CN105204022A - Inversion method of sea surface wind field and apparatus thereof - Google Patents

Abstract

The invention discloses an inversion method of a sea surface wind field and an apparatus thereof. The method comprises the following steps of acquiring measurement data of a GNSS reflection signal at a specular reflection point on a sea surface and processing the measurement data so as to obtain smooth measurement data; based on a DDM power integration function expression obtained based on a double-base radar observation equation, acquiring a relation between the measurement data and a sea surface scattering coefficient, and calculating the sea surface scattering coefficient at the specular reflection point according to the relation and the smooth measurement data; based on a Z-V model, acquiring a relation between the sea surface scattering coefficient and a sea surface slope probability density function, and calculating a probability density function of a sea surface slope according to the calculated sea surface scattering coefficient and the relation between the sea surface scattering coefficient and the sea surface slope probability density function; according to the probability density function of the sea surface slope, calculating a sea surface wind speed and a wind direction. By using the method and the apparatus of the invention, a sea surface state can be rapidly and accurately inverted in real time.

Description

The inversion method of Ocean Wind-field and device

Technical field

The present invention relates to technical field of satellite navigation, particularly relate to a kind of inversion method and device of spaceborne GNSS-R Ocean Wind-field real-time.

Background technology

In recent years, along with to GLONASS (Global Navigation Satellite System) (GlobalNavigationSatelliteSystem, GNSS) the constantly dark people studied, some scholars find, outside traditional field of satellite navigation, the reflected signal of GNSS can be received and utilize, open a new research field thus, GNSS reflects (globalnavigationsatellitesystem-reflection, GNSS-R) technology, therefore the GNSS-R Detection Techniques of research earth sea condition also develop into one of a kind of novel space exploration technology.GNSS-R sea condition Detection Techniques are subject to the scattering on sea when inciding on sea based on GNSS signal, different sea conditions can produce the principle of Different Effects to the scattering of GNSS signal, inverting can obtain sea condition parameter by carrying out research to the characteristic of the scattered signal received, thus can realize detecting the marine environment of global range.

Ocean Wind-field GNSS-R Detection Techniques obtain Ocean Wind-field mainly through carrying out research inverting to sea GNSS scattering power characteristic.GNSS-R sea inversion method conventional in prior art is scattering power waveform fitting, as shown in Figure 1, its ultimate principle is: first, is obtained the theoretical waveform of the surface scattering power under the conditions such as different satellite altitude, satellite elevation angle, ocean surface wind speed, wind direction of ocean surface by wave spectrum model; Then, carrying out the aftertreatments such as filtering noise reduction by measuring to receiver the surface scattering power data obtained, obtaining the measured waveform of surface scattering power; Finally, theoretical waveform and measured waveform are carried out matching, and inverting obtains corresponding ocean surface wind speed and wind direction of ocean surface.There is many-sided limitation and the deficiencies such as calculated amount is large, wind direction blur level is high, matching out of true in this inversion method.

Summary of the invention

In view of this, for overcoming at least one shortcoming above-mentioned, and following at least one advantage is provided.The invention discloses a kind of inversion method and device of Ocean Wind-field, for inverting sea condition parameter wind speed and direction, there is rapidity and real-time, and accuracy is high, GNSS-R Ocean Wind-field field of detecting can be widely used in.

For solving the problems of the technologies described above, the present invention by the following technical solutions:

An inversion method for Ocean Wind-field, comprising:

Obtain the measurement data of the GNSS reflected signal at specular reflection point place on sea, and described measurement data is processed obtain level and smooth measurement data;

Based on the DDM power integral function expression obtained based on multistatic sonar observation equation, obtain the relation between the measurement data of GNSS reflected signal and surface scattering coefficient, calculate the surface scattering coefficient at described specular reflection point place according to described level and smooth measurement data and the relation between described measurement data and surface scattering coefficient;

Obtain the relation between surface scattering coefficient and sea slope probability density function based on Z-V model, calculate the probability density function of sea slope according to the described surface scattering coefficient calculated and the relation between described surface scattering coefficient and sea slope probability density function; And

Probability density function according to described sea slope calculates ocean surface wind speed and wind direction of ocean surface.

In the inversion method of Ocean Wind-field as above, the relation between the measurement data of described GNSS reflected signal and surface scattering coefficient represents with formula (1):

${\mathrm{\σ}}^0\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)=\frac{\mathrm{\Σ}(\mathrm{\τ},f_D)}{\left|J(\mathrm{\τ},f_D)\right|}\frac{1}{P_T{\mathrm{\λ}}^2{T_i}^2}\×\frac{{\left(4\mathrm{\π}\right)}^3{R}_t^2\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)R_r^2\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)}{G_t\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)G_r\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)}---\left(1\right)$

Wherein, σ ⁰for the scattering coefficient at specular reflection point place on sea, for the position vector of reflection spot each on sea, τ be on sea each other reflection spot described relative to the delay of described specular reflection point, f _dfor other reflection spot described each on sea is relative to the Doppler shift of described specular reflection point, λ is signal wavelength, T _ifor coherent integration time, R _tfor other reflection spot to the distance of transmitter, R _rfor other reflection spot to the distance of receiver, G _tfor transmitter antenna gain (dBi), G _rfor receiving antenna gain; Described reflection spot comprises described specular reflection point and other reflection spot.

In the inversion method of Ocean Wind-field as above, the relation between described surface scattering coefficient and sea slope probability density function represents with formula (14):

Wherein, σ ⁰the scattering coefficient at specular reflection point place on described sea, for sea slope, for scattering vector, for the fresnel reflection coefficient of given polarization mode, for wind set-up probability density function.

In the inversion method of Ocean Wind-field as above, the described probability density function according to described sea slope calculates ocean surface wind speed and comprises:

Sea slope is calculated based on formula (15) and formula (16):

$\begin{array}{c}\mathrm{PDF}(m,\mathrm{\α})=[1+T(m,\mathrm{\α})]{\left(2\mathrm{\π}{\mathrm{\σ}}_c{\mathrm{\σ}}_u\right)}^{-1}\exp \{-{(m/2{\mathrm{\σ}}_c{\mathrm{\σ}}_u)}^2[{\mathrm{\σ}}_c^2+{\mathrm{\σ}}_u^2\\ +({\mathrm{\σ}}_c^2-{\mathrm{\σ}}_u^2)\cos 2\mathrm{\α}\left]\right\}\end{array}---\left(15\right)$

$m={(S_c^2+S_u^2)}^{0.5},\mathrm{\α}={\tan }^{-1}(S_c/S_u)---\left(16\right)$

Wherein, S _cfor the sea slope of cross-wind direction, S _ufor the sea slope of downwind, for the slope variance of cross-wind direction, for the slope variance of downwind;

Based on calculated sea slope, calculate sea Mean Square Slope according to formula (17);

${\mathrm{MSS}}_u=(s_{u1}^2+s_{u2}^2+...+s_{\mathrm{ui}}^2)/i,{\mathrm{MSS}}_c=(s_{c1}^2+s_{c2}^2+...+s_{\mathrm{cj}}^2)/j---\left(17\right)$

Wherein, MSS _ufor the sea Mean Square Slope of downwind, MSS _cfor the sea Mean Square Slope of cross-wind direction, S _cfor the sea slope of cross-wind direction, S _ufor the sea slope of downwind, i is the quantity of the sea slope participating in the sea Mean Square Slope calculating downwind, and j is the quantity of the sea slope participating in the sea Mean Square Slope calculating cross-wind direction; And

Based on calculated described sea Mean Square Slope, calculate described ocean surface wind speed according to formula (18):

MSS _u(U)＝0.45·(0.00+0.00316·f(U))

MSS _c(U)＝0.45·(0.003+0.00192·f(U))(18)

Wherein, U is and local actual wind speed U _truerelevant wind speed, and meet formula (19):

f(U)＝U0.00＜U≤3.49

f(U)＝6·in(U)-4.03.49＜U≤46

f(U)＝0.411·U46＜U(19)。

In the inversion method of Ocean Wind-field as above, the described probability density function according to described sea slope calculates wind direction of ocean surface and comprises:

Based on formula (20) and (21), and the probability density function of described sea slope calculates wind direction of ocean surface:

$\mathrm{PDF}\left(\stackrel{\→}{s}\right)=\frac{1}{2\mathrm{\π}\sqrt{\det \left(M\right)}}\exp [-\frac{1}{2}{\left(\begin{array}{c}{S}_x\\ S_y\end{array}\right)}^T{M}^{-1}\left(\begin{array}{c}{S}_x\\ S_y\end{array}\right)]---\left(20\right)$

Wherein, for the angle in (or against the wind) direction and x-axis direction with the wind in plane of incidence, MSS _urepresent the sea Mean Square Slope of downwind, MSS _crepresent the sea Mean Square Slope of cross-wind direction.

In the inversion method of Ocean Wind-field as above, on described acquisition sea, the measurement data of the GNSS reflected signal at specular reflection point place comprises:

The method adopting wave beam to control obtains the measurement data of the GNSS reflected signal at specular reflection point place on sea.

For solving the problems of the technologies described above, the present invention also by the following technical solutions:

An inverting device for Ocean Wind-field, comprising:

Measurement data acquisition module, for obtaining the measurement data of the GNSS reflected signal at specular reflection point place on sea, and processes described measurement data and obtains level and smooth measurement data;

Scattering coefficient computing module, for based on the DDM power integral function expression obtained based on multistatic sonar observation equation, obtain the relation between the measurement data of GNSS reflected signal and surface scattering coefficient, calculate the surface scattering coefficient at described specular reflection point place according to described level and smooth measurement data and the relation between described measurement data and surface scattering coefficient;

Probability density function computing module, for obtaining the relation between surface scattering coefficient and sea slope probability density function based on Z-V model, calculate the probability density function of sea slope according to the described surface scattering coefficient calculated and the relation between described surface scattering coefficient and sea slope probability density function; And

Inverting module, calculates ocean surface wind speed and wind direction of ocean surface for the probability density function according to described sea slope.

In the inverting device of Ocean Wind-field as above, described scattering coefficient computing module calculates described scattering coefficient based on the measurement data obtained handled by described measurement data acquisition module and formula (1);

${\mathrm{\σ}}^0\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)=\frac{\mathrm{\Σ}(\mathrm{\τ},f_D)}{\left|J(\mathrm{\τ},f_D)\right|}\frac{1}{P_T{\mathrm{\λ}}^2{T_i}^2}\×\frac{{\left(4\mathrm{\π}\right)}^3{R}_t^2\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)R_r^2\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)}{G_t\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)G_r\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)}---\left(1\right)$

Wherein, σ ⁰for the scattering coefficient at specular reflection point place on sea, for the position vector of reflection spot each on sea, τ be on sea each other reflection spot described relative to the delay of described specular reflection point, f _dfor other reflection spot described each on sea is relative to the Doppler shift of described specular reflection point, λ is signal wavelength, T _ifor coherent integration time, R _tfor other reflection spot to the distance of transmitter, R _rfor other reflection spot to the distance of receiver, G _tfor transmitter antenna gain (dBi), G _rfor receiving antenna gain; Described reflection spot comprises described specular reflection point and other reflection spot.

In the inverting device of Ocean Wind-field as above, the scattering coefficient that described probability density function computing module calculates based on described scattering coefficient computing module and formula (14) calculate described probability density function;

Wherein, σ ⁰the scattering coefficient at specular reflection point place on described sea, for sea slope, for scattering vector, for the fresnel reflection coefficient of given polarization mode, for wind set-up probability density function.

In the inverting device of Ocean Wind-field as above, described inverting module comprises:

Wind speed computing unit, for calculating sea slope based on formula (15) and formula (16):

$\begin{array}{c}\mathrm{PDF}(m,\mathrm{\α})=[1+T(m,\mathrm{\α})]{\left(2\mathrm{\π}{\mathrm{\σ}}_c{\mathrm{\σ}}_u\right)}^{-1}\exp \{-{(m/2{\mathrm{\σ}}_c{\mathrm{\σ}}_u)}^2[{\mathrm{\σ}}_c^2+{\mathrm{\σ}}_u^2\\ +({\mathrm{\σ}}_c^2-{\mathrm{\σ}}_u^2)\cos 2\mathrm{\α}\left]\right\}\end{array}---\left(15\right)$

$m={(S_c^2+S_u^2)}^{0.5},\mathrm{\α}={\tan }^{-1}(S_c/S_u)---\left(16\right)$

Wherein, S _cfor the sea slope of cross-wind direction, S _ufor the sea slope of downwind, for the slope variance of cross-wind direction, for the slope variance of downwind;

Described wind speed computing unit also for based on calculated sea slope, calculates sea Mean Square Slope according to formula (17);

${\mathrm{MSS}}_u=(s_{u1}^2+s_{u2}^2+...+s_{\mathrm{ui}}^2)/i,{\mathrm{MSS}}_c=(s_{c1}^2+s_{c2}^2+...+s_{\mathrm{cj}}^2)/j---\left(17\right)$

Wherein, MSS _ufor the sea Mean Square Slope of downwind, MSS _cfor the sea Mean Square Slope of cross-wind direction, S _cfor the sea slope of cross-wind direction, S _ufor the sea slope of downwind, i is the quantity of the sea slope participating in the sea Mean Square Slope calculating downwind, and j is the quantity of the sea slope participating in the sea Mean Square Slope calculating cross-wind direction; And

Described wind speed computing unit, also for based on calculated described sea Mean Square Slope, calculates described ocean surface wind speed according to formula (18):

MSS _u(U)＝0.45·(0.00+0.00316·f(U))

MSS _c(U)＝0.45·(0.003+0.00192·f(U))(18)

Wherein, U is and local actual wind speed U _truerelevant wind speed, and meet formula (19):

f(U)＝U0.00＜U≤3.49

f(U)＝6·in(U)-4.03.49＜U≤46

f(U)＝0.411·U46＜U(19)。

In the inverting device of Ocean Wind-field as above, described inverting module also comprises:

Wind direction computing unit, for based on formula (20) and (21), and the probability density function of described sea slope calculates wind direction of ocean surface:

$\mathrm{PDF}\left(\stackrel{\→}{s}\right)=\frac{1}{2\mathrm{\π}\sqrt{\det \left(M\right)}}\exp [-\frac{1}{2}{\left(\begin{array}{c}{S}_x\\ S_y\end{array}\right)}^T{M}^{-1}\left(\begin{array}{c}{S}_x\\ S_y\end{array}\right)]---\left(20\right)$

Wherein, for the angle in (or against the wind) direction and x-axis direction with the wind in plane of incidence; MSS _urepresent the sea Mean Square Slope of downwind, MSS _crepresent the sea Mean Square Slope of cross-wind direction.

In the inverting device of Ocean Wind-field as above, the measurement data of described measurement data acquisition module specifically for adopting the method for wave beam control to obtain the GNSS reflected signal at specular reflection point place on sea.

By adopting technique scheme, of the present invention reached beneficial effect is: compared with prior art, simple to operate, avoids the larger calculated amount of measured waveform and the matching of theoretical waveform subsequent treatment; And this invention removes the uneven impact on ocean surface wind retrieving in sea, improve validity and the real-time of sea condition parametric inversion; Can be applicable to the fields such as sea storm initial stage formation detection, the quick early warning of sea storm, there is important using value and wide popularizing application prospect.

Accompanying drawing explanation

In order to be illustrated more clearly in the technical scheme in the embodiment of the present invention, below the accompanying drawing used required in describing the embodiment of the present invention is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to the content of the embodiment of the present invention and these accompanying drawings.

Fig. 1 is the process flow diagram of the inversion method of Ocean Wind-field of the prior art;

The process flow diagram of the inversion method of the Ocean Wind-field that Fig. 2 provides for one embodiment of the present of invention;

The structural representation of the inverting device of the Ocean Wind-field that Fig. 3 provides for an alternative embodiment of the invention.

Embodiment

The technical matters solved for making the present invention, the technical scheme of employing and the technique effect that reaches are clearly, be described in further detail below in conjunction with the technical scheme of accompanying drawing to the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those skilled in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

Technical scheme of the present invention is further illustrated by embodiment below in conjunction with accompanying drawing.

embodiment 1

As shown in Figure 2, the process flow diagram of the inversion method of the Ocean Wind-field provided for one embodiment of the invention, the method comprises the following steps:

Step S10, the sea surface reflection receiver GNSS signal (i.e. GNSS reflected signal) to specular reflection point place reflection on sea is measured, obtain the measurement data comprising power data, and pre-service is carried out to the measurement data obtained, obtain level and smooth measurement data;

In the present embodiment, the power data obtained due to actual measurement is affected by noise larger, resolving of follow-up data can not be directly used in, therefore need to carry out pre-service to measurement data, the process such as such as non-coherent integration, filtering noise reduction, normalization, to obtain level and smooth scattering power measurement data and other measurement data;

Step S20, calculate the scattering coefficient at specular reflection point place based on formula (1);

${\mathrm{\σ}}^0\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)=\frac{\mathrm{\Σ}(\mathrm{\τ},f_D)}{\left|J(\mathrm{\τ},f_D)\right|}\frac{1}{P_T{\mathrm{\λ}}^2{T_i}^2}\×\frac{{\left(4\mathrm{\π}\right)}^3{R}_t^2\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)R_r^2\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)}{G_t\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)G_r\left(\stackrel{\→}{\mathrm{\ρ}}(\mathrm{\τ},f_D)\right)}---\left(1\right)$

Wherein, σ ⁰for the scattering coefficient at specular reflection point place on sea, for the position vector of reflection spot each on sea, τ be on sea other reflection spot each relative to the delay of specular reflection point, f _dfor other reflection spot each on sea is relative to the Doppler shift of specular reflection point, λ is signal wavelength, T _ifor coherent integration time, R _tfor reflection spot to the distance of transmitter, R _rfor reflection spot to the distance of receiver, G _tfor transmitter antenna gain (dBi), G _rfor receiving antenna gain; Wherein reflection spot comprises specular reflection point and other reflection spot, and specular reflection point is the point that power signal is the strongest; τ, f _d, R _t, R _rbe the measurement data that receiver receives.

Step S30, according to the scattering coefficient calculated in step S20, relation based on scattering coefficient in Zavorotny-Voronavich model (Z-V model) and sea slope probability density function calculates the probability density function of sea slope, scattering coefficient σ ⁰with sea slope probability density function relation such as formula shown in (14):

Wherein, for sea slope, for scattering vector, for the fresnel reflection coefficient of given polarization mode, for wind set-up probability density function, here it is the key parameter solving Ocean Wind-field.

Step S40, calculate ocean surface wind speed according to the probability density function that calculates in step S30;

Particularly, first, according to the model that CoxandMunk proposes, sea slope is approximate meet Gaussian distribution time, have formula (15) and (16) establishment:

$\begin{array}{c}\mathrm{PDF}(m,\mathrm{\α})=[1+T(m,\mathrm{\α})]{\left(2\mathrm{\π}{\mathrm{\σ}}_c{\mathrm{\σ}}_u\right)}^{-1}\exp \{-{(m/2{\mathrm{\σ}}_c{\mathrm{\σ}}_u)}^2[{\mathrm{\σ}}_c^2+{\mathrm{\σ}}_u^2\\ +({\mathrm{\σ}}_c^2-{\mathrm{\σ}}_u^2)\cos 2\mathrm{\α}\left]\right\}\end{array}---\left(15\right)$

$m={(S_c^2+S_u^2)}^{0.5},\mathrm{\α}={\tan }^{-1}(S_c/S_u)---\left(16\right)$

Wherein, S _cfor the sea slope of cross-wind direction, S _ufor the sea slope of downwind, for the slope variance of cross-wind direction, for the slope variance of downwind.

Then, according to the sea slope of calculated cross-wind direction and downwind, sea Mean Square Slope (mean-square-slope, MSS) of cross-wind direction and downwind can be solved based on formula (17):

${\mathrm{MSS}}_u=(s_{u1}^2+s_{u2}^2+...+s_{\mathrm{ui}}^2)/i,{\mathrm{MSS}}_c=(s_{c1}^2+s_{c2}^2+...+s_{\mathrm{cj}}^2)/j---\left(17\right)$

Wherein, MSS _urepresent the sea Mean Square Slope of downwind, MSS _crepresent the sea Mean Square Slope of cross-wind direction.

Finally, ocean surface wind speed can be calculated according to the sea Mean Square Slope solved and formula (18):

MSS _u(U)＝0.45·(0.00+0.00316·f(U))

MSS _c(U)＝0.45·(0.003+0.00192·f(U))(18)

Wherein, U is and local actual wind speed U _truerelevant wind speed, its relation is such as formula shown in (19):

f(U)＝U0.00＜U≤3.49

f(U)＝6·in(U)-4.03.49＜U≤46

f(U)＝0.411·U46＜U(19)

By above relational expression, just actual wind speed U can be solved.

Step S50, according to the probability density function calculated in step S30, based on formula (20), namely anisotropic binary Gaussian approximation distribution relation formula calculates wind direction of ocean surface:

$\mathrm{PDF}\left(\stackrel{\→}{s}\right)=\frac{1}{2\mathrm{\π}\sqrt{\det \left(M\right)}}\exp [-\frac{1}{2}{\left(\begin{array}{c}{S}_x\\ S_y\end{array}\right)}^T{M}^{-1}\left(\begin{array}{c}{S}_x\\ S_y\end{array}\right)]---\left(20\right)$

Wherein, the expression formula of matrix M is formula (21):

Wherein, for the angle in downwind or upwind and x-axis direction in plane of incidence, MSS _urepresent the sea Mean Square Slope of downwind, MSS _crepresent the sea Mean Square Slope of cross-wind direction.

Through type (20) and formula (21), just can solve actual wind direction.

After aforesaid operations completes, i.e. the inversion result of exportable sea condition parameter wind speed and direction.

In the present embodiment, for above-mentioned formula (1), its derivation is specific as follows:

Measuring the most perfect in GNSS-R equipment is delay-Doppler figure (Delay-DopplerMap, DDM), and it is based on multistatic sonar observation equation, derives the power integral form of DDM, and expression is such as formula shown in (2):

$\⟨{\left|Y(\mathrm{\τ},f_D)\right|}^2\⟩={T_i}^2{\∫}_{\stackrel{\→}{\mathrm{\ρ}}}{G}_t\left(\stackrel{\→}{\mathrm{\ρ}}\right)G_r\left(\stackrel{\→}{\mathrm{\ρ}}\right){\mathrm{\χ}}^2[t_0,\mathrm{\τ};f_D]\×g\left(\stackrel{\→}{\mathrm{\ρ}}\right)d^2\stackrel{\→}{\mathrm{\ρ}}---\left(2\right)$

Wherein, τ be on sea other reflection spot each relative to the delay of specular reflection point, f _dfor other reflection spot each on sea is relative to the Doppler shift of specular reflection point, T _ifor coherent integration time, for the position vector of reflection spot each on sea, χ is the Woodward ambiguity function (WAF) of C/A code, G _tfor transmitter antenna gain (dBi), G _rfor receiving antenna gain, g is a geometric condition describing scattering.

In the gps receiver, by antenna at t ₀+ t export signal u from different moment t ₀the PRN code a copied carries out cross-correlation, obtains the expression formula of Woodward ambiguity function, i.e. formula (3):

$\mathrm{\χ}[t_0,\mathrm{\τ};f_D]=\frac{1}{T_i}{\∫}_0^{T_i}a(t_0+t^{\′})a[t_0+t^{\′}+t]\×\exp [-2\mathrm{\πi}{f}_D{t}^{\′}]{\mathrm{dt}}^{\′}---\left(3\right)$

Further, following formula (4) is had to set up:

$\mathrm{\τ}\left(\stackrel{\→}{r}\right)=t-[R_0\left(\stackrel{\→}{r}\right)+R\left(\stackrel{\→}{r}\right)]/c;$

f _D(t ₀+t)＝f(t ₀+t)-f _c(4)

Wherein, represent the position vector of reflection spot, c represents the light velocity, f _crepresent the frequency transmitted.Suppose at time t ~ (R _{0, sp}+ R _spduring)/c, Doppler frequency does not have greatly changed, then set f (t ₀+ t) ≈ f (t ₀), and can convert to it is noted herein that, time t ₀as a reflection Doppler frequency f (t ₀) transmitter and the dependent parameter of receiver instantaneous velocity bring in the middle of function χ, like this, function χ can be regarded as function χ (τ, the f that has Two Variables _d).

Function a (t) in integral process be one about+1 and-1 pseudo-random sequence, here function χ (τ, f _d) assuming a simple model, it is resolve that this model depends on along time shaft and frequency axis.So function χ (τ, f _d) at f _d=0 place can convert a known function Λ (τ) to:

$\begin{array}{c}\mathrm{\Λ}\left(\mathrm{\τ}\right)\≡\mathrm{\χ}(\mathrm{\τ},0)=\frac{1}{T_i}{\∫}_0^{T_i}a(t_0+t^{\′})a(t_0+t^{\′}+\mathrm{\τ}){\mathrm{dt}}^{\′}\\ =\left\{\begin{array}{c}1-\left|\mathrm{\τ}\right|/{\mathrm{\τ}}_c,\left|\mathrm{\τ}\right|\≤{\mathrm{\τ}}_c(1+{\mathrm{\τ}}_c/T_i)\\ -{\mathrm{\τ}}_c/T_i,\left|{\mathrm{\τ}}_c\right|>{\mathrm{\τ}}_c(1+{\mathrm{\τ}}_c/T_i)\end{array}\right.\end{array}---\left(5\right)$

Function Λ (τ) exists | τ | and≤τ _c(1+ τ _c/ T _i) triangular form at place is overlap based on the function a (t+ τ) identical rectangle " chip " from function a (t) and distortion.For | τ _c| > τ _c(1+ τ _c/ T _i), result-τ _c/ T _icome from the special nature of the so-called maximum-length code used in GPS, that is the quantity of "-" will exceed the quantity of "+" once, due to τ _c< < T _i, the τ in above formula thus in the present embodiment, is replaced with 0 _c< < T _i, come further to calculate.

When τ=0, because code a has a ²the character of (t) ≡ 1, thus function χ (τ, f _d) convert another known function to, i.e. formula (6):

$S\left(f_D\right)\&equiv;\mathrm{\&chi;}(0,f_D)=\frac{1}{T_i}{\&Integral;}_0^T\exp (-2\mathrm{\&pi;i}{f}_D{t}^{\&prime;}){\mathrm{dt}}^{\&prime;}=\frac{\sin \left(\mathrm{\&pi;}{f}_D{T}_i\right)}{\mathrm{\&pi;}{f}_D{T}_i}\exp (-\mathrm{\&pi;i}{f}_D{T}_i)---\left(6\right)$

Wherein, function χ can be similar to by the form of following factorization:

χ(τ,f _D)＝Λ(τ)S(f _D)(7)

Formula (7) represents the function of a complex variable of scattering surface and reflected signal propagation factor proportion, above-mentioned energy equation (7) is rewritten into the form of two-dimensional convolution, shown in (8):

<|Y(τ,f _D)| ²>＝χ[t ₀,τ；f _D]**Σ(τ,f _D)(8)

Wherein, Σ (τ, f _d) be and scattering cross-section, the function of observing geometry, antenna radiation pattern and propagation factor relevant that its expression formula is such as formula shown in (9):

$\mathrm{\&Sigma;}(\mathrm{\&tau;},f_D)=\frac{P_T{\mathrm{\&lambda;}}^2{T_i}^2}{{\left(4\mathrm{\&pi;}\right)}^3}{\&Integral;}_{\stackrel{\&RightArrow;}{\mathrm{\&rho;}}}\frac{G_t\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}\right)G_r\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}\right){\mathrm{\&sigma;}}^0\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}\right)}{R_t^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}\right)R_r^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}\right)}\mathrm{\&delta;}\left(\mathrm{\&tau;}\right)\mathrm{\&delta;}\left(f_D\right)d^2\stackrel{\&RightArrow;}{\mathrm{\&rho;}}---\left(9\right)$

Wherein, P _tfor emissive power, λ is signal wavelength, R _tfor reflection spot to the distance of transmitter, R _rfor reflection spot to the distance of receiver.

If directly calculated above formula (9), operand can be very large, replaced by variable in the present embodiment and in DD (space) territory, its value estimated, the huge operand that the integration in formula (9) brings can be avoided, particularly, formula (9) can be rewritten into:

$\mathrm{\&Sigma;}(\mathrm{\&tau;},f_D)=\frac{P_T{\mathrm{\&lambda;}}^2{T_i}^2}{{\left(4\mathrm{\&pi;}\right)}^3}\frac{G_t\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)G_r\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right){\mathrm{\&sigma;}}^0\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)}{R_t^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)R_r^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)}\&times;\left|J(\mathrm{\&tau;},f_D)\right|---\left(10\right)$

Wherein, J (τ, f _d) be that variable (x, y) is transformed into (τ, f _d) time produce Jacobi matrix, σ ⁰for the scattering coefficient at specular reflection point place on ocean surface, wushu (10) is brought formula (8) into and can be obtained:

$\&lang;{\left|Y(\mathrm{\&Delta;\&tau;},\mathrm{\&Delta;}{f}_D)\right|}^2\&rang;={\mathrm{\&chi;}}^2(\mathrm{\&Delta;\&tau;},\mathrm{\&Delta;}{f}_D)**[\frac{P_T{\mathrm{\&lambda;}}^2{T_i}^2}{{\left(4\mathrm{\&pi;}\right)}^3}\frac{G_t\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)G_r\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right){\mathrm{\&sigma;}}^0\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)}{R_t^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)R_r^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)}\&times;|J(\mathrm{\&tau;},f_D)\left|\right]---\left(11\right)$

Formula (11) solves σ ⁰basic relational expression, parameters all in formula has and clearly defines, and obtains, or directly can be calculated by the geometric relationship of scene in the measurement data that can be obtained by receiver.

Formula (11) is solved and can obtain scattering coefficient σ ⁰, this process need obtains DDM according to formula (12) to measurement and deconvolutes, to obtain function Σ (τ, f _d) estimation F.Based on the conversion characteristics of Fourier transform in the present embodiment, use clearly defined χ ²function deconvolutes, specifically such as formula shown in (12) to measuring the DDM obtained:

$F\left[\widetilde{\mathrm{\&Sigma;}}(\mathrm{\&Delta;\&tau;},\mathrm{\&Delta;}{f}_D)\right]=\frac{F[\&lang;{\left|Y(\mathrm{\&Delta;\&tau;},\mathrm{\&Delta;}{f}_D)\right|}^2{\&rang;}_{\mathrm{measured}}]}{F\left[{\mathrm{\&chi;}}^2(\mathrm{\&Delta;\&tau;},\mathrm{\&Delta;}{f}_D)\right]}---\left(12\right)$

When through type (12) obtains Σ (τ, f _d) estimation after, can by solving to obtain scattering coefficient σ to formula (10) ⁰, i.e. formula (1):

${\mathrm{\&sigma;}}^0\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)=\frac{\mathrm{\&Sigma;}(\mathrm{\&tau;},f_D)}{\left|J(\mathrm{\&tau;},f_D)\right|}\frac{1}{P_T{\mathrm{\&lambda;}}^2{T_i}^2}\&times;\frac{{\left(4\mathrm{\&pi;}\right)}^3{R}_t^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)R_r^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)}{G_t\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)G_r\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)}---\left(1\right)$

Solving scattering coefficient σ ⁰process in, due at Doppler domain (τ, f _d) and spatial domain exist uncertain in the process of coupling, 2 points that is in spatial domain with at Doppler domain (τ, f _d) the corresponding same point of middle possibility, so adopt the DDM of single-measurement to be difficult to estimation separately with

In order to avoid this situation, preferably, the method adopting wave beam to control in step slo obtains measurement data.Particularly, by adopting controllable antenna beam, 2 DDM can be obtained from same flicker region measurement, thus uncertain region can be distinguished, and then accurately can obtain the scattering coefficient in delay Doppler domain the scattering coefficient in spatial domain is obtained finally by the coordinate corresponding relation postponing Doppler domain physical space territory specifically such as formula shown in (13):

${\mathrm{\&sigma;}}^0\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)\&RightArrow;{\mathrm{\&sigma;}}^0\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}\right)---\left(13\right)$

embodiment 2

As shown in Figure 3, the structural representation of the inverting device of the Ocean Wind-field provided for another embodiment of the present invention, the inverting device 100 of this Ocean Wind-field comprises: measurement data acquisition module 10, scattering coefficient computing module 20, probability density function computing module 30 and inverting module 40.

Wherein, measurement data acquisition module 10 obtains the measurement data of the GNSS reflected signal at specular reflection point place on sea for the method adopting wave beam to control, and processes obtained measurement data and obtain level and smooth measurement data; Scattering coefficient computing module 20 is for based on the DDM power integral function expression obtained based on multistatic sonar observation equation, obtain the relation between the measurement data of GNSS reflected signal and surface scattering coefficient, process according to measurement data acquisition module 10 the surface scattering coefficient that the level and smooth measurement data that obtains and the relation between above-mentioned measurement data and surface scattering coefficient calculate specular reflection point place; Probability density function computing module 30 is for obtaining the relation between surface scattering coefficient and sea slope probability density function based on Z-V model, the surface scattering coefficient calculated according to scattering coefficient computing module 20 and the relation between above-mentioned surface scattering coefficient and sea slope probability density function calculate the probability density function of sea slope; Inverting module 40 calculates ocean surface wind speed and wind direction of ocean surface for the probability density function of the sea slope calculated according to probability density function computing module 30.

Particularly, in conjunction with the embodiments 1, scattering coefficient computing module 20 calculates scattering coefficient based on the measurement data obtained handled by measurement data acquisition module 10 and formula (1).

The scattering coefficient that probability density function computing module 30 calculates based on scattering coefficient computing module 20 and formula (14) calculating probability density function;

Inverting module 40 comprises wind speed computing unit 401 and wind direction computing unit 402.Wherein wind speed computing unit 401, for calculating sea slope based on formula (15) and formula (16), then calculate sea Mean Square Slope based on calculated sea slope according to formula (17), then calculate ocean surface wind speed based on calculated sea Mean Square Slope according to formula (18) and formula (19).Wind direction computing unit 402 calculates wind direction of ocean surface for the probability density function based on formula (20) and (21) and sea slope.

The inversion method of Ocean Wind-field provided by the invention and device, adopt the method directly utilizing theoretical formula Derivation sea condition parameter, compared with the inversion method of traditional sea condition parameter wind speed and direction, calculated amount is little, degree of accuracy is high, improves validity and the real-time of the inverting of sea condition parameter wind speed and direction.And utilize the method and device can well meet the needs of spaceborne GNSS-R real time inversion wind field software, can be applicable to GNSS-R marine reflection Signal reception disposal system, there is important using value and wide popularizing application prospect.

All or part of content in the technical scheme that above embodiment provides can be realized by software programming, and its software program is stored in the storage medium that can read, storage medium such as: the hard disk in computing machine, CD or floppy disk.

Note, above are only preferred embodiment of the present invention and institute's application technology principle.Skilled person in the art will appreciate that and the invention is not restricted to specific embodiment described here, various obvious change can be carried out for a person skilled in the art, readjust and substitute and can not protection scope of the present invention be departed from.Therefore, although be described in further detail invention has been by above embodiment, the present invention is not limited only to above embodiment, when not departing from the present invention's design, can also comprise other Equivalent embodiments more, and scope of the present invention is determined by appended right.

Claims (12)

1. an inversion method for Ocean Wind-field, is characterized in that, comprising:

Obtain the measurement data of the GNSS reflected signal at specular reflection point place on sea, and described measurement data is processed obtain level and smooth measurement data;

Based on the DDM power integral function expression obtained based on multistatic sonar observation equation, obtain the relation between the measurement data of GNSS reflected signal and surface scattering coefficient, calculate the surface scattering coefficient at described specular reflection point place according to described level and smooth measurement data and the relation between described measurement data and surface scattering coefficient;

Obtain the relation between surface scattering coefficient and sea slope probability density function based on Z-V model, calculate the probability density function of sea slope according to the described surface scattering coefficient calculated and the relation between described surface scattering coefficient and sea slope probability density function; And

Probability density function according to described sea slope calculates ocean surface wind speed and wind direction of ocean surface.

2. the inversion method of Ocean Wind-field as claimed in claim 1, is characterized in that, the relation between the measurement data of described GNSS reflected signal and surface scattering coefficient represents with formula (1):

${\mathrm{\&sigma;}}^0\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)=\frac{\mathrm{\&Sigma;}(\mathrm{\&tau;},f_D)}{\left|J(\mathrm{\&tau;},f_D)\right|}\frac{1}{P_T{\mathrm{\&lambda;}}^2{T_i}^2}\&times;\frac{{\left(4\mathrm{\&pi;}\right)}^3{R}_t^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)R_r^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)}{G_t\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)G_r\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)}---\left(1\right)$

Wherein, σ ⁰for the scattering coefficient at specular reflection point place on sea, for the position vector of reflection spot each on sea, τ be on sea each other reflection spot described relative to the delay of described specular reflection point, f _dfor other reflection spot described each on sea is relative to the Doppler shift of described specular reflection point, λ is signal wavelength, T _ifor coherent integration time, R _tfor other reflection spot to the distance of transmitter, R _rfor other reflection spot to the distance of receiver, G _tfor transmitter antenna gain (dBi), G _rfor receiving antenna gain; Described reflection spot comprises described specular reflection point and other reflection spot.

3. the inversion method of Ocean Wind-field as claimed in claim 1 or 2, it is characterized in that, the relation between described surface scattering coefficient and sea slope probability density function represents with formula (14):

Wherein, σ ⁰the scattering coefficient at specular reflection point place on described sea, for sea slope, for scattering vector, for the fresnel reflection coefficient of given polarization mode, for wind set-up probability density function.

4. the inversion method of Ocean Wind-field as claimed in claim 3, is characterized in that, the described probability density function according to described sea slope calculates ocean surface wind speed and comprises:

Sea slope is calculated based on formula (15) and formula (16):

$\begin{array}{c}\mathrm{PDF}(m,\mathrm{\&alpha;})=[1+T(m,\mathrm{\&alpha;})]{\left(2\mathrm{\&pi;}{\mathrm{\&sigma;}}_c{\mathrm{\&sigma;}}_u\right)}^{-1}\exp \{-{(m/2{\mathrm{\&sigma;}}_c{\mathrm{\&sigma;}}_u)}^2[{\mathrm{\&sigma;}}_c^2+{\mathrm{\&sigma;}}_u^2\\ +({\mathrm{\&sigma;}}_c^2-{\mathrm{\&sigma;}}_u^2)\cos 2\mathrm{\&alpha;}\left]\right\}\end{array}---\left(15\right)$

$\begin{array}{cc}m={(S_c^2+S_u^2)}^{0.5}& \mathrm{\&alpha;}={\tan }^{-1}(S_c/S_u)---\left(16\right)\end{array}$

Wherein, S _cfor the sea slope of cross-wind direction, S _ufor the sea slope of downwind, for the slope variance of cross-wind direction, for the slope variance of downwind;

Based on calculated sea slope, calculate sea Mean Square Slope according to formula (17);

$\begin{array}{cc}{\mathrm{MSS}}_u=(s_{u1}^2+s_{u2}^2+\&CenterDot;\&CenterDot;\&CenterDot;+s_{\mathrm{ui}}^2)/i& {\mathrm{MSS}}_c=(s_{c1}^2+s_{c2}^2+\&CenterDot;\&CenterDot;\&CenterDot;+s_{\mathrm{cj}}^2)/j---\left(17\right)\end{array}$

Wherein, MSS _ufor the sea Mean Square Slope of downwind, MSS _cfor the sea Mean Square Slope of cross-wind direction, S _cfor the sea slope of cross-wind direction, S _ufor the sea slope of downwind, i is the quantity of the sea slope participating in the sea Mean Square Slope calculating downwind, and j is the quantity of the sea slope participating in the sea Mean Square Slope calculating cross-wind direction; And

Based on calculated described sea Mean Square Slope, calculate described ocean surface wind speed according to formula (18):

MSS _u(U)＝0.45·(0.00+0.00316·f(U))

MSS _c(U)＝0.45·(0.003+0.00192·f(U))(18)

Wherein, U is and local actual wind speed U _truerelevant wind speed, and meet formula (19):

f(U)＝U0.00＜U≤3.49

f(U)＝6·in(U)-4.03.49＜U≤46

f(U)＝0.411·U46＜U(19)。

5. the inversion method of Ocean Wind-field as claimed in claim 3, is characterized in that, the described probability density function according to described sea slope calculates wind direction of ocean surface and comprises:

Based on formula (20) and (21), and the probability density function of described sea slope calculates wind direction of ocean surface:

$\mathrm{PDF}\left(\stackrel{\&RightArrow;}{s}\right)=\frac{1}{2\mathrm{\&pi;}\sqrt{\det \left(M\right)}}\exp [-\frac{1}{2}{\left(\begin{array}{c}{S}_x\\ S_y\end{array}\right)}^T{M}^{-1}\left(\begin{array}{c}{S}_x\\ S_y\end{array}\right)]---\left(20\right)$

Wherein, for the angle in (or against the wind) direction and x-axis direction with the wind in plane of incidence, MSS _urepresent the sea Mean Square Slope of downwind, MSS _crepresent the sea Mean Square Slope of cross-wind direction.

6. the inversion method of Ocean Wind-field as claimed in claim 1, it is characterized in that, on described acquisition sea, the measurement data of the GNSS reflected signal at specular reflection point place comprises:

The method adopting wave beam to control obtains the measurement data of the GNSS reflected signal at specular reflection point place on sea.

7. an inverting device for Ocean Wind-field, is characterized in that, comprising:

Measurement data acquisition module, for obtaining the measurement data of the GNSS reflected signal at specular reflection point place on sea, and processes described measurement data and obtains level and smooth measurement data;

Scattering coefficient computing module, for based on the DDM power integral function expression obtained based on multistatic sonar observation equation, obtain the relation between the measurement data of GNSS reflected signal and surface scattering coefficient, calculate the surface scattering coefficient at described specular reflection point place according to described level and smooth measurement data and the relation between described measurement data and surface scattering coefficient;

Probability density function computing module, for obtaining the relation between surface scattering coefficient and sea slope probability density function based on Z-V model, calculate the probability density function of sea slope according to the described surface scattering coefficient calculated and the relation between described surface scattering coefficient and sea slope probability density function; And

Inverting module, calculates ocean surface wind speed and wind direction of ocean surface for the probability density function according to described sea slope.

8. the inverting device of Ocean Wind-field as claimed in claim 7, is characterized in that, described scattering coefficient computing module calculates described scattering coefficient based on the measurement data obtained handled by described measurement data acquisition module and formula (1);

${\mathrm{\&sigma;}}^0\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)=\frac{\mathrm{\&Sigma;}(\mathrm{\&tau;},f_D)}{\left|J(\mathrm{\&tau;},f_D)\right|}\frac{1}{P_T{\mathrm{\&lambda;}}^2{T_i}^2}\&times;\frac{{\left(4\mathrm{\&pi;}\right)}^3{R}_t^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)R_r^2\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)}{G_t\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)G_r\left(\stackrel{\&RightArrow;}{\mathrm{\&rho;}}(\mathrm{\&tau;},f_D)\right)}---\left(1\right)$

Wherein, σ ⁰for the scattering coefficient at specular reflection point place on sea, for the position vector of reflection spot each on sea, τ be on sea each other reflection spot described relative to the delay of described specular reflection point, f _dfor other reflection spot described each on sea is relative to the Doppler shift of described specular reflection point, λ is signal wavelength, T _ifor coherent integration time, R _tfor other reflection spot to the distance of transmitter, R _rfor other reflection spot to the distance of receiver, G _tfor transmitter antenna gain (dBi), G _rfor receiving antenna gain; Described reflection spot comprises described specular reflection point and other reflection spot.

9. the inverting device of as claimed in claim 7 or 8 Ocean Wind-field, is characterized in that, the scattering coefficient that described probability density function computing module calculates based on described scattering coefficient computing module and formula (14) calculate described probability density function;

Wherein, σ ⁰the scattering coefficient at specular reflection point place on described sea, for sea slope, for scattering vector, for the fresnel reflection coefficient of given polarization mode, for wind set-up probability density function.

10. the inverting device of Ocean Wind-field as claimed in claim 9, it is characterized in that, described inverting module comprises:

Wind speed computing unit, for calculating sea slope based on formula (15) and formula (16):

$\begin{array}{c}\mathrm{PDF}(m,\mathrm{\&alpha;})=[1+T(m,\mathrm{\&alpha;})]{\left(2\mathrm{\&pi;}{\mathrm{\&sigma;}}_c{\mathrm{\&sigma;}}_u\right)}^{-1}\exp \{-{(m/2{\mathrm{\&sigma;}}_c{\mathrm{\&sigma;}}_u)}^2[{\mathrm{\&sigma;}}_c^2+{\mathrm{\&sigma;}}_u^2\\ +({\mathrm{\&sigma;}}_c^2-{\mathrm{\&sigma;}}_u^2)\cos 2\mathrm{\&alpha;}\left]\right\}\end{array}---\left(15\right)$

$\begin{array}{cc}m={(S_c^2+S_u^2)}^{0.5}& \mathrm{\&alpha;}={\tan }^{-1}(S_c/S_u)---\left(16\right)\end{array}$

Wherein, S _cfor the sea slope of cross-wind direction, S _ufor the sea slope of downwind, for the slope variance of cross-wind direction, for the slope variance of downwind;

Described wind speed computing unit also for based on calculated sea slope, calculates sea Mean Square Slope according to formula (17);

$\begin{array}{cc}{\mathrm{MSS}}_u=(s_{u1}^2+s_{u2}^2+\&CenterDot;\&CenterDot;\&CenterDot;+s_{\mathrm{ui}}^2)/i& {\mathrm{MSS}}_c=(s_{c1}^2+s_{c2}^2+\&CenterDot;\&CenterDot;\&CenterDot;+s_{\mathrm{cj}}^2)/j---\left(17\right)\end{array}$

Wherein, MSS _ufor the sea Mean Square Slope of downwind, MSS _cfor the sea Mean Square Slope of cross-wind direction, S _cfor the sea slope of cross-wind direction, S _ufor the sea slope of downwind, i is the quantity of the sea slope participating in the sea Mean Square Slope calculating downwind, and j is the quantity of the sea slope participating in the sea Mean Square Slope calculating cross-wind direction; And

Described wind speed computing unit, also for based on calculated described sea Mean Square Slope, calculates described ocean surface wind speed according to formula (18):

MSS _u(U)＝0.45·(0.00+0.00316·f(U))

MSS _c(U)＝0.45·(0.003+0.00192·f(U))(18)

Wherein, U is and local actual wind speed U _truerelevant wind speed, and meet formula (19):

f(U)＝U0.00＜U≤3.49

f(U)＝6·in(U)-4.03.49＜U≤46

f(U)＝0.411·U46＜U(19)。

The inverting device of 11. Ocean Wind-field as claimed in claim 9, it is characterized in that, described inverting module also comprises:

Wind direction computing unit, for based on formula (20) and (21), and the probability density function of described sea slope calculates wind direction of ocean surface:

$\mathrm{PDF}\left(\stackrel{\&RightArrow;}{s}\right)=\frac{1}{2\mathrm{\&pi;}\sqrt{\det \left(M\right)}}\exp [-\frac{1}{2}{\left(\begin{array}{c}{S}_x\\ S_y\end{array}\right)}^T{M}^{-1}\left(\begin{array}{c}{S}_x\\ S_y\end{array}\right)]---\left(20\right)$

Wherein, for the angle in (or against the wind) direction and x-axis direction with the wind in plane of incidence, MSS _urepresent the sea Mean Square Slope of downwind, MSS _crepresent the sea Mean Square Slope of cross-wind direction.

The inverting device of 12. Ocean Wind-field as claimed in claim 7, is characterized in that, the measurement data of described measurement data acquisition module specifically for adopting the method for wave beam control to obtain the GNSS reflected signal at specular reflection point place on sea.