A device for suppressing background radiation of medium- and long-wave infrared hyperspectral remote sensor

Abstract

The present invention discloses a device for suppressing background radiation of a medium- and long-wave infrared hyperspectral remote sensor, comprising a first refrigerator assembly, a second refrigerator assembly and a cold box assembly, wherein the first refrigerator assembly and the second refrigerator assembly are respectively connected to the cold box assembly, a spectrometer assembly is arranged inside the cold box assembly, the spectrometer assembly comprises a first spectrometer, a second spectrometer and a third spectrometer, the first refrigerator assembly is respectively connected to the first spectrometer and the second spectrometer through a flexible cold chain, the second refrigerator assembly is connected to the third spectrometer through a flexible cold chain, a window mounting base is arranged on the cold box assembly, and the first spectrometer, the second spectrometer and the third spectrometer are arranged around the window mounting base. The present invention adopts a two-stage refrigeration method for refrigeration, effectively avoids the problem of long startup time of the refrigerator, ensures vacuum deep low temperature refrigeration, and effectively realizes background radiation suppression of the medium- and long-wave infrared hyperspectral remote sensor.

Description

Technical Field

[0001] The invention relates to the field of infrared detectors, and in particular to a refrigeration device for suppressing background radiation of a medium- and long-wave infrared hyperspectral remote sensor. Background Art

[0002] Hyperspectral imaging technology is a remote sensing technology developed in the 1980s. Unlike traditional spectrometers, hyperspectral imaging technology integrates images and spectra (image-spectrum integration). With nanometer-level high spectral resolution, it can simultaneously obtain continuous and fine spectral information of the target while obtaining the target's two-dimensional spatial image information, greatly improving the detection capability of space remote sensing. Compared with visible, near-infrared, and short-wave infrared, medium- and long-wave infrared (5.0μm~15μm) hyperspectral imaging technology has unique advantages. The spectral coverage range reaches nearly 10,000 nanometers, and it can obtain the fine spectral information of the target's own thermal radiation. It can not only effectively identify the composition of the ground object, but also effectively distinguish the structural characteristics of the ground object, and obtain parameter information such as the temperature and emissivity of the ground object. It can be widely used in observations of land, atmosphere, and ocean.

[0003] However, according to Wien's displacement law, the equivalent blackbody temperature value of the peak wavelength in the mid- and long-wave infrared spectrum range of 5.0 ~ 12.5μm is 240 ~ 3-70K (-3-3°C ~ 97°C). This temperature range includes most objects on the earth's surface, that is, almost all objects can radiate energy in this band. Therefore, the mid- and long-wave infrared hyperspectral imager is seriously affected by the background radiation stray light. If no background radiation suppression is taken, the target signal energy will be completely submerged in the stray radiation noise of the hyperspectral imager itself. Therefore, for long-wave infrared spectrometers, the performance level of mid- and long-wave hyperspectral imagers depends largely on the suppression level of background radiation.

[0004] From the basic theory of thermal radiation, it can be known that the temperature of an object has a great influence on its thermal radiation energy. The radiation energy of an object decreases exponentially as the temperature of the object decreases. Therefore, refrigeration of the optomechanical system is a very effective means to suppress background radiation. 99% of the background radiation of the hyperspectral imager comes from the back-end spectrometer. If the back-end spectrometer or detector is cooled, the background radiation of the system will be reduced from the source. The traditional optomechanical system refrigeration method generally adopts a single heat conduction refrigeration method, that is, a cold box or Dewar device that can realize a vacuum system is used, and the refrigerator is used to output cold to the medium- and long-wave spectrometer or medium- and long-wave infrared detector through a cold chain or a cold head to achieve the temperature conditions required for the normal operation of the medium- and long-wave infrared background radiation suppression and the detector. This method is simple to implement and easy to implement. When cooling a single object at the back end, it is not affected by other objects in the system, and can quickly reduce the background radiation of the system. However, this method also has the disadvantages of a long time required for a single system startup, low refrigeration efficiency, high power consumption, and high resource occupation.

[0005] Infrared detection is widely used as an important method of cosmic science and remote sensing detection. However, the existing medium and long wave infrared detection devices are relatively simple, and most of them are system devices for realizing long wave detection. In order to better suppress background radiation, refrigeration is generally used to suppress background radiation, and the existing technology generally adopts a single heat conduction refrigeration method, that is, a cold box device that can realize a vacuum system is used, and a refrigerator is used to output cold to the long wave spectrometer through a cold chain to achieve the temperature conditions for long wave infrared detection. The advantages of this technology are simple implementation and easy implementation. The cooling of a single object does not need to take into account the impact of other objects in the system. The disadvantages of this method are that it takes a long time for the system to start up once, the cooling efficiency is low, the power consumption is large, and it occupies a lot of resources. Summary of the invention

[0006] The technical problem to be solved by the present invention is to solve the problems of the startup time of the refrigeration device, improving the refrigeration efficiency and reducing the power consumption in the single heat conduction refrigeration method adopted in the traditional method of background radiation suppression of medium and long wave infrared hyperspectral remote sensors. A refrigeration device for background radiation suppression of medium and long wave infrared hyperspectral remote sensors is proposed. The refrigeration device adopts two-stage refrigeration to avoid the problem of the startup time of the refrigerator, and performs vacuum deep low temperature refrigeration to effectively realize the background radiation suppression of medium and long wave infrared hyperspectral remote sensors.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A refrigeration device for suppressing background radiation of a medium- and long-wave infrared hyperspectral remote sensor comprises a first refrigerator assembly, a second refrigerator assembly and a cold box, wherein the first refrigerator assembly and the second refrigerator assembly are connected to the cold box respectively, a spectrometer assembly is arranged inside the cold box, the spectrometer assembly comprises a first spectrometer, a second spectrometer and a third spectrometer, the first refrigerator assembly is connected to the first spectrometer and the second spectrometer respectively through a flexible cold chain, the second refrigerator assembly is connected to the third spectrometer through a flexible cold chain, a window mounting base is arranged on the cold box, and the first spectrometer, the second spectrometer and the third spectrometer are arranged around the window mounting base. Light converged from a hyperspectral remote sensing main optical telescope is split by a beam splitter and deflection mirror structure of the window mounting base and enters the first spectrometer, the second spectrometer and the third spectrometer respectively, and is subjected to primary refrigeration through a refrigeration gas pipe and vacuuming, and then subjected to secondary refrigeration through a refrigerator assembly through a flexible cold chain, and the corresponding target detection information with background radiation suppression is obtained by using a detector assembly respectively.

[0009] Furthermore, the cold box assembly is a cold box capable of independent refrigeration.

[0010] Furthermore, the cold box assembly includes a cold box body, a cold box cover, a cold box support frame, a first flexible chain and a second flexible chain, the first flexible chain connects the first refrigeration machine assembly and the first spectrometer and the second spectrometer, the second flexible chain connects the second refrigeration machine assembly and the third spectrometer, the cold box cover is covered on the cold box body, the spectrometer assembly is fixed on the base of the cold box body, and a cold box support frame is provided at the bottom of the cold box body.

[0011] Furthermore, a first vacuuming interface and a second vacuuming interface are provided on the side of the cold box body, and the first vacuuming interface and the second vacuuming interface are provided separately.

[0012] Furthermore, a sealing ring is provided between the cold box cover and the cold box body.

[0013] Furthermore, a cold box heat pipe mounting surface is provided on the upper surface of the cold box cover plate, and the shape of the cold box heat pipe mounting surface is arranged along the arrangement position facing the first spectrometer, the second spectrometer and the third spectrometer.

[0014] Furthermore, spectrometer support cups are provided at the bottom of the first spectrometer, the second spectrometer and the third spectrometer, and the first spectrometer, the second spectrometer and the third spectrometer are respectively fixed on the base of the cold box through the spectrometer support cups.

[0015] Furthermore, the spectrometer support cup includes a support cup body, an upper patch, an upper screw sleeve, a lower pressure ring, a lower patch and an auxiliary fixing screw. The upper patch and the lower patch are respectively arranged on the upper and lower end surfaces of the support cup body. The support cup body is in the shape of a hollow truncated cone. A skirt is arranged around the lower end surface of the support cup body. The lower pressure ring is arranged above the skirt. An upper screw sleeve is arranged at the center of the upper end of the support cup body. An upper auxiliary fixing screw is also arranged at the upper end of the support cup body. The upper screw sleeve fixes the spectrometer assembly with screws, and the skirt at the lower end of the support cup body is fixedly connected to the base of the cold box by the lower auxiliary fixing screw.

[0016] Furthermore, the support cup body is a structure made of epoxy fiberglass, and an aluminum-plated film layer is provided on the inner and outer surfaces of the support cup body.

[0017] Furthermore, the upper portion of the support cup body and the outer portion of the skirt at the bottom of the support cup body are both Invar steel wire structures.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention utilizes refrigeration gas pipes and vacuuming for primary refrigeration, and then utilizes refrigerator components through a flexible cold chain for secondary refrigeration, which can effectively avoid the problem of refrigerator startup time and effectively realize vacuum deep low temperature refrigeration; a light splitting and deflecting mirror structure is provided on the window mounting base on the cold box body, and three spectrometers are arranged in the cold box, and two flexible cold chains are used to provide refrigeration for the three spectrometers at the same time, which can simultaneously realize the background radiation suppression of medium wave, long wave and very long wave infrared spectrometers, so that the refrigeration efficiency is greatly improved and the refrigeration power consumption is reduced; and a spectrometer support cup is provided inside the cold box, and a "zero" linear The cold box is made of special Invar material with a large expansion coefficient, and a support frame is set at the bottom of the cold box. This ensures that when the temperature inside the cold box drops from the ambient temperature to the required deep low temperature, there is little outgassing of the device materials, the temperature inside the cold box is uniform, the vacuum degree is high, and the deformation and displacement of each structure caused by temperature changes are small, which effectively guarantees the refrigeration effect inside the cold box, provides a continuous and stable vacuum deep low temperature environment for the spectrometer and detector of the medium and long wave infrared hyperspectral remote sensor, effectively realizes the suppression of the background radiation of the medium and long wave infrared hyperspectral remote sensor, and provides the necessary conditions for the high sensitivity and high precision detection of the medium and long wave infrared hyperspectral remote sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an axonometric schematic diagram of the device of the present invention;

[0021] Figure 2 A schematic diagram of the position of the spectrometer of the device of the present invention;

[0022] Figure 3 A schematic diagram of a cold box of the device of the present invention;

[0023] Figure 4 It is a schematic diagram of the flexible cold chain position of the device of the present invention;

[0024] Figure 5 A schematic diagram of a spectrometer support cup of the device of the present invention;

[0025] Figure 6 for Figure 5 Cross-sectional view at AA in the middle. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] like Figure 1-6 As shown, this specific embodiment discloses a refrigeration device for suppressing background radiation of medium and long wave infrared hyperspectral remote sensor, including a first refrigerator assembly 1, a second refrigerator assembly 2 and a cold box assembly 3, the first refrigerator assembly 1 and the second refrigerator assembly 2 are respectively connected to the cold box assembly 3, a spectrometer assembly 3-6 is arranged inside the cold box assembly 3, the spectrometer assembly 3-6 includes a first spectrometer 3-6-1, a second spectrometer 3-6-2 and a third spectrometer 3-6-3, the first refrigerator assembly 1 is connected to the first spectrometer 3-6-1 and the second spectrometer 3-6-2 respectively through a flexible cold chain, the second refrigerator assembly 2 is connected to the third spectrometer 3-6-3 through a flexible cold chain, a window mounting base 3-1-3 is arranged on the cold box assembly 3, the first spectrometer 3-6-1, the second spectrometer 3-6-2 and the third spectrometer 3-6-3 are arranged around the window mounting base 3-1-3. The flexible cold chain is used as the conduction medium for heat conduction. The three spectrometers use two flexible cold chains, which is feasible. One of them is for medium and low temperature (120K~160K) refrigeration, and the other is for deep low temperature (90K~120K) refrigeration. Both cold chains have flexible functions, that is, the flexible links of the cold chain are used to offset the thermal deformation caused by the temperature from room temperature to deep low temperature, which better guarantees the stability of the system under room temperature to low temperature environment. The flexible cold chain is used for refrigeration as the secondary refrigeration structure of this device, and the refrigeration of the cold box component 3 is the primary refrigeration. The light converged from the self-hyperspectral remote sensing main optical telescope is split by the beam splitting mirror structure of the window mounting base and enters the first spectrometer, the second spectrometer, and the third spectrometer respectively, and the corresponding target detection information with background radiation suppression is obtained by using the detector components respectively.

[0028] The present invention provides a refrigeration device for suppressing background radiation of medium and long wave infrared hyperspectral remote sensors, which is used to realize low temperature of 100K ambient temperature of medium and long wave spectrometers. The layout of common cold boxes can be mainly divided into a single cold box for a single spectrometer and three spectrometers in one cold box. The present invention adopts a structural form of an integrated cover plate and a box body, which can make the device easier to maintain and convenient to use, and occupy less resources.

[0029] The cold box assembly 3 is a cold box that can be refrigerated independently. The upper part of the cold box cover 3-2 is provided with a mounting surface for installing a heat pipe and a vacuum device mounting hole. This part can realize primary refrigeration in the system; the spectrometer assembly is a cooled object in the vacuum deep cryogenic system device. The spectrometer assembly includes a first spectrometer 3-6-1, a second spectrometer 3-6-2 and a third spectrometer 3-6-3, all of which are made of special Invar material with a "zero" linear expansion coefficient.

[0030] The cold box assembly 3 includes a cold box body 3-1, a cold box cover 3-2, a cold box support frame 3-3, a first flexible chain 3-4 and a second flexible chain 3-5. The first flexible chain 3-4 is connected to the first refrigerator assembly 1 and the first spectrometer 3-6-1 and the second spectrometer 3-6-2. The second flexible chain 3-5 is connected to the third spectrometer 3-6-3. The cold box cover 3-2 is covered on the cold box body 3-1. The spectrometer assembly 3-6 is fixed on the base of the cold box body 3-1. The bottom of the cold box body 3-1 is provided with a cold box support frame 3-3. The cold box body 3-1 and the cold box cover 3-2 are both made of special invar material with a "zero" linear expansion coefficient. By selecting a material with a "zero" expansion coefficient, it is greatly ensured that other related components of the system are not affected when the cold box itself expands and contracts after the system is reduced from a normal temperature environment to a deep low temperature environment. The cold box body 3-1 is a cavity structure, with 7 mounting holes for support at the bottom, and 6 mounting holes for mounting detectors, vacuum devices and refrigerators on the side walls. The first vacuum interface 3-1-1 and the second vacuum interface 3-1-2 are provided on the side of the cold box body 3-1, and the first vacuum interface 3-1-1 and the second vacuum interface 3-1-2 are provided separately. The first vacuum interface 3-1-1 and the second vacuum interface 3-1-2 are used to connect the vacuum device respectively. The vacuum device is divided into two, one is mainly used for vacuuming, and the other serves as a backup for the vacuuming function and also takes into account the role of vacuum degree detection.

[0031] A sealing ring 3-2-1 is provided between the cold box cover plate 3-2 and the cold box body 3-1. By providing the sealing ring, the sealing performance of the device and the vacuum degree are ensured. Preferably, the two can be connected by bolts and sealed by a silicone rubber sealing ring.

[0032] The upper surface of the cold box cover plate 3-2 is provided with a cold box heat pipe installation surface 3-2-2, and the shape of the cold box heat pipe installation surface 3-2-2 is arranged along the arrangement position facing the first spectrometer 3-6-1, the second spectrometer 3-6-2 and the third spectrometer 3-6-3.

[0033] A spectrometer support cup 3-7 is provided at the bottom of the first spectrometer 3-6-1, the second spectrometer 3-6-2 and the third spectrometer 3-6-3. The first spectrometer 3-6-1, the second spectrometer 3-6-2 and the third spectrometer 3-6-3 are respectively fixed to the base of the cold box 3 through the spectrometer support cup 3-7.

[0034] The spectrometer support cup 3-7 includes a support cup body 3-7-0, an upper patch 3-7-1, an upper screw sleeve 3-7-2, a lower pressure ring 3-7-3, a lower patch 3-7-4 and an auxiliary fixing screw 3-7-5. The upper patch 3-7-1 and the lower patch 3-7-4 are respectively arranged on the upper and lower end surfaces of the support cup body 3-7-0. The support cup body 3-7-0 is in the shape of a hollow truncated cone. The surrounding support surfaces of the support cup body 3-7-0 are thin-walled support surfaces. The lower end surface of the support cup 3-7-0 is provided with a skirt around it, the lower pressure ring 3-7-3 is provided above the skirt, the upper end center of the support cup body 3-7-0 is provided with an upper screw sleeve 3-7-2, the upper end of the support cup body 3-7-0 is also provided with an upper auxiliary fixing screw 3-7-5, the upper screw sleeve 3-7-2 is fixed to the spectrometer assembly 3-6 by screws, and the skirt at the lower end of the support cup body 3-7-0 is fixedly connected to the base of the cold box assembly 3 by the lower auxiliary fixing screw 3-7-6. The spectrometer support cup 3-7 is between the bottom plate of the cold box and the bottom plate of the spectrometer, and it adopts a hollow truncated cone structure, which can have a higher strength and can provide stable support for the spectrometer.

[0035] The support cup body 3-7-0 is made of epoxy fiberglass. The inner and outer surfaces of the support cup body 3-7-0 are provided with an aluminum-plated film layer. By providing the aluminum-plated film layer, the radiation heat leakage of the support cup can be effectively reduced. It is feasible that the support cup body 3-7-0 adopts a thin-walled structure. The use of such a high thermal resistance material and thin-walled structure can greatly reduce the heat leakage of the spectrometer. The upper part of the support cup body 3-7-0 and the outer skirt of the bottom of the support cup body 3-7-0 are both Invar steel structures. The use of Invar steel structures can greatly ensure the strength of the support.

[0036] The present invention adopts a one-stage and two-stage refrigeration method, that is, heat radiation and heat conduction are used to cool the cold objects in the system. The cold box is first cooled to about 273K by a one-stage refrigeration method, and then the cold object is cooled to the required temperature by a two-stage refrigeration method. The materials used in the system of the present invention are mostly special Invar materials with a "zero" linear expansion coefficient, which greatly reduces the thermal deformation and displacement caused by temperature; the present invention has high refrigeration efficiency and can adapt to different temperature requirements by adjusting the cold chain; the present invention can use a small space to cool three spectrometers at the same time, with high utilization rate and high heat utilization rate, and the power consumption of the refrigerator with graded refrigeration requirements is much lower than the same period last year. The present invention has flexible refrigeration objects and a wide range of applications, that is, it can cool three spectrometers at the same time, or it can cool them separately. Compared with the traditional single refrigeration form, the present invention has the advantages of less resource consumption, low cost, low efficiency and good effect.

[0037] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A device for suppressing background radiation of a mid- and long-wave infrared hyperspectral remote sensor, comprising a first refrigerator component (1), a second refrigerator component (2) and a cold box component (3), characterized in that: The first refrigerator component (1) and the second refrigerator component (2) are respectively connected to the cold box component (3); a spectrometer component (3-6) is arranged inside the cold box component (3); the spectrometer component (3-6) comprises a first spectrometer (3-6-1), a second spectrometer (3-6-2) and a third spectrometer (3-6-3); the first refrigerator component (1) is respectively connected to the first spectrometer (3-6-1) and the second spectrometer (3-6-2) through a flexible cold chain; the second refrigerator component (2) is connected to the third spectrometer (3-6-3) through a flexible cold chain; a window mounting base (3-1-3) is arranged on the cold box component (3); the first spectrometer (3-6-1), the second spectrometer (3-6-2) and the third spectrometer (3-6-3) are arranged around the window mounting base (3-1-3); The cold box assembly (3) comprises a cold box body (3-1), a cold box cover plate (3-2), a cold box support frame (3-3), a first flexible chain (3-4) and a second flexible chain (3-5); the first flexible chain (3-4) is connected to the first refrigerator assembly (1) and the first spectrometer (3-6-1) and the second spectrometer (3-6-2); the second flexible chain (3-5) is connected to the third spectrometer (3-6-3); the cold box cover plate (3-2) is covered on the cold box body (3-1); the spectrometer assembly (3-6) is fixed to the base of the cold box body (3-1) through a spectrometer support cup (3-7); and the cold box support frame (3-3) is provided at the bottom of the cold box body (3-1); A first vacuuming interface (3-1-1) and a second vacuuming interface (3-1-2) are arranged on the side of the cold box body (3-1), and the first vacuuming interface (3-1-1) and the second vacuuming interface (3-1-2) are arranged separately; The upper surface of the cold box cover plate (3-2) is provided with a cold box heat pipe installation surface (3-2-2), and the shape of the cold box heat pipe installation surface (3-2-2) is arranged along the arrangement position facing the first spectrometer (3-6-1), the second spectrometer (3-6-2) and the third spectrometer (3-6-3).

2. The device for suppressing background radiation of a mid- and long-wave infrared hyperspectral remote sensor according to claim 1, characterized in that: A sealing ring (3-2-1) is provided between the cold box cover plate (3-2) and the cold box body (3-1).

3. The device for suppressing background radiation of a mid- and long-wave infrared hyperspectral remote sensor according to claim 1, characterized in that: Spectrometer support cups (3-7) are provided at the bottom of the first spectrometer (3-6-1), the second spectrometer (3-6-2) and the third spectrometer (3-6-3); the first spectrometer (3-6-1), the second spectrometer (3-6-2) and the third spectrometer (3-6-3) are respectively fixed on the base of the cold box (3) through the spectrometer support cups (3-7).

4. A device for suppressing background radiation of a mid- and long-wave infrared hyperspectral remote sensor according to claim 1 or 3, characterized in that: The spectrometer support cup (3-7) comprises a support cup body (3-7-0), an upper patch (3-7-1), an upper screw sleeve (3-7-2), a lower pressure ring (3-7-3), a lower patch (3-7-4) and an auxiliary fixing screw (3-7-5); the upper patch (3-7-1) and the lower patch (3-7-4) are respectively arranged on the upper and lower end surfaces of the support cup body (3-7-0); the support cup body (3-7-0) is in the shape of a hollow truncated cone; the support surface of the support cup body (3-7-0) is a thin-walled support surface; the support cup body ( The lower end surface of the support cup body (3-7-0) is provided with a skirt around it, the lower pressure ring (3-7-3) is arranged above the skirt, the upper end center of the support cup body (3-7-0) is provided with an upper screw sleeve (3-7-2), the upper end of the support cup body (3-7-0) is also provided with an upper auxiliary fixing screw (3-7-5), the upper screw sleeve (3-7-2) is fixed to the spectrometer component (3-6) by screws, and the skirt at the lower end of the support cup body (3-7-0) is fixedly connected to the base of the cold box (3) by the lower auxiliary fixing screw (3-7-6).

5. The device for suppressing background radiation of a mid- and long-wave infrared hyperspectral remote sensor according to claim 4, characterized in that: The support cup body (3-7-0) is a structure made of epoxy glass fiber reinforced plastic, and an aluminum-plated film layer is provided on the inner and outer surfaces of the support cup body (3-7-0).

6. The device for suppressing background radiation of a mid- and long-wave infrared hyperspectral remote sensor according to claim 4, characterized in that: The upper part of the support cup body (3-7-0) and the outer skirt of the bottom of the support cup body (3-7-0) are both invar structures.

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