CN108303118A - The in-orbit spectral radiometric calibration system of space camera based on active radiation illumination source and method - Google Patents
The in-orbit spectral radiometric calibration system of space camera based on active radiation illumination source and method Download PDFInfo
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Abstract
The in-orbit Calibration Method of space camera provided by the invention based on active radiation illumination source, multiple active radiation illumination sources are used to provide required radiance for the in-orbit radiation calibration of space camera, with small, it is light-weight, the angle of divergence is big, it is readily transported, it calibrates place and chooses the features such as flexible, the In-flight calibration system being made of multiple active radiation illumination sources is equivalent to a moveable radiation calibration field, task is calibrated according to satellite in orbit, flexibly choose calibration place, avoid the influence of the unfavorable factors such as weather, substantially shorten calibration duty cycle, improve the calibration frequency, reduce calibration cost, it will play a significant role in the in-orbit radiation calibration field of future space camera, the present invention also provides a kind of in-orbit spectral radiometric calibration systems.
Description
Technical field
The present invention relates to space optics fields, and in particular to a kind of in-orbit spectral radiometric calibration system of space camera and method.
Background technology
With space optical remote sensor fast development, the quantification demand of optical remote sensing application is increasingly urgent to, and utilizes radiation
Response relation between calibration space camera output gray level value and ground scenery radiance, and then can using satellite image
To be finally inversed by the radiance information of atural object.Space camera in orbit after, by the factors shadow such as space environment, High energy particles Radiation
It rings, optical sensor rdaiation response performance declines, and picture quality declines therewith, needs to reacquire by in-orbit radiation calibration exhausted
To rdaiation response degree, improves picture quality simultaneously, meet the needs of quantitative remote sensing.In-orbit radiation calibration be divided into onboard process method and
In-orbit vicarious calibration method, in-orbit onboard process method refer to carrying out radiation calibration to sensor using the targeting device carried on satellite
Method, mainly include onboard process lamp method, solar reflection optical scaling method and moon scaling method.In-orbit vicarious calibration method is mainly wrapped
Include radiometric calibration site method, scene scaling method, intersect scaling method, reflection mirror array scaling method etc., these methods mainly utilize ground
Radiation calibration field, ground natural scene, ground are laid with the modes such as artificial target, the reflection mirror array put and implement for space camera
In-orbit radiation calibration.
It is that space camera implements in-orbit radiation calibration that these in-orbit vicarious calibration methods, which are all by reflected sunlight,.And
Atmospheric scattering radiance when rail radiation calibration is mainly combined using softwares such as atmospheric radiative transfer software such as MODTRN, 6S
Typical Atmospheric models are estimated, and true atmospheric scattering radiance has certain deviation.Since these are in-orbit fixed
Mark method uses fixed calibration field, be laid with by calibration field weather conditions, satellite recursion period, target, speculum put etc. because
The influence of element causes the problems such as In-flight calibration period is long, the calibration frequency is low, consuming a large amount of manpower and materials.
Invention content
In view of this, an embodiment of the present invention provides a kind of in-orbit radiation of space camera based on active radiation illumination source is fixed
Mark system and method effectively deduct place background radiation brightness and atmospheric scattering radiance, greatly improve radiation calibration precision,
With calibration place choose flexibly, the calibration period it is short, the calibration frequency is high, expends the features such as low.
In a first aspect, the present invention provides a kind of in-orbit spectral radiometric calibration system of the space camera based on active radiation illumination source,
Including multiple active radiation illumination sources, space camera, atmospheric transmittance test device, the active radiation illumination source is using more
The LED light source of kind wavelength passes through the surface radiation light source that Spectral matching is formed, and the space camera is the optics in operation satellite
Remote sensing load, obtains the corresponding digital picture of the active radiation illumination source, and the active spoke is determined according to the digital picture
The corresponding gray value of image of light source is penetrated, the first radiance and air generated according to each active radiation illumination source
Transmitance and described image gray value establish linear response relationship, true using the linear response relationship and the atmospheric transmittance
The absolute radiation responsiveness of the fixed scaled space camera.
Optionally, the active radiation illumination source includes three groups of sub- active radiation illumination sources, the respectively first sub- active spoke
Penetrate light source group, the second sub- active radiation illumination source group and third sub- active radiation illumination source group, the first sub- active spoke
Light source group, the second sub- active radiation illumination source group and the third active radiation illumination source group are penetrated, respectively by 5
Sub- active radiation illumination source forms, and 5 to 10 times of pixel resolution is divided between active radiation illumination source.
Optionally, between the transverse direction of the described first sub- active radiation illumination source group and the second sub- active radiation illumination source group
Every 5.2 times or 10.2 times of pixel resolution, the second sub- active radiation illumination source group and third actively radiate
The pixel resolution that 5.2 times or 10.2 times of the lateral separation of light source group.
Optionally, the described first sub- active radiation illumination source group, the second sub- active radiation illumination source group are spaced in
0.2 times of pixel resolution of vertical misalignment, the second sub- active radiation illumination source group and the actively radiation illumination of third
Source group is spaced in 0.2 times of pixel resolution of vertical misalignment.
Optionally, the described first sub- active radiation illumination source group includes that the radiance of the first sub- active radiation illumination source is
0.8L, the second sub- active radiation illumination source radiance be 0.6L, the radiance of third sub- active radiation illumination source is
0.4L, the 4th sub- active radiation illumination source radiance be 0.2L, the radiance of the 5th sub- active radiation illumination source is 0L,
It does not light, is mainly used for the deduction of background radiation brightness and the back-scattered radiation brightness of air, the active radiation illumination
The greatest irradiation brightness that source provides is 1.0L.
Optionally, the described second sub- active radiation illumination source group includes that the radiance of the 6th sub- active radiation illumination source is
0.9L, the 7th sub- active radiation illumination source radiance be 0.7L, the radiance of the 8th sub- active radiation illumination source is
0.5L, the 9th sub- active radiation illumination source radiance be 0.3L, the radiance of the tenth sub- active radiation illumination source is
0.1L。
Optionally, the third active radiation illumination source group includes the radiance of the 11st sub- active radiation illumination source
Radiance for 0.75L, the 12nd sub- active radiation illumination source is the radiation of 0.55L, the 13rd sub- active radiation illumination source
Brightness is 0.35L, the radiance of the 14th sub- active radiation illumination source is 0.25L, the 15th sub- active radiation illumination source
Radiance is 0.15L.
Second aspect, the present invention provide a kind of in-orbit Calibration Method of the space camera based on active radiation illumination source,
The method includes：
Calibration place is chosen, puts active radiation illumination source as required, and be respectively controlled by brightness requirement, air is saturating
The rate test device of mistake carries out test job preparation, and carries out calibration and prepare；
Space camera obtains the corresponding digital picture of all active radiation illumination sources；
Determine that all active radiation illumination sources generate gray value of image according to the digital picture；
According to the first radiance and atmospheric transmittance that the active radiation illumination source generates, with corresponding image ash
Angle value establishes linear response relationship second equation group
Using the linear response relationship second equation group and the atmospheric transmittance, equation is solved using least square method
Group determines the responsiveness of the space camera.
Optionally, described to determine that the active radiation illumination source generates gray value of image according to the digital picture, including：
Obtain the gray value of adjacent N × N pixels in the digital picture of the corresponding active radiation illumination source, and according to the
One calculation formula calculates gray value of image Y, and first calculation formula is：
Wherein：K is active radiation illumination source serial number, and x, y are pixel serial number, and i, j are upper left corner pixel serial number, and M, N are the right side
Inferior horn pixel serial number.
Optionally, the first radiance and atmospheric transmittance generated according to the active radiation illumination source, and it is corresponding
Gray value of image establish linear response relationship, second at the space camera entrance pupil is calculated including the use of the second calculation formula
Radiance, second calculation formula are：
LCAM=LS·τATM+LSCE·τATM+LATM；
In formula：
LCAMIndicate the second radiance at camera entrance pupil, LSIndicate that the first radiation that active radiation illumination source generates is bright
Degree, τATMIndicate atmospheric transmittance, LSCEAfter indicating that sunlight and skylight are incident on active radiation illumination source and periphery place
Reflected radiation brightness, LATMIndicate atmospheric scattering radiance；
The first equation group, first equation group are established according to the rdaiation response relationship of the second calculation formula and space camera
For：
The responsiveness that the space camera is determined using the linear response relationship and the atmospheric transmittance, packet
It includes：
Background correction radiance in first equation group and atmospheric scattering radiance are obtained into second equation group, root
According to the second equation group and atmospheric transmittance, the rdaiation response degree R of space camera is calculated using least square method, described second
Equation group is
The present invention uses the in-orbit Calibration Method and system that active radiation illumination source implemented for space camera, has body
Product is small, light-weight, the angle of divergence is big, be readily transported, calibrates place chooses the features such as flexible, is made of multiple active radiation illumination sources
In-flight calibration system be equivalent to a moveable radiation calibration field, calibrate task according to satellite in orbit, flexibly choose calibration
Place, avoids the influence of the unfavorable factors such as weather, substantially shortens calibration duty cycle, improves the calibration frequency, reduces calibration cost,
The in-orbit radiation calibration field of future space camera will play a significant role.
Description of the drawings
Fig. 1 is to use the in-orbit spectral radiometric calibration system based on active radiation illumination source for space camera in the embodiment of the present invention
Implement the schematic diagram of in-orbit radiation calibration, in figure：1 is active radiation illumination source, the angle of divergence of 2 active radiation illumination sources
(120 °), 3 put satellite spatial camera to put active radiation illumination source ground, 4 for left side, and 5 be flat winged satellite spatial phase camera,
6 put satellite spatial camera for right side, and 7 be satellite flight height, and 8 be the field angle of satellite, and 9 be atmospheric transmittance test device；
Fig. 2 is that the active radiation illumination source of the in-orbit spectral radiometric calibration system provided in the embodiment of the present invention puts schematic diagram,
In figure A1, A2, A3, A4, A5 be A group active radiation illumination sources, B1, B2, B3, B4, B5 be B group active radiation illumination sources, C1,
C2, C3, C4, C5 are C group active radiation illumination sources, and F is atmospheric transmittance test device；
Fig. 3 a are the in-orbit radiation calibration system of the space camera based on active radiation illumination source provided in the embodiment of the present invention
The ideal image schematic diagram that active radiation illumination source generates in system；
Fig. 3 b are that active radiation illumination source is produced in the in-orbit spectral radiometric calibration system of space camera provided in the embodiment of the present invention
Raw disperse is 2 × 2 image schematic diagrames；
Fig. 3 c are the in-orbit radiation calibration system of the space camera based on active radiation illumination source provided in the embodiment of the present invention
The image schematic diagram of 3 × 3 pixels of disperse that active radiation illumination source generates in system；
Fig. 4 is the in-orbit spectral radiometric calibration system of the space camera based on active radiation illumination source provided in the embodiment of the present invention
Rdaiation response relation schematic diagram, in figure, L1, L2, L3, L4, L5 are the radiance of active radiation illumination source, Y1, Y2, Y3,
Y4, Y5 are the gray value of image that corresponding active radiation illumination source generates；
Fig. 5 is the in-orbit Calibration Method of the space camera based on active radiation illumination source provided in the embodiment of the present invention
Flow chart.
Specific implementation mode
In order to enable those skilled in the art to better understand the solution of the present invention, below in conjunction in the embodiment of the present invention
Attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is only
The embodiment of a part of the invention, instead of all the embodiments.Based on the embodiments of the present invention, ordinary skill people
All other embodiment that member is obtained without making creative work should all belong to the model that the present invention protects
It encloses.
Term " first ", " second ", " third " in description and claims of this specification and above-mentioned attached drawing, "
Four ", " 5th " etc. (if present) is for distinguishing similar object, without being used to describe specific sequence or priority time
Sequence.It should be appreciated that the data used in this way can be interchanged in the appropriate case, so as to the embodiments described herein can in addition to
Sequence other than the content for illustrating or describing herein is implemented.In addition, term " comprising " and " having " and their any change
Shape, it is intended that cover it is non-exclusive include, for example, containing the process of series of steps or unit, method, system, product
Or equipment those of is not necessarily limited to clearly to list step or unit, but may include not listing clearly or for these
The intrinsic other steps of process, method, product or equipment or unit.
In conjunction with shown in Fig. 1, a kind of in-orbit spectral radiometric calibration system of present invention offer, including active radiation illumination source, air are saturating
Rate test device, space camera are crossed, the active radiation illumination source is formed using the LED light source of multi-wavelength by Spectral matching
Surface radiation light source, the space camera is the load of Optical remote satellite, and the space camera obtains the active radiation
The corresponding digital picture of light source determines the gray value of image of the active radiation illumination source according to the digital picture, according to
The first radiance and atmospheric transmittance that the active radiation illumination source generates determine at the Optical Imaging Satellite entrance pupil
The second radiance, linear response relationship equation group is established according to second radiance and described image gray value, profit
The responsiveness of the space camera is determined with the linear response relationship equation group and the atmospheric transmittance.
In conjunction with shown in Fig. 1, active radiation illumination source 1 is placed on ground 3, and the angle of divergence 2 reaches 120 °, saturating using air
The atmospheric transmittance at the test calibration moment of rate test device 9 is crossed, the radiation that active radiation illumination source 1 is sent out is convenient for by different directions
Space camera on satellite is received, and the imaging satellite space camera 4 that either left side is put puts down winged imaging satellite space camera
5 or right side pendulum imaging satellite space camera 6, the radiation that active radiation illumination source is sent out connect by space camera on satellite
It receives, and is converted to digital picture, in bright day gas, in the flying height of satellite be 7 and space camera field angle is 8
And in the ground region that is covered of lateral swinging angle, active radiation illumination source is put on the ground, it is only necessary to pass through simple leveling,
In-orbit radiation calibration requirement can be met.
As shown in Fig. 2, active radiation illumination source includes three groups of sub- active radiation illumination sources, the respectively first son actively radiates
Light source group, the second sub- active radiation illumination source group and third sub- active radiation illumination source group, first son actively radiate
Include 5 inside light source group, the second sub- active radiation illumination source group and the third active radiation illumination source group
Active radiation illumination source, between them between be divided into 5 or 10 times of space camera ground pixel resolution.
Specifically, between the transverse direction of the described first sub- active radiation illumination source group and the second sub- active radiation illumination source group
Every 5.2 times or 10.2 times of space camera ground pixel resolution, the second sub- active radiation illumination source group and described
The space camera ground pixel resolution of 5.2 times or 10.2 times of the lateral separation of three sub- active radiation illumination source groups.
Specifically, the described first sub- active radiation illumination source group, the second sub- active radiation illumination source group are spaced in
0.2 times of pixel resolution of vertical misalignment, the second sub- active radiation illumination source group and the actively radiation illumination of third
Source group is spaced in 0.2 times of space camera ground pixel resolution of vertical misalignment.
Specifically, the described first sub- active radiation illumination source group includes the radiance of the first sub- active radiation illumination source A1
Radiance for 0.8L, the second sub- active radiation illumination source A2 is 0.6L, the radiation of third sub- active radiation illumination source A3 is bright
Degree is 0.4L, the radiance of the 4th sub- active radiation illumination source A4 is 0.2L, the radiation of the 5th sub- active radiation illumination source is bright
It is 0L is not lighted wherein the radiance of the 5th sub- active radiation illumination source A5 is 0L to spend, for background radiation brightness and greatly
Gas scatters the deduction of radiance, and the greatest irradiation brightness that the active radiation illumination source can be provided is 1.0L.
Specifically, the described second sub- active radiation illumination source group includes the radiance of the 6th sub- active radiation illumination source B1
Radiance for 0.9L, the 7th sub- active radiation illumination source B2 is 0.7L, the radiation of the 8th sub- active radiation illumination source B3 is bright
Degree is 0.5L, the radiance of the 9th sub- active radiation illumination source B4 is the radiation of 0.3L, the tenth sub- active radiation illumination source B5
Brightness is 0.1L.
Optionally, the third active radiation illumination source group includes that the radiation of the 11st sub- active radiation illumination source C1 is bright
Degree is 0.75L, the radiance of the 12nd sub- active radiation illumination source C2 is 0.55L, the 13rd sub- active radiation illumination source C3
Radiance be 0.35L, the radiance of the 14th sub- active radiation illumination source C4 be 0.25L, the 15th son actively radiate
The radiance of light source C5 is 0.15L.
Optionally, the radiance of the first to the 15th active radiation illumination source, the needs that can be calibrated according to space camera
It is changed, this is not limited.
As shown in figure 3, the area due to active radiation illumination source is less than or equal to the pixel resolution of space camera, it is equivalent to
Point source is imaged, and after the imaging of satellite spatial camera optics on being imaged on focal plane, comparatively ideal image is as shown in 3a, still
Due to pixel spot dispersion, image is obtained as shown in 3b or 3c, therefore in the corresponding gray value of image Y of the radiation illumination source of calculating
When, adjacent 2 × 2,3 × 3,4 × 4 or 5 × 5 pixel gray value summations are calculated, the calculation formula of gray value of image Y is：
Wherein：K is active radiation illumination source serial number, and x, y are pixel serial number, and i, j are upper left corner pixel serial number, and M, N are the right side
Inferior horn pixel serial number.
When implementing in-orbit radiation calibration, atmospheric transmittance test device real-time testing atmospheric transmittance is utilized.
As shown in figure 4, the radiance that active radiation illumination source is sent out is closed with the linear response of corresponding pixel gray value
System, in figure L1, L2, L3, L4, L5 be active radiation illumination source A1, A2, A3, A4, A5 either B1, B2, B3, B4, A5 or C1,
The radiance that C2, C3, C4, A5 are sent out, for the radiance surveyed on ground.Wherein A5 is not lighted, when being mainly used for calibration
The deduction of background radiation brightness and atmospheric scattering radiance.Y1, Y2, Y3, Y4, Y5 are the generation of corresponding active radiation illumination source
Gray value of image, the corresponding gray values of wherein Y5 are to be irradiated to active radiation illumination source A5 and periphery by sunlight and skylight
The radiance that the radiation generated after background generates after atmospheric radiative transfer, including atmospheric transmittance and atmospheric scattering radiation
Brightness.
The data processing method of rdaiation response degree, shown in the radiance such as formula (2) at camera entrance pupil, main includes three
Point, first, the radiation that Ground emitter signals are sent out reaches the radiance at camera entrance pupil by atmospheric radiative transfer；Second, too
Sunlight and skylight are incident on Ground emitter signals and periphery place, by its reflection, then reach camera through atmospheric radiative transfer and enter
The radiance of pupil；Third, atmospheric scattering radiance.
LCAM=LS·τATM+LSCE·τATM+LATM (2)
In formula：
LCAMIndicate the second radiance at camera entrance pupil；
LSIndicate the first radiance that active radiation illumination source generates；
τATMIndicate atmospheric transmittance；
LSCEIndicate that sunlight and skylight are incident on the reflected radiation brightness behind active radiation illumination source and periphery place,
That is background radiation brightness；
LATMIndicate atmospheric scattering radiance.
Space camera is typical radiance system, gray value of image and the radiance at camera entrance pupil of output
Linear response relation.
According to formula (2) and the Calibration Method, equation group (3) is established：
After background correction radiance and atmospheric scattering radiance, equation group (4) is obtained：
In equation group (4), only atmospheric transmittance τATMIt is unknown quantity with responsiveness R, and atmospheric transmittance is available
The atmospheric transmittances test device such as CE318 measures in real time, solves equation group (4) using least square method, you can obtain space phase
The responsiveness R of machine.
5 equations are only listed in the present invention in equation group (3), can also utilize actively to radiate in B groups and C groups and shine
The radiance in bright source and corresponding gray value of image, establish more equations.Using least square method, absolute radiation is solved
Responsiveness.
The present invention uses the in-orbit spectral radiometric calibration system that active radiation illumination source is implemented for space camera, have it is small,
The light-weight, angle of divergence is big, be readily transported, calibrate the features such as place selection is flexible, by multiple active radiation illumination sources form
Rail scaling system is equivalent to a moveable radiation calibration field, calibrates task according to satellite in orbit, flexibly chooses calibration place,
The influence of the unfavorable factors such as weather is avoided, calibration duty cycle is substantially shortened, improves the calibration frequency, calibration cost is reduced, in future
The in-orbit radiation calibration field of space camera will play a significant role.
In conjunction with shown in Fig. 5, accordingly, the present invention provides a kind of in-orbit Calibration Method, the method includes：
S501, terrestrial surface radiation calibration work prepare, including calibration place is chosen, the putting of active radiation illumination source, brightness
Control, atmospheric transmittance device enter test mode etc..
S502, the corresponding digital picture of active radiation illumination source is obtained；
S503, the gray value of image that the active radiation illumination source generates is determined according to the digital picture；
S504, the first radiance generated according to the active radiation illumination source and atmospheric transmittance determine the sky
Between the second radiance at camera entrance pupil；
S505, linear response relationship is established according to second radiance and described image gray value；
S506, the responsiveness that the space camera is determined using the linear response relationship and the atmospheric transmittance.
Optionally, described to determine that the active radiation illumination source generates gray value of image according to the digital picture, including：
The gray value of the adjacent N × N pixels of active radiation illumination source in the digital picture is obtained, and is calculated according to first
Formula calculates gray value of image Y, and first calculation formula is：
Wherein：K is active radiation illumination source serial number, and x, y are pixel serial number, and i, j are upper left corner pixel serial number, and M, N are the right side
Inferior horn pixel serial number.
Optionally, root determines the response of the space camera using the linear response relationship and the atmospheric transmittance
Degree, including
The second radiance at the space camera entrance pupil is calculated using the second calculation formula, the of the second radiance
Two calculation formula are：
LCAM=LS·τATM+LSCE·τATM+LATM；
In formula：
LCAMIndicate the second radiance at camera entrance pupil, LSIndicate that the first radiation that active radiation illumination source generates is bright
Degree, τATMIndicate atmospheric transmittance, LSCEAfter indicating that sunlight and skylight are incident on active radiation illumination source and periphery place
Reflected radiation brightness, LATMIndicate atmospheric scattering radiance；
The first equation group, first equation group are established according to the rdaiation response relationship of the second calculation formula and space camera
For：
The responsiveness that the space camera is determined using the linear response relationship and the atmospheric transmittance, packet
It includes：
Background correction radiation and atmospheric scattering radiance in first equation group are obtained into second equation group, according to institute
It states second equation group and atmospheric transmittance calculates the rdaiation response degree R of space camera, the second equation group is
As shown in Fig. 2, A1, A2, A3, A4, A5 form A group active radiation illumination sources, B1, B2, B3, B4, B5 form B groups master
Dynamic radiation illumination source, C1, C2, C3, C4, C5 form C group active radiation illumination sources.Single place is radiated in earth background, such as
The broad highway in playground, stadium, suburb, grassland, reservoir dam etc. choose the region of about 50m × 15m or the region of bigger,
Active radiation illumination source is put by mode as shown in Figure 2.Between 5 active radiation illumination sources wherein in A groups, B groups and C groups
It is divided into 5 to 10 times of pixel resolution, the pixel resolution of 5.2 times or 10.2 times of A groups and B groups lateral separation, B groups and C groups are horizontal
To 5.2 times or 10.2 times of the pixel resolution in interval, the B1 of B groups is spaced in 0.2 times of pixel of vertical misalignment compared with the A1 of A groups and differentiates
Rate, the C1 of C groups be spaced in 0.2 times of GSD of vertical misalignment compared with the B1 of B groups, and active radiation illumination source it can be sent out with autonomous control
Radiance, such as the greatest irradiation brightness of radiation illumination source is L, and the radiance of each active radiation illumination source can be arranged
As follows, it be the radiance of 0.6L, A3 is that the radiance of 0.4L, A4 is that the radiance of A1, which is the radiance of 0.8L, A2,
The radiance of 0.2L, A5 are 0L；The radiance of B1 is that the radiance of 0.9L, B2 are that the radiance of 0.7L, B3 is
The radiance of 0.5L, B4 are that the radiance of 0.3L, B5 are 0.1L；The radiance of C1 is that the radiance of 0.75L, C2 are
It is the radiance of 0.25L, C5 is 0.15L that the radiance of 0.55L, C3, which are the radiance of 0.35L, C4,；Formed it is various not
Same radiance grade.Wherein the radiance of A5 is 0L, i.e., does not light, and is radiated for background radiation brightness and atmospheric scattering
The deduction of brightness.When implementing in-orbit radiation calibration, atmospheric transmittance test device F real-time testing atmospheric transmittances are utilized.
As shown in Fig. 3 a, 3b, 3c, since the pixel that the area of active radiation illumination source is less than or equal to space camera is differentiated
Rate is equivalent to point source imaging, after the imaging of satellite spatial camera optics on being imaged on focal plane, comparatively ideal image such as 3a
It is shown, but due to pixel spot dispersion, image is obtained as shown in 3b or 3c, therefore in the corresponding figure of the radiation illumination source of calculating
When as gray value, adjacent 2 × 2,3 × 3,4 × 4 or 5 × 5 pixel gray value summations are calculated.As shown in formula (1)
Wherein：K is active radiation illumination source serial number, and x, y are pixel serial number, and i, j are upper left corner pixel serial number, and M, N are the right side
Inferior horn pixel serial number.
As shown in figure 4, the radiance that active radiation illumination source is sent out is closed with the linear response of corresponding pixel gray value
System, in figure L1, L2, L3, L4, L5 be active radiation illumination source A1, A2, A3, A4, A5 either B1, B2, B3, B4, A5 or C1,
The radiance that C2, C3, C4, A5 are sent out, for the radiance surveyed on ground.Wherein A5 is not lighted, when being mainly used for calibration
The deduction of background radiation brightness and atmospheric scattering radiance.Y1, Y2, Y3, Y4, Y5 are the generation of corresponding active radiation illumination source
Gray value of image, by formula (1) obtain.The corresponding gray values of wherein Y5 are to be irradiated to actively to radiate by sunlight and skylight
The radiance that the radiation generated after light source A5 and periphery background generates after atmospheric radiative transfer, including atmospheric transmittance
With atmospheric scattering radiance.
The data processing method of rdaiation response degree, shown in the radiance such as formula (2) at camera entrance pupil, main includes three
Point, first, the radiation that Ground emitter signals are sent out reaches the radiance at camera entrance pupil by atmospheric radiative transfer；Second, too
Sunlight and skylight are incident on Ground emitter signals and periphery place, by its reflection, then reach camera through atmospheric radiative transfer and enter
The radiance of pupil；Third, atmospheric scattering radiance.
LCAM=LS·τATM+LSCE·τATM+LATM (2)
In formula：
LCAM--- the radiance at camera entrance pupil；
LS--- the radiance that active radiation illumination source generates；
τATM--- atmospheric transmittance；
LSCE--- sunlight and skylight are incident on the reflected radiation brightness behind active radiation illumination source and periphery place,
That is background radiation brightness；
LATM--- atmospheric scattering radiance.
Space camera is typical radiance system, gray value of image and the radiance at camera entrance pupil of output
Linear response relation.
According to formula (2) and the Calibration Method, equation group (3) is established：
After background correction radiance and atmospheric scattering radiance, equation group (4) is obtained：
In equation group (4), only atmospheric transmittance τATMIt is unknown quantity with responsiveness R.And atmospheric transmittance is available
The atmospheric transmittances test device such as CE318 measures in real time.Equation group (4) is solved using least square method, you can obtains space phase
The responsiveness R of machine.
5 equations are only listed in the present invention in equation group (3), can also utilize actively to radiate in B groups and C groups and shine
The radiance in bright source and corresponding gray value of image, establish more equations, using least square method, solve absolute radiation
Responsiveness.
The present invention uses the in-orbit Calibration Method that active radiation illumination source is implemented for space camera, and establishes corresponding
In-flight calibration system, has the characteristics that small, the light-weight, angle of divergence is big, is readily transported, calibrate place selection flexible, by more
The In-flight calibration system of a active radiation illumination source composition is equivalent to a moveable radiation calibration field, fixed according to satellite in orbit
Mark task flexibly chooses calibration place, avoids the influence of the unfavorable factors such as weather, substantially shortens calibration duty cycle, improves calibration
The frequency reduces calibration cost, will play a significant role in the in-orbit radiation calibration field of future space camera.
It is apparent to those skilled in the art that for convenience and simplicity of description, the system of foregoing description,
The specific work process of device and unit, can refer to corresponding processes in the foregoing method embodiment, and details are not described herein.
In several embodiments provided herein, it should be understood that disclosed system, device and method can be with
It realizes by another way.For example, the apparatus embodiments described above are merely exemplary, for example, the unit
It divides, only a kind of division of logic function, formula that in actual implementation, there may be another division manner, such as each active radiation is shone
The brightness in bright source controls, and other ratios may be used, form multiple luminance points.Such as multiple units or component can combine or
Person is desirably integrated into another system, or some features can be ignored or not executed.Another point, shown or discussed is mutual
Between coupling, direct-coupling or communication connection can be INDIRECT COUPLING or communication link by some interfaces, device or unit
It connects, can be electrical, machinery or other forms.
The unit illustrated as separating component may or may not be physically separated, aobvious as unit
The component shown may or may not be physical unit, you can be located at a place, or may be distributed over multiple
In network element.Some or all of unit therein can be selected according to the actual needs to realize the mesh of this embodiment scheme
's.
In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, it can also
It is that each unit physically exists alone, it can also be during two or more units be integrated in one unit.Above-mentioned integrated list
The form that hardware had both may be used in member is realized, can also be realized in the form of SFU software functional unit.
One of ordinary skill in the art will appreciate that all or part of step in the various methods of above-described embodiment is can
It is completed with instructing relevant hardware by program, which can be stored in a computer readable storage medium, storage
Medium may include：Read-only memory (ROM, Read Only Memory), random access memory (RAM, Random
Access Memory), disk or CD etc..
Above to a kind of in-orbit spectral radiometric calibration system of space camera based on active radiation illumination source provided by the present invention
And method is described in detail, and for those of ordinary skill in the art, the thought of embodiment according to the present invention, specific real
There will be changes in mode and application range are applied, in conclusion the content of the present specification should not be construed as the limit to the present invention
System.
Claims (10)
1. a kind of in-orbit spectral radiometric calibration system of space camera based on active radiation illumination source, which is characterized in that including multiple masters
Dynamic radiation illumination source, space camera, atmospheric transmittance test device, the active radiation illumination source use the LED of multi-wavelength
Light source passes through the surface radiation light source that Spectral matching is formed, and implements in-orbit radiation calibration, the atmospheric transmittance for space camera
Test device tests the atmospheric transmittance at in-orbit radiation calibration moment, and the space camera is the optical remote sensing load in operation satellite
Lotus obtains the digital picture of the active radiation illumination source, determines that the active radiation illumination source is produced according to the digital picture
Raw gray value of image, the first radiance and atmospheric transmittance that are generated according to the active radiation illumination source and the figure
As gray value establishes linear response relationship, the scaled sky is determined using the linear response relationship and the atmospheric transmittance
Between camera absolute radiation responsiveness.
2. the in-orbit spectral radiometric calibration system of the space camera according to claim 1 based on active radiation illumination source, feature
Be, the active radiation illumination source include three groups of sub- active radiation illumination sources, the respectively first sub- active radiation illumination source group,
Second sub- active radiation illumination source group and third sub- active radiation illumination source group, the first sub- active radiation illumination source group,
Active radiation illumination source inside the second sub- active radiation illumination source group and the third active radiation illumination source group
Between be divided into 5 to 10 times of pixel resolution.
3. the in-orbit spectral radiometric calibration system of the space camera according to claim 2 based on active radiation illumination source, feature
Be, 5.2 times of the lateral separation of the first sub- active radiation illumination source group and the second sub- active radiation illumination source group or
10.2 times of pixel resolution, the second sub- active radiation illumination source group and the third active radiation illumination source group
The pixel resolution that 5.2 times or 10.2 times of lateral separation.
4. the in-orbit spectral radiometric calibration system of the space camera according to claim 3 based on active radiation illumination source, feature
It is, the first sub- active radiation illumination source group, the second sub- active radiation illumination source group are spaced in vertical misalignment 0.2
Times pixel resolution, the second sub- active radiation illumination source group and the third active radiation illumination source group are spaced in
0.2 times of pixel resolution of vertical misalignment.
5. the in-orbit spectral radiometric calibration system of the space camera according to claim 2 based on active radiation illumination source, feature
It is, the radiance that the first sub- active radiation illumination source group includes the first sub- active radiation illumination source is 0.8L, second
The radiance of sub- active radiation illumination source is 0.6L, the radiance of third sub- active radiation illumination source is 0.4L, the 4th son
The radiance of active radiation illumination source is 0.2L, the radiance of the 5th sub- active radiation illumination source is 0L, described per height
The greatest irradiation brightness of active radiation illumination source provided is 1.0L.
6. the in-orbit spectral radiometric calibration system of the space camera according to claim 2 based on active radiation illumination source, feature
It is, the radiance that the second sub- active radiation illumination source group includes the 6th sub- active radiation illumination source is 0.9L, the 7th
The radiance of sub- active radiation illumination source is 0.7L, the radiance of the 8th sub- active radiation illumination source is 0.5L, the 9th son
The radiance of active radiation illumination source is 0.3L, the radiance of the tenth sub- active radiation illumination source is 0.1L.
7. the in-orbit spectral radiometric calibration system of the space camera according to claim 2 based on active radiation illumination source, feature
It is, the radiance that the third active radiation illumination source group includes the 11st sub- active radiation illumination source is 0.75L, the
The radiance of 12 sub- active radiation illumination sources is 0.55L, the radiance of the 13rd sub- active radiation illumination source is
0.35L, the 14th sub- active radiation illumination source radiance be that 0.25L, the radiation of the 15th sub- active radiation illumination source are bright
Degree is 0.15L.
8. a kind of in-orbit Calibration Method of space camera based on active radiation illumination source, which is characterized in that the method packet
It includes：
Calibration place is chosen, puts active radiation illumination source as required, and be respectively controlled by brightness requirement, atmospheric transmittance
Test device is carried out test and is prepared, and carries out calibration and prepare
Space camera obtains the digital picture that active radiation illumination source generates；
The corresponding gray value of image of the active radiation illumination source is determined according to the digital picture；
According to the first radiance and atmospheric transmittance that the active radiation illumination source generates, with corresponding gray value of image
Establish linear response relationship；
The responsiveness of the space camera is determined using the linear response relationship and the atmospheric transmittance.
9. the in-orbit Calibration Method of the space camera according to claim 8 based on active radiation illumination source, feature
It is, it is described that the corresponding gray value of image of the active radiation illumination source is determined according to digital picture, including：
The gray value that the active radiation illumination source corresponds to N × N pixels adjacent in digital picture is obtained, and is calculated according to first
Formula calculates gray value of image Y, and first calculation formula is：
Wherein：K is active radiation illumination source serial number, and x, y are pixel serial number, and i, j are upper left corner pixel serial number, and M, N are the lower right corner
Pixel serial number.
10. the in-orbit Calibration Method of the space camera according to claim 9 based on active radiation illumination source, feature
It is, first radiance and atmospheric transmittance generated according to the active radiation illumination source, with corresponding image
Gray value establishes linear response relationship, including：
The second radiance at the space camera entrance pupil, the second meter of the second radiance are calculated using the second calculation formula
Calculating formula is：
LCAM=LS·τATM+LSCE·τATM+LATM；
In formula：
LCAMIndicate the second radiance at camera entrance pupil, LSIndicate the first radiance that active radiation illumination source generates, τATM
Indicate atmospheric transmittance, LSCEIndicate that sunlight and skylight are incident on the reflection spoke behind active radiation illumination source and periphery place
Penetrate brightness, LATMIndicate atmospheric scattering radiance；
The first equation group is established according to the rdaiation response relationship of the second calculation formula and space camera, first equation group is：
Y5 is by the corresponding image ash of the in scaling system the 5th sub- active radiation illumination source radiance in first equation group
Angle value, the 5th sub- active radiation illumination source are not lighted, and the radiance of itself output is 0, the spoke at camera entrance pupil
It penetrates brightness and is mainly incident on the reasons for its use spoke behind active radiation illumination source and periphery place due to sunlight and skylight
Brightness and atmospheric scattering radiance are penetrated, the effect that the 5th sub- active radiation illumination source is not lighted is in calibration process
Background radiation brightness and atmospheric scattering radiance deduction；
The responsiveness that the space camera is determined using the linear response relationship and the atmospheric transmittance, including：
Background correction radiance in first equation group and atmospheric scattering radiance are obtained into second equation group, according to institute
It states second equation group and atmospheric transmittance calculates space camera responsiveness R, wherein atmospheric transmittance can be penetrated with the air
Rate test device obtains measured data, and the second equation group is
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109737987A (en) * | 2018-12-29 | 2019-05-10 | 中国科学院长春光学精密机械与物理研究所 | Infrared radiometric calibration system on a kind of how photosynthetic in-orbit star of diameter space camera at a gulp |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102901516A (en) * | 2012-09-29 | 2013-01-30 | 航天恒星科技有限公司 | Multispectral image radiation correction method based on absolute radiometric calibration |
| US20140058695A1 (en) * | 2012-08-23 | 2014-02-27 | Raytheon Company | Geometric calibration of a remote sensor |
| CN104089627A (en) * | 2014-06-24 | 2014-10-08 | 中国资源卫星应用中心 | Absolute radiometric calibration method for satellite staring planar array CCD camera |
| CN104458591A (en) * | 2014-12-03 | 2015-03-25 | 中国科学院光电研究院 | On-orbit spectrum calibration method of chromatic dispersion type spectral imaging system |
| CN104729535A (en) * | 2015-03-17 | 2015-06-24 | 航天东方红卫星有限公司 | Space camera in-orbit absolute calibration method based on fixed star |
| CN104880702A (en) * | 2014-10-31 | 2015-09-02 | 航天恒星科技有限公司 | Method and device for on-orbit absolute radiation calibration |
| CN105631886A (en) * | 2015-12-01 | 2016-06-01 | 中国科学院上海技术物理研究所 | Relative positioning method for laser light spot and foot print camera on basis of aviation image |
| CN107036629A (en) * | 2017-04-20 | 2017-08-11 | 武汉大学 | The in-orbit relative radiometric calibration method and system of video satellite |
-
2017
- 2017-12-29 CN CN201711480972.5A patent/CN108303118B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140058695A1 (en) * | 2012-08-23 | 2014-02-27 | Raytheon Company | Geometric calibration of a remote sensor |
| CN102901516A (en) * | 2012-09-29 | 2013-01-30 | 航天恒星科技有限公司 | Multispectral image radiation correction method based on absolute radiometric calibration |
| CN104089627A (en) * | 2014-06-24 | 2014-10-08 | 中国资源卫星应用中心 | Absolute radiometric calibration method for satellite staring planar array CCD camera |
| CN104880702A (en) * | 2014-10-31 | 2015-09-02 | 航天恒星科技有限公司 | Method and device for on-orbit absolute radiation calibration |
| CN104458591A (en) * | 2014-12-03 | 2015-03-25 | 中国科学院光电研究院 | On-orbit spectrum calibration method of chromatic dispersion type spectral imaging system |
| CN104729535A (en) * | 2015-03-17 | 2015-06-24 | 航天东方红卫星有限公司 | Space camera in-orbit absolute calibration method based on fixed star |
| CN105631886A (en) * | 2015-12-01 | 2016-06-01 | 中国科学院上海技术物理研究所 | Relative positioning method for laser light spot and foot print camera on basis of aviation image |
| CN107036629A (en) * | 2017-04-20 | 2017-08-11 | 武汉大学 | The in-orbit relative radiometric calibration method and system of video satellite |
Non-Patent Citations (1)
| Title |
|---|
| 徐伟伟等: "基于反射点源的高分辨率光学卫星传感器在轨辐射定标方法", 《光学学报》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109737987A (en) * | 2018-12-29 | 2019-05-10 | 中国科学院长春光学精密机械与物理研究所 | Infrared radiometric calibration system on a kind of how photosynthetic in-orbit star of diameter space camera at a gulp |
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