CN111220557A - Full-field solar reference spectrum acquisition method of hyperspectral large-field imaging spectrometer - Google Patents
Full-field solar reference spectrum acquisition method of hyperspectral large-field imaging spectrometer Download PDFInfo
- Publication number
- CN111220557A CN111220557A CN201911146481.6A CN201911146481A CN111220557A CN 111220557 A CN111220557 A CN 111220557A CN 201911146481 A CN201911146481 A CN 201911146481A CN 111220557 A CN111220557 A CN 111220557A
- Authority
- CN
- China
- Prior art keywords
- spectral
- spectrum
- field
- solar
- lambda
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000001228 spectrum Methods 0.000 title claims abstract description 174
- 238000003384 imaging method Methods 0.000 title claims abstract description 73
- 238000000034 method Methods 0.000 title claims abstract description 20
- 230000003595 spectral effect Effects 0.000 claims abstract description 207
- 238000005316 response function Methods 0.000 claims abstract description 82
- 238000005070 sampling Methods 0.000 claims abstract description 21
- 239000004576 sand Substances 0.000 claims description 10
- 238000005452 bending Methods 0.000 claims description 7
- 238000001514 detection method Methods 0.000 claims description 4
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000004164 analytical calibration Methods 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/27—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands using photo-electric detection ; circuits for computing concentration
- G01N21/274—Calibration, base line adjustment, drift correction
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/28—Investigating the spectrum
- G01J3/2803—Investigating the spectrum using photoelectric array detector
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/28—Investigating the spectrum
- G01J3/2823—Imaging spectrometer
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
Landscapes
- Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Spectrometry And Color Measurement (AREA)
Abstract
The invention discloses a full-field solar reference spectrum acquisition method of a hyperspectral large-field-of-view imaging spectrometer, which comprises the steps of firstly selecting a standard solar spectrum with high spectral resolution, acquiring measured values of spectral response functions of the imaging spectrometer at different spectral intervals and different field intervals by adopting high-precision spectral calibration equipment in a laboratory, secondly interpolating the spectral response functions to match the sampling rate of the standard solar spectrum, then setting convolution windows corresponding to each spectral response function, adjusting convolution windows with different field intervals based on spectral curvature values, after the convolution windows are set, convolving the spectral response functions with the high-resolution solar standard spectrum in the convolution windows, thus obtaining the solar reference spectrum of each convolution window, carrying out down-sampling on the solar reference spectrum to match the spectral sampling intervals of the imaging spectrometer, and finally splicing the solar reference spectrum of each convolution window in spectral dimension, and interpolating other fields of view in the spatial dimension to obtain the solar reference spectrum of the full field of view.
Description
Technical Field
The invention belongs to the field of application of remote sensing data of a hyperspectral large-view-field imaging spectrometer, and particularly relates to a full-view-field solar reference spectrum acquisition method of the hyperspectral large-view-field imaging spectrometer.
Background
When the satellite-borne hyperspectral large-field-of-view imaging spectrometer remote sensing data is quantitatively applied, a solar reference spectrum without atmospheric gas absorption is required to invert an earth atmospheric scattering spectrum to obtain the concentration of atmospheric pollutants, then, when the on-orbit radiation calibration precision of the spectrometer is investigated, an instrument solar reference spectrum is required to be used as a standard input parameter, and in addition, when the imaging spectrometer is calibrated by an orbit spectrum, a Fraunhofer line of the solar reference spectrum is also required to be used as a standard spectral line for spectrum fitting. Because the spectral response function of the imaging spectrum represents the spectral response characteristic, the accurate spectral response function is the premise of obtaining the high-precision solar reference spectrum.
The satellite-borne hyperspectral large-field-of-view imaging spectrometer generally has the characteristics of high resolution (0.3-0.5nm) and large field angle (114-degree large field of view), and the detector of the spectrometer adopts an area array CCD (charge coupled device) and can acquire spectral data of spectral dimension and spatial dimension. Due to the fact that the spectral resolution of the imaging spectrometer is high, the spectral response function of the imaging spectrometer changes along with the spectral position in the spectral dimension direction, and the spectral response function also changes along with the spatial field of view due to spectral bending caused by the large field of view in the spatial dimension direction. Therefore, in order to ensure that the acquired solar reference spectrum of the imaging spectrometer can better represent the response characteristics of the imaging spectrometer, it is necessary to use the measured value as a spectral response function and consider the change condition of the measured value along with the spectrum and the spatial field of view, and a full-field solar reference spectrum acquisition method of the hyperspectral large-field-of-view imaging spectrometer is provided.
The spectral response function of the imaging spectrometer OMI (ozone Monitoring instrument) of the same type abroad at present adopts a widened gaussian function model, a solar reference spectrum is obtained based ON the model, the OMI does not consider the change of the spectral response function along with the spectral AND spatial field of view (see Marcel r. dobber, et al. ozone Monitoring instrument calibration. ieee transport operations ON geo center AND REMOTE sensor sing,44(5),2003: 1209-.
In summary, when the imaging spectrometer acquires the solar reference spectrum, a function model such as Gaussian, Super-Gaussian, Lorentzian and the like is usually adopted as the spectral response function of the instrument, an actually measured spectral response value is not adopted, the change of the spectral response function along with the spectrum and the space field of view is not considered, the function model may not accurately represent the response characteristic of the instrument, and the deviation may exist between the solar reference spectrum acquired based on the function model and the actual response characteristic of the instrument.
Disclosure of Invention
The technical problem of the invention is solved: the method adopts a spectral response function measured value and fully considers the change of the spectral response function along with the spectrum and the space, and can obtain the full-view field spectrum reference spectrum which better represents the response characteristic of an instrument.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a full-view field solar reference spectrum acquisition method of a hyperspectral large-view field imaging spectrometer comprises the steps of selecting a standard solar spectrum with high spectral resolution, acquiring measured values of spectral response functions of the imaging spectrometer at different spectral intervals and different view field intervals in a laboratory, setting convolution windows of the spectral response functions based on spatial view field spectral curvature values, convolving the spectral response functions with the standard solar spectrum with the high spectral resolution in the convolution windows, splicing the solar reference spectrum of each convolution window in a spectral dimension after convolution is completed, interpolating the solar reference spectra in a spatial view field, and finally acquiring the full-view field solar reference spectrum of the imaging spectrometer.
The specific implementation method comprises the following steps:
firstly, selecting a high-resolution solar standard spectrum;
detecting spectral range lambda based on imaging spectrometersThe spectral resolution is also the full width at half maximum FWHM, and the SAO2010 solar spectrum is selected as the high resolution standard spectrum I (lambda)s,Δλs) The spectral range of the standard solar spectrum is lambdas，ΔλsIs the sampling interval of the standard solar spectrum.
Secondly, acquiring a spectral response function of the imaging spectrometer;
selecting a tunable laser as a high-precision spectrum calibration system, scanning the characteristic peak emitted by the tunable laser in the spectral dimension and the spatial dimension of an imaging spectrometer, and obtaining a spectral response function of R (v)l,λl,λ′l)，vlIs a spatial field of view, λlIs the central spectral position of the spectral response function, λ'lAt a central spectrum lambda for the spectral response functionlThe spectral ranges before and after;
thirdly, setting a convolution window;
setting the corresponding convolution window to F (v) for each spectral response functionl,λl+δ,λ′f)，vlIs a spatial field of view, λlThe central spectral position of the spectral response function is delta, the spectral curvature value of the space field is delta, and the spectral curvature value delta corresponding to the central field is 0 and lambda'fIs the spectral range of the convolution window;
fourthly, spectrum convolution;
first, the spectral response function R (v)l,λl,λ′l) Interpolation is carried out, the number of interpolation points N is used for high resolution standard spectrum I (lambda)s,Δλs) Is sampled at an interval delta lambdasAnd spectral range λ 'of the spectral response function'lDetermining and interpolating to obtain a sampling interval delta lambdasSpectral response function R' (v)l,λl,λ′l,Δλs). Then R' (v)l,λl,λ′l,Δλs) At its corresponding convolution window F (v)l,λl+δ,λ′f) Internal and high resolution standard spectrum I (lambda)s,Δλs) Convolution is carried out, and therefore the solar reference spectrum S (F, v) under different convolution windows can be obtainedl,λl+δ,λ′f,Δλs) Wherein F is the convolution window mark and is down-sampled to match the number of sampling points of the imaging spectrometer;
fifthly, acquiring a full-field solar reference spectrum;
solar reference spectrum S (F, v) under different convolution windows in spectral dimension pairl,λl+δ,λ′f,Δλs) And splicing to obtain the solar reference spectrum in the spectral dimension direction, interpolating to obtain the solar reference spectrum in the full field of view when the space field of view is tested, and finally obtaining the solar reference spectrum in the full field of view of the imaging spectrometer.
Further, in the first step, the high-resolution solar standard spectrum is selected, and the acquisition is specifically realized as follows:
(11) determining spectral range lambda of an imaging spectrometersAnd spectral resolution, i.e., full width at half maximum FWHM;
(12) spectral range lambda based on the determinationsAnd selecting the SAO2010 solar spectrum as a high-resolution standard spectrum I (lambda) by the spectral resolution FWHMs,Δλs) The spectral range is the detection spectral range lambda of the imaging spectrometers，ΔλsThe value of the sampling interval is determined by the solar standard spectrum. I (lambda)s,Δλs) The spectral resolution is 10 times better than that of the imaging spectrometer.
Further, in the second step, the acquisition of the spectral response function of the imaging spectrometer is specifically realized as follows:
(21) setting a spectral characteristic peak range output by a tunable laser to cover a spectral detection range of an imaging spectrometer;
(22) setting the spectral interval of spectral characteristic peak of tunable laser to the spectral dimension scanning of imaging spectrometer as delta lambdalField of view spacing for spatial dimension scanning of Δ vl；
(23) Field of view acquired is vlThe central spectral position is lambdalSpectral response function ofThe number R (v)l,λl,λ′l) Wherein λ'lAt a central spectrum lambda for the spectral response functionlThe values of the front and rear spectral ranges can be determined according to the full width at half maximum FWHM of the spectral response function;
further, the third step is to set a convolution window, which is specifically implemented as follows:
(31) determining a spatial dimension spectrum bending value, wherein delta is a spatial field spectrum bending value, and a spectrum bending value delta corresponding to a central field is 0;
(32) setting a field of view vlThe central spectral position is lambdalSpectral response function R (v) ofl,λl,λ′l) Corresponding convolution window F (v)l,λl+δ,λ′f) The central wavelength position of the convolution window under different fields is corrected by a space field spectrum curvature value delta, and the spectrum curvature value delta corresponding to the central field is 0;
further, in the fourth step, the spectrum convolution is specifically realized as follows:
(41) first, the spectral response function is R (v)l,λl,λ′l) Interpolation is carried out, the number of interpolation points N is used for high resolution standard spectrum I (lambda)s,Δλs) Is sampled at an interval delta lambdasAnd spectral range λ 'of the spectral response function'lIs determined, i.e. is
After interpolation, the sampling interval is also delta lambdasSpectral response function R' (v)l,λl,λ′l,Δλs)；
(42) Spectral response function R' (v) for different fields of view and different spectral positions after interpolationl,λl,λ′l,Δλs) At its corresponding convolution window F (v)l,λl+δ,λ′f) Internal and high resolution standard spectrum I (lambda)s,Δλs) Convolution is carried out, and the sun reference spectrum S (F, v) under different convolution windows is obtainedl,λl+δ,λ′f,Δλs)；
(43) Down-sampling the convolution result at each convolution window to match the number of sampling points of the imaging spectrometer;
further, in the fifth step, the full-field solar reference spectrum is obtained, which is specifically realized as follows:
(51) solar reference spectra S (F, v) at spectral dimensions for different convolution windowsl,λl+δ,λ′f,Δλs) Splicing to obtain a solar reference spectrum under the spectrum dimension;
(52) in this way, the field interval Δ v can be obtainedlLower solar reference spectrum S (v)l,Δλs) The sun reference spectrum S (lambda) of the full field of view can be obtained by interpolating the sun reference spectrums,Δλs)；
(53) Because the standard solar spectrum is a spectrum value under the average distance between the day and the ground, and because the change generated by the difference of the distance between the day and the ground reaches about 3 percent, the distance between the day and the ground is corrected for the solar reference spectrum of the full view field, and finally the solar reference spectrum of each day of the full view field of the imaging spectrometer is obtained.
Compared with the prior art, the invention has the advantages that:
(1) according to the invention, a high-precision spectral response function measured value obtained in a laboratory is convoluted with a high-resolution spectrum, and a function model is selected as a spectral response with the current research, so that the characterization precision of the spectral response function can be improved.
(2) The invention sets a corresponding convolution window for each spectral response function measured value of the spectral dimension, and compared with the current method of setting a convolution window for the spectral dimension, the invention can more finely control the convolution range and improve the spectral convolution precision.
(3) The invention requires that measured values of the spectral response function are obtained at certain spectral intervals in the spectral dimension and at certain angular intervals in the spatial dimension, changes of the spectral response function along with the spectrum and the space are fully considered, spectral response characteristics of the spectrometer to different spectral bands under different view field angles can be more comprehensively reflected, and further the representation precision of the full-view field solar reference spectrum of the imaging spectrometer is improved.
Drawings
FIG. 1 is a flow of acquiring a full-field solar reference spectrum of a hyperspectral large-field imaging spectrometer;
FIG. 2 is a laboratory measured value of a spectral response function of an imaging spectrometer in a spectral dimension direction obtained based on a tunable laser;
FIG. 3 is a spectral response function taken from FIG. 2 at a center wavelength of 480.0 nm.
FIG. 4 is a convolution of the interpolated measured spectral response function values of FIG. 3 in the convolution window, the convolution having been down-sampled;
FIG. 5 is a graph of spectral curvature values of an imaging spectrometer in the spatial field of view to adjust the center wavelength position of a convolution window at different fields of view;
FIG. 6 is a solar reference spectrum, for example, with a central field of view and an edge field of view, as applied to an implementation of the present invention.
Detailed Description
The invention is further described with reference to the following figures and detailed description.
As shown in fig. 1 to 6, in the present invention, a full-view solar reference spectrum of a hyperspectral large-view-field imaging spectrometer is obtained, and the full-view solar reference spectrum is obtained for the hyperspectral large-view-field imaging spectrometer, so that the problem that a spectral response function changes with a spectrum and a spatial view field due to high spectral resolution and spatial view field spectrum curvature is solved, and a full-view solar reference spectrum with higher precision and better characteristic of instrument response characteristics is obtained.
Firstly, selecting a high-resolution solar standard spectrum;
detecting spectral range lambda based on imaging spectrometersThe spectral resolution is also the full width at half maximum FWHM, and the SAO2010 solar spectrum is selected as the high resolution standard spectrum I (lambda)s,Δλs) The spectral range of the standard solar spectrum is lambdas，ΔλsIs the sampling interval of the standard solar spectrum.
Secondly, acquiring a spectral response function of the imaging spectrometer;
selecting a tunable laser as a high-precision spectrum calibration system, scanning the characteristic peak emitted by the tunable laser in the spectral dimension and the spatial dimension of an imaging spectrometer, and obtaining the spectral responseThe response function is R (v)l,λl,λ′l)，vlIs a spatial field of view, λlIs the central spectral position of the spectral response function, λ'lAt a central spectrum lambda for the spectral response functionlThe spectral ranges before and after;
thirdly, setting a convolution window;
setting the corresponding convolution window to F (v) for each spectral response functionl,λl+δ,λ′f)，vlIs a spatial field of view, λlThe central spectral position of the spectral response function is delta, the spectral curvature value of the space field is delta, and the spectral curvature value delta corresponding to the central field is 0 and lambda'fIs the spectral range of the convolution window;
fourthly, spectrum convolution;
first, the spectral response function R (v)l,λl,λ′l) Interpolation is carried out, the number of interpolation points N is used for high resolution standard spectrum I (lambda)s,Δλs) Is sampled at an interval delta lambdasAnd spectral range λ 'of the spectral response function'lDetermining and interpolating to obtain a sampling interval delta lambdasSpectral response function R' (v)l,λl,λ′l,Δλs). Then R' (v)l,λl,λ′l,Δλs) At its corresponding convolution window F (v)l,λl+δ,λ′f) Internal and high resolution standard spectrum I (lambda)s,Δλs) Convolution is carried out, and therefore the solar reference spectrum S (F, v) under different convolution windows can be obtainedl,λl+δ,λ′f,Δλs) Wherein F is the convolution window mark and is down-sampled to match the number of sampling points of the imaging spectrometer;
fifthly, acquiring a full-field solar reference spectrum;
solar reference spectrum S (F, v) under different convolution windows in spectral dimension pairl,λl+δ,λ′f,Δλs) Splicing to obtain the solar reference spectrum in the spectral dimension direction, interpolating to obtain the solar reference spectrum in the full view field when the space view field test is performed and finally obtaining the solar reference spectrum in the full view fieldAnd the solar reference spectrum of the imaging spectrometer in the full field of view is corrected based on the distance between the day and the ground, and the solar reference spectrum corresponding to each day in one year can be obtained.
Specifically, in the first step, the high-resolution solar standard spectrum is selected, and the acquisition is specifically realized as follows:
(11) spectral range lambda corresponding to the central field of view of the imaging spectrometer in figure 2s400-550nm, the spectral resolution FWHM is 0.5nm, and the parameters are used for determining the selection of the standard solar spectrum;
(12) spectral range lambda based on imaging spectrometersAnd spectral resolution FWHM, selecting SAO2010 solar spectrum as high resolution standard spectrum I (lambda)s,Δλs) In the spectral range λsIs 400-550nm, delta lambdasThe sampling interval is 0.01nm, I (lambda)s,Δλs) The spectral resolution of (2) is 10 times better than that of the imaging spectrometer.
Specifically, in the second step, the acquisition of the spectral response function of the imaging spectrometer is specifically realized as follows:
(21) setting the spectral characteristic peak range of the tunable laser to 400-550nm, wherein the spectral output precision is 10pm, which is superior to the spectral calibration precision of 500pm of an imaging spectrometer, and obtaining a high-precision spectral response function based on the laser;
(22) setting spectral interval delta lambda of spectral characteristic peak pair imaging spectrometer of tunable laserl10nm, field interval Δ v for a spatial dimension scanlFig. 2 is a result of scanning of the tunable laser in the spectral dimension direction of the central field of view of the imaging spectrometer;
(23) selected field of view vlIs a central field of view, a central spectral position lambdalIs a spectral response function R (v) at 486.0nml,λl,λ′l) As shown in fig. 3, the central spectrum λlFront and rear spectral ranges λ'l0.5nm, which can be determined from the full width at half maximum FWHM of the spectral response function of 0.5 nm;
specifically, the third step is to set a convolution window, which is specifically implemented as follows:
(31) the spatial-dimensional spectral curvature value δ is shown in fig. 5, and the spectral curvature value δ corresponding to the central field of view is 0;
(32) setting a field of view vlThe central spectral position is lambdalSpectral response function R (v) ofl,λl,λ′l) Corresponding convolution window F (v)l,λl+δ,λ′f) The central wavelength position of the convolution window under different fields is corrected by the space field spectrum curvature value delta, and the selected field vlIs a central field of view, a central spectral position lambdalIs a spectral response function R (v) at 486.0nml,λl,λ′l) Corresponding convolution window F (v)l,λl+δ,λ′f) As shown in fig. 4, the spectral curvature δ corresponding to the central field of view is 0, and the spectral range λ 'of the convolution window'f10nm, the spectral interval Δ λ scanned by the spectral dimensionlDetermined at 10 nm;
specifically, the fourth step, the spectrum convolution, is specifically implemented as follows:
(41) first, the spectral response function is R (v)l,λl,λ′l) Interpolation is carried out, the number of interpolation points N is used for high resolution standard spectrum I (lambda)s,Δλs) Is sampled at an interval delta lambdas0.01nm, spectral range λ 'of the spectral response function'lDetermined at 0.5nm, i.e.
After interpolation, the sampling interval is also delta lambdasSpectral response function R' (v)l,λl,λ′l,Δλs)；
(42) Spectral response function R' (v) for different fields of view and different spectral positions after interpolationl,λl,λ′l,Δλs) At its corresponding convolution window F (v)l,λl+δ,λ′f) Internal and high resolution standard spectrum I (lambda)s,Δλs) Convolution is carried out, and the sun reference spectrum S (F, v) under different convolution windows is obtainedl,λl+δ,λ′f,Δλs) (ii) a FIG. 4 is a view field vlIs a central field of view, a central spectral position lambdalAt 486.0nmConvolution window F (v)l,λl+δ,λ′f) The corresponding convolution results.
(43) The convolution result at each convolution window is downsampled to match the number of sampling points of the imaging spectrometer, fig. 4 is a downsampled convolution result.
Specifically, the fifth step of obtaining the full-field sun reference spectrum is specifically realized as follows:
(51) solar reference spectra S (F, v) at spectral dimensions for different convolution windowsl,λl+δ,λ′f,Δλs) Splicing is carried out to obtain a solar reference spectrum under the spectral dimension, and the solar reference spectrum under the spectral dimension of the central view field and the edge view field is shown in FIG. 6;
(52) in this way, the field interval Δ v can be obtainedlLower solar reference spectrum S (v)l,Δλs) The sun reference spectrum S (lambda) of the full field of view can be obtained by interpolating the sun reference spectrums,Δλs)；
(53) Since the standard solar spectrum is a spectrum value under the average distance between the day and the earth, and the change caused by the difference of the distance between the day and the earth reaches about 3%, the solar reference spectrum of the full field of view is corrected for the distance between the day and the earth, and finally the solar reference spectrum of each day of the full field of view of the imaging spectrometer is obtained, and fig. 6 is the solar reference spectrum under the average distance between the day and the earth.
Claims (6)
1. A full-field solar reference spectrum acquisition method of a hyperspectral large-field imaging spectrometer is characterized by comprising the following steps of:
firstly, selecting a high-resolution solar standard spectrum;
detecting spectral range lambda based on imaging spectrometersThe spectral resolution is also the full width at half maximum FWHM, and the SAO2010 solar spectrum is selected as the high resolution standard spectrum I (lambda)s,Δλs) The spectral range of the standard solar spectrum is lambdas，ΔλsIs the sampling interval of the standard solar spectrum;
secondly, acquiring a spectral response function of the imaging spectrometer;
selecting tunable laser as high-precision spectrum calibration systemThe characteristic peak is scanned in the spectral dimension and space dimension of the imaging spectrometer, and the obtained spectral response function is R (v)l,λl,λ′l)，vlIs a spatial field of view, λlIs the central spectral position of the spectral response function, λ'lAt a central spectrum lambda for the spectral response functionlThe spectral ranges before and after;
thirdly, setting a convolution window;
setting the corresponding convolution window to F (v) for each spectral response functionl,λl+δ,λ′f)，vlIs a spatial field of view, λlThe central spectral position of the spectral response function is delta, the spectral curvature value of the space field is delta, and the spectral curvature value delta corresponding to the central field is 0 and lambda'fIs the spectral range of the convolution window;
fourthly, spectrum convolution;
first, the spectral response function R (v)l,λl,λ′l) Interpolation is carried out, the number of interpolation points N is used for high resolution standard spectrum I (lambda)s,Δλs) Is sampled at an interval delta lambdasAnd spectral range λ 'of the spectral response function'lDetermining and interpolating to obtain a sampling interval delta lambdasSpectral response function R' (v)l,λl,λ′l,Δλs) Then R' (v)l,λl,λ′l,Δλs) At its corresponding convolution window F (v)l,λl+δ,λ′f) Internal and high resolution standard spectrum I (lambda)s,Δλs) Convolution is carried out, and therefore the solar reference spectrum S (F, v) under different convolution windows can be obtainedl,λl+δ,λ′f,Δλs) Wherein F is the convolution window mark and is down-sampled to match the number of sampling points of the imaging spectrometer;
fifthly, acquiring a full-field solar reference spectrum;
solar reference spectrum S (F, v) under different convolution windows in spectral dimension pairl,λl+δ,λ′f,Δλs) Splicing to obtain the solar reference spectrum in the spectral dimension direction, and testing in the space view fieldAnd (3) field intervals exist, interpolation is carried out to obtain a full-field solar reference spectrum, finally the full-field solar reference spectrum of the imaging spectrometer is obtained, and the solar reference spectrum corresponding to each day in one year can be obtained based on the correction of the distance between the day and the ground.
2. The method for acquiring the full-field solar reference spectrum of the hyperspectral large-field-of-view imaging spectrometer according to claim 1, wherein the method comprises the following steps: in the first step, a high-resolution solar standard spectrum is selected, and the acquisition is specifically realized as follows:
(11) determining spectral range lambda of an imaging spectrometersAnd spectral resolution, i.e., full width at half maximum FWHM;
(12) spectral range lambda based on the determinationsAnd selecting the SAO2010 solar spectrum as a high-resolution standard spectrum I (lambda) by the spectral resolution FWHMs,Δλs) The spectral range is the detection spectral range lambda of the imaging spectrometers，ΔλsFor the sampling interval, the value is determined by the solar standard spectrum, I (lambda)s,Δλs) The spectral resolution is 10 times better than that of the imaging spectrometer.
3. The method for acquiring the full-field solar reference spectrum of the hyperspectral large-field-of-view imaging spectrometer according to claim 1, wherein the method comprises the following steps: and step two, acquiring a spectral response function of the imaging spectrometer, which is specifically realized as follows:
(21) setting a spectral characteristic peak range output by a tunable laser to cover a spectral detection range of an imaging spectrometer;
(22) setting the spectral interval of spectral characteristic peak of tunable laser to the spectral dimension scanning of imaging spectrometer as delta lambdalField of view spacing for spatial dimension scanning of Δ vl；
(23) Field of view acquired is vlThe central spectral position is lambdalHas a spectral response function of R (v)l,λl,λ′l) Wherein λ'lAt a central spectrum lambda for the spectral response functionlThe values of the spectral ranges before and after can be determined from the full width at half maximum FWHM of the spectral response function.
4. The method for acquiring the full-field solar reference spectrum of the hyperspectral large-field-of-view imaging spectrometer according to claim 1, wherein the method comprises the following steps: step three, setting a convolution window, which is specifically realized as follows:
(31) determining a spatial dimension spectrum bending value, wherein delta is a spatial field spectrum bending value, and a spectrum bending value delta corresponding to a central field is 0;
(32) setting a field of view vlThe central spectral position is lambdalSpectral response function R (v) ofl,λl,λ′l) Corresponding convolution window F (v)l,λl+δ,λ′f) The central wavelength position of the convolution window under different fields is corrected by a spatial field spectrum curvature value delta, and the spectrum curvature value delta corresponding to the central field is 0.
5. The method for acquiring the full-field solar reference spectrum of the hyperspectral large-field-of-view imaging spectrometer according to claim 1, wherein the method comprises the following steps: fourthly, spectrum convolution is specifically realized as follows:
(41) first, the spectral response function is R (v)l,λl,λ′l) Interpolation is carried out, the number of interpolation points N is used for high resolution standard spectrum I (lambda)s,Δλs) Is sampled at an interval delta lambdasAnd the spectral range lambda of the spectral response functionl' determining, i.e.
After interpolation, the sampling interval is also delta lambdasSpectral response function R' (v)l,λl,λ′l,Δλs)；
(42) Spectral response function R' (v) for different fields of view and different spectral positions after interpolationl,λl,λ′l,Δλs) At its corresponding convolution window F (v)l,λl+δ,λ′f) Internal and high resolution standard spectrum I (lambda)s,Δλs) Convolution is carried out, and the sun reference spectrum S (F, v) under different convolution windows is obtainedl,λl+δ,λ′f,Δλs)；
(43) The convolution results at each convolution window are down-sampled to match the number of sample points of the imaging spectrometer.
6. The method for acquiring the full-field solar reference spectrum of the hyperspectral large-field-of-view imaging spectrometer according to claim 1, wherein the method comprises the following steps: and step five, acquiring a full-field solar reference spectrum, which is specifically realized as follows:
(51) solar reference spectra S (F, v) at spectral dimensions for different convolution windowsl,λl+δ,λ′f,Δλs) Splicing to obtain a solar reference spectrum under the spectrum dimension;
(52) in this way, the field interval Δ v can be obtainedlLower solar reference spectrum S (v)l,Δλs) The sun reference spectrum S (lambda) of the full field of view can be obtained by interpolating the sun reference spectrums,Δλs)；
(53) Because the standard solar spectrum is a spectrum value under the average distance between the day and the ground, and because the change generated by the difference of the distance between the day and the ground reaches about 3 percent, the distance between the day and the ground is corrected for the solar reference spectrum of the full view field, and finally the solar reference spectrum of each day of the full view field of the imaging spectrometer is obtained.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911146481.6A CN111220557B (en) | 2019-11-21 | 2019-11-21 | Full-field solar reference spectrum acquisition method of hyperspectral large-field imaging spectrometer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911146481.6A CN111220557B (en) | 2019-11-21 | 2019-11-21 | Full-field solar reference spectrum acquisition method of hyperspectral large-field imaging spectrometer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111220557A true CN111220557A (en) | 2020-06-02 |
| CN111220557B CN111220557B (en) | 2022-08-23 |
Family
ID=70829016
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911146481.6A Active CN111220557B (en) | 2019-11-21 | 2019-11-21 | Full-field solar reference spectrum acquisition method of hyperspectral large-field imaging spectrometer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111220557B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113686797A (en) * | 2021-08-19 | 2021-11-23 | 中国科学院合肥物质科学研究院 | On-orbit calibration method of hyperspectral edge-scanning imaging spectrometer based on bi-diffuse transmission plate |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6333501B1 (en) * | 2000-01-27 | 2001-12-25 | Perkin-Elmer Corporation | Methods, apparatus, and articles of manufacture for performing spectral calibration |
| US7554667B1 (en) * | 2005-08-25 | 2009-06-30 | Ball Aerospace & Technologies Corp. | Method and apparatus for characterizing hyperspectral instruments |
| CN102446351A (en) * | 2010-10-15 | 2012-05-09 | 江南大学 | Multispectral and high-resolution full-color image fusion method study |
| CN103776532A (en) * | 2014-01-14 | 2014-05-07 | 北京空间机电研究所 | Hyperspectral-imager index optimization method based on remote-sensing application |
| CN104457985A (en) * | 2014-09-15 | 2015-03-25 | 中国资源卫星应用中心 | On-orbit spectrum calibrating method of dispersion type hyperspectral imaging remote sensor |
| US20170264833A1 (en) * | 2016-03-09 | 2017-09-14 | Galileo Group Inc. | Spectral Enhancements to Mobile Devices |
| CN109238991A (en) * | 2018-11-14 | 2019-01-18 | 中国科学院合肥物质科学研究院 | A kind of big view field imaging spectrometer spectrum curvature correction method of EO-1 hyperion |
| DE102018205400A1 (en) * | 2018-04-10 | 2019-10-10 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | SPECTRAL ANALYSIS SYSTEM, MOBILE DEVICE WITH A SPECTRAL ANALYSIS SYSTEM, A METHOD FOR DETERMINING A CORRECTION FUNCTION FOR THE IMAGING CORRECTION OF A SPECTRUM RECEIVED BY A SPECTRAL ANALYSIS SYSTEM AND A COMPUTER PROGRAM |
| CN110458212A (en) * | 2019-07-29 | 2019-11-15 | 天津大学 | A kind of hyperspectral image classification method based on different scale convolutional neural networks |
-
2019
- 2019-11-21 CN CN201911146481.6A patent/CN111220557B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6333501B1 (en) * | 2000-01-27 | 2001-12-25 | Perkin-Elmer Corporation | Methods, apparatus, and articles of manufacture for performing spectral calibration |
| US7554667B1 (en) * | 2005-08-25 | 2009-06-30 | Ball Aerospace & Technologies Corp. | Method and apparatus for characterizing hyperspectral instruments |
| CN102446351A (en) * | 2010-10-15 | 2012-05-09 | 江南大学 | Multispectral and high-resolution full-color image fusion method study |
| CN103776532A (en) * | 2014-01-14 | 2014-05-07 | 北京空间机电研究所 | Hyperspectral-imager index optimization method based on remote-sensing application |
| CN104457985A (en) * | 2014-09-15 | 2015-03-25 | 中国资源卫星应用中心 | On-orbit spectrum calibrating method of dispersion type hyperspectral imaging remote sensor |
| US20170264833A1 (en) * | 2016-03-09 | 2017-09-14 | Galileo Group Inc. | Spectral Enhancements to Mobile Devices |
| DE102018205400A1 (en) * | 2018-04-10 | 2019-10-10 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | SPECTRAL ANALYSIS SYSTEM, MOBILE DEVICE WITH A SPECTRAL ANALYSIS SYSTEM, A METHOD FOR DETERMINING A CORRECTION FUNCTION FOR THE IMAGING CORRECTION OF A SPECTRUM RECEIVED BY A SPECTRAL ANALYSIS SYSTEM AND A COMPUTER PROGRAM |
| CN109238991A (en) * | 2018-11-14 | 2019-01-18 | 中国科学院合肥物质科学研究院 | A kind of big view field imaging spectrometer spectrum curvature correction method of EO-1 hyperion |
| CN110458212A (en) * | 2019-07-29 | 2019-11-15 | 天津大学 | A kind of hyperspectral image classification method based on different scale convolutional neural networks |
Non-Patent Citations (3)
| Title |
|---|
| 汪世美: "星载大气痕量气体差分吸收光谱仪基于太阳的在轨辐射定标", 《大气与环境光学学报》 * |
| 赵敏杰: "基于谱线匹配技术的星载成像光谱仪星上光谱定标方法研究", 《光谱学与光谱分析》 * |
| 黄珊: "星载大气痕量气体差分吸收光谱仪狭缝函数研究", 《光谱学与光谱分析》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113686797A (en) * | 2021-08-19 | 2021-11-23 | 中国科学院合肥物质科学研究院 | On-orbit calibration method of hyperspectral edge-scanning imaging spectrometer based on bi-diffuse transmission plate |
| CN113686797B (en) * | 2021-08-19 | 2023-06-30 | 中国科学院合肥物质科学研究院 | Imaging spectrometer on-orbit calibration method based on double diffuse transmission plates |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111220557B (en) | 2022-08-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Peterson et al. | Aperture Effects and Limitations on the Accuracy of Ground-Based Spectrophotometry of Active Galactic Nuclei | |
| Shi et al. | First level 1 product results of the greenhouse gas monitoring instrument on the GaoFen-5 satellite | |
| CN111220557B (en) | Full-field solar reference spectrum acquisition method of hyperspectral large-field imaging spectrometer | |
| Zhao et al. | First year on-orbit calibration of the Chinese environmental trace gas monitoring instrument onboard GaoFen-5 | |
| Strobl et al. | Laboratory calibration and inflight validation of the Digital Airborne Imaging Spectrometer DAIS 7915 | |
| Schläpfer et al. | Spectral polishing of high resolution imaging spectroscopy data | |
| CN112665829B (en) | Method for calibrating wave bands of optical remote sensing satellite | |
| CN109238991A (en) | A kind of big view field imaging spectrometer spectrum curvature correction method of EO-1 hyperion | |
| Nieke et al. | Uniformity of imaging spectrometry data products | |
| Green et al. | In-flight validation and calibration of the spectral and radiometric characteristics of the airborne visible/infrared imaging spectrometer | |
| Yamamoto et al. | Initial Analysis of Spectral Smile Calibration of Hyperspectral Imager Suite (HISUI) Using Atmospheric Absorption Bands | |
| US8258449B1 (en) | Narrowband solar calibration system for a radiometric system | |
| de Miguel et al. | AHS and CASI processing for the REFLEX remote sensing campaign: methods and results | |
| US6713764B2 (en) | Field based spectral radiometer | |
| Pan et al. | Solar observation of Ozone Mapping and Profiler Suite nadir system during the first 3 years of on-orbit operation | |
| US20070179729A1 (en) | Numerical data processing dedicated to an integrated microspetrometer | |
| Zhao et al. | Overview of the Fourier transform hyperspectral imager (HSI) boarded on HJ-1A satellite | |
| Jehle et al. | Detection and correction of radiance variations during spectral calibration in APEX | |
| Green et al. | On-orbit calibration of a multi-spectral satellite sensor using a high altitude airborne imaging spectrometer | |
| Xiong et al. | On-orbit spatial characterizations for Terra MODIS | |
| US7764383B1 (en) | Adaptively determining the sign in a fringe count detection system | |
| Trim et al. | Characterising Spectroradiometer Instrumental Spectral Performance and Its Impact on Retrieved Reflectances | |
| Meister et al. | Correction of subframe striping in high-resolution MODIS ocean color products | |
| US20230349759A1 (en) | Multi-slit configured hyperspectral imager | |
| Zhou et al. | Smile effect detection for dispersive hypersepctral imager based on the doped reflectance panel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |