CN110879107A - Large-area source infrared remote sensing radiometric calibration target based on micro-tube absorption technology - Google Patents

Abstract

The invention provides a large-area-source infrared remote sensing radiation calibration target based on a micro-tube absorption technology, which comprises a temperature control box body and a micro-tube array absorption assembly, wherein the temperature control box body comprises a side wall and a bottom wall connected to the side wall, the micro-tube array absorption assembly is arranged on the side wall and the bottom wall in the temperature control box body, the micro-tube array absorption assembly is of a honeycomb structure, and a diffuse reflection coating is coated on the surface of the inner wall of the honeycomb structure. According to the invention, the cavity absorption and surface absorption diffusion theories are combined, and the stability, uniformity and controllability of the temperature of the calibration target cavity are ensured by arranging the temperature control box body.

Description

Large area source infrared remote sensing radiation calibration target based on microtubule absorption technology

technical field

The invention relates to the field of calibration, in particular to a calibration target for infrared remote sensing.

Background technique

Obtaining surface information through satellite remote sensing technology is currently the only way to quickly obtain large-scale and even global-scale surface information. Providing accurate and reliable quantitative remote sensing information products in an operational manner is an inevitable trend in the development of the international earth observation field. The accuracy of remote sensing information extraction depends on the accuracy of load calibration and the stability and reliability of data quality. In the process of remote sensing load operation, when the environment changes or the instrument ages, its radiation performance will change. Therefore, The key to ensuring the quality of remote sensing payload data acquisition is to perform external field substitution calibration for remote sensing payloads, effectively monitor the dynamic changes in performance of remote sensing payloads during operation, accurately detect the degree of changes, and accurately discover the causes of changes and formulate targeted remedial measures.

At present, high-precision blackbody radiation sources are usually used for laboratory calibration of thermal infrared remote sensing payloads, and calibration is performed by adjusting the temperature of the blackbody. The external field alternative calibration of thermal infrared remote sensing load currently mainly uses a large area of water with an emissivity close to 1 for external field radiation calibration. Although the difference of water surface temperature changes is small, it is difficult to accurately describe the response changes in the temperature dynamic range because the water body can only be used as a low temperature radiation source, and it is difficult to achieve on-orbit calibration of loads with high adaptability.

SUMMARY OF THE INVENTION

In order to overcome at least one aspect of the above problems, the embodiments of the present invention provide a high-emissivity large-area radiation calibration target based on the microtube absorption cavity technology, which combines cavity absorption with surface absorption/diffusion theory, A large box-type semi-closed temperature control box is used with built-in partitioned stainless steel electric heating tubes to ensure the stability, uniformity and controllability of the target cavity temperature.

According to one aspect of the present invention, there is provided a large area source infrared remote sensing radiation calibration target based on microtube absorption technology, the calibration target includes: a temperature control box, the temperature control box includes a side wall and is connected to the side wall The bottom wall; and the microtube array absorption component, the microtube array absorption component is arranged on the side wall and the bottom wall in the temperature control box, the microtube array absorption component is a honeycomb structure, and is coated on the inner wall surface of the honeycomb structure Diffuse coating.

According to some embodiments of the large-area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, the side wall and bottom wall of the temperature control box body sequentially include a protective layer, a thermal insulation layer, a heating layer and a bottom wall from the outside to the inside, respectively. Microtubule Array Absorbent Assembly.

According to some embodiments of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, an electric heating tube is arranged in the heating layer, and the side wall and the bottom wall are heated by the electric heating tube.

According to some embodiments of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, the heating layer includes a cast aluminum layer.

According to some embodiments of the large-area source infrared remote sensing radiation calibration target based on the microtubule absorption technology of the present invention, the microtubule array absorption component includes a microtubule cavity array, and the microtubule cavity array has a regular hexagonal structure.

According to some embodiments of the large-area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, the diffuse reflection coating is black.

According to some embodiments of the large-area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, the calibration target further includes an aperture diaphragm located at its exit to limit the effective area of the calibration target's exit.

According to some embodiments of the large-area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, the temperature control box includes two protective doors that are oppositely arranged on the side walls.

According to some embodiments of the microtube absorption technology-based large-area source infrared remote sensing radiation calibration target of the present invention, protective doors are provided as part of the side walls, and each protective door is connected to the side walls by hinges.

According to some embodiments of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, a switch device is provided on the protective door, and the switch device includes a stud and a disc crank.

According to some embodiments of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, the temperature control box further includes a temperature control system, and the temperature control system includes a temperature control probe and a temperature measurement probe, and the temperature control probe is provided with In the heating layer, the temperature measuring probe is arranged in the microtube array absorption assembly.

According to some embodiments of the large-area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, each side wall is equally divided into two upper and lower temperature control areas, and the bottom wall is equally divided into four temperature control areas , the temperature control system uses a separate controller to control each temperature control area.

According to some embodiments of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, the temperature control system further includes a data display and collection device, and the data display and collection device is arranged on one of the side walls.

According to some embodiments of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology of the present invention, the calibration target further includes a base, the temperature control box is arranged on the base, and the base can move; Multiple support legs of the control box.

Compared with the prior art, the present invention has at least one of the following advantages:

(1) The target temperature can be adjusted, controlled, and automatically collected;

(2) The target radiation surface is much larger than the laboratory black body;

(3) The target has high emissivity and uniformity.

Description of drawings

Other objects and advantages of the present invention will be apparent from the following description of the present invention with reference to the accompanying drawings, and may assist in a comprehensive understanding of the present invention.

Fig. 1 is a three-dimensional schematic diagram of a large area source infrared remote sensing radiation calibration target based on microtubule absorption technology according to an embodiment of the present invention;

2 is a schematic longitudinal section of a side wall or a bottom wall of a large-area source infrared remote sensing radiation calibration target based on a microtube absorption technology according to an embodiment of the present invention;

3 is a schematic perspective view of a microtube array absorption assembly of a large area source infrared remote sensing radiation calibration target based on microtube absorption technology according to an embodiment of the present invention;

4 is a side view of a large-area-source infrared remote sensing radiation calibration target based on microtube absorption technology according to an embodiment of the present invention, viewed from one side of a protective door;

Fig. 5 is the positional schematic diagram of the temperature measurement probe and the temperature control probe of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of the base of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology according to an embodiment of the present invention.

Detailed ways

In order to make the purposes, 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 with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. Unless otherwise defined, technical or scientific terms used in the present invention should have the ordinary meaning as understood by one of ordinary skill in the art to which the present invention belongs.

The embodiment of the present invention provides a large area source infrared remote sensing radiation high emissivity large area source radiation calibration target based on the microtube absorption technology. The target combines cavity absorption and surface absorption/diffusion theory, and adopts a large box type The semi-closed temperature control box has built-in partitioned stainless steel electric heating tubes to ensure the stability, uniformity and controllability of the target cavity temperature.

The embodiments of the present invention will be further described below with reference to the accompanying drawings.

FIG. 1 is a three-dimensional schematic diagram of a large-area source infrared remote sensing radiation calibration target based on a microtubule absorption technology according to an embodiment of the present invention. As shown in FIG. 1 , a large area source infrared remote sensing radiation calibration target 100 based on the microtube absorption technology includes a temperature control box 1 and a microtube array absorption component 4 arranged in the temperature control box 1 . The temperature control box 1 A side wall 2 and a bottom wall 3 connected to the side wall 2 are included. The microtube array absorption component 4 is disposed on the side wall 2 and the bottom wall 3 in the temperature control box 1 . The microtube array absorption component 4 has a honeycomb structure, and a diffuse reflection coating is applied on the inner wall surface of the honeycomb structure. According to a preferred embodiment, the diffusely reflective coating is black.

As can be seen from the figure, the temperature control box 1 of this embodiment includes four side walls 2 and a bottom wall 3, and the upper part is opened, that is, the temperature control box 1 is in a semi-closed state. In other embodiments, the temperature control box 1 of the large-area source infrared remote sensing radiation calibration target 100 based on the microtube absorption technology of the present invention can also be in other shapes, such as a cylinder, a cube, a regular polyhedron, and the like.

Fig. 2 is a longitudinal cross-sectional view of a large-area source infrared remote sensing radiation calibration target based on micropipe absorption technology according to an embodiment of the present invention; The inner layer respectively includes a protective layer 21 , a thermal insulation layer 22 , a heating layer 23 and a microtube array absorption component 4 . The protective layer 21 is used to prevent external objects from colliding with the temperature control box, to protect the components in the box from damage, and to reduce the radiation of internal substances toward the outside; the thermal insulation layer 22 is used to slow down heat loss; the heating layer 23 is used for for heating the entire box. For example, an electric heating tube may be provided in the heating layer 23, and the side wall 2 and the bottom wall 3 are heated by the electric heating tube.

According to a preferred embodiment, the heating layer 23 comprises a cast aluminum layer. Electric heating tubes and thermocouples can be set in the cast aluminum layer to achieve better heating effect.

The microtube array absorption assembly 4 includes a microtube lumen array 41, and the microtube lumen array 41 is a regular hexagonal structure. 3 is a schematic three-dimensional structural diagram of a microtube array absorption assembly 4 of a large area source infrared remote sensing radiation calibration target based on a microtube absorption technology according to an embodiment of the present invention. In this embodiment, in order to solve the technical problems of large-area blackbody fabrication and ensure technical problems such as emissivity and uniformity, the cavity absorption and surface absorption/diffusion theory are combined, and the microcavity array 41 is used as the basic working unit. The surface of the cavity is coated with a low-reflection diffusive extinction material to enhance the absorption and diffusion characteristics and ensure the emissivity and uniformity of the black body. At the same time, a plurality of micro-lumen arrays 41 arranged on the side wall 2 and the bottom wall 3 form a semi-closed composite cavity, which further suppresses the influence of the environment on the target emissivity and uniformity. The microtube array absorption component 4 is composed of large-area honeycomb aluminum with a regular hexagonal three-dimensional structure arranged continuously, and the cross-section of the microtubes is a regular hexagon. In this embodiment, the inscribed circle radius R of the regular hexagon can be 3mm, the pipe length L can be 25mm, and the pipe wall thickness can be 0.06mm. Of course, in other embodiments, the size of the regular hexagon can be different, Alternatively, microtubes with other cross-sectional shapes can also be used, such as triangles, quadrilaterals, and other regular polygons. The surface of the microtube array absorption component 4 is oxidized and blackened and sprayed with a black diffusion coating. Rivets can be used to fix the microtube array absorption assembly 4 to the side wall 2 and the bottom wall 3 inside the cavity, and of course other fixing methods that can be conceived by those of ordinary skill in the art can also be used.

The emissivity of the cavity can be calculated by the following formula: Assuming that the reflectivity of the cavity is ρc, the reflectivity of the cavity wall is ρ0, the inner diameter of the cavity is R, and the cavity depth is L, according to the cavity absorption theory and Kirchhoff’s law, The intracavity emissivity ε is:

ε=1-ρc=1-ρ0/[(1-ρ0)·(1+(L/R) ² )]

If ρ0=0.1 and L/R=8.5, the target theoretical emissivity ε is greater than 0.99. Therefore, when the surface of the microtube array absorption component 4 is sprayed with a black diffusion coating with an emissivity greater than 0.9, the cavity emissivity will be greater than 0.99. In this embodiment, Pyromark1200, a matte coating material with high emissivity and low diffuse reflection, is used. Corrosive characteristics. The microtube array absorption component 4 and the black diffusing coating ensure that the blackbody source has good Lambertian property and uniformity from two aspects of structural extinction and surface extinction.

The calibration target also includes an aperture stop at its exit for limiting the effective area of the exit of the calibration target. In this embodiment, the aperture diaphragm is located at the exit port above the target cavity, and the size of the aperture diaphragm can be customized to limit the effective area of the target exit, which can maximize the uniformity of the target cavity emissivity and temperature.

The temperature control box 1 includes two protective doors 5 arranged on the side wall 2 opposite to each other. Of course, one protective door can also be provided.

FIG. 4 is an external schematic diagram of the protective door 5 of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology according to an embodiment of the present invention. As shown in FIG. 4 , the protective door 5 includes an outer frame 51 , a hinge 52 and a switch device 53 . The guard doors 5 are provided as part of the side walls 2 , each guard door 5 is connected to the side walls 2 by hinges 52 . A switch device 53 is provided on the protective door 5, and the switch device 53 includes a stud and a disc rocker. The stud can be combined or separated from the relevant components on the side wall 2 by rotating the disc rocker, so that the protective door 5 Sealing fit or separation with side wall 2 . In this embodiment, there are two front and rear protective doors 5, that is, protective doors 5 are respectively provided on the opposite side walls 2, and each protective door 5 is fixed by three high-strength hinges 52, equipped with upper and lower studs and The disc crank is used to realize the opening and closing of the protective door 5. Before the protective door 5 is opened or closed, it is necessary to adjust the bottom support of the calibration target so that it is in a horizontal state as a whole, and then rotate the disc crank to open or close it. The protective doors 5 are located on both sides of the temperature control box, which is convenient for the maintenance of the target.

5 is a schematic diagram of the positions of the temperature measurement probe and the temperature control probe of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology according to an embodiment of the present invention. The temperature control box 1 further includes a temperature control system, and the temperature control system includes a temperature control probe 61 and a temperature measurement probe 62 . As shown in FIG. 5 , the temperature control probe 61 is arranged in the heating layer 23 , and the temperature measurement probe 62 is arranged in the microtube array absorption assembly 4 .

In this embodiment, the temperature control is realized by a large box-type temperature control device, which adopts a large box-type semi-closed cavity, built-in zone heating elements cooperate with real-time temperature feedback and PID (Proportion Integration Differentiation, proportional-integral-derivative controller) continuously bottoming The temperature of the wall 3 and the side wall 2 is controlled to ensure the stability, uniformity and controllability of the overall temperature. The temperature measuring probe 62 and the temperature control probe 61 both use pt100 thermal resistance temperature sensor. The measurement accuracy of pt100 thermal resistance temperature sensor is as high as 0.1K, which is suitable for temperature measurement in the range of -200℃～500℃. It is characterized by accurate and stable measurement. Good performance and reliable performance. The temperature control probe is used to monitor the temperature of the heating layer 23 so as to control the temperature of the heating layer 23 . The temperature probe 62 is the detection probe used by the thermometer, and its position passes through the thermal insulation layer 22 and the heating layer 23, stays in the hole of the microtube array absorption assembly 4, and fits the four walls of the microtube array absorption assembly 4. , the temperature of the middle part of the microtubule array absorption assembly 4 is measured.

In order to make the temperature of the heating layer 23 of the bottom wall 3 and the side wall 2 of the temperature control box 1 controllable, the bottom wall 3 and the side wall 2 can be divided into a plurality of large areas, and electric heating tubes can be built in the heating layer 23 Perform zone heating to keep the temperature in the cabin uniform and stable. In this embodiment, each side wall 2 is divided into two upper and lower temperature control areas, and the bottom wall 3 is divided into four temperature control areas. The temperature control system uses a separate controller to control each temperature control area. .

The temperature control system also includes a data display and collection device 63, which is arranged on one of the side walls. In this embodiment, the data display and collection device 63 includes a high-precision intelligent digital display temperature control instrument and a temperature recorder. The high-precision intelligent digital display temperature control instrument is mainly used to control the internal temperature of the heating layer 23 of the bottom wall 3 and the side wall 2 and the display of the data of the temperature control probe 61; the temperature recorder includes a storage SD card, which is mainly used to display and record the The microtube array absorbs the measurement data of the temperature measuring probe 62 inside the assembly 4 .

The calibration target further includes a base 8 on which the temperature control box is disposed, and the base 8 can move; the base 8 includes a plurality of support legs 81 for supporting the temperature control box 1 . 6 is a schematic diagram of the base 8 of the large area source infrared remote sensing radiation calibration target based on the microtube absorption technology according to an embodiment of the present invention. In practical application, since the weight of the target is as high as several tons, in order to facilitate the movement of the target, a base 8 can be set, and the target can be placed on the base 8, and the target can be moved by a trailer or by multiple people manually. The base 8 has the functions of front suspension slewing support steering and rear suspension orientation. The base 8 is equipped with a plurality of hand-cranked support legs 81, for example, there may be four. The support legs 81 are usually contracted on the base 8, and the support legs 81 can be supported by manual shaking, so as to be used for long-term placement of the target in a stationary state. . In other embodiments, the support legs 81 can also be remotely supported by means of infrared rays or the like.

The invention can realize the automatic acquisition of the temperature of the calibration target and the temperature control under the external field test condition, and solve the problem that the traditional thermal infrared load external field substitute calibration only has low temperature endpoints; , tower crane, airborne and other medium and low-altitude platforms, high-resolution thermal infrared remote sensing load external field replacement calibration, the target radiation surface can reach up to 1.7m × 1.7m, and the size of the surface source is much larger than that of the laboratory blackbody; the present invention adopts a large box. Type semi-enclosed cavity, built-in partitioned stainless steel electric heating tubes are evenly embedded in the whole aluminum block, multi-channel temperature measuring elements are installed at the bottom and around the target cavity, and high-precision instruments are used to monitor and adjust the temperature of the whole electric heating aluminum block to ensure The stability, uniformity and real-time temperature change capability of the target cavity temperature; the invention combines cavity absorption and surface absorption/diffusion theory, adopts micro-tube cavity array as the basic unit, and coats the cavity surface with black matting material; The micro-lumen array is integrated with the aluminum blocks at the bottom and surrounding of the target cavity to ensure high emissivity and uniformity of the target cavity.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (14)

1. a large area source infrared remote sensing radiation calibration target based on microtube absorption technology, is characterized in that, the described large area source infrared remote sensing radiation calibration target based on microtube absorption technology comprises: a temperature control box including a side wall and a bottom wall connected to the side wall; and A microtube array absorption assembly, the microtube array absorption assembly is arranged on the side wall and the bottom wall in the temperature control box, the microtube array absorption assembly is a honeycomb structure, and the The inner wall surface of the structure is coated with a diffuse reflection coating. 2 . The large-area source infrared remote sensing radiation calibration target based on microtube absorption technology according to claim 1 , wherein the side wall and the bottom wall of the temperature control box are respectively from outside to inside. 3 . It includes a protective layer, a thermal insulation layer, a heating layer and the microtube array absorption assembly in sequence. 3. The large-area source infrared remote sensing radiation calibration target based on micro-tube absorption technology according to claim 2, characterized in that, an electric heating tube is arranged in the heating layer, and the electric heating tube is used for the The side walls and the bottom wall are heated. 4 . The large-area source infrared remote sensing radiation calibration target based on microtube absorption technology according to claim 3 , wherein the heating layer comprises a cast aluminum layer. 5 . 5. The large-area source infrared remote sensing radiation calibration target based on microtubule absorption technology according to claim 1, wherein the microtubule array absorption assembly comprises a microtubule cavity array, and the microtubule cavity array is a normal six Edge structure. 6 . The large-area source infrared remote sensing radiation calibration target based on the microtube absorption technology according to claim 1 , wherein the diffuse reflection coating is black. 7 . 7. The large-area-source infrared remote sensing radiation calibration target based on microtube absorption technology according to claim 1, wherein the calibration target further comprises an aperture stop located at its exit port for limiting all Describe the effective area of exit of the calibration target. 8 . The large-area source infrared remote sensing radiation calibration target based on the microtube absorption technology according to claim 1 , wherein the temperature control box comprises two protective doors that are relatively arranged on the side walls. 9 . . 9 . The large-area source infrared remote sensing radiation calibration target based on microtube absorption technology according to claim 8 , wherein the protective door is arranged as a part of the side wall, and each of the protective doors passes through a hinge. 10 . connected to the side wall. 10 . The large-area source infrared remote sensing radiation calibration target based on microtube absorption technology according to claim 9 , wherein a switch device is provided on the protective door, and the switch device comprises a stud and a disc shaker. 11 . Bundle. 11. The large-area source infrared remote sensing radiation calibration target based on microtube absorption technology according to claim 1, wherein the temperature control box further comprises a temperature control system, and the temperature control system comprises a temperature control probe and a temperature measurement probe, the temperature control probe is arranged in the heating layer, and the temperature measurement probe is arranged in the microtube array absorption component. 12. The large-area-source infrared remote sensing radiation calibration target based on microtube absorption technology according to claim 11, wherein each side wall is equally divided into two upper and lower temperature control regions, and the bottom wall is equally divided into two temperature control regions. Four temperature control zones, the temperature control system uses a separate controller for each temperature control zone. 13 . The large-area source infrared remote sensing radiation calibration target based on microtube absorption technology according to claim 1 , wherein the temperature control system further comprises a data display and collection device, and the data display and collection device is set to 14 . on one of the side walls. 14 . The large-area source infrared remote sensing radiation calibration target based on microtube absorption technology according to claim 1 , wherein the calibration target further comprises a base, and the temperature control box is arranged on the base. 15 . , the base can move; the base includes a plurality of support legs for supporting the temperature control box.

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