CN102645279A - Interference imaging spectrometer hyperspectral data simulation method for lunar-surface minerals - Google Patents

Abstract

The invention discloses an interference imaging spectrometer hyperspectral data simulation method for lunar-surface minerals. The hyperspectral data simulation method for lunar-surface minerals is characterized by comprising the following steps of: S1, resampling the spectral curve of the known lunar mineral sample by use of a Gauss spectral response model; S2, establishing pure mixed spectral image data; S3, calculating the real data signal-to-noise ratio of the interference imaging spectrometer; and S4, adding noise to the simulated data by referring to the real interference imaging spectrometer data noise distribution. The interference imaging spectrometer hyperspectral data simulating the lunar-surface minerals can be applied to the verification and precision evaluation of the algorithms such as end member extraction, mixed pixel decomposition, mineral abundance inversion and the like of the real interference imaging spectrometer data so as to compensate for the deficiencies of the lunar-surface sampling data and verification data.

Description

The inteference imaging spectrometer high-spectral data analogy method of menology mineral

Technical field

The present invention relates to survey of deep space high-spectral data analogue technique field, particularly a kind of inteference imaging spectrometer high-spectral data analogy method of menology mineral.

Background technology

Because the spectrum and its attribute of material are closely related; Solar irradiation is mapped to behind the menology by diffuse reflection; Different materials will present different reflectance spectrums; Imaging spectrometer has just utilized this principle, compares through different reflectance spectrums and the known multispectral sequence image of mineral typical case, just can draw detection of a target mineral type and content information.

Through inteference imaging spectrometer (Interference Imaging Spectrometer; IIM) detecting devices carries out the high-spectrum remote-sensing detection to moonscape; Through to being observed the processing of element and mineral, rock data, can understand their type, content and distributions, and utilize the result who surveys to draw the ball distribution plan whole month of each element at moonscape; Find moonscape resource enrichment region, the data of relevant resource distribution are provided for the development and use of the moon

2007, China's emission Chang'e I moon probing satellite drew back the prelude that China independently surveys the moon.The inteference imaging spectrometer that carries on the Chang'e I satellite (IIM) has obtained the high-spectral data that covers table 84% whole month, and 32 continuous wave bands cover the ranges of 480-960nm, and spectral resolution reaches 325.5cm ^-1, be intended for use in identification and abundance distribution drawing to moon mantle rock ore deposit.

High-spectral data to the menology mineral is simulated, and at first need understand the fundamental type and the distribution of menology mineral.According to the existing detection knowledge (Ouyang Ziyuan, 2005) to the moon, the mineral type of moonscape is relatively simple, mainly is made up of plagioclase, pyroxene, peridot, ilmenite etc.Wherein plagioclase content is the abundantest, can reach 70% on the highland; Pyroxene is the menology mineral that content is only second to plagioclase, in lunar maria and area, highland distribution is arranged all, reaches as high as about 60%; Ilmenite mainly is distributed in mare lunar basalt; Peridot abundance scope differs greatly in different regions.

The remote sensing image simulation technology is on remote sensing theoretical model, remote sensing priori basis, calculates through mathematical physics, obtains the technology of the analog image under the specified conditions.The high-spectral data analogue technique mainly is divided into two kinds according to the difference of atural object mixture model: linear hybrid analog-digital simulation technology of spectrum and the non-linear hybrid analog-digital simulation technology of spectrum.The spectrum linear hybrid is primarily aimed at the type of ground objects of planar mixing, and the non-linear hybrid technology of spectrum is primarily aimed at the type of ground objects that compacts and mix.

Generally, the mixed spectra of target can be thought the linear hybrid (Tong Qingxi, 2006) of its each end-member composition spectrum:

$m={\mathrm{\Σ}}_{i=1}^N{c}_i{e}_i+n---\left(1\right)$

${\mathrm{\Σ}}_{i=1}^N{c}_i=1---\left(2\right)$

0≤c _i≤1 (3)

Wherein N is the end member number, and m is a L dimension mixed spectra vector (L is the image wave hop count), e _iBe end member vector, c _iExpression end member e _iShared ratio in mixed spectra, n is an error term.Linear mixed model is applicable to the spectral resolution of planar mixing atural object.

The mixing in rock ore deposit belongs to the mixing of compacting, and for the atural object that compacts and mix, sun incident radiation takes place repeatedly to interact with different atural objects, causes mixed spectra to show nonlinear speciality.The spectrum mixture model is the model that the one matter spectral reflectivity concerns before describing different material mixing back compounding substances spectral reflectivity and mixing; Using the most non-linear mixture model at present is the Hapke spectrum mixture model with scientist Bruce Hapke name, and it is based upon on the tight radiation transfer theory basis of a cover.

Precision to the remotely-sensed data inversion result is estimated, and is one of committed step of remote sensing mapping.But owing to human sampling to moon sample only limits to the 20th century 50-70 limited place that U.S. Apollo plans and the Luna of the USSR (Union of Soviet Socialist Republics) plans in the age; The U.S. and USSR's moonfall landing point concentrate on the near side of the moon low latitudes; The representativeness that the moon sample of collecting is formed from quantity, Regional Distribution and lithochemistry all has significant limitation.In addition, the data space resolution that IIM obtains is 200 meters, and the sampled point of moon sample and IIM data difference on spatial resolution are huge, and this has also caused being difficult to utilizing sampled point to analyze data the inversion method and the result of IIM data carried out precision evaluation.

Simulated data is to a kind of effective way that IIM data end member extracts, mineral abundance isoinversion method is carried out precision evaluation owing to have the advantage artificial controlled, that parameter is known, helps to confirm mineral inversion method and the flow process towards true IIM data.The excacation of IIM data is in the ascendant, and the menology of IIM data is mineral simulated not to be carried out as yet.

Summary of the invention

The technical matters that (one) will solve

The technical matters that the present invention will solve is a kind of inteference imaging spectrometer high-spectral data analogy method of menology mineral; Be used for the checking and the precision evaluation work of true inteference imaging spectrometer data end member extraction, mixed pixel decomposition and mineral abundance inverting scheduling algorithm, remedy the deficiency of menology sampled data and verification msg.

(2) technical scheme

For achieving the above object; The present invention provides a kind of inteference imaging spectrometer high-spectral data analogy method of menology mineral, and said menology mineral high-spectral data analogy method may further comprise the steps: S1: utilize Gauss's spectrum response model that known lunar mineral sample spectra curve is resampled; S2: make up pure mixed spectra view data; S3: calculate inteference imaging spectrometer True Data signal to noise ratio (S/N ratio); S4: distribute with reference to true inteference imaging spectrometer data noise, simulated data is added noise.

Better; It is characterized in that; Gauss's spectrum response model among the said S1 is:

wherein μ is centre wavelength,

wherein FWHM is wide for the half-wave of response wave spectrum curve.

Better; Said S2 comprises: S21: respectively lunar maria, zone of transition and the highland of the moon are simulated according to the different of plagioclase and ilmenite blending ratio; Calculate background mineral view data through the non-linear mixture model of Hapke, the plagioclase on said lunar maria, zone of transition and highland and ilmenite blending ratio are: 60%: 40%, 80%: 20%, 90%: 10%; S22: utilize the menology essential mineral: the end member of plagioclase, clinopyroxene, peridot and ilmenite mixes with the background mineral view data described in the S21, and calculates menology mineral mixed pixel through the non-linear mixture model of Hapke; S23: the menology mineral mixed pixel among the said S22 is arranged in order, to form pure mixed spectra view data.

Better, said S3 may further comprise the steps: S31: calculating noise variance behind the image block;

S32: noise optimal estimation; S33: the signal to noise ratio (S/N ratio) of calculating the inteference imaging spectrometer data.

Better, in the calculating noise variance, said image is divided into the square of 6 row, 8 row behind the image block of S31.

(3) beneficial effect

The menology mineral high-spectral data of simulating to the Chang'e I inteference imaging spectrometer; Have the noise profile with the true corresponding to ranges of inteference imaging spectrometer data, centre wavelength, spectral resolution, wave band number and same trend, and mineral blending ratio and the mineral curve of spectrum are known.This inteference imaging spectrometer can be used for to the high spectral simulation data of menology mineral that true inteference imaging spectrometer data end member extracts, mixed pixel decomposes and the checking and the precision evaluation work of mineral abundance inverting scheduling algorithm, remedies the deficiency of menology sampled data and verification msg.

Description of drawings

Fig. 1 is the inteference imaging spectrometer high-spectral data simulated technological process figure of menology mineral of the present invention;

Fig. 2 returns sample mineral reflectance spectrum for the moon in the prior art;

Fig. 3 returns sample mineral spectrum for the moon that the present invention samples the inteference imaging spectrometer spectral resolution;

Fig. 4 is the menology mineral inteference imaging spectrometer high-spectral data synoptic diagram of the present invention's simulation

Fig. 5 is each wave band snr computation result of True Data of inteference imaging spectrometer of the present invention;

Fig. 6 is a design sketch behind the inteference imaging spectrometer simulated data interpolation noise of the present invention;

Fig. 7 is a wave spectrum variation diagram behind the inteference imaging spectrometer simulated data interpolation noise of the present invention.

Embodiment

Below in conjunction with accompanying drawing and embodiment, specific embodiments of the invention describes in further detail.Following examples are used to explain the present invention, but are not used for limiting scope of the present invention.

Fig. 1 is the inteference imaging spectrometer high-spectral data simulated technological process figure of menology mineral of the present invention, and as shown in Figure 1, the inteference imaging spectrometer high-spectral data simulated technological process of menology mineral of the present invention is following:

S1: utilize Gauss's spectrum response model that known lunar mineral sample spectra curve is resampled

At first collect the U.S. Apollo of the RELAB of Brown University laboratory measurement and the spectrum that the Luna of the USSR (Union of Soviet Socialist Republics) plan moon returns sample; Essential mineral comprise plagioclase (numbering: LS-CMP-011), clinopyroxene (numbering: LS-CMP-009), peridot (numbering: LS-CMP-005), ilmenite (numbering: PI-CMP-006), these mineral curves of spectrum are as shown in Figure 2.

Utilizing Gauss's spectrum response model to carry out spectrum resamples; With the mineral spectrum of RELAB laboratory measurement the resample spectral resolution and the centre wavelength (the inteference imaging spectrometer technical parameter is seen table one) of each wave band of inteference imaging spectrometer, the spectrum after the resampling is as shown in Figure 3.Wherein, the Gaussian response function is formula (4), and for guaranteeing that the central wavelength spectral response is 1, Gauss model of the present invention is reduced to formula (5).

$f\left(x\right)=\frac{1}{\sqrt{2\mathrm{\π}}\mathrm{\σ}}{e}^{-\frac{{(x-\mathrm{\μ})}^2}{2{\mathrm{\σ}}^2}}---\left(4\right)$

$f\left(x\right)=e^{-\frac{{(x-\mathrm{\μ})}^2}{2{\mathrm{\σ}}^2}}---\left(5\right)$

$\mathrm{\σ}=\frac{\mathrm{FWHM}}{2\sqrt{2\ln 2}}---\left(6\right)$

Wherein μ is a centre wavelength; FWHM is the half-wave wide (Full Width at Half Maximum) of response wave spectrum curve, and μ and FWHM can be read by the inteference imaging spectrometer header file, and integrating range is chosen ± 3 σ; Responsiveness is 99.74%, and is can guarantee information undistorted.

Table one inteference imaging spectrometer leading indicator parameter

The imaging width	25.6km
		Ground resolution	200m (substar)
Imaging region	75 ° of N-75 ° of S (sun altitude less than 15 ° time)
		Spectral range	480-960nm
Spectral resolution	325.5cm -1

The wave band number	32
		Quantification gradation	12bit
MTF	>;=0.2 (the fast view of black and white)

S2: make up pure mixed spectra view data

Plagioclase, clinopyroxene and peridot are the essential minerals the most common in lunar crust and the lunar mantle rock, that content is the highest, and one of notable feature of mare lunar basalt is to contain a large amount of ilmenites, are more than 2 times of earth Irish touchstone ilmenite.This modeling scheme is chosen plagioclase, clinopyroxene, peridot and four kinds of menology essential minerals of ilmenite and is mixed.Moon major landform unit is highland and lunar maria.Principal character on the mineral of highland and lunar maria distribute is that plagioclase extensively distributes on the highland, and content is the highest, though ilmenite is not the highest at the content of lunar maria, but the background mineral of mare lunar basalt extensively distribute.

S21: respectively lunar maria, zone of transition and the highland of the moon are simulated according to the different of plagioclase and ilmenite blending ratio; And calculating background mineral view data through the non-linear mixture model of Hapke, the plagioclase on said lunar maria, zone of transition and highland and ilmenite blending ratio are: 60%: 40%, 80%: 20%, 90%: 10%;

Fig. 4 is the inteference imaging spectrometer high-spectral data synoptic diagram of the menology mineral of the present invention's simulation; As shown in Figure 4; Specifically, simulated data is divided into lunar maria, zone of transition, three areas, highland according to the ratio of plagioclase and ilmenite and simulates in S21, and the ratio of three regional plagioclases and ilmenite was mixed according to 60%: 40%, 80%: 20%, 90%: 10% respectively; Utilize the non-linear mixture model of Hapke to calculate background mineral data, concrete calculation procedure is following:

S211: the mineral reflectance spectrum is converted into single scattering albedo:

The mineral reflectivity is a relative reflectance, at first need try to achieve intermediate value γ by relative reflectance:

$\mathrm{\γ}=\frac{{[{({\mathrm{\μ}}_0+\mathrm{\μ})}^2{\mathrm{\τ}}^2+(1+4{\mathrm{\μ}}_0\mathrm{\μ\τ})(1-\mathrm{\τ})]}^{\frac{1}{2}}-({\mathrm{\μ}}_0+\mathrm{\μ})\mathrm{\τ}}{1+4{\mathrm{\μ}}_0\mathrm{\μ\τ}}---\left(7\right)$

Wherein, τ is a relative reflectance, μ ₀=cosi, μ=cose, i and e are respectively the incident angle and the emergence angle of light.

Single scattering albedo is calculated by formula (8) and is obtained:

ω＝1-γ ² (8)

S212: with each mineral single scattering albedo linear hybrid:

Mix the single scattering albedo of atural object and can think linear hybrid, the single scattering albedo of four kinds of mineral therefore will choosing is carried out linear hybrid according to the hybrid plan of above setting, obtains the single scattering albedo of mixed mineral;

S213: mixed single scattering albedo is converted into the mixed spectra reflectivity;

The mixed mineral single scattering albedo that obtains after mixing is converted into the mixed mineral spectral reflectivity, at first calculates intermediate value γ by mixing single scattering albedo according to formula (9):

$\mathrm{\γ}={(1-\mathrm{\ω})}^{\frac{1}{2}}---\left(9\right)$

Calculate the relative reflectance that obtains mixed mineral by formula (10) then:

$\mathrm{\τ}\left(\mathrm{\γ}\right)=\frac{r\left(\mathrm{sample}\right)}{r\left(s\tan \mathrm{dard}\right)}=\frac{1-{\mathrm{\γ}}^2}{(1+2\mathrm{\γ}{\mathrm{\μ}}_0)(1+2\mathrm{\γ\μ})}---\left(10\right)$

Wherein sample is the sample reflectivity, and standard is a standard reflectivity.

S214: the mixed spectra reflectivity that obtains is combined into background mineral view data:

Calculate each pixel of the mixed spectra reflectivity formation mixed spectra image of the plagioclase obtain and ilmenite according to different mixing proportion, be combined into background mineral view data by the pixel of each mixed spectra image.

S22: utilize the menology essential mineral: plagioclase, clinopyroxene, peridot and ilmenite mix with the background mineral view data described in the S21, and calculate menology mineral mixed pixel through the non-linear mixture model of Hapke;

Four kinds of mineral end members (reflectivity of four kinds of pure mineral) mix according to ratio shown in Fig. 4 left hand edge and background mineral view data respectively in S22; And calculate menology mineral mixed pixel through the non-linear mixture model of Hapke, form menology mixed mineral image.For ease of checking, each pixel is made up of 6 row * 8 a row identical pixel.Wherein the same with above-mentioned computation process through the non-linear mixture model computation process of Hapke, repeat no more at this, calculate the mixed spectra reflectivity that draws at last and promptly constitute the menology mineral mixed pixel in this step.

S23: the menology mineral mixed pixel among the said S22 is arranged according to the hybrid plan among Fig. 4 in order, to form pure mixed spectra view data.

S3: calculate inteference imaging spectrometer True Data signal to noise ratio (S/N ratio);

Main operational steps is following:

S31: calculating noise variance behind the image block:

Image is divided into the capable square of w row h, and (w=8 in this programme h=8), calculates the noise variance of each square.At first calculate the residual error of single pixel, make x _{I, j, k}The capable j of expression i is listed as the pixel value of K-band, and the residual error of single pixel is passed through formula:

Calculate, wherein

Be x _{I, j, k}Estimated value, wherein, ${\hat{x}}_{i,j,k}={\mathrm{Ax}}_{i,j,k-1}+{\mathrm{Bx}}_{i,j,k+1}+{\mathrm{Cx}}_{p,k}+d,$ $x_{p,k}=\left\{\begin{array}{cc}{x}_{i-1,j,k}& i>1\\ x_{i,j-1,k}& i=1,j>1\end{array}\right.,$ ${\hat{x}}_{i,j,k}={\mathrm{Ax}}_{i,j,k-1}+{\mathrm{Bx}}_{i,j,k+1}+{\mathrm{Cx}}_{p,k}+d$ Middle a, b, c, the value of d is to retrain through least square method

(i, the S in j) ≠ (1,1) ²Calculate during for minimum value.

Calculate the noise variance of each grid according to formula

M=ω * h-1 at last.

S32: noise optimal estimation

With the noise variance of each all grid of wave band according to arranging from small to large, remove minimum 15% with 15% maximum noise variance, remaining 70% noise variance is carried out the further calculating of signal to noise ratio (S/N ratio).

S33: calculate signal to noise ratio (S/N ratio)

The mean value of all pixels is as signal value in each grid after cutting apart, and the noise variance of each grid is represented noise figure, and signal value is signal to noise ratio (S/N ratio) with the ratio of noise figure.The signal to noise ratio (S/N ratio) of entire image is the average of the signal to noise ratio (S/N ratio) of residue grid after the noise optimal estimation.

Fig. 5 is each wave band snr computation result of True Data of inteference imaging spectrometer of the present invention; As shown in Figure 5; Copernius's impact crater near zone with inteference imaging spectrometer True Data 2874 bands is a research object, calculates the signal to noise ratio (S/N ratio) of inteference imaging spectrometer data according to the method described above.

S4: distribute with reference to true inteference imaging spectrometer data noise, simulated data is added noise

Owing to all have The noise in the processes such as instrument and equipment, radiation delivery, opto-electronic conversion, intend to simulated data add with True Data in the consistent noise effect of each band noise horizontal distribution.

The inteference imaging spectrometer noise belongs to additive noise, and each band noise distributes as shown in Figure 5.According to the real noise profile of IIM data,, add back effect such as Fig. 6 and shown in Figure 7 to the random noise that the inteference imaging spectrometer simulated data is added the same noise distribution trend.

Above embodiment only is used to explain the present invention; And be not limitation of the present invention; The those of ordinary skill in relevant technologies field under the situation that does not break away from the spirit and scope of the present invention, can also be made various variations and modification; Therefore all technical schemes that are equal to also belong to category of the present invention, and scope of patent protection of the present invention should be defined by the claims.

Claims (5)

1. the inteference imaging spectrometer high-spectral data analogy method of menology mineral is characterized in that, said menology mineral high-spectral data analogy method may further comprise the steps:

S1: utilize Gauss's spectrum response model that known lunar mineral sample spectra curve is resampled;

S2: make up pure mixed spectra view data;

S3: calculate inteference imaging spectrometer True Data signal to noise ratio (S/N ratio);

S4: distribute with reference to true inteference imaging spectrometer data noise, simulated data is added noise.

2. the inteference imaging spectrometer high-spectral data analogy method of menology mineral as claimed in claim 1; It is characterized in that; Gauss's spectrum response model among the said S1 is:

wherein μ is centre wavelength,

wherein FWHM is wide for the half-wave of response wave spectrum curve.

3. the inteference imaging spectrometer high-spectral data analogy method of menology mineral as claimed in claim 1 is characterized in that said S2 comprises:

S21: respectively lunar maria, zone of transition and the highland of the moon are simulated according to the different of plagioclase and ilmenite blending ratio; Calculate background mineral view data through the non-linear mixture model of Hapke, the plagioclase on said lunar maria, zone of transition and highland and ilmenite blending ratio are: 60%: 40%, 80%: 20%, 90%: 10%;

S22: utilize the menology essential mineral: the end member of plagioclase, clinopyroxene, peridot and ilmenite mixes with the background mineral view data described in the S21, and calculates menology mineral mixed pixel through the non-linear mixture model of Hapke;

S23: the menology mineral mixed pixel among the said S22 is arranged in order, to form pure mixed spectra view data.

4. the inteference imaging spectrometer high-spectral data analogy method of menology mineral as claimed in claim 1 is characterized in that said S3 may further comprise the steps:

S31: calculating noise variance behind the image block;

S32: noise optimal estimation;

S33: the signal to noise ratio (S/N ratio) of calculating the inteference imaging spectrometer data.

5. the inteference imaging spectrometer high-spectral data analogy method of menology mineral as claimed in claim 4 is characterized in that, in the calculating noise variance, said image is divided into the square of 6 row, 8 row behind the image block of S31.

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