Vegetation composite parameter synchronous monitoring remote sensing imaging system

Abstract

The invention discloses a vegetation composite parameter synchronous monitoring remote sensing imaging system. Incident parallel light is imaged through an off-axis three-mirror telescopic system, and is divided into a front view field and a rear view field after passing through a view field scanning assembly and a view field division element; wherein one view field is imaged on a detector focal plane of the first detector focal plane circuit assembly after passing through the relay optical system and the low-distortion high-dispersion light splitting system; the other view field is imaged on the detector focal plane of the second detector focal plane circuit assembly after passing through the low-distortion high-resolution light splitting system; the integrated electronics assembly drives the first detector focal plane circuit assembly and the second detector focal plane circuit assembly to carry out photoelectric signal conversion, hyperspectral and hyper-spectral imaging detection is completed, and vegetation composite parameter synchronous monitoring remote sensing imaging is achieved. According to the system, the problem that the monitoring precision of the vegetation health state and the carbon sink capacity is limited by multiple parameters and cannot be synchronously detected due to the fact that key elements of existing land surface vegetation parameter detection load measurement are not synchronous is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of ecological parameter detection, and in particular relates to a remote sensing imaging system for synchronous monitoring of vegetation composite parameters. Background Art

[0002] Various parameters of the vegetation canopy are important bases for terrestrial ecological governance, carbon sink accounting, and agricultural precision management, and are of great significance for practicing the "two mountains" and realizing the "dual carbon" strategy. In remote sensing detection, the parameters of the vegetation canopy are mainly detected by active and passive optical means and radar. Among them, in addition to structural parameters, pigments, nitrogen, water content, photosynthesis, xylem content, leaf area, plant species and even soil components are currently obtained by passive optical detection methods. Among them, except for photosynthesis efficiency, hyperspectral imaging can be used for accurate detection. However, as a key element of carbon sink accounting and an important reference for agricultural precision management, photosynthesis efficiency is difficult to obtain simply by direct measurement of plant pigments. The most effective detection method is to simultaneously detect plant pigments, non-photochemical quenching (NPQ) and fluorescence SIF, and classify and identify vegetation.

[0003] Since the spectral bands required for the above detection elements are different and the spectral resolutions differ by dozens of times, the spatial resolution and width of the corresponding spectral imagers also differ significantly. Currently, no payload has the ability to simultaneously detect the above vegetation parameters in satellite remote sensing detection, and multiple payload data fusion applications are required. The use of hyperspectral and hyperspectral payloads on different platforms for inversion inevitably faces the influence of different observation directions, mismatched spatial resolutions, and different imaging times, resulting in errors in the inversion of actual ecological parameters, especially carbon sink parameters. Summary of the invention

[0004] The technology of the present invention solves the problem: it overcomes the shortcomings of the prior art and provides a remote sensing imaging system for synchronous monitoring of composite parameters of vegetation, which can meet the requirements of satellite platforms for high-precision comprehensive monitoring of the health status and carbon sequestration capacity of land surface and nearshore vegetation, and the detection capability is much higher than the existing land surface vegetation parameter detection load, which comprehensively improves the vegetation parameter detection capability and solves the problem that the key elements of the existing land surface vegetation parameter detection load measurement are not synchronized, resulting in the monitoring accuracy of vegetation health status and carbon sequestration capacity being limited by the inability to synchronously detect multiple parameters.

[0005] In order to solve the above technical problems, the present invention discloses a vegetation composite parameter synchronous monitoring remote sensing imaging system, comprising: an off-axis three-mirror telescope system, a field of view scanning component, a field of view dividing element, a relay optical system, a low-distortion high-dispersion spectroscopic system, a low-distortion high-resolution spectroscopic system, a first detector focal plane circuit component, a second detector focal plane circuit component and a comprehensive electronic component; the relay optical system, the low-distortion high-dispersion spectroscopic system and the first detector focal plane circuit component constitute a fluorescence detection channel; the low-distortion high-resolution spectroscopic system and the second detector focal plane circuit component constitute a visible light near-infrared channel; wherein, incident parallel light is imaged by the off-axis three-mirror telescope system, and the field of view scanning component is used to scan the visible light. After reflection, it is divided into two fields of view, front and rear, by the field-of-view dividing element; one of the fields of view is imaged to the slit A of the low-distortion and high-dispersion spectroscopic system after passing through the relay optical system, and is imaged to the detector focal plane of the first detector focal plane circuit component after being split by the low-distortion and high-dispersion spectroscopic system; the other field of view is imaged to the slit B of the low-distortion and high-resolution spectroscopic system, and is imaged to the detector focal plane of the second detector focal plane circuit component after being split by the low-distortion and high-resolution spectroscopic system; finally, the integrated electronic component drives the first detector focal plane circuit component and the second detector focal plane circuit component respectively to perform photoelectric signal conversion, completes high-spectral and hyper-spectral imaging detection, and realizes synchronous monitoring and remote sensing imaging of composite vegetation parameters.

[0006] In the above-mentioned vegetation composite parameter synchronous monitoring remote sensing imaging system, the off-axis three-mirror telescope system is used to image the radiation received by the entrance pupil of the spectrometer after passing through the field of view scanning component and the field of view dividing element, respectively, onto the slits of the low-distortion high-dispersion spectroscopic system and the low-distortion high-resolution spectroscopic system.

[0007] In the above-mentioned vegetation composite parameter synchronous monitoring remote sensing imaging system, the field of view scanning component is used to fold the optical path and adjust the optical axis in front of the image plane of the off-axis three-mirror telescope system, and realize super-resolution spectral imaging through field of view scanning.

[0008] In the above-mentioned vegetation composite parameter synchronous monitoring remote sensing imaging system, the field of view splitting element is used to divide the outgoing light of the field of view scanning component into two front and rear fields of view in front of the off-axis three-mirror telescope system image surface, and respectively refract them into the fluorescence detection channel and the visible light near-infrared channel.

[0009] In the above-mentioned vegetation composite parameter synchronous monitoring remote sensing imaging system, the relay optical system is used to convert the focal length of the off-axis three-mirror telescope system into a focal length matching the fluorescence hyperspectral imaging.

[0010] In the above-mentioned vegetation composite parameter synchronous monitoring remote sensing imaging system, the low-distortion and high-dispersion spectroscopic system is used to perform super-spectral resolution spectroscopic analysis on one of the fields of view of the off-axis three-mirror telescope image plane and to form an image on the detector focal plane of the first detector focal plane circuit assembly.

[0011] In the above-mentioned vegetation composite parameter synchronous monitoring remote sensing imaging system, the low-distortion high-resolution spectroscopic system is used to perform high spatial resolution spectroscopic analysis on another field of view of the off-axis three-mirror telescope image plane and to image it on the detector focal plane of the second detector focal plane circuit assembly.

[0012] In the above vegetation composite parameter synchronous monitoring remote sensing imaging system, the first detector focal plane circuit component is used to perform spectral imaging of the fluorescence detection channel on the image plane of the low-distortion and high-dispersion spectroscopic system.

[0013] In the above-mentioned vegetation composite parameter synchronous monitoring remote sensing imaging system, the second detector focal plane circuit component is used to perform spectral imaging of the visible light near-infrared channel on the image plane of the low-distortion and high-resolution spectroscopic system.

[0014] In the above-mentioned vegetation composite parameter synchronous monitoring remote sensing imaging system, the integrated electronic component is used to power the field of view scanning component, the first detector focal plane circuit component and the second detector focal plane circuit component, and send driving signals to the field of view scanning component, the first detector focal plane circuit component and the second detector focal plane circuit component.

[0015] The present invention has the following advantages:

[0016] (1) The present invention discloses a remote sensing imaging system for synchronous monitoring of vegetation composite parameters. By sharing an off-axis three-mirror telescope system, a field of view scanning component, and a field of view segmentation element, the visible light near-infrared channel and the fluorescence detection channel are split to achieve simultaneous measurement of multiple parameters such as vegetation observation SIF, species, pigment content, etc., thereby improving the comprehensiveness and synchronization rate of vegetation canopy data acquisition during remote sensing detection, thereby comprehensively analyzing the efficiency of vegetation photosynthesis, and improving the accuracy of satellite remote sensing monitoring of vegetation health status and carbon sink capacity; and solving the problem that the key elements of the existing land surface vegetation parameter detection payload measurement are not synchronized, resulting in the monitoring accuracy of vegetation health status and carbon sink capacity being limited by the inability to synchronously detect multiple parameters.

[0017] (2) The present invention discloses a remote sensing imaging system for synchronous monitoring of vegetation composite parameters. The entire optical path adopts a reflection system design to eliminate spectral imaging chromatic aberration, and is suitable for a frame structure to achieve lightweight optical-mechanical systems. All optical devices adopt a non-thermal design to improve system stability. The above optical design solves the problems of large field of view spectral detection, large aberrations and spectral distortions, and low quantitative accuracy of spectral detection.

[0018] (3) The present invention discloses a remote sensing imaging system for synchronous monitoring of vegetation composite parameters, which adopts a field of view scanning component to realize field of view modulation in the push-scan imaging process, thereby improving the spatial resolution of the system and keeping the field of view of the system unchanged, solving the problems of difficulty in improving the spatial resolution of spectral detection and the contradiction between high spatial resolution and large field of view imaging.

[0019] (4) The present invention discloses a vegetation composite parameter synchronous monitoring remote sensing imaging system. The low distortion and high dispersion spectroscopic system adopts a small F-number Littrow-Offner configuration to achieve low distortion and ultra-spectral resolution spectroscopic system, meeting the requirements of SIF detection for signal-to-noise ratio, spectral resolution, and wavelength accuracy. It solves the problem of weak high spatial resolution SIF signals and great difficulty in satellite remote sensing detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a block diagram of a vegetation composite parameter synchronous monitoring remote sensing imaging system according to an embodiment of the present invention;

[0021] Figure 2 is an optical design diagram of a low-distortion and high-resolution spectroscopic system in an embodiment of the present invention;

[0022] Figure 3 It is an optical design diagram of a low-distortion and high-dispersion spectroscopic system in an embodiment of the present invention;

[0023] Figure 4 It is a structural schematic diagram of a field of view scanning component in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] Reference Figure 1In this embodiment, the vegetation composite parameter synchronous monitoring remote sensing imaging system includes: an off-axis three-mirror telescope system 1, a field scanning component 2, a field dividing element 3, a relay optical system 4, a low-distortion high-dispersion spectroscopic system 5, a low-distortion high-resolution spectroscopic system 6, a first detector focal plane circuit component, a second detector focal plane circuit component and a comprehensive electronic component. The relay optical system, the low-distortion high-dispersion spectroscopic system 5 and the first detector focal plane circuit component constitute a fluorescence detection channel; the low-distortion high-resolution spectroscopic system 6 and the second detector focal plane circuit component constitute a visible light near-infrared channel. Among them, the incident parallel light is imaged by the off-axis three-mirror telescope system 1, reflected by the field of view scanning component 2 and then divided into two front and rear fields of view by the field of view dividing element 3; one of the fields of view is imaged to the slit A11 of the low-distortion and high-dispersion spectroscopic system 5 after passing through the relay optical system 4, and is imaged to the detector focal plane of the first detector focal plane circuit component after being split by the low-distortion and high-dispersion spectroscopic system 5; the other field of view is imaged to the slit B7 of the low-distortion and high-resolution spectroscopic system 6, and is imaged to the detector focal plane of the second detector focal plane circuit component after being split by the low-distortion and high-resolution spectroscopic system 6; finally, the integrated electronic component drives the first detector focal plane circuit component and the second detector focal plane circuit component respectively to perform photoelectric signal conversion, completes high-spectral and hyper-spectral imaging detection, and realizes synchronous monitoring remote sensing imaging of vegetation composite parameters.

[0026] In this embodiment, the off-axis three-mirror telescope system 1 is used to image the radiation received by the entrance pupil of the spectrometer, after passing through the field of view scanning component 2 and the field of view dividing element 3, respectively, at the slits of the low-distortion high-dispersion spectroscopic system 5 and the low-distortion high-resolution spectroscopic system 6. The focal length of the off-axis three-mirror telescope system 1 is designed according to the spatial resolution of the visible light near-infrared channel imaging, and the frame structure support is used to achieve the lightweight of the entire system.

[0027] In this embodiment, the field of view scanning component 2 is used to fold the optical path and adjust the optical axis in front of the image surface of the off-axis three-mirror telescope system 1, and realize super-resolution spectral imaging through field of view scanning. Figure 4 As shown, the field scanning assembly 2 mainly includes: a reflector 15, a piezoelectric two-dimensional scanning mechanism 16 and a scanning control mechanism 17. In the push-scan imaging process, the piezoelectric two-dimensional scanning mechanism drives the reflector to adjust the optical axis to achieve a sub-pixel shift of 1 / n pixels. 2 The frame rate is increased by times, achieving n-fold super-resolution detection and relative radiation correction. Specifically: During the imaging process, the satellite is scanned in two dimensions in the along-track and through-track directions; during the scanning process, n-fold super-resolution detection and relative radiation correction are achieved. 2Double frame rate encrypted sampling and pixel-level reciprocating scanning are performed, and sub-pixel offset scanning of 1 / n pixels is performed in the cross-track direction. For the spatially encrypted sampling spectral image acquired by push-scanning, the probability density function is constructed using the two-dimensional transfer function and the oversampling scene to solve the super-resolution image, thereby achieving super-resolution and relative radiation correction in the spatial dimension.

[0028] In this embodiment, the field of view splitting element 3 is used to split the output light of the field of view scanning assembly 2 into two front and rear fields of view in front of the image plane of the off-axis three-mirror telescope system 1, and respectively deflect them into the fluorescence detection channel and the visible light near-infrared channel.

[0029] In this embodiment, the relay optical system 4 is used to convert the focal length of the off-axis three-mirror telescope system 1 into a focal length that matches the fluorescence hyperspectral imaging. The relay optical system 4 adopts an off-axis three-mirror form, and by matching the off-axis three-mirror telescope system 1, the focal length of the fluorescence detection channel is adjusted to Among them, the spatial resolution of the fluorescence detection channel is k times the spatial resolution of the visible light near-infrared channel, f represents the focal length of the off-axis three-mirror telescope system 1, and the pixel spacing of the first detector focal plane circuit component is m times the pixel spacing of the second detector focal plane circuit component.

[0030] In this embodiment, the low-distortion high-dispersion spectroscopic system 5 is used to perform super-spectral resolution spectroscopic analysis on one of the fields of view of the image plane of the off-axis three-mirror telescope system 1, and to form an image on the detector focal plane of the first detector focal plane circuit assembly. Figure 3 The Littrow-Offner spectroscopic form shown includes: a prism grating A13 and a spherical reflector A14; after passing through the slit A11, the light passes through the transmission area of ​​the prism grating A13, is reflected by the spherical reflector A14, is dispersed by the grating area of ​​the prism grating A13, is reflected by the spherical reflector A14, is corrected for aberration by the transmission area of ​​the prism grating A13, and is finally imaged on the detector focal plane A12 of the first detector focal plane circuit assembly. Furthermore, a high-line-density convex blazed grating is used on the prism grating A13 to achieve a high dispersion coefficient to meet the ultra-spectral resolution detection requirements of 0.67μm to 0.78μm spectral range and 0.3nm spectral resolution.

[0031] In this embodiment, the low-distortion high-resolution spectroscopic system 6 is used to perform high spatial resolution spectroscopic analysis on another field of view of the image plane of the off-axis three-mirror telescope system 1 and to form an image on the detector focal plane of the second detector focal plane circuit assembly.

[0032] The low distortion and high resolution spectroscopic system 6 adopts Figure 2The Offner-Wynne spectroscopic form shown achieves high-resolution large-field spectral imaging with a spectral range of 0.45μm to 0.9μm and a spectral resolution of 10nm. The low-distortion high-resolution spectroscopic system 6 mainly includes: a prism grating B8 and a spherical reflector B9;

[0033] The system consists of a slit B7 and a spherical center. After passing through the slit A7, the prism grating A8 and the spherical reflector A9, the light is imaged on the detector focal plane B10 of the second detector focal plane circuit assembly.

[0034] In this embodiment, the first detector focal plane circuit assembly is used to perform spectral imaging of the fluorescence detection channel on the image plane of the low-distortion and high-dispersion spectroscopic system 5 .

[0035] In this embodiment, the second detector focal plane circuit assembly is used to perform spectral imaging of the visible light near-infrared channel on the image plane of the low-distortion and high-resolution spectroscopic system 6 .

[0036] In this embodiment, the integrated electronic component is used to power the field of view scanning component 2, the first detector focal plane circuit component and the second detector focal plane circuit component, and send driving signals to the field of view scanning component 2, the first detector focal plane circuit component and the second detector focal plane circuit component.

[0037] In this embodiment, the off-axis three-mirror telescope system 1, the field of view scanning component 2, the field of view dividing element 3, the relay optical system 4, the low-distortion and high-dispersion spectroscopic system 5, the low-distortion and high-resolution spectroscopic system 6, etc. all adopt a reflective form, and the optical materials and optomechanical structure materials are selected according to the thermal expansion coefficient. The optomechanical structure adopts a athermal design to improve the stability of the system.

[0038] In summary, the present invention designs a remote sensing imaging system for synchronous monitoring of vegetation composite parameters from multiple aspects such as the overall architecture of the remote sensing imaging system, the field of view scanning component, and the optical design of the spectroscopic system. The visible near-infrared channel and the fluorescence detection channel share an off-axis three-mirror telescope system; the athermal design of the reflective light path is adopted to achieve high-stability and chromatic aberration-free imaging; the field of view scanning is used to achieve n-fold spatial dimensional super-resolution and relative radiation correction; and Offner spectrometry is used to achieve large-field-of-view and low-distortion spectral detection.

[0039] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0040] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A vegetation composite parameter synchronous monitoring remote sensing imaging system, characterized in that: include: An off-axis three-mirror telescope system (1), a field of view scanning component (2), a field of view dividing element (3), a relay optical system (4), a low-distortion high-dispersion spectroscopic system (5), a low-distortion high-resolution spectroscopic system (6), a first detector focal plane circuit component, a second detector focal plane circuit component and an integrated electronic component; the relay optical system (4), the low-distortion high-dispersion spectroscopic system (5) and the first detector focal plane circuit component constitute a fluorescence detection channel; the low-distortion high-resolution spectroscopic system (6) and the second detector focal plane circuit component constitute a visible light near-infrared channel; wherein incident parallel light is imaged by the off-axis three-mirror telescope system (1), reflected by the field of view scanning component (2) and then divided into front and rear fields of view by the field of view dividing element (3); One of the fields of view is imaged onto a slit A (11) of a low-distortion high-dispersion spectroscopic system (5) after passing through a relay optical system (4), and is imaged onto a detector focal plane of a first detector focal plane circuit component after being split by the low-distortion high-dispersion spectroscopic system (5); the other field of view is imaged onto a slit B (7) of a low-distortion high-resolution spectroscopic system (6), and is imaged onto a detector focal plane of a second detector focal plane circuit component after being split by the low-distortion high-resolution spectroscopic system (6); finally, the integrated electronic component drives the first detector focal plane circuit component and the second detector focal plane circuit component to perform photoelectric signal conversion, thereby completing high-spectral and hyper-spectral imaging detection and realizing remote sensing imaging of synchronous monitoring of composite vegetation parameters.

2. The vegetation composite parameter synchronous monitoring remote sensing imaging system according to claim 1 is characterized in that: The off-axis three-mirror telescope system (1) is used to image radiation received by an entrance pupil of a spectrometer through a field of view scanning component (2) and a field of view dividing element (3) onto the slits of a low-distortion high-dispersion spectroscopic system (5) and a low-distortion high-resolution spectroscopic system (6).

3. The vegetation composite parameter synchronous monitoring remote sensing imaging system according to claim 1 is characterized in that: The field of view scanning component (2) is used to fold the optical path and adjust the optical axis in front of the image surface of the off-axis three-mirror telescope system (1), and realize super-resolution spectral imaging through field of view scanning.

4. The vegetation composite parameter synchronous monitoring remote sensing imaging system according to claim 1 is characterized in that: The field of view splitting element (3) is used to split the output light of the field of view scanning component (2) into two front and rear fields of view in front of the image surface of the off-axis three-mirror telescope system (1), and respectively deflect the light to the fluorescence detection channel and the visible light near-infrared channel.

5. The vegetation composite parameter synchronous monitoring remote sensing imaging system according to claim 1 is characterized in that: The relay optical system (4) is used to convert the focal length of the off-axis three-mirror telescope system (1) into a focal length matching the fluorescence hyperspectral imaging.

6. The vegetation composite parameter synchronous monitoring remote sensing imaging system according to claim 1 is characterized in that: A low-distortion and high-dispersion spectroscopic system (5) is used to perform super-spectral resolution spectroscopic analysis on one of the fields of view on the image plane of an off-axis three-mirror telescope system (1), and to form an image on the detector focal plane of a first detector focal plane circuit assembly.

7. The vegetation composite parameter synchronous monitoring remote sensing imaging system according to claim 1 is characterized in that: A low-distortion high-resolution spectroscopic system (6) is used to perform high spatial resolution spectroscopic analysis on another field of view of the image plane of the off-axis three-mirror telescope system (1), and to form an image on the detector focal plane of the second detector focal plane circuit assembly.

8. The vegetation composite parameter synchronous monitoring remote sensing imaging system according to claim 1 is characterized in that: The first detector focal plane circuit component is used for performing spectral imaging of the fluorescence detection channel on the image plane of the low-distortion and high-dispersion spectroscopic system (5).

9. The vegetation composite parameter synchronous monitoring remote sensing imaging system according to claim 2, characterized in that: The second detector focal plane circuit component is used for performing spectral imaging of the visible light near-infrared channel on the image plane of the low-distortion and high-resolution spectroscopic system (6).

10. The vegetation composite parameter synchronous monitoring remote sensing imaging system according to claim 1, characterized in that: The integrated electronic component is used to supply power to the field of view scanning component (2), the first detector focal plane circuit component and the second detector focal plane circuit component, and to send a driving signal to the field of view scanning component (2), the first detector focal plane circuit component and the second detector focal plane circuit component.

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