Focusing method and system for push-broom imaging spectrometer

Abstract

The invention discloses a focusing method and system for a push-broom imaging spectrometer. The push-broom imaging spectrometer at least comprises a front imaging mirror and a spectrum detection module; the method comprises the following steps: setting an imaging observation module connected with an image space focal plane of the front imaging mirror; a light splitting module is placed in the rear working distance of the front imaging mirror, the light splitting module is used for splitting a light path penetrating out of the front imaging mirror into a first light path and a second light path which are equal in light path, the first light path enters an imaging observation module for imaging observation, and the second light path enters a spectrum detection module for spectrum detection; a front imaging mirror is arranged on the displacement table, and the front imaging mirror can move back and forth on the displacement table in the optical axis direction; during working, image information of a measured target is observed through the imaging observation module, the position of the front imaging mirror on the displacement table is adjusted based on an observation result until a clear image is obtained, and focusing is completed. According to the invention, real-time focusing of the imaging spectrometer can be realized, and the measurement efficiency of the imaging spectrum is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging spectrum measurement, and in particular to a focusing method and system for a push-broom imaging spectrometer. Background Art

[0002] The push-broom imaging spectrometer uses an array detector. Its one-dimensional pixel completes spatial imaging along the direction of movement through the movement of the payload platform, and the other-dimensional pixel obtains the spectral information of the corresponding spatial dimension. After continuous acquisition and image stitching, the spatial and spectral information data of the target are obtained.

[0003] A push-broom imaging spectrometer can only collect image data of one column or one row of the target at a time. To obtain a complete image of the target, multiple push-broom operations are required. For push-broom imaging spectrometers whose detection distance changes frequently, they need to be focused. Each time they focus, a complete push-broom scan is required, and then the device parameters are adjusted according to the clarity of the image. The above steps are repeated again until the image is clear. This focusing method has problems such as cumbersome process and slow focusing speed, and it is difficult to complete the focusing work of the device in a short time.

[0004] Therefore, there is an urgent need for a focusing method and system for a push-broom imaging spectrometer to solve the above problems. Summary of the invention

[0005] The present invention provides a focusing method and system for a push-broom imaging spectrometer, which can realize real-time focusing of the imaging spectrometer and improve the measurement efficiency of the imaging spectrum. The technical solution is as follows:

[0006] In one aspect, a focusing method for a push-broom imaging spectrometer is provided, wherein the push-broom imaging spectrometer comprises at least a front imaging mirror and a spectrum detection module; the method comprises:

[0007] An imaging observation module connected to the image side focal plane of the front imaging mirror is provided, and the imaging observation module is used to observe image information of the measured target;

[0008] A spectroscopic module is placed in the rear working distance of the front imaging mirror, and the spectroscopic module is used to divide the light path passing through the front imaging mirror into a first light path and a second light path with equal optical paths, the first light path enters the imaging observation module for imaging observation, and the second light path enters the spectrum detection module for spectrum detection;

[0009] The front imaging mirror is arranged on a translation stage, and the front imaging mirror can move forward and backward on the translation stage along the optical axis direction;

[0010] During operation, the image information of the measured target is observed through the imaging observation module, and the position of the front imaging mirror on the displacement stage is adjusted based on the observation result until a clear image is obtained, thereby completing the focusing operation.

[0011] In a possible design, adjusting the position of the front imaging mirror on the translation stage based on the observation result until a clear image is obtained includes:

[0012] Determine whether the image observed by the imaging observation module meets the clarity requirement; if so, do not adjust the position of the front imaging mirror on the translation stage; if not, move the front imaging mirror back and forth on the translation stage along the optical axis until the image observed by the imaging observation module meets the clarity requirement.

[0013] In one possible design, it also includes:

[0014] When the image observed by the imaging observation module meets the definition requirement, the spectrum detection module is used to obtain the single-line image information of the measured target and the complete spectrum information of the corresponding spatial dimension; and so on, until a complete push-scanning operation is completed;

[0015] Each single-line image information obtained is spliced ​​in sequence to obtain a complete two-dimensional image of the target under each spectral channel.

[0016] In a possible design, the spectrum detection module includes an incident slit, a collimating mirror, a spectrum splitting unit, a focusing mirror and a detector;

[0017] The position of the incident slit is the image focal plane of the front imaging mirror. The second light path is a line image after passing through the incident slit, and then passes through the collimator, the spectral splitter unit, and the focusing mirror in sequence to obtain the spectral information of the target on the detector.

[0018] In a possible design, along the transmission direction of the optical path, the front imaging mirror includes a plurality of mirror surfaces;

[0019] The rear working distance of the front imaging mirror is the distance between its image focal plane and its last mirror surface.

[0020] On the other hand, a focusing system for a push-broom imaging spectrometer is provided, the system comprising:

[0021] Front imaging mirror, spectrum detection module, imaging observation module, spectroscopic module and translation stage;

[0022] The front imaging mirror is movably arranged on the displacement platform;

[0023] The imaging observation module is connected to the image side focal plane of the front imaging mirror to observe the image information of the measured target;

[0024] The spectroscopic module is placed in the rear working distance of the front imaging mirror, and is used to split the light path passing through the front imaging mirror into a first light path and a second light path with equal optical paths, the first light path enters the imaging observation module for imaging observation, and the second light path enters the spectrum detection module for spectrum detection;

[0025] During operation, the image information of the measured target is observed through the imaging observation module, and the position of the front imaging mirror on the displacement stage is adjusted based on the observation result until a clear image is obtained, thereby completing the focusing operation.

[0026] In a possible design, adjusting the position of the front imaging mirror on the translation stage based on the observation result until a clear image is obtained includes:

[0027] Determine whether the image observed by the imaging observation module meets the clarity requirement; if so, do not adjust the position of the front imaging mirror on the translation stage; if not, move the front imaging mirror back and forth on the translation stage along the optical axis until the image observed by the imaging observation module meets the clarity requirement.

[0028] In one possible design, it also includes:

[0029] When the image observed by the imaging observation module meets the definition requirement, the spectrum detection module is used to obtain the single-line image information of the measured target and the complete spectrum information of the corresponding spatial dimension; and so on, until a complete push-scanning operation is completed;

[0030] Each single-line image information obtained is spliced ​​in sequence to obtain a complete two-dimensional image of the target under each spectral channel.

[0031] In a possible design, the spectrum detection module includes an incident slit, a collimating mirror, a spectrum splitting unit, a focusing mirror and a detector;

[0032] The position of the incident slit is the image focal plane of the front imaging mirror. The second light path is a line image after passing through the incident slit, and then passes through the collimator, the spectral splitter unit, and the focusing mirror in sequence to obtain the spectral information of the target on the detector.

[0033] In a possible design, along the transmission direction of the optical path, the front imaging mirror includes a plurality of mirror surfaces;

[0034] The rear working distance of the front imaging mirror is the distance between its image focal plane and its last mirror surface.

[0035] The embodiment of the present invention provides a focusing method for a push-broom imaging spectrometer. By setting a spectroscopic module, the optical path can be divided into two. By setting an imaging observation module, the clarity of the image of the measured target at different detection distances can be observed in real time during the push-broom process. When the clarity requirement is not met, the clarity of the image can be adjusted by moving the position of the front imaging mirror on the displacement stage, so that the entire system can be focused in real time, effectively improving the measurement efficiency and accuracy of the push-broom imaging spectrometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 is a flow chart of a focusing method for a push-broom imaging spectrometer provided by an embodiment of the present invention;

[0038] Figure 2 The diagram is a schematic structural diagram of a focusing system for a push-broom imaging spectrometer provided by an embodiment of the present invention.

[0039] Reference numerals:

[0040] 1-Front imaging mirror;

[0041] 2- Spectrum detection module;

[0042] 21-incident slit; 22-collimating mirror; 23-spectral spectrometer unit; 24-focusing mirror; 25-detector; 3-imaging observation module; 4-spectrometry module; 5-translation stage. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0044] The specific implementation of the above concept is described below.

[0045] Please refer to Figure 1The embodiment of the present invention provides a focusing method for a push-broom imaging spectrometer, wherein the push-broom imaging spectrometer at least includes a front imaging mirror 1 and a spectrum detection module 2; the method includes:

[0046] Step 100, setting an imaging observation module 3 connected to the image side focal plane of the front imaging mirror 1, the imaging observation module 3 is used to observe the image information of the measured target;

[0047] Step 102, placing a spectroscopic module 4 in the rear working distance of the front imaging mirror 1, the spectroscopic module 4 is used to split the light path passing through the front imaging mirror 1 into a first light path and a second light path with equal optical path lengths, the first light path enters the imaging observation module 3 for imaging observation, and the second light path enters the spectrum detection module 2 for spectrum detection;

[0048] Step 104, placing the front imaging mirror 1 on the translation stage 5, and the front imaging mirror 1 can move forward and backward on the translation stage 5 along the optical axis direction;

[0049] Step 106, when working, the image information of the measured target is observed through the imaging observation module 3, and the position of the front imaging mirror 1 on the displacement stage 5 is adjusted based on the observation result until a clear image is obtained, and the focusing operation is completed.

[0050] In this embodiment, a spectroscopic module 4 is added to the optical path of the working distance behind the front imaging mirror 1 to split the optical path into two. The two optical paths enter the imaging observation module 3 and the spectrum detection module 2 respectively. The clarity of the measured image is evaluated in the imaging observation module 3. The working distance behind the front imaging mirror 1 is changed by adjusting the displacement stage 5, and then the system is focused. Since the optical path lengths of the two optical paths are the same, the spectrum detection module 2 can also be focused clearly, which greatly simplifies the focusing process of the push-broom imaging spectrometer, and can perform real-time focusing, effectively improving the measurement efficiency and measurement accuracy of the push-broom imaging spectrometer.

[0051] Specifically, the front imaging mirror 1 images the target to be measured, and the spectroscopic module 4 is placed in the rear working distance of the front imaging mirror 1, and the optical path of the front imaging mirror 1 is divided into two beams, one of which is the imaging observation optical path, which enters the imaging observation module 3 and is used for imaging observation of the target to be measured, and the other is the spectrum detection optical path, which enters the spectrum detection module 2 and is used for spectrum detection of the target to be measured to obtain its spectrum information. The displacement stage 5 is used to carry the front imaging mirror 1, and can make the front imaging mirror 1 move forward and backward along the optical path, and then adjust the rear working distance of the front imaging mirror 1 according to the clarity of the target image obtained by the imaging observation module 3, so as to ensure that the measured image is in clear focus. At the same time, since the optical path of the front optical path of the imaging observation module 3 and the spectrum detection module 2 is the same, that is, the optical path of the two optical paths after passing through the spectroscopic module 4 is the same, after the imaging observation module 3 is clearly imaged, the corresponding spectrum detection module 2 is also clearly imaged, so that the simultaneous focusing of the entire system can be achieved, so that the image data is clear and the spectrum information is accurate when the push-broom imaging spectrometer is working.

[0052] In some embodiments, adjusting the position of the front imaging mirror 1 on the translation stage 5 based on the observation result until a clear image is obtained includes:

[0053] Determine whether the image observed by the imaging observation module 3 meets the clarity requirement; if so, do not adjust the position of the front imaging mirror 1 on the displacement stage 5; if not, move the front imaging mirror 1 back and forth on the displacement stage 5 along the optical axis until the image observed by the imaging observation module 3 meets the clarity requirement.

[0054] In some embodiments, it further comprises:

[0055] When the image observed by the imaging observation module 3 meets the definition requirement, the spectrum detection module 2 is used to obtain the single-line image information of the measured target and the complete spectrum information of the corresponding spatial dimension; and so on, until a complete push-scan operation is completed;

[0056] Each single-line image information obtained is spliced ​​in sequence to obtain a complete two-dimensional image of the target under each spectral channel.

[0057] In some embodiments, the spectrum detection module 2 includes an incident slit 21, a collimating lens 22, a spectrum splitting unit 23, a focusing lens 24, and a detector 25;

[0058] The position of the incident slit 21 is the image focal plane of the front imaging mirror 1. The second light path passes through the incident slit 21 to form a line image, and then passes through the collimator 22, the spectral splitter unit 23, and the focusing mirror 24 in sequence to obtain the spectral information of the target on the detector 25.

[0059] In this embodiment, the image of the front imaging mirror 1 is formed at the incident slit 21; since the optical paths of the first optical path and the second optical path are the same, the image at the incident slit 21 has the same clarity as the image of the imaging observation module 3. When the image observed by the imaging observation module 3 meets the clarity requirement, the image information and spectral information detected by the spectrum detection module 2 also meet the clarity requirement, and the push-broom imaging spectrometer can be quickly focused.

[0060] In some embodiments, along the light transmission direction, the front imaging mirror 1 includes a plurality of mirror surfaces;

[0061] The back working distance of the front imaging mirror 1 is the distance between its image focal plane and its last mirror surface.

[0062] Please refer to Figure 2 , an embodiment of the present invention provides a focusing system for a push-broom imaging spectrometer, the system comprising:

[0063] The front imaging mirror 1 is movably arranged on the displacement stage 5;

[0064] The imaging observation module 3 is connected to the image focal plane of the front imaging mirror 1 to observe the image information of the measured target;

[0065] The spectroscopic module 4 is placed in the rear working distance of the front imaging mirror 1. The spectroscopic module 4 is used to divide the light path passing through the front imaging mirror 1 into a first light path and a second light path with equal optical path lengths. The first light path enters the imaging observation module 3 for imaging observation, and the second light path enters the spectrum detection module 2 for spectrum detection.

[0066] During operation, the image information of the target is observed through the imaging observation module 3, and the position of the front imaging mirror 1 on the displacement stage 5 is adjusted based on the observation result until a clear image is obtained, thereby completing the focusing operation.

[0067] In some embodiments, adjusting the position of the front imaging mirror 1 on the translation stage 5 based on the observation result until a clear image is obtained includes:

[0068] Determine whether the image observed by the imaging observation module 3 meets the clarity requirement; if so, do not adjust the position of the front imaging mirror 1 on the displacement stage 5; if not, move the front imaging mirror 1 back and forth on the displacement stage 5 along the optical axis until the image observed by the imaging observation module 3 meets the clarity requirement.

[0069] In some embodiments, it further comprises:

[0070] When the image observed by the imaging observation module 3 meets the definition requirement, the spectrum detection module 2 is used to obtain the single-line image information of the measured target and the complete spectrum information of the corresponding spatial dimension; and so on, until a complete push-scan operation is completed;

[0071] Each single-line image information obtained is spliced ​​in sequence to obtain a complete two-dimensional image of the target under each spectral channel.

[0072] In some embodiments, the spectrum detection module 2 includes an incident slit 21, a collimator 22, a spectrum splitter unit 23, a focusing lens 24 and a detector 25;

[0073] The position of the incident slit 21 is the image focal plane of the front imaging mirror 1. The second light path passes through the incident slit 21 to form a line image, and then passes through the collimator 22, the spectral splitter unit 23, and the focusing mirror 24 in sequence to obtain the spectral information of the target on the detector 25.

[0074] In some embodiments, along the light transmission direction, the front imaging mirror 1 includes a plurality of mirror surfaces;

[0075] The back working distance of the front imaging mirror 1 is the distance between its image focal plane and its last mirror surface.

[0076] It should be noted that the focusing system for a push-broom imaging spectrometer provided in the above embodiment is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the focusing system for a push-broom imaging spectrometer provided in the above embodiment and the focusing method embodiment for a push-broom imaging spectrometer belong to the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0077] Finally, it should be noted that, in this article, relational terms such as first, second, third and fourth are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0078] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A focusing method for a push-broom imaging spectrometer, characterized in that: The push-broom imaging spectrometer comprises at least a front imaging mirror (1) and a spectrum detection module (2); the method comprises: An imaging observation module (3) connected to the image-side focal plane of the front imaging mirror (1) is provided, wherein the imaging observation module (3) is used to observe image information of a measured target; A light splitting module (4) is placed in the rear working distance of the front imaging mirror (1), and the light splitting module (4) is used to split the light path passing through the front imaging mirror (1) into a first light path and a second light path with equal optical paths, the first light path enters the imaging observation module (3) for imaging observation, and the second light path enters the spectrum detection module (2) for spectrum detection; The front imaging mirror (1) is arranged on a displacement platform (5), and the front imaging mirror (1) can move forward and backward on the displacement platform (5) along the optical axis direction; When working, the image information of the measured target is observed through the imaging observation module (3), and the position of the front imaging mirror (1) on the displacement stage (5) is adjusted based on the observation result until a clear image is obtained, thereby completing the focusing operation.

2. The method according to claim 1, characterized in that The step of adjusting the position of the front imaging mirror (1) on the translation stage (5) based on the observation result until a clear image is obtained comprises: It is determined whether the image observed by the imaging observation module (3) meets the clarity requirement; if so, the position of the front imaging mirror (1) on the displacement stage (5) is not adjusted; if not, the front imaging mirror (1) is moved forward and backward along the optical axis on the displacement stage (5) until the image observed by the imaging observation module (3) meets the clarity requirement.

3. The method according to claim 1, characterized in that: Also includes: When the image observed by the imaging observation module (3) meets the definition requirement, the spectrum detection module (2) is used to obtain single-line image information of the target and complete spectrum information of the corresponding spatial dimension; and so on and so forth until a complete push-scan operation is completed; Each single-line image information obtained is spliced ​​in sequence to obtain a complete two-dimensional image of the target under each spectral channel.

4. The method according to claim 1, characterized in that The spectrum detection module (2) comprises an incident slit (21), a collimating mirror (22), a spectrum splitting unit (23), a focusing mirror (24) and a detector (25); The position of the incident slit (21) is the image-side focal plane of the front imaging mirror (1); the second light path passes through the incident slit (21) to form a line image, and then passes through the collimator (22), the spectral splitting unit (23), and the focusing mirror (24) in sequence to obtain spectral information of the target to be measured on the detector (25).

5. The method according to claim 1, characterized in that Along the transmission direction of the optical path, the front imaging mirror (1) comprises a plurality of mirror surfaces; The rear working distance of the front imaging mirror (1) is the distance between its image-side focal plane and its last mirror surface.

6. A focusing system for a push-broom imaging spectrometer, characterized in that: The system comprises: a front imaging mirror (1), a spectrum detection module (2), an imaging observation module (3), a spectroscopic module (4) and a displacement stage (5); The front imaging mirror (1) is movably arranged on the displacement stage (5); The imaging observation module (3) is connected to the image-side focal plane of the front imaging mirror (1) to observe image information of the measured target; The light splitting module (4) is placed in the rear working distance of the front imaging mirror (1), and is used to split the light path passing through the front imaging mirror (1) into a first light path and a second light path with equal optical paths, the first light path entering the imaging observation module (3) for imaging observation, and the second light path entering the spectrum detection module (2) for spectrum detection; When working, the image information of the measured target is observed through the imaging observation module (3), and the position of the front imaging mirror (1) on the displacement stage (5) is adjusted based on the observation result until a clear image is obtained, thereby completing the focusing operation.

7. The system according to claim 6, characterized in that The step of adjusting the position of the front imaging mirror (1) on the translation stage (5) based on the observation result until a clear image is obtained comprises: It is determined whether the image observed by the imaging observation module (3) meets the clarity requirement; if so, the position of the front imaging mirror (1) on the displacement stage (5) is not adjusted; if not, the front imaging mirror (1) is moved forward and backward along the optical axis on the displacement stage (5) until the image observed by the imaging observation module (3) meets the clarity requirement.

8. The system according to claim 6, characterized in that Also includes: When the image observed by the imaging observation module (3) meets the definition requirement, the spectrum detection module (2) is used to obtain single-line image information of the target and complete spectrum information of the corresponding spatial dimension; and so on and so forth until a complete push-scan operation is completed; Each single-line image information obtained is spliced ​​in sequence to obtain a complete two-dimensional image of the target under each spectral channel.

9. The system according to claim 6, characterized in that The spectrum detection module (2) comprises an incident slit (21), a collimating mirror (22), a spectrum splitting unit (23), a focusing mirror (24) and a detector (25); The position of the incident slit (21) is the image-side focal plane of the front imaging mirror (1); the second light path passes through the incident slit (21) to form a line image, and then passes through the collimator (22), the spectral splitting unit (23), and the focusing mirror (24) in sequence to obtain spectral information of the target to be measured on the detector (25).

10. The system according to claim 6, characterized in that Along the transmission direction of the optical path, the front imaging mirror (1) comprises a plurality of mirror surfaces; The rear working distance of the front imaging mirror (1) is the distance between its image-side focal plane and its last mirror surface.

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