CN102401896B - Method for calculating Doppler signal spectrum - Google Patents
Method for calculating Doppler signal spectrum Download PDFInfo
- Publication number
- CN102401896B CN102401896B CN 201110249636 CN201110249636A CN102401896B CN 102401896 B CN102401896 B CN 102401896B CN 201110249636 CN201110249636 CN 201110249636 CN 201110249636 A CN201110249636 A CN 201110249636A CN 102401896 B CN102401896 B CN 102401896B
- Authority
- CN
- China
- Prior art keywords
- frequency
- doppler
- antennas
- doppler signal
- signal
- 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
Landscapes
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention discloses a method for calculating Doppler signal spectrum, which sequentially comprises the following steps that: two antennas with different launch angles are arranged in a speed measurement radar system so as to acquire the Doppler signal; the original signals are subjected to band-pass or low-pass filtering and then FFT (Fast Fourier Transform Algorithm) transform to acquire the corresponding spectrums; the two spectrums are synthetized, and points of discontinuity of the two spectrums are removed; the strength and signal to noise ratio of the signal are assessed, and the proximal frequency points are searched in the spectrum synthesis; and the spectral line of the crossed spectral line is gathered to obtain the frequency estimate as well as smooth and calculate the parameters. The method disclosed by the invention can effectively avoid the error of calculation of the single Doppler signal spectrum caused by roadbed function, so that the relative running speed of a railway locomotive with high accuracy can be acquired.
Description
Technical field
The present invention relates to a kind of method for calculating Doppler signal spectrum, especially relate to a kind of method that in the railway locomotive speed-measuring radar system, is used for the signal spectrum of computing machine vehicle speed.
Background technology
The frequency spectrum Doppler technology is widely used in auto industry as a kind of method of basis, and for rail vehicles, the rapid variation of considering track ground must cause the variation of Doppler frequency spectrum, the center of Doppler frequency spectrum also can change simultaneously, and the correction factor that causes speed is also changing, for this problem, we have introduced a kind of computing method of the railway locomotive travelling speed being carried out valuation according to the intersection frequency of double antenna frequency spectrum.
Summary of the invention
The purpose of this invention is to provide a kind of method for calculating Doppler signal spectrum, it can be according to the Doppler signal amplitude, centre frequency, the bandwidth that estimate, utilize the singularity of Doppler frequency spectrum, calculate exactly required parameter, the various defectives that exist to overcome prior art.
The so-called a kind of method for calculating Doppler signal spectrum of the present invention is characterized in that it experiences following step successively:
Emission angle is installed in speed-measuring radar system is respectively 40 ° and 50 ° and two antennas that highly are 500mm are set, their distinguish radiation millimeter wave, and with transmitted wave and reflection echo difference frequency, the signal that obtains is Doppler signal; Be with logical or low-pass filtering to original Doppler signal, should the filtering high frequency interference and noise in high fdrequency component, also to finish necessary anti-aliasing filter before the AD sampling, to satisfy nyquist sampling theorem; Data after the sampling are carried out the FFT conversion to obtain corresponding frequency spectrum; The frequency spectrum of two antennas synthesized and remove catastrophe point; Intensity, signal to noise ratio (S/N ratio) to Doppler signal are assessed, immediate frequency during the search frequency spectrum is synthetic; The intersection frequency that searches is gathered the heart to obtain Frequency Estimation; Determine filter range according to frequency change rate repeatedly, be with logical or low-pass filtering further to reduce parameter error; Calculating two Doppler's expression formulas corresponding to antenna is
Add the relational expression by two formulas arrangement gained
With
, can obtain F from relational expression 3 and 4
dNamely the Doppler frequency of 40 ° of antennas also has
The i.e. Doppler frequency of 50 ° of antennas, again substitution relational expression 1 and 2 just can obtain corresponding railway locomotive travelling speed V, the f in the relational expression 1
0The transmission frequency of 40 ° of antennas, in the relational expression 2
Be the transmission frequency of 50o antenna, the C in two formulas then is the light velocity 3 * 10
8M/s.
The invention has the beneficial effects as follows: when measuring the railway locomotive travelling speed according to these computing method, can effectively avoid different surface state on the impact of spectrum analysis, significantly improve the accuracy of parameter estimation, thereby obtain high-precision measurement result.
Description of drawings
Fig. 1 is radar microwave radiation areas figure;
Fig. 2 is the vertical view of Fig. 1;
Fig. 3 is the two microwave antenna spectrograms ideally of vehicle-mounted speed measuring radar.
Among the figure: the frequency spectrum that 1, obtains under the 2 one multidirectional same sex reflection cases, the frequency spectrum that obtains under 3, the 4 one multidirectional different in nature reflection cases, F
KThe intersection point of one frequency spectrum.
Embodiment
Measuring the railway locomotive travelling speed as example, Vehicular radar system is provided with two antennas that emission angle is respectively 40 ° and 50 ° at the 500mm height, and the millimeter wave of two antenna transmissions is in reflecting surface existence covering to a certain degree.A kind of method for calculating Doppler signal spectrum provided by the invention experiences following step successively: with the transmitted wave of two antennas and reflection echo difference frequency to obtain Doppler signal; Be with logical or low-pass filtering to original Doppler signal, should the filtering high frequency interference and noise in high fdrequency component, also to finish necessary anti-aliasing filter before the sampling, to satisfy nyquist sampling theorem; Data after the sampling are carried out the FFT conversion to obtain corresponding frequency spectrum; The frequency spectrum of two antennas synthesized and remove catastrophe point; Intensity, signal to noise ratio (S/N ratio) to Doppler signal are assessed, immediate frequency during the search frequency spectrum is synthetic; The Frequency Estimation that obtains that the spectral line of the intersection frequency that searches is gathered the heart; Determine filter range according to frequency change rate repeatedly, be with logical or low-pass filtering with further minimizing parameter error; Calculating two Doppler's expression formulas corresponding to antenna is:
Claims (1)
1. method that is used for calculating Doppler signal spectrum is characterized in that it experiences following step successively:
1. emission angle is installed in speed-measuring radar system is respectively 40 ° and 50 ° and two antennas that highly are 500mm are set, their distinguish radiation millimeter wave, and with transmitted wave and reflection echo difference frequency, the signal that obtains is Doppler signal;
2. be with logical or low-pass filtering to original Doppler signal, should the filtering high frequency interference and noise in high fdrequency component, also to finish necessary anti-aliasing filter before the AD sampling, to satisfy nyquist sampling theorem;
3. the data after the sampling are carried out the FFT conversion to obtain corresponding frequency spectrum;
4. the frequency spectrum of two antennas is synthesized and remove catastrophe point;
5. intensity, the signal to noise ratio (S/N ratio) of Doppler signal are assessed immediate frequency during the search frequency spectrum is synthetic;
6. the spectral line of the intersection frequency that searches gathered the heart to obtain Frequency Estimation;
7. determine filter range according to frequency change rate repeatedly, be with logical or low-pass filtering further to reduce parameter error;
8. calculating two Doppler's expression formulas corresponding to antenna is
Add the relational expression by two formulas arrangement gained
Also have
Can obtain F from relational expression 3 and 4
dNamely the Doppler frequency of 40 ° of antennas also has
The i.e. Doppler frequency of 50 ° of antennas, again substitution relational expression 1 and 2 just can obtain corresponding rail locomotive travelling speed V, the f in the relational expression 1
0The transmission frequency of 40 ° of antennas, in the relational expression 2
Be the transmission frequency of 50o antenna, the C in two formulas then is the light velocity 3 * 10
8M/s concerns the F in 4
KIntersection point for frequency spectrum.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110249636 CN102401896B (en) | 2011-08-26 | 2011-08-26 | Method for calculating Doppler signal spectrum |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110249636 CN102401896B (en) | 2011-08-26 | 2011-08-26 | Method for calculating Doppler signal spectrum |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102401896A CN102401896A (en) | 2012-04-04 |
| CN102401896B true CN102401896B (en) | 2013-04-24 |
Family
ID=45884300
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201110249636 Active CN102401896B (en) | 2011-08-26 | 2011-08-26 | Method for calculating Doppler signal spectrum |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102401896B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104678367B (en) * | 2013-11-28 | 2017-02-22 | 中国航空工业集团公司雷华电子技术研究所 | Velocity deception interference resisting method for airborne pulse Doppler radar |
| CN104635231B (en) * | 2015-02-12 | 2017-07-18 | 西安电子科技大学 | Locomotive radar velocity measurement method based on adaptive Kalman filter |
| CN105334511A (en) * | 2015-11-03 | 2016-02-17 | 周青松 | Railroad locomotive velocity measurement method based on extraction of Doppler signal frequency |
| CN105372649A (en) * | 2015-11-03 | 2016-03-02 | 黄中瑞 | Railroad locomotive speed measurement method based on adaptive double-path sampling filtering |
| CN112557420A (en) * | 2019-09-26 | 2021-03-26 | 深圳市雷立科技有限公司 | Probe of microwave moisture meter |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5252980A (en) * | 1992-07-23 | 1993-10-12 | The United States Of America As Represented By The Secretary Of The Air Force | Target location system |
| DE4406404C2 (en) * | 1994-02-26 | 2000-01-20 | Daimler Chrysler Ag | Method and arrangement for determining the position and movement of an object |
| CN1119974C (en) * | 1999-12-30 | 2003-09-03 | 复旦大学 | Dual-ultrasonic doppler method for measuring blood flow speed |
| KR20050103400A (en) * | 2004-04-26 | 2005-10-31 | 이시동 | Radio position finder with radio-direction finder |
| CN101320086B (en) * | 2008-06-27 | 2011-03-30 | 北京航空航天大学 | Echo signal processing equipment and method of Doppler speed measuring laser radar |
-
2011
- 2011-08-26 CN CN 201110249636 patent/CN102401896B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN102401896A (en) | 2012-04-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102401896B (en) | Method for calculating Doppler signal spectrum | |
| CN107678003B (en) | Target detection method under ground wave radar sea clutter background | |
| CN107683422B (en) | Vehicle radar system | |
| JP5595496B2 (en) | Radar equipment | |
| CN109188379B (en) | Automatic calibration method for driving auxiliary radar working angle | |
| CN102356332B (en) | Radar system having arrangements and method for decoupling transmission and reception signals and suppression of interference radiation | |
| CN102426360B (en) | Two-dimensional ISRA imaging method of object with micro rotation in air | |
| CN106524967B (en) | A kind of automobile core wheel actual travel displacement measurement and extracting method | |
| CN109375202B (en) | Vehicle distance and speed measurement method based on vehicle-mounted millimeter wave radar | |
| CN101738611B (en) | Underwater acoustic target signal detection and identification method | |
| CN105093227B (en) | A kind of traffic flux measurement device and vehicle operating information preparation method | |
| CN102707285A (en) | Method for detecting frequency domain constant false alarm of vehicle-mounted millimeter-wave anti-collision radar system | |
| US6703966B2 (en) | Method and device for measuring the speed of a moving object | |
| CN104635231B (en) | Locomotive radar velocity measurement method based on adaptive Kalman filter | |
| JP6624601B2 (en) | Radar apparatus and target object detection method | |
| CN102914773B (en) | Multi-pass circumference SAR three-dimensional imaging method | |
| CN107783121B (en) | Unmanned automobile anti-collision radar system signal processing system and method based on combined waveform | |
| CN106199582A (en) | The method being applied to the two-frequency CW radar human body locating and tracking of indoor | |
| CN104730518A (en) | Gaussian-fitting-based radar Doppler-spectrum method for estimating sea-surface flow field | |
| CN104919331A (en) | Radar device | |
| CN101363913B (en) | Signal processing method of fan-shaped beam circular cone scanning microwave scatterometer | |
| JP7075925B2 (en) | Speed measuring device and speed measuring method | |
| CN113805166A (en) | Target tracking and ranging method and system of radar level meter | |
| US8884814B2 (en) | Processing method for FMCW radar signal with dual pulse repetition frequency | |
| CN113812932A (en) | Millimeter wave radar-based in-vehicle life target detection and positioning technology |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |