig. 3 is flow chart of the present invention based on the extracting method of the electric wave multi-path information of emulation；
Fig. 4 is the schematic diagram that the present invention calculates electric field intensity difference；
Fig. 5 is that the present invention obtains time delay method flow chart of the multipath relative to main footpath using the method for multifrequency fitting；
Fig. 6 is the multi-path information example schematic produced by the electric dipole Jing metal balls reflection adopted in the present invention.
Specific embodiment
The specific implementation method of the present invention is described in detail below in conjunction with the accompanying drawings.
A kind of extracting method of the electric wave multi-path information based on emulation of the present invention, as shown in Fig. 2 first simulation calculation is not deposited
Electric field information in radio wave scattering body and the electric field information in the presence of whole scattering objects, then using the vector calculus of electric field with
And the method for far field multifrequency fitting, obtain the amplitude of electric wave multipath, the time delay of phase place and multipath relative to main footpath.
Concrete steps are as shown in figure 3, comprising following：
Step one, in two adjacent frequency f of certain electromagnetic environment1With f2, according to the scattering object source for producing multipath, emulation
Electric field information after scattering object is removed；
Principle of the invention, needs electric field information when first there is scattering object；Therefore need first to determine electricity
In magnetic environment, the scattering object source of multipath is produced, remove scattering object post-simulation and obtain electric field information, need to obtain very close
The amplitude and phase place of the electric field information in two frequency bins.
In two adjacent frequency f1With f2It is interior, f1<f2, removing the electric field information after scattering object includes electric field amplitude and electric field
Phase place.
f1Frequency removes the electric field amplitude after scattering objectFor：
Wherein,Represent in f1Electric field amplitude size and direction after scattering object, θ are removed under frequency00Represent electric field in f1
The phase place after scattering object is removed under frequency,Represent in f1The time-harmonic factor of electric wave under frequency.
f2Frequency removes the electric field amplitude after scattering objectFor：
WhereinRepresent in f2Electric field amplitude size and direction after scattering object, θ are removed under frequency01Represent electric field in f2Frequently
Phase place after the lower removal scattering object of point,Represent in f2The time-harmonic factor of electric wave under frequency.
Step 2, emulate two adjacent frequency f1With f2In, the electric field information when there is scattering object；
The electric field information of the whole systems of emulation, so as to obtain the electric field information in the presence of scattering object, it is also desirable to obtain with
Electric field amplitude and phase place in step one identical two frequency bins.
In two adjacent frequency f1With f2Interior, electric field information when there is scattering object includes the amplitude of electric field and the phase of electric field
Position.
f1There is electric field amplitude during scattering object in frequencyFor：
WhereinRepresent in f1Electric field amplitude size and direction when there is scattering object under frequency, θ0Represent electric field in f1Frequently
There is phase place during scattering object under point；
f2There is electric field amplitude during scattering object in frequencyIt is calculated as follows：
WhereinRepresent in f2Electric field amplitude size and direction when there is scattering object under frequency, θ1Represent electric field in f2Frequently
There is phase place during scattering object under point.
Step 3, according to Electric Field Simulation information when there is scattering object and there is no scattering object, by calculating electric field
Phasor difference, obtains two adjacent frequency f1With f2Multipath signal amplitude and phase place.
As shown in figure 4, calculating f1The phasor difference of two electric field amplitudes under frequencyFor：
Represent electric field in f1The amplitude size and Orientation of multipath signal under frequency；θ10Represent electric field in f1Multipath under frequency
The phase place of signal；
f2The phasor difference of two electric field amplitudes under frequencyFor：
Represent electric field in f2The amplitude size and Orientation of multipath signal under frequency；θ11Represent electric field in f2Multipath under frequency
The phase place of signal；
Step 4, by two frequency bins f1With f2Multipath signal amplitude size and Orientation, and phase place is used as input, profit
The method being fitted with multifrequency obtains time delay of the multipath relative to main footpath.
Often also need to obtain time delay of the multipath relative to main footpath in actual analysis, time delay mainly passes through phase
Position carries out pushing away, but phase information tends not to accurately describe relative time-delay, because phase information has cycle mould
The problem of paste.The present invention using the multipath amplitude of two frequency bins and phase place as input, just can be with after multifrequency process of fitting treatment
Obtain accurate relative time-delay of the multipath relative to main footpath.
As shown in figure 5, being specifically calculated as follows：
Step 401, by f1Frequency and f2The phase theta of two multipath signals of frequency10And θ11, multipath is calculated relative to master
Phase-delay difference Δ θ of the footpath under two frequency bins1With Δ θ2
By analyzing two adjacent frequency f1With f2(f1<f2) multi-path information, it is possible to obtain two different multipath signals
Phase theta10And θ11, in two frequency bins the phase place of multipath signal is made the difference with the phase place of main footpath signal respectively, obtain f1The phase of frequency
Position delay difference Δ θ1With f2The phase-delay difference Δ θ of frequency2, it is as follows：
Δθ1=θ00-θ10
Δθ2=θ01-θ11
Step 402, using the phase-delay difference Δ θ under two frequency bins1With Δ θ2, and corresponding wavelength under two frequency bins
λ1With λ2, the complete cycle issue n of phase difference is calculated respectively1And n2；
Due to two adjacent frequency f1With f2Select close enough, therefore f1The corresponding wavelength X of frequency1With f2Frequency is corresponding
Wavelength X2It is close enough, it is desirable to so that equation is set up, then n1、n2Also must be close enough, but n1、n2It is periodicity, therefore must is
Integer, so in this n1、n2It is equal.
n1For f1The periodicity of phase difference, n under frequency2For f2The periodicity of phase difference under frequency；It is calculated as follows：
As Δ θ2λ2-Δθ1λ1When >=0,
Obtain periodicity n1、n2After restore out accurate phase place, obtain relative time-delay, it is to be noted herein that recover
The relative time-delay for going out, needs to consider inverting function of the electric wall to electric wave.
Certainly, can also there is n1、n2Unequal situation.According to hypothesis f2 above>F1, when there is cycle slip, often
First there is cycle slip in the higher side of frequency, so that n1、n2It is unequal, at this moment n1＞ n2, it is therefore desirable to add in the algorithm
Criterion, works as n1＞ n2When, there is Δ θ '2=Δ θ2+ 2 π, so that all jumping figures of two frequency bins meet equal relation.
Namely as Δ θ2λ2-Δθ1λ1During ＜ 0, now：
Step 403, using the complete cycle issue n of phase difference1And the phase information of multipath signal calculates multipath apart from d；
When two working frequency points of antenna are close enough, the far-field pattern of antenna will not change substantially, and in frequency
Point is when being more or less the same, the signal that antenna sends reach scattering object apart from d, often size is identical, this is the basic of the present invention
Principle；
So using f1The periodicity n of phase difference under frequency1And the phase information of multipath signal calculates multipath apart from d, such as
Under：
2 π d=2 π n1λ1+Δθ1λ1；
Using f2The periodicity n of phase difference under frequency2It is as follows and the phase information of multipath signal calculates multipath apart from d：
2 π d=2 π n2λ2+Δθ2λ2；
Step 404, using multipath apart from d divided by the light velocity obtain multipath relative to main footpath time delay.
The amplitude and phase place of the multipath signal that step 5 obtains step 3, and the multipath that step 4 is obtained is relative to master
The time delay in footpath, calculates the navigation error caused due to multipath.
Embodiment：
As shown in fig. 6, calculating an electric dipole being located at the 300mm of z-axis top, Jing mono- is 1000mm with its distance
Metal ball reflection produced by multi-path information, observation station is that z-axis is positive, and coordinate system is right-handed system.Multipath is relative to main footpath
Multipath Distance Theory value is two times of distance between the two, i.e. 2000mm.
First, learn that main footpath electric field is respectively in the electric field of 1.2GHz and 1.201GHz after emulation
Then, learn that total electric field is respectively in the electric field of 1.2GHz and 1.201GHz after emulation：
Then can be obtained after subtraction of vector：
The periodicity of multipath phase is calculated again, notes now being considered as 180 ° of the caused phase difference due to desired electrical wall,
Therefore
Δθ1=θ00-θ10=-360.77 °
Δθ2=θ01-θ11=-358.42 °
Because periodicity must be integer, therefore：n1=n2=9
Therefore multipath is relative to the multipath distance in main footpath：
Multipath distance is divided by the light velocity, as time delay of the multipath relative to main footpath；Therefore multipath is relative to the time in main footpath
Postponing Δ τ is：C is the light velocity.
The analysis by more than can be seen that the errors simulation analysis that the present invention can be used for pseudorange, can be in electricity using this method
Sub- navigation system at the beginning of design, analyze by the Quantitative Simulation for instructing multipath, so as to instruct the scattering object layout of electronic system, instructs
Design.
Claims (2)
1. it is a kind of based on emulation electric wave multi-path information extracting method, it is characterised in that comprise the following steps that：
Step one, in two adjacent frequency f of certain electromagnetic environment1With f2, according to the scattering object source for producing multipath, emulate to work as and go
Except the electric field information after scattering object；
f1Frequency removes the electric field amplitude after scattering objectFor：
Wherein,Represent in f1Electric field amplitude size and direction after scattering object, θ are removed under frequency00Represent electric field in f1Frequency
Phase place after lower removal scattering object,Represent in f1The time-harmonic factor of electric wave under frequency；
f2Frequency removes the electric field amplitude after scattering objectFor：
Wherein,Represent in f2Electric field amplitude size and direction after scattering object, θ are removed under frequency01Represent electric field in f2Frequency
Phase place after lower removal scattering object,Represent in f2The time-harmonic factor of electric wave under frequency；
Step 2, emulate two adjacent frequency f1With f2In, the electric field information when there is scattering object；
f1There is electric field amplitude during scattering object in frequencyFor：
Wherein,Represent in f1Electric field amplitude size and direction when there is scattering object under frequency, θ0Represent electric field in f1Under frequency
There is phase place during scattering object；
f2There is electric field amplitude during scattering object in frequencyIt is calculated as follows：
Wherein,Represent in f2Electric field amplitude size and direction when there is scattering object under frequency, θ1Represent electric field in f2Under frequency
There is phase place during scattering object；
Step 3, according to Electric Field Simulation information when there is scattering object and there is no scattering object, by calculating phasor difference, obtain
Two adjacent frequency f1With f2Multipath signal amplitude and phase place；
f1The phasor difference of two electric field amplitudes under frequencyFor：
Represent electric field in f1The amplitude size and Orientation of multipath signal under frequency；θ10Represent electric field in f1Multipath signal under frequency
Phase place；
f2The phasor difference of two electric field amplitudes under frequencyFor：
Represent electric field in f2The amplitude size and Orientation of multipath signal under frequency；θ11Represent electric field in f2Multipath signal under frequency
Phase place；
Step 4, by two frequency bins f1With f2Multipath signal amplitude size and Orientation, and phase place is used as input, using many
The method of frequency fitting obtains time delay of the multipath relative to main footpath；
Step 5 is by the amplitude and phase place of the multipath signal for obtaining, and multipath is relative to the time delay in main footpath, extracts and counts
Calculate the navigation error caused due to multipath.
2. the extracting method of a kind of electric wave multi-path information based on emulation as claimed in claim 1, it is characterised in that described
Step 4 is specific as follows：
Step 401, by f1Frequency and f2The phase theta of two multipath signals under frequency10And θ11, calculate multipath and exist relative to main footpath
Phase-delay difference Δ θ under two frequency bins1With Δ θ2；
The phase place of multipath is made the difference respectively with the phase place of main footpath signal, f is obtained1The phase-delay difference Δ θ of frequency1With f2Frequency
Phase-delay difference Δ θ2, it is as follows：
Δθ1=θ00-θ10
Δθ2=θ01-θ11
Step 402, using the phase-delay difference Δ θ under two frequency bins1With Δ θ2, and corresponding wavelength X under two frequency bins1With
λ2, the complete cycle issue n of phase difference is calculated respectively1And n2；
According to Δ θ2λ2-Δθ1λ1Relation with 0, calculates respectively f1The complete cycle issue n of phase difference under frequency1, and f2Phase under frequency
The complete cycle issue n of potential difference2；
Specially：
As Δ θ2λ2-Δθ1λ1When >=0,
λ1For f1The corresponding wavelength of frequency, λ2For f2The corresponding wavelength of frequency；
As Δ θ2λ2-Δθ1λ1During ＜ 0, now：
Δθ′2=Δ θ2+2π；
Step 403, using the complete cycle issue n of phase difference1And the phase information of multipath signal calculates multipath apart from d；
2 π d=2 π n1λ1+Δθ1λ1；
Step 404, using multipath apart from d divided by the light velocity obtain multipath relative to main footpath time delay.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611178525.XA CN106646536B (en) | 2016-12-19 | 2016-12-19 | A kind of extracting method of the electric wave multi-path information based on emulation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611178525.XA CN106646536B (en) | 2016-12-19 | 2016-12-19 | A kind of extracting method of the electric wave multi-path information based on emulation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106646536A true CN106646536A (en) | 2017-05-10 |
| CN106646536B CN106646536B (en) | 2019-06-04 |
Family
ID=58833669
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611178525.XA Active CN106646536B (en) | 2016-12-19 | 2016-12-19 | A kind of extracting method of the electric wave multi-path information based on emulation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106646536B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1768276A (en) * | 2003-03-31 | 2006-05-03 | 洛克达公司 | A system and method for multipath mitigation using clustered positioning signals |
| CN101394233A (en) * | 2007-09-21 | 2009-03-25 | 哈尔滨工业大学深圳研究生院 | Pulse wideband multipath signal modeling method and system under indoor view distance environment |
| CN105891800A (en) * | 2016-03-30 | 2016-08-24 | 中国人民解放军国防科学技术大学 | Single-emission tri-reception antenna radar anti-multipath scattering detection method |
| CN105939299A (en) * | 2016-06-08 | 2016-09-14 | 西安电子科技大学 | Channel parameter estimation method based on improved SAGE algorithm |
-
2016
- 2016-12-19 CN CN201611178525.XA patent/CN106646536B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1768276A (en) * | 2003-03-31 | 2006-05-03 | 洛克达公司 | A system and method for multipath mitigation using clustered positioning signals |
| CN101394233A (en) * | 2007-09-21 | 2009-03-25 | 哈尔滨工业大学深圳研究生院 | Pulse wideband multipath signal modeling method and system under indoor view distance environment |
| CN105891800A (en) * | 2016-03-30 | 2016-08-24 | 中国人民解放军国防科学技术大学 | Single-emission tri-reception antenna radar anti-multipath scattering detection method |
| CN105939299A (en) * | 2016-06-08 | 2016-09-14 | 西安电子科技大学 | Channel parameter estimation method based on improved SAGE algorithm |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106646536B (en) | 2019-06-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104318059B (en) | Method for tracking target and tracking system for non-linear Gaussian Systems | |
| RU2465613C1 (en) | Method and apparatus for determining location of radio source | |
| CN101858975A (en) | Target location method based on through-wall radar imaging | |
| CN104678371B (en) | A kind of sea level height measurement apparatus based on time delay amendment | |
| Huang et al. | MoM based current reconstruction using near-field scanning | |
| CN103777186A (en) | Method for calculating near-field radar echo characteristics of moving object based on beam decomposition and local irradiation | |
| HRP20210578T1 (en) | Methods for forming 3d image data and associated apparatuses | |
| CN104765055A (en) | GPS observation station coordinate time sequence periodic-detection method and system | |
| CN110231620A (en) | A kind of noise correlation system tracking filter method | |
| CN102928829B (en) | Space target parameter tetrieval method | |
| CN102902841A (en) | Method for calculating cross sectional areas of computer-loaded radars with complex structures | |
| CN104535067A (en) | Method for quickly calculating arrival time of pulse signal based on sector search | |
| CN105353228A (en) | Estimation method of antenna phase center on the basis of adaptive filtering | |
| Kweon et al. | FDTD analysis of electromagnetic wave propagation in an inhomogeneous ionosphere under arbitrary-direction geomagnetic field | |
| Zhou et al. | Long‐range Loran‐C ground‐wave propagation prediction based on adaptive moving window finite‐difference time‐domain method with compute unified device architecture parallel computing techniques | |
| CN106646536A (en) | Method for extracting multipath information of electric wave based on simulation | |
| Lee et al. | Simulation of UWB radar-based positioning performance for a UAV in an urban area | |
| Cheng et al. | A Rao-Blackwellized particle filter with variational inference for state estimation with measurement model uncertainties | |
| CN112036011A (en) | Very low frequency wave communication transmission analysis method and system for underwater vehicle | |
| Zernov et al. | On the effects of scintillation of low-latitude bubbles on transionospheric paths of propagation | |
| RU2659810C1 (en) | Method and apparatus for determining coordinates of radio emission sources | |
| CN105549031B (en) | A kind of time domain numerical computation method of the ionospheric propagation time delay of satellite-signal | |
| Motamed et al. | A fast phase space method for computing creeping rays | |
| CN111257881A (en) | Dynamic road intersection scene target vehicle scattering modeling method | |
| CN104181533A (en) | SAR echo simulating method based on time delay scattering |
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 |