Circulating water film device for measuring sky background radiation temperature field

Abstract

The invention discloses a circulating water film device for measuring a sky background radiation temperature field, which can accurately measure the whole sky background radiation temperature field, and has the core content that a water film with uniform temperature and stable flow velocity can be formed on the surface of a hemispherical main body, and the skin temperature of the water film can be measured by a thermal infrared imager. The temperature of the water body can be measured by the temperature measurement probe, and after two kinds of temperature measurement data are obtained, the whole sky background radiation temperature field is obtained through formula calculation. The device comprises a shell, the top of which is provided with a buffer cap and the side wall of which is provided with a water inlet, a temperature measuring hole and a calibration black body; a thermal infrared imager is arranged above the shell and connected with the rotating wheel disc through a connecting column, and the side face of the connecting column is covered with a light barrier; and the lower end of the circulating water pump is connected with the reservoir. According to the circulating water film device designed by the invention, the measurement of a sky background radiation temperature field in an indirect mode is realized; the device is simple in structure, high in cost performance and high in practicability.

Description

Technical Field

[0001] The invention relates to the field of sky background radiation measurement, and in particular to a circulating water film device for measuring sky background radiation temperature field, which can accurately calculate the sky background radiation temperature field and realize the measurement of the sky background radiation temperature field in an indirect manner. Background Art As a parameter of atmospheric optical properties, sky background radiation plays a very important role in atmospheric and ocean satellite remote sensing, space target / background identification applications and research. Sky background radiation observation is of great significance, and sky background radiation temperature field data has more and more applications and demands. Existing sky background radiation observations mostly use the following methods or devices: 1. The traditional method of measuring sky background radiation is to use the CE318 solar radiometer, also known as the sun photometer. This instrument has only four wavelength channels: 440nm / 670nm / 870nm / 1020nm. The sky background radiation integral of this band is fitted through the four wavelengths. However, this fitting method is difficult to accurately give the sky radiation characteristics of the entire section. 2. In 2005, the Applied Electronics Institute of China Academy of Engineering Physics used the Sr5000 spectroradiometer to measure the brightness of sky light radiation and obtained preliminary results. However, this type of equipment is generally highly integrated, which is not conducive to equipment maintenance, repair and maintenance. 3. Use theoretical calculations to obtain the sky background radiation characteristics of the required area. The most famous of these are the Lowtran and Modtran software from the United States. However, the software mainly applies the atmospheric environmental parameters of the continental United States. When applied to various specific geographical conditions and environments, there are many problems in quantifying a variety of climate state parameters. The theoretical simulation has great limitations, ignores regional differences, and cannot truly reflect the sky background radiation characteristics of specific areas under complex and diverse climate conditions and geographical environments. 4. Although it is a common method to use mercury cadmium telluride infrared detectors to measure the background radiation characteristics of the sky, its working environment requires a low temperature, the equipment is expensive, the operation process is complicated, and it is inconvenient to use, making it difficult to popularize and promote. Summary of the invention In order to make up for the shortcomings of the existing technology and reduce the cost of measuring the sky background radiation, the purpose of the present invention is to provide a device capable of measuring the sky background radiation temperature field, which can form a hemispherical circulating water film with uniform temperature and stable flow rate, can measure the water film surface temperature and water body temperature, and can realize the function of measuring the overall sky background radiation temperature field. To achieve the above objectives, the technical solution adopted by the present invention is: the present invention provides a circulating water film device for measuring the sky background radiation temperature field, characterized in that it includes a shell, a water circulation module, and a temperature measurement component. Furthermore, the shell is integrally processed using heat-conducting metal, and consists of three parts: an upper buffer cap, a middle hemispherical main body, and a lower cylinder. The buffer cap has a water outlet inside, and a certain gap is left between the buffer cap and the hemispherical main body. The hemispherical main body has a supporting column for supporting the buffer cap, and the side of the cylinder is provided with a water inlet and a temperature measuring hole. Furthermore, the water film is characterized in that: water from the water reservoir is pumped by a circulating water pump, injected into the horizontal water pipe inside the shell from the water inlet, reaches the water outlet through the vertical water pipe, and after the water flow is blocked by the buffer cap of the water outlet device, a water film with uniform temperature and stable flow rate is formed on the surface of the hemispherical main body outside the water outlet. Furthermore, the temperature measurement component includes an infrared thermal imager, a precision temperature measuring probe, a connecting column and a calibration black body. The infrared thermal imager is located directly above the water film and can accurately measure the surface temperature of the water film affected by the background radiation of the sky. The precision temperature measuring probe is installed in the temperature measuring hole and can measure the accurate water temperature. After obtaining the water temperature measured by the precision temperature measuring probe and the water film surface temperature measured by the infrared thermal imager, the radiation temperature field of the overall sky background can be obtained by using the formula. Furthermore, the calibration blackbody of the temperature measuring component is characterized in that two calibration blackbodies are connected to the side wall of the cylinder, one of which is a high-temperature calibration blackbody and the other is a low-temperature calibration blackbody. By using two reference blackbodies with a temperature difference, the infrared thermal imager can be calibrated at two points, thereby ensuring the accuracy of the infrared thermal imager when measuring temperature. Furthermore, the connecting column part of the temperature measuring component, the lateral and side parts of the connecting column are covered with light shielding plates, which can effectively prevent direct sunlight from hitting the water film and forming flares, and the other end of the connecting column is connected to a rotating wheel, which can drive the connecting column to rotate around the center of the wheel under the control of a motor. Furthermore, inside the shell, there is a support column at the center, and the support column passes through the water pipe in the shell and is connected to the buffer cap. Furthermore, the middle hemispherical body is characterized in that: in order to better measure the background radiation temperature field of the entire sky, its shape can be designed into various shapes such as a hyperbolic surface, a conical surface, an ellipsoidal surface, etc. Furthermore, the water circulation module includes a water reservoir located at the bottom layer, a water pipe inside the shell, and a circulating water pump connecting the water reservoir and the water inlet of the water pipe. A precision temperature measuring probe is also installed in the water reservoir. The top of the water pipe is the water outlet, and the horizontal part of the water pipe is connected to the water inlet on the side of the cylinder. Compared with the prior art, the advantages of the present invention are: (1) The circulating water film device designed in the present invention measures the water film surface temperature and the water body temperature, thereby obtaining the radiation received when measuring the water film surface temperature and the real radiation of the water body temperature. Therefore, the device can indirectly measure the sky background radiation temperature field and effectively suppress the influence of flare caused by direct sunlight. (2) The present invention has the characteristics of simple structure and low cost, and the device has extremely high practicality. Its operation mode is very convenient, and its design is light and compact, which is easy to carry and install. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be further described below in conjunction with the accompanying drawings. Figure 1 , a schematic diagram of the structure of the present invention Figure 2 , three views of the present invention Figure 3 , a cross-sectional view of the present invention Among them, 1, shell; 2, buffer cap; 3, water inlet; 4, water outlet; 5, temperature measuring hole; 6, water pipe; 7, support column; 8, rotating wheel; 9, circulating water pump; 10, water reservoir; 11, connecting column; 12, light shielding plate; 13, infrared thermal imager; 14, high temperature calibration black body; 15, low temperature calibration black body. DETAILED DESCRIPTION In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of the present invention are further described in detail below with reference to the accompanying drawings. The water reservoir (10) can select different water bodies according to the requirements of the target to be measured, and can be water bodies such as oceans, lakes, rivers, etc. The water body of the water reservoir is pumped by a circulating water pump (9) and injected into the water pipe (6) through the water inlet (3). After the water reaches the water outlet (4), it is blocked by the buffer cap (2) and forms a water film with uniform temperature and stable flow rate on the surface of the hemispherical body (1) outside the water outlet. Because the water film is affected by the radiation from the sky, there is a certain difference between the surface temperature of the water film measured by the infrared thermal imager and the water body temperature measured by the precision temperature measuring probe. The infrared thermal imager (13) calibrated with two black body points measures the surface temperature of the water film in a vertical downward direction, and the temperature sensor at the temperature measuring hole (5) measures the temperature of the water body. After obtaining the two temperature data, the overall sky background radiation temperature field can be calculated by a formula. In addition, a precision temperature measuring probe is also installed in the water storage tank. At the same time, the rotating wheel (8) controlled by the motor can drive the connecting column (11) to rotate, and the light shielding plate (12) on the connecting column can block the flare formed by the direct sunlight on the water film. The principle of temperature measurement by infrared thermal imagers: In nature, objects with a temperature higher than absolute zero are constantly radiating infrared radiation. When the temperature of an object is below 2000K, the radiation emitted is mainly infrared radiation. The infrared spectrum is usually divided into three regions: the wavelength range of 0.75-2.5um is the near infrared region, the wavelength range of 2.5-25um is the mid-infrared region, and the wavelength range of 25-1000mm is the far infrared region. Infrared radiation has good penetration into the atmosphere within several specific wavelength ranges, namely the thermal infrared band of 8-14um and the mid-infrared band of 3.5-5.5um. Infrared thermal imaging technology uses the two infrared bands mentioned above to obtain the thermal radiation of the objects in the scene, and converts the infrared radiation of the target to be measured into a visible light image after being collected and processed by the corresponding readout circuit. The object to be measured continuously emits infrared radiation. The infrared thermal imager detects the infrared radiation of the object to be measured and decomposes the surface temperature of the object on the pixels of the detector. The readout circuit of the detector outputs an electrical signal. The stronger the energy of the object's radiation, the larger the electrical signal. Then, after further circuit processing, the electrical signal of each pixel is converted into each pixel in the grayscale image and sent to the display for imaging. The infrared image after imaging is analyzed, and its temperature-grayscale model is obtained with the help of a black body, thereby realizing the temperature analysis function and achieving the purpose of infrared temperature measurement. When an infrared thermal imager measures the surface temperature of a water film, the radiation received within a certain spectral range consists of two parts: one part is the actual radiation of the water temperature, and the other part is the background radiation from the sky reflected from the surface of the water film. Since the infrared thermal imager can only output the target temperature value but not the target radiation value, the blackbody radiation at any temperature can be obtained by integrating the Planck formula within the band used by the infrared thermometer, thereby directly obtaining the conversion relationship between the radiation and temperature within the infrared thermal imager measurement band (assuming that the response coefficient of the thermal imager in this measurement frequency band is always 1). Given the water temperature measured by the precision temperature probe and the water film surface temperature measured by the infrared thermal imager, the true radiation of the water temperature and the radiation received by the infrared thermal imager when measuring the water film surface temperature can be calculated based on the conversion relationship between radiation and temperature. The sky radiation can be calculated by subtracting the true radiation of the water temperature from the radiation received by the infrared thermal imager when measuring the water film surface temperature. The radiation in different directions constitutes the sky background radiation temperature field. In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the simplified description of the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "connect", "pass through", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electric welding connection; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The above description is only an embodiment of the present invention, and further describes in detail the purpose, technical scheme and beneficial effects of the present invention. The above description does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the content of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A circulating water film device for measuring sky background radiation temperature field, characterized in that: It includes a shell, a water circulation module, and a temperature measuring component; the shell is integrally processed using heat-conducting metal, and is composed of an upper buffer cap, a middle hemispherical main body, and a lower cylinder; a support column for supporting the buffer cap is arranged inside the hemispherical main body, a water outlet is arranged inside the buffer cap, and a certain gap is left between the buffer cap and the hemispherical main body; a water inlet and a temperature measuring hole are arranged on the side of the cylinder; the water circulation module pumps water out of the water outlet to form a water film with uniform temperature and stable flow rate on the surface of the hemispherical main body outside the water outlet; the temperature measuring component includes an infrared thermal imager, a precision temperature measuring probe, a connecting column, and a calibration black body; the infrared thermal imager is located directly above the center of the water film, and can accurately measure the surface temperature of the water film affected by the sky background radiation; the precision temperature measuring probe is installed in the temperature measuring hole, and can measure the precise water temperature; after obtaining the water temperature measured by the precision temperature measuring probe and the water film surface temperature measured by the infrared thermal imager, the overall sky background radiation temperature field can be accurately calculated.

2. The water circulation module according to claim 1, characterized in that: The water circulation module includes a water reservoir located at the bottom layer, a water pipe inside the shell, and a circulating water pump connecting the water reservoir and the water inlet of the water pipe. A precision temperature measuring probe is also installed in the water reservoir. The horizontal part of the water pipe is connected to the water inlet on the side of the cylinder, and the top of the water pipe is the water outlet.

3. The water film according to claim 1, characterized in that: The water in the reservoir is pumped by a circulating water pump and injected into the horizontal water pipe inside the shell from the water inlet, and reaches the water outlet through the vertical water pipe. After the water flow is blocked by the buffer cap, a water film with uniform temperature and stable flow rate is formed on the surface of the hemispherical body outside the water outlet.

4. The connecting column of the temperature measuring assembly according to claim 1, characterized in that: A communication cable is installed inside the connecting column, and the lateral and side parts of the connecting column are covered with light shielding plates, which can effectively prevent direct sunlight from hitting the water film and forming flare. The other end of the connecting column is connected to a rotating wheel, which can drive the connecting column to rotate around the center of the wheel under the control of a motor.

5. The calibration blackbody of the temperature measuring assembly according to claim 1, characterized in that: Two calibration black bodies are connected to the side wall of the cylinder, one of which is a high-temperature calibration black body and the other is a low-temperature calibration black body. By using two reference black bodies with a temperature difference, the infrared thermal imager can be calibrated at two points.

6. The intermediate hemispherical body according to claim 1, characterized in that: In order to better measure the background radiation temperature field of the entire sky, the hemisphere is a generalized hemisphere, and its shape can be designed into various shapes such as hyperbolic surface, cone surface, ellipsoid surface, etc.

Images