CN103604944B - Surface flow measurement method based on monostation shipborne high-frequency ground wave radar - Google Patents

Abstract

The invention provides a surface flow measurement method based on a monostation shipborne high-frequency ground wave radar, belonging to the space-time processing field of shipborne high-frequency ground wave over-the-horizon radar signals and the ocean surface flow remote sensing field. The surface flow measurement method solves the problems of difficult synchronizing detection, small remote sensing field, high measurement cost and low observation efficiency of the traditional shore-based high-frequency ground wave radar which measures the surface flow vector field by using a two-station measurement scheme. A sea area to be measured is divided into a plurality of sector grids, and each grid is a detection unit; the position of actually measured positive/negative first-order Bragg spectral peak on each detection unit is obtained by a time-space joint spectrum estimation method and through spectrum search, and a radial flow velocity on the corresponding detection unit is obtained so that the radial flow field distribution of the measured sea area can be obtained; the optimal surface flow vector field on each unit is obtained by the least square method; the optimal surface flow vector fields which are measured in the same detection unit at a plurality of measurement moments are weighted and averaged so that the surface flow vector field of the measured sea area can be obtained. The surface flow measurement method based on the monostation shipborne high-frequency ground wave radar is specifically used for measuring the ocean surface flow.

Description

A kind of surperficial flow measuring method based on single station boat-carrying high-frequency ground wave radar

Technical field

The invention belongs to boat-carrying High frequency ground wave over-the-horizon aadar signal Space-Time process field and Ocean surface currents remote sensing fields.

Background technology

High-frequency ground wave (surface wave) radar utilizes vertical polarization frequency electromagnetic waves to have the features such as propagation attenuation is little, diffraction characteristics is good when seawater surface is propagated, can be over-the-horizon target detection and marine dynamic process remote measurement good detection means is provided.Compared with traditional marine monitoring means, high-frequency ground wave radar has that operating distance is far away, wide coverage, detection accuracy are high, real-time good and the advantage such as 24-hour service, and at sea the aspect such as traffic monitoring, marine development of resources, marine meterologal prediction and oceanographic research is with a wide range of applications.

In theory, the positive and negative single order Bragg peak of high-frequency ground wave radar sea echo should to appear at exactly about zero Doppler frequency about two discrete frequencies on.But in actual measurement, because ocean also exists surface flow field, thus cause their Doppler frequency to there occurs corresponding frequency displacement.Obviously, this frequency shift amount is proportional to surface flow field radial velocity.Bank base high-frequency ground wave radar realizes Ocean surface currents remote measurement according to this principle.Utilize single station high-frequency ground wave radar can only obtain detecting the Radial current map in marine site, want to obtain the distribution situation of ocean surface flow vector field in this region, two radars being positioned at diverse location just must be utilized to carry out synchronizing detection to this marine site.But, utilize dual station formula measured surface flow vector field to there are problems, be first need to drop into more manpower and materials, cause cost to be multiplied; Secondly when the horizontal ordinate detecting position is comparatively large, ordinate is less, namely the line (being called baseline) between sensing point and two radars is at a distance of nearer, and and distant between the perpendicular bisector of baseline time, can instability be produced when calculating the longitudinal component of ocean current flow velocity, causing the larger error of calculation; Moreover must ensure that when radar bus station position sensing point can be arrived by two radar illuminations simultaneously, that is sensing point simultaneously within the investigative range of two radars, and can not must be covered by land or island etc.Therefore, how to utilize monostatic radar to obtain the distribution of Ocean surface currents vector field is studying a question of Radio oceanography research field emphasis always.

Boat-carrying high-frequency ground wave radar is going deep into and development of bank base high-frequency ground wave radar ocean telemetry, except retaining the advantage of bank base high-frequency ground wave radar, also has the flexible performance of boat-carrying platform.In addition, boat-carrying high-frequency ground wave radar is similar to airborne radar, and therefore, many Space Time disposal routes of getting up based on airborne radar research and development may be used for the Space Time process of boat-carrying high-frequency ground wave radar sea echo signal.

Summary of the invention

The present invention is the problem that synchronizing detection is difficult, remote sensing area is little, measurement expense is expensive and observed efficiency is low adopting dual station formula measurement scheme measured surface flow vector field to exist to solve traditional bank base high-frequency ground wave radar, the invention provides a kind of surperficial flow measuring method based on single station boat-carrying high-frequency ground wave radar.

Based on a surperficial flow measuring method for single station boat-carrying high-frequency ground wave radar, it comprises the steps:

The first step, systematic parameter according to boat-carrying high-frequency ground wave radar, tested marine site equidistantly, is angularly divided into multiple fan-shaped grid, and each grid is a probe unit;

Second step, utilize the sea echo Space Time spectrum of Space Time combined spectrum method of estimation to each distance annulus that boat-carrying high-frequency ground wave radar detects to estimate, obtained on each probe unit by spectrum search and survey the position that positive and negative single order Bragg composes peak;

3rd step, compose the position at peak ask for radial flow velocity on corresponding probe unit according to each probe unit being surveyed positive and negative single order Bragg, thus obtain the radial flow fields distribution in whole tested marine site, and the angular resolution of the now radial flow fields distribution in whole tested marine site is initial angle resolution A;

4th step, be located at boat-carrying high-frequency ground wave radar measure time range in, the surface flow field in tested marine site is consistent, and only there is a flow field in each probe unit;

5th step, adjacent three probe units in same distance annulus are merged as a whole, radial flow valuve in these three probe units be by same vector flow field they separately projection in the radial direction produce, reduce initial angle resolution A, obtain current angular resolution B, and described B=3A, then utilize least square method to ask for each surperficial flow vector field optimum on the whole;

6th step, boat-carrying high-frequency ground wave radar to same probe unit adjacent multiple measurement the moment institute obtain optimum surperficial flow vector field be same flow field, utilizing the surperficial flow vector field to being engraved in the optimum recorded in same probe unit during multiple measurement to be weighted on average, obtaining flow vector field, surface, tested marine site.

A kind of surperficial flow measuring method based on single station boat-carrying high-frequency ground wave radar of the present invention make use of the flexible performance of platform that the gradual characteristic in actual ocean surface flow field and boat-carrying high-frequency ground wave radar have, to reduce the angular resolution of boat-carrying system for high-frequency earth wave radar for cost, realize the object of boat-carrying high-frequency ground wave radar measured surface flow vector field, single station.This not only will reduce the observation cost of surperficial flow vector field greatly, can also carry out synchronizing detection, and remote sensing area is large, effectively improve observed efficiency, and observed efficiency improves more than 20%, has actual application value widely.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of a kind of surperficial flow measuring method based on single station boat-carrying high-frequency ground wave radar described in embodiment one;

Fig. 2 is the schematic diagram dividing the multiple fan-shaped grid obtained in embodiment one through the first step; Wherein, △ θ be fan-shaped grid cell distance to interval, △ R is that grid cell orientation is to interval; v _pfor Platform movement speed;

Fig. 3 is the geometric relationship figure in the vector flow field that in embodiment one, the 5th step obtains; represent the two-dimensional vector flow field on kth probe unit in r range unit; for this vector flow field radial flow fields on the detection unit;

Fig. 4 is in embodiment five, the distribution situation schematic diagram of two-dimensional vector flow field in nine continuous print distance annulus of simulation;

In Fig. 5 embodiment five, being without in radial flow measuring error situation, utilizing the vector flow field of Least-squares inversion by reducing system perspective resolution;

In Fig. 6 embodiment five, being having in radial flow measuring error situation, utilizing the vector flow field of Least-squares inversion by reducing system perspective resolution;

In Fig. 7 embodiment five, be that boat-carrying high-frequency ground wave radar measures the geometric relationship figure of two-dimensional vector ocean current at diverse location to same probe unit;

In Fig. 8 embodiment five, be when there being measuring error, the vector flow field obtained after the vector flow field weighted mean that 9 observation positions are recorded in same probe unit.

Embodiment

Embodiment one: present embodiment is described see Fig. 1,2 and 3, a kind of surperficial flow measuring method based on single station boat-carrying high-frequency ground wave radar described in present embodiment, it comprises the steps:

The first step, systematic parameter according to boat-carrying high-frequency ground wave radar, tested marine site equidistantly, is angularly divided into multiple fan-shaped grid, and each grid is a probe unit;

Second step, utilize the sea echo Space Time spectrum of Space Time combined spectrum method of estimation to each distance annulus that boat-carrying high-frequency ground wave radar detects to estimate, obtained on each probe unit by spectrum search and survey the position that positive and negative single order Bragg composes peak;

3rd step, compose the position at peak ask for radial flow velocity on corresponding probe unit according to each probe unit being surveyed positive and negative single order Bragg, thus obtain the radial flow fields distribution in whole tested marine site, and the angular resolution of the now radial flow fields distribution in whole tested marine site is initial angle resolution A;

4th step, be located at boat-carrying high-frequency ground wave radar measure time range in, the surface flow field in tested marine site is consistent, and only there is a flow field in each probe unit;

5th step, adjacent three probe units in same distance annulus are merged as a whole, radial flow valuve in these three probe units be by same vector flow field they separately projection in the radial direction produce, reduce initial angle resolution A, obtain current angular resolution B, and described B=3A, then utilize least square method to ask for each surperficial flow vector field optimum on the whole;

6th step, boat-carrying high-frequency ground wave radar to same probe unit adjacent multiple measurement the moment institute obtain optimum surperficial flow vector field be same flow field, utilizing the surperficial flow vector field to being engraved in the optimum recorded in same probe unit during multiple measurement to be weighted on average, obtaining flow vector field, surface, tested marine site.

In present embodiment, for the full-blown marine site of a slice, (except the exceedingly odious situations such as tsunami) that its surface flow field normally slowly changes, and the radargrammetry time is generally 100 ~ 200s, therefore the 4th step is rational.

Embodiment two: present embodiment is described see Fig. 1,2 and 3, the difference of present embodiment and a kind of surperficial flow measuring method based on single boat-carrying high-frequency ground wave radar of standing described in embodiment one is, according to the systematic parameter of boat-carrying high-frequency ground wave radar in the described first step, the detailed process tested marine site equidistantly, being angularly divided into multiple fan-shaped grid is

First, tested marine site equidistantly divides by the system range resolution according to boat-carrying high-frequency ground wave radar, and then tested marine site angularly divides by this moment angular resolution adopting orientation algorithm for estimating to obtain, thus obtain all fan-shaped grid in tested survey marine site.

Embodiment three: present embodiment is described see Fig. 1,2 and 3, the difference of present embodiment and a kind of surperficial flow measuring method based on single boat-carrying high-frequency ground wave radar of standing described in embodiment two is, the sea echo Space Time spectrum of Space Time combined spectrum method of estimation to each distance annulus that boat-carrying high-frequency ground wave radar detects is utilized to estimate in described second step, the detailed process being obtained the position of each probe unit being surveyed positive and negative single order Bragg spectrum peak by spectrum search is

21 step, each sea echo covariance matrix R apart from annulus that boat-carrying high-frequency ground wave radar is detected _occarry out feature decomposition, obtain

$\begin{array}{c}{R}_{\mathrm{oc}}=\underset{i=1}{\overset{N_r}{\mathrm{\Σ}}}{\mathrm{\λ}}_i{e}_i{e}_i^H+\underset{j=N_r+1}{\overset{\mathrm{MK}}{\mathrm{\Σ}}}{\mathrm{\λ}}_j{e}_j{e}_j^H\\ =U_s{\mathrm{\Σ}}_s{U}_s^H+U_n{\mathrm{\Σ}}_n{U}_n^H\end{array}$ (formula one);

U is asked for by formula one _n;

Wherein, N _rfor the order of covariance matrix, and

$N_r=\mathrm{int}[\frac{4d}{\mathrm{\λ}}(M-1+\mathrm{\β}(K-1))+2]$ (formula two);

M is array number;

K is fast umber of beats;

Int [] represents that positive dirction rounds;

represent the number of half array element distance that Texas tower moves within a frequency modulation cycle;

V _pfor the Platform movement speed of boat-carrying high-frequency ground wave radar;

T _rfor the frequency modulation cycle;

λ is radar operation wavelength,

D is array element distance, and d=λ/2,

λ _ifor R _oci-th eigenwert, i=1,2 ..., N _r,

λ _jfor R _oca jth eigenwert, j=N _r+ 1, N _r+ 2 ..., MK,

And ${\mathrm{\λ}}_1\≥{\mathrm{\λ}}_2\≥...{\mathrm{\λ}}_{N_r}>{\mathrm{\λ}}_{N_r+1}=...={\mathrm{\λ}}_{\mathrm{MK}}={\mathrm{\σ}}^2,$

σ ²for noise power,

E _ifor R _octhe i-th eigenvalue λ _icharacteristic of correspondence vector,

${\mathrm{\Σ}}_s=\mathrm{diag}(\left[\begin{array}{cccc}{\mathrm{\λ}}_1& {\mathrm{\λ}}_2& ...& {\mathrm{\λ}}_{N_r}\end{array}\right])$ For the diagonal matrix that large eigenwert forms,

$U_s=\left[\begin{array}{cccc}{e}_1& e_2& ...& e_{N_r}\end{array}\right]$ For the wave subspace that large eigenwert is corresponding;

${\mathrm{\Σ}}_n=\mathrm{diag}(\left[\begin{array}{cccc}{\mathrm{\λ}}_{N_r+1}& {\mathrm{\λ}}_{N_r+2}& ...& {\mathrm{\λ}}_{\mathrm{MK}}\end{array}\right])$ For the diagonal matrix that little eigenwert forms,

$U_n=\left[\begin{array}{cccc}{e}_{N_r+1}& e_{N_r+2}& ...& e_{\mathrm{MK}}\end{array}\right]$ For the wave subspace that little eigenwert is corresponding;

[] ^hfor complex conjugate transpose operation;

Two or two step, the U will asked in the 21 step _nvalue substitute into Space Time combined spectrum algorithm for estimating

$P(\mathrm{\θ},f)=\frac{v^H(\mathrm{\θ},f)v(\mathrm{\θ},f)}{v^H(\mathrm{\θ},f)U_n{U_n}^{H}v(\mathrm{\θ},f)}$ (formula three)

In, obtain sea echo Space Time Power estimation value P (θ, f) of each distance annulus, then search for the positive and negative single order Bragg of actual measurement in P (θ, f) and compose position, peak with obtain the positive and negative single order Bragg of actual measurement and compose the position of peak in corresponding probe unit;

Wherein, $v(\mathrm{\θ},f)=b\left(f\right)\⊗a\left(\mathrm{\θ}\right)$ For steering vector during sky,

A (θ)=[1 exp (j2 π d cos (θ) λ) ... exp (j2 π (M-1) d cos (θ) λ)] ^tfor the steric direction vector of orientation angle θ,

B (f)=[1 exp (j2 π fT _r) ... exp (j2 π (K-1) fT _r)] ^tfor pointing to the time steering vector of frequency f,

survey positive single order Bragg for boat-carrying high-frequency ground wave radar to compose in angle on Doppler frequency,

for the negative single order Bragg of boat-carrying high-frequency ground wave radar actual measurement composes in angle on Doppler frequency.

Embodiment four: present embodiment is described see Fig. 1,2 and 3, the difference of present embodiment and a kind of surperficial flow measuring method based on single boat-carrying high-frequency ground wave radar of standing described in embodiment three is, ask for the radial flow velocity on corresponding probe unit according to the position of each probe unit being surveyed positive and negative single order Bragg spectrum peak in the 3rd described step, thus the detailed process obtaining the radial flow fields distribution in whole tested marine site is

31 step, calculate the position that in each distance annulus, theoretical positive and negative single order Brgg composes place, peak on each probe unit and be respectively with wherein

for the theoretical positive single order Bragg of boat-carrying high-frequency ground wave radar composes in angle on Doppler frequency,

for boat-carrying high-frequency ground wave radar theoretical negative single order Bragg composes in angle on Doppler frequency,

for Bragg frequency,

G is acceleration of gravity;

The Doppler frequency that three or two step, the Doppler frequency of being composed by the actual measurement positive single order Bragg on each probe unit in same distance annulus and the positive single order Bragg of theory compose does difference, obtains

Actual measurement in same distance annulus on each probe unit is born the Doppler frequency that single order Bragg composes and do difference with the Doppler frequency that theoretical negative single order Bragg composes, acquisition

Seek out the Doppler frequency change on each probe unit caused by radial ocean current in same distance annulus

△ f=(△ f _{positive Bragg}+ △ f _{negative Bragg})/2 (formula four),

Three threes, the Doppler frequency change △ f in the same distance annulus sought out in the three or two step on each probe unit caused by radial ocean current to be substituted into

$v=\frac{\mathrm{\λ\Δf}}{2}$ (formula five),

Obtain the radial flow velocity v of each probe unit, thus obtain the radial flow fields distribution (v in whole tested marine site _r,k, θ _r,k);

Wherein, v _r,kbe the radial flow velocity in r distance annulus on a kth probe unit,

θ _r,kbe the angle in r distance annulus on a kth probe unit,

R=1,2 ..., R _b, R _bfor distance annulus number,

K=1,2 ..., R _a, R _afor probe unit number in each distance annulus.

Embodiment five: present embodiment is described see Fig. 1,2 and 3, the difference of present embodiment and a kind of surperficial flow measuring method based on single boat-carrying high-frequency ground wave radar of standing described in embodiment four is, the detailed process utilizing least square method to ask for each surperficial flow vector field optimum on the whole in the 5th described step is

Will

${\mathrm{\Δv}}_{n,k}^r=v_{r,n+k}-\frac{1}{3}\underset{n=-1}{\overset{1}{\mathrm{\Σ}}}{v}_{r,n+k}$ (formula six)

Substitute into

$V_{r,k}=\frac{\underset{n=-1}{\overset{1}{\mathrm{\Σ}}}{v}_{r,n+k}\cos ({\mathrm{\φ}}_{r,k}-{\mathrm{\θ}}_{r,n+k})/{\left({\mathrm{\Δv}}_{n,k}^r\right)}^2}{\underset{n=-1}{\overset{1}{\mathrm{\Σ}}}{[\cos ({\mathrm{\φ}}_{r,k}-{\mathrm{\θ}}_{r,n+k})/{\mathrm{\Δr}}_{n,k}^r]}^2}$ (formula seven)

In, obtain V _r,kvalue, then by V _r,kvalue substitute into

$({\hat{V}}_{r,k},{\widehat{\mathrm{\φ}}}_{r,k})=\underset{{\mathrm{\φ}}_{r,k}}{\min }\underset{n=-1}{\overset{1}{\mathrm{\Σ}}}{\left[\frac{v_{r,n+k}-V_{r,k}\cos ({\mathrm{\φ}}_{r,k}-{\mathrm{\θ}}_{r,n+k})}{{\mathrm{\Δv}}_{n,k}^r}\right]}^2$ (formula eight)

In, obtain surperficial flow vector field optimum on each probe unit work as n+k>R _atime, get n+k=R _a; As n+k<1, get n+k=1;

Wherein, n=-1,0,1;

it is the amplitude in the vector flow field in r distance annulus on a kth probe unit;

it is the angle in r distance annulus on a kth probe unit;

V _{r, n+k}it is the radial flow velocity in r distance annulus on the n-th+k probe unit;

V _r,kfor the amplitude of vector flow field search on a kth probe unit in r distance annulus;

φ _r,kfor the angle of vector flow field search on a kth probe unit in r distance annulus;

θ _{r, n+k}it is the angle in r distance annulus on the n-th+k probe unit;

it is the error flow velocity of radial flow velocity in r distance annulus on the n-th+k probe unit and mean flow rate.

In present embodiment, the coverage distance of actual boat-carrying system for high-frequency earth wave radar can reach 200km, get △ R=2km, △ θ=2 °, here the situation in vector flow field in 9 range units is provided, to simulate the flow velocity in vector flow field for 0.5m/s, the performance of the 5th step is checked along the even ocean current in Platform movement direction in direction.The two-dimensional vector flow field of simulation is specifically see Fig. 4, and the vector flow field of inverting the results are shown in 5 and Fig. 6,

The distribution situation of two-dimensional vector flow field in nine continuous print distance annulus of simulation, specifically see Fig. 4.Without in radial flow measuring error situation, utilized the two-dimensional vector flow field of Least-squares inversion by the angular resolution reducing system, specifically see Fig. 5; But in actual measurement process, measuring error is unavoidable;

Having in radial flow measuring error situation, utilized the two-dimensional vector flow field of Least-squares inversion by the angular resolution reducing system, specifically see Fig. 6; Providing average in Fig. 6 is 0, variance be 0.01 white Gaussian noise join the inversion result in vector flow field after accurate radial flow fields, obviously, the measurement performance of the method is subject to considerable influence.Therefore, the present invention on this basis, think boat-carrying high-frequency ground wave radar to same probe unit adjacent multiple measurement the moment institute obtain optimum surperficial flow vector field be same flow field, the temporal resolution of system is reduced, therefore, be engraved in the vector flow field recorded in same probe unit when utilizing multiple and be weighted the measurement performance reduction problem that on average can effectively reduce because systematic error causes;

Wherein, the 1m/s in Fig. 4,5,6 and 8 is all for the reference of stream field flow velocity;

Boat-carrying high-frequency ground wave radar measures the geometric relationship figure of two-dimensional vector ocean current, specifically see Fig. 7 at diverse location to same probe unit; A, b and c to be respectively in boat-carrying Platform movement process three adjacent observation positions; for the vector flow field that a observation position records in same probe unit; for the vector flow field that b observation position records in same probe unit; for the vector flow field that c observation position records in same probe unit;

When there being measuring error, the vector flow field obtained after the vector flow field weighted mean record in same probe unit adjacent 9 observation positions, specifically see Fig. 8.

Embodiment six: present embodiment is described see Fig. 1 and 2, the difference of present embodiment and a kind of surperficial flow measuring method based on single boat-carrying high-frequency ground wave radar of standing described in embodiment four is, the span of described A is from 0.5 ° to 2 °.

Claims (6)

1., based on a surperficial flow measuring method for single station boat-carrying high-frequency ground wave radar, it is characterized in that, it comprises the steps:

The first step, systematic parameter according to boat-carrying high-frequency ground wave radar, tested marine site equidistantly, is angularly divided into multiple fan-shaped grid, and each grid is a probe unit;

Second step, utilize the sea echo Space Time spectrum of Space Time combined spectrum method of estimation to each distance annulus that boat-carrying high-frequency ground wave radar detects to estimate, obtained on each probe unit by spectrum search and survey the position that positive and negative single order Bragg composes peak;

3rd step, compose the position at peak ask for radial flow velocity on corresponding probe unit according to each probe unit being surveyed positive and negative single order Bragg, thus obtain the radial flow fields distribution in whole tested marine site, and the angular resolution of the now radial flow fields distribution in whole tested marine site is initial angle resolution A;

4th step, be located at boat-carrying high-frequency ground wave radar measure time range in, the surface flow field in tested marine site is consistent, and only there is a flow field in each probe unit;

5th step, adjacent three probe units in same distance annulus are merged as a whole, radial flow valuve in these three probe units be by same vector flow field they separately projection in the radial direction produce, reduce initial angle resolution A, obtain current angular resolution B, and described B=3A, then utilize least square method to ask for each surperficial flow vector field optimum on the whole;

6th step, boat-carrying high-frequency ground wave radar to same probe unit adjacent multiple measurement the moment institute obtain optimum surperficial flow vector field be same flow field, utilizing the surperficial flow vector field to being engraved in the optimum recorded in same probe unit during multiple measurement to be weighted on average, obtaining flow vector field, surface, tested marine site.

2. a kind of surperficial flow measuring method based on single station boat-carrying high-frequency ground wave radar according to claim 1, it is characterized in that, according to the systematic parameter of boat-carrying high-frequency ground wave radar in the described first step, the detailed process tested marine site equidistantly, being angularly divided into multiple fan-shaped grid is

First, tested marine site equidistantly divides by the system range resolution according to boat-carrying high-frequency ground wave radar, and then tested marine site angularly divides by this moment angular resolution adopting orientation algorithm for estimating to obtain, thus obtain all fan-shaped grid in tested survey marine site.

3. a kind of surperficial flow measuring method based on single station boat-carrying high-frequency ground wave radar according to claim 2, it is characterized in that, the sea echo Space Time spectrum of Space Time combined spectrum method of estimation to each distance annulus that boat-carrying high-frequency ground wave radar detects is utilized to estimate in described second step, the detailed process being obtained the position of each probe unit being surveyed positive and negative single order Bragg spectrum peak by spectrum search is

21 step, each sea echo covariance matrix R apart from annulus that boat-carrying high-frequency ground wave radar is detected _occarry out feature decomposition, obtain

$\begin{array}{c}{R}_{\mathrm{oc}}=\underset{i=1}{\overset{N_r}{\mathrm{\&Sigma;}}}{\mathrm{\&lambda;}}_i{e}_i{e}_i^H+\underset{j=N_r+1}{\overset{\mathrm{MK}}{\mathrm{\&Sigma;}}}{\mathrm{\&lambda;}}_j{e}_j{e}_j^H\\ =U_s{\mathrm{\&Sigma;}}_s{U}_s^H+U_n{\mathrm{\&Sigma;}}_n{U}_n^H\end{array}---\left(1\right);$

U is asked for by formula (1) _n;

Wherein, N _rfor the order of covariance matrix, and

$N_r=\mathrm{int}[\frac{4d}{\mathrm{\&lambda;}}(M-1+\mathrm{\&beta;}(K-2))+2]---\left(2\right);$

M is array number;

K is fast umber of beats;

Int [] represents that positive dirction rounds;

β=2v _pt _r/ d represents the number of half array element distance that Texas tower moves within a frequency modulation cycle;

V _pfor the Platform movement speed of boat-carrying high-frequency ground wave radar;

T _rfor the frequency modulation cycle;

λ is radar operation wavelength,

D is array element distance, and d=λ/2

λ _ifor R _oci-th eigenwert, i=1,2 ..., N _r,

λ _jfor R _oca jth eigenwert, j=N _r+ 1, N _r+ 2 ..., MK,

And ${\mathrm{\&lambda;}}_1\&GreaterEqual;{\mathrm{\&lambda;}}_2\&GreaterEqual;...{\mathrm{\&lambda;}}_{N_r}>{\mathrm{\&lambda;}}_{N_r+1}=...={\mathrm{\&lambda;}}_{\mathrm{MK}}={\mathrm{\&sigma;}}^2,$

σ ²for noise power,

E _ifor R _octhe i-th eigenvalue λ _icharacteristic of correspondence vector,

${\mathrm{\&Sigma;}}_s=\mathrm{diag}\left(\left[\begin{array}{cccc}{\mathrm{\&lambda;}}_1& {\mathrm{\&lambda;}}_2& ...& {\mathrm{\&lambda;}}_{N_r}\end{array}\right]\right)$ For the diagonal matrix that large eigenwert forms,

$U_s=\left[\begin{array}{cccc}{e}_1& e_2& ...& e_{N_r}\end{array}\right]$ For the wave subspace that large eigenwert is corresponding;

${\mathrm{\&Sigma;}}_n=\mathrm{diag}\left(\left[\begin{array}{cccc}{\mathrm{\&lambda;}}_{N_r+1}& {\mathrm{\&lambda;}}_{N_r+2}& ...& {\mathrm{\&lambda;}}_{\mathrm{MK}}\end{array}\right]\right)$ For the diagonal matrix that little eigenwert forms,

$U_n=\left[\begin{array}{cccc}{e}_{N_r+1}& e_{N_r+2}& ...& e_{\mathrm{MK}}\end{array}\right]$ For the wave subspace that little eigenwert is corresponding;

[] ^hfor complex conjugate transpose operation;

Two or two step, the U will asked in the 21 step again _nvalue substitute into Space Time combined spectrum algorithm for estimating

$P(\mathrm{\&theta;},f)=\frac{v^H(\mathrm{\&theta;},f)v(\mathrm{\&theta;},f)}{v^H(\mathrm{\&theta;},f)U_n{U_n}^{H}v(\mathrm{\&theta;},f)}---\left(3\right)$

In, obtain sea echo Space Time Power estimation value P (θ, f) of each distance annulus, then search for the positive and negative single order Bragg of actual measurement in P (θ, f) and compose position, peak with obtain the positive and negative single order Bragg of actual measurement and compose the position of peak in corresponding probe unit;

Wherein, $v(\mathrm{\&theta;},f)=b\left(f\right)\&CircleTimes;a\left(\mathrm{\&theta;}\right)$ For steering vector during sky,

A (θ)=[1 exp (j2 π dcos (θ)/λ) ... exp (j2 π (M-1) dcos (θ)/λ)] ^tfor the steric direction vector of orientation angle θ,

B (f)=[1 exp (j2 π fT _r) ... exp (j2 π (K-1) fT _r)] ^tfor pointing to the time steering vector of frequency f,

survey positive single order Bragg for boat-carrying high-frequency ground wave radar to compose in angle on Doppler frequency,

for the negative single order Bragg of boat-carrying high-frequency ground wave radar actual measurement composes in angle on Doppler frequency.

4. a kind of surperficial flow measuring method based on single station boat-carrying high-frequency ground wave radar according to claim 3, it is characterized in that, ask for the radial flow velocity on corresponding probe unit according to the position of each probe unit being surveyed positive and negative single order Bragg spectrum peak in the 3rd described step, thus the detailed process obtaining the radial flow fields distribution in whole tested marine site is

31 step, calculate the position that in each distance annulus, theoretical positive and negative single order Brgg composes place, peak on each probe unit and be respectively with wherein

for the theoretical positive single order Bragg of boat-carrying high-frequency ground wave radar composes in angle on Doppler frequency,

for boat-carrying high-frequency ground wave radar theoretical negative single order Bragg composes in angle on Doppler frequency,

for Bragg frequency,

G is acceleration of gravity;

The Doppler frequency that three or two step, the Doppler frequency of being composed by the actual measurement positive single order Bragg on each probe unit in same distance annulus and the positive single order Bragg of theory compose does difference, obtains

Actual measurement in same distance annulus on each probe unit is born the Doppler frequency that single order Bragg composes and do difference with the Doppler frequency that theoretical negative single order Bragg composes, acquisition

Seek out the Doppler frequency change on each probe unit caused by radial ocean current in same distance annulus

△ f=(△ f _{positive Bragg}+ △ f _{negative Bragg})/2 (4),

Three threes, the Doppler frequency change △ f in the same distance annulus sought out in the three or two step on each probe unit caused by radial ocean current to be substituted into

$v=\frac{\mathrm{\&lambda;\&Delta;f}}{2}---\left(5\right),$

Obtain the radial flow velocity v of each probe unit, thus obtain the radial flow fields distribution (v in whole tested marine site _{r, k,}θ _r,k);

Wherein, v _r,kbe the radial flow velocity in r distance annulus on a kth probe unit,

θ _r,kbe the angle in r distance annulus on a kth probe unit,

R=1,2 ..., R _b, R _bfor distance annulus number,

K=1,2 ..., R _a, R _afor probe unit number in each distance annulus.

5. a kind of surperficial flow measuring method based on single station boat-carrying high-frequency ground wave radar according to claim 4, is characterized in that, the detailed process utilizing least square method to ask for each surperficial flow vector field optimum on the whole in the 5th described step is,

Will

${\mathrm{\&Delta;v}}_{n,k}^r=v_{r,n+k}-\frac{1}{3}\underset{n=-1}{\overset{1}{\mathrm{\&Sigma;}}}{v}_{r,n+k}---\left(6\right)$

Substitute into

$V_{r,k}=\frac{\underset{n=-1}{\overset{1}{\mathrm{\&Sigma;}}}{v}_{r,n+k}\cos ({\mathrm{\&phi;}}_{r,k}-{\mathrm{\&theta;}}_{r,n+k})/{\left({\mathrm{\&Delta;v}}_{n,k}^r\right)}^2}{\underset{n=-1}{\overset{1}{\mathrm{\&Sigma;}}}{[\cos ({\mathrm{\&phi;}}_{r,k}-{\mathrm{\&theta;}}_{r,n+k})/{\mathrm{\&Delta;v}}_{n,k}^r]}^2}---\left(7\right)$

In, obtain V _r,kvalue, then by V _r,kvalue substitute into

$({\hat{V}}_{r,k},{\widehat{\mathrm{\&phi;}}}_{r,k})=\underset{{\mathrm{\&phi;}}_{r,k}}{\min }\underset{n=-1}{\overset{1}{\mathrm{\&Sigma;}}}{\left[\frac{v_{r,n+k}-V_{r,k}\cos ({\mathrm{\&phi;}}_{r,k}-{\mathrm{\&theta;}}_{r,n+l})}{{\mathrm{\&Delta;v}}_{n,k}^r}\right]}^2---\left(8\right)$

In, obtain surperficial flow vector field optimum on each probe unit work as n+k>R _atime, get n+k=R _a; As n+k<1, get n+k=1;

Wherein, n=-1,0,1;

it is the amplitude in the vector flow field in r distance annulus on a kth probe unit;

it is the angle in r distance annulus on a kth probe unit;

V _{r, n+k}it is the radial flow velocity in r distance annulus on the n-th+k probe unit;

V _r,kfor the amplitude of vector flow field search on a kth probe unit in r distance annulus;

φ _r,kfor the angle of vector flow field search on a kth probe unit in r distance annulus;

θ _{r, n+k}it is the angle in r distance annulus on the n-th+k probe unit;

it is the error flow velocity of radial flow velocity in r distance annulus on the n-th+k probe unit and mean flow rate.

6. a kind of surperficial flow measuring method based on single station boat-carrying high-frequency ground wave radar according to claim 1, it is characterized in that, the span of described A is from 0.5 ° to 2 °.