System and method for detecting external field optical performance of infrared thermal imaging instrument
By setting up target plates in the field environment and using small portable bold and other equipment, using infrared thermal imaging instruments to observe the target, the problem that existing infrared thermal imaging instruments need to be carried out in the laboratory is solved, and the infrared thermal imaging instruments are realized in the field environment Fast and convenient performance detection.
Patent Information
- Application Number
- CN202411759893.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-03
- Publication Date
- 2025-02-11
AI Technical Summary
The detection of existing infrared thermal imaging instrument MRTD needs to be carried out in the laboratory. The device is costly, large in size, and is not easy to carry, so it cannot be used for rapid detection in an external field environment.
A system for field optical performance detection of infrared thermal imaging instruments is designed, including a bracket, target plate, target, level, small portable bold and portable power supply. By setting up a target plate in the field environment, the target is observed using the measured infrared thermal imaging instrument. Realize instant and fast detection of its spatial resolution and other performance.
It realizes instant and rapid detection of infrared thermal imaging instruments in the external field environment, reduces the cost and volume of the detection device, and improves the convenience and efficiency of detection.
Smart Images
Figure CN119413289A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of optical performance detection, and in particular relates to an outfield optical performance detection system of an infrared thermal imaging instrument, and also relates to a detection method. Background Art
[0002] As infrared imaging technology is increasingly used in military and civilian fields, infrared imaging test technology needs to be continuously improved to adapt to the development of infrared technology. Among the multiple performance parameters of infrared thermal imaging systems, MRTD is an important parameter for comprehensively evaluating the system temperature resolution and spatial resolution of infrared thermal imaging systems. Therefore, MRTD has become the most important parameter for comprehensively evaluating the performance of infrared imaging systems.
[0003] The existing infrared thermal imager MRTD test generally needs to be carried out in a laboratory, and the detection device generally includes a collimator, a black body, a target, a rotating target wheel, a control unit, an image acquisition unit, etc. This method has high detection accuracy, but the device cost is relatively high, and the size is large and not easy to carry. It can only be used in laboratories or base-level places. With the increase in the use scenarios of infrared thermal imaging instruments, it is often necessary to test its spatial resolution and other performance in an outdoor environment. In this case, it is generally only a routine test of the spatial resolution and other performance of the infrared thermal imager. The above-mentioned laboratory detection methods and means cannot be applied to such outdoor detection needs. There is an urgent need for a portable infrared thermal imaging instrument outdoor optical performance detection system that is relatively low in cost, can be quickly built, and can be quickly detected instantly. Summary of the invention
[0004] The first purpose of the present invention is to provide an infrared thermal imaging instrument outdoor optical performance detection system, by setting up a target plate in an outdoor environment, using the infrared thermal imaging instrument to observe the target, to achieve instant and rapid detection of its spatial resolution performance.
[0005] The second object of the present invention is to provide a method for detecting the out-of-field optical performance of an infrared thermal imaging instrument.
[0006] The first technical solution adopted by the present invention is an infrared thermal imaging instrument field optical performance detection system, comprising a bracket, a target plate is connected to the bracket, a target is connected to the front surface of the target plate, a level is connected to the top of the target plate, a small portable black body is connected to the back surface of the target plate, and the small portable black body is connected to a portable power supply; It also includes an infrared thermal imaging instrument to be tested, and the infrared thermal imaging instrument to be tested is used for imaging the target.
[0007] The first technical solution of the present invention is also characterized in that: The bracket has telescopic adjustment capability and can adjust the height of the target plate; the level is fixed directly above the target plate to adjust the bracket to be perpendicular to the ground.
[0008] The target is a four-rod target in the directions of 0° and 90°. The thickness of the target is not less than 0.5mm and the geometric dimension deviation is less than 3%.
[0009] The length-to-width ratio of the target bars in the target is 7:1, and the width of the translucent strip target and the opaque four-bar target are the same.
[0010] The side of the target facing the infrared thermal imaging instrument to be tested is coated with a film layer with an emissivity of not less than 95%, and the side facing the small portable black body is coated with a film layer with a reflectivity of not less than 90%.
[0011] The weight of a small portable black body shall not exceed 5kg, the temperature resolution shall be less than 10mK, the absolute temperature range shall not be less than +15℃~+35℃, the emissivity shall not be less than 96%, and the uniformity shall not be greater than ±20mK.
[0012] The second technical solution adopted by the present invention is a method for detecting the optical performance of an infrared thermal imaging instrument in an outfield, which is specifically implemented by the following steps: Step 1: Determine the relative distance between the infrared thermal imaging instrument under test and the target plate according to the spatial resolution index value of the infrared thermal imaging instrument under test. l ; Step 2: Based on the relative distance determined in step 1 l Select an open and flat location to build the bracket and target board, install the target on the target board, and connect the portable power supply and the small portable black body; Step 3: Set the relative distance between the target plates l The infrared thermal imaging instrument to be tested is set at the position, and after being turned on, the infrared thermal imaging instrument to be tested is aimed at the targets with different spatial frequencies on the target plate for imaging; Step 4, observe the target patterns of different spatial frequencies on the target plate through the infrared thermal imaging instrument under test. When a clear target pattern can be observed, find the corresponding spatial resolution value by comparing the spatial frequency, find the smallest unit pattern that can be seen clearly, and thus determine the spatial resolution value of the infrared thermal imaging instrument under test.
[0013] The second technical solution of the present invention is also characterized in that: The calculation formula for spatial frequency in step 4 is: (1) In the formula, d is the target bar width of the four-bar target, l is the relative distance between the infrared thermal imaging instrument under test and the target plate, is the spatial frequency.
[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) The infrared thermal imaging instrument outdoor optical performance detection system and method provided by the present invention can realize instant and rapid detection of its spatial resolution and other performance by setting up a target plate in an outdoor environment and using the infrared thermal imaging instrument to observe the target. It has the advantages of small size, light weight, simple installation and disassembly, and easy operation, which improves the convenience and detection efficiency of infrared thermal imaging instrument performance detection and reduces the cost of the detection device. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a structural schematic diagram of the outfield optical performance detection system of the infrared thermal imaging instrument of the present invention.
[0016] Figure 2 It is a schematic diagram of the target minimum unit structure of the present invention.
[0017] Figure 3 It is a schematic diagram of the target pattern on the target plate of the present invention.
[0018] In the figure, 1. bracket, 2. target plate, 3. target, 4. level, 5. small portable black body, 6. portable power supply, 7. infrared thermal imaging instrument under test. DETAILED DESCRIPTION
[0019] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.
[0020] The infrared thermal imaging instrument outfield optical performance detection system provided by the present invention is as follows: Figure 1 As shown, it includes a bracket 1, a target plate 2 is connected to the bracket 1, a target 3 is connected to the front surface of the target plate 2, a level 4 is connected to the top of the target plate 2, a small portable black body 5 is connected to the back surface of the target plate 2, and the small portable black body 5 is connected to a portable power supply 6; it also includes a measured infrared thermal imaging instrument 7, which is used for imaging the target 3.
[0021] Among them, the bracket 1 has the ability of telescopic adjustment, and can adjust the height of the target plate 2; the level 4 is fixed directly above the target plate 2, and the bracket 1 is adjusted to be vertical to the ground; the target 3 is a four-bar target in the directions of 0° and 90°, the thickness of the target 3 is not less than 0.5mm, and the geometric dimension deviation is less than 3%; the length-to-width ratio of the target bar in the four-bar target 3 is 7:1, and the translucent strip target and the opaque four-bar target have the same width; the side of the target 3 facing the infrared thermal imaging instrument 7 to be tested is coated with a film layer with an emissivity of not less than 95%, and the side facing the small portable black body 5 is coated with a film layer with a reflectivity of not less than 90%; the weight of the small portable black body 5 does not exceed 5kg, the temperature resolution is less than 10mK, the absolute temperature range is not less than +15℃~+35℃, the emissivity is not less than 96%, and the uniformity is not greater than ±20mK.
[0022] The present invention also provides an outfield optical performance detection method for an infrared thermal imaging instrument, which is specifically implemented by the following steps: Step 1: Determine the relative distance between the infrared thermal imaging device 7 and the target plate 2 according to the spatial resolution index value of the infrared thermal imaging device 7 under test. l ; Step 2: Based on the relative distance determined in step 1 l Select an open and flat location to build the bracket 1 and the target plate 2, and install the target 3 on the target plate 2, and connect the portable power source 6 and the small portable black body 5; Step 3: The target plate 2 is spaced at a relative distance l The infrared thermal imaging device 7 to be tested is arranged at the target plate 2, and after being turned on, the infrared thermal imaging device 7 is aimed at the target 3 with different spatial frequencies on the target plate 2 for imaging; Step 4, observe the target 3 patterns of different spatial frequencies on the target plate 2 through the infrared thermal imaging instrument 7 under test. When a clear target pattern can be observed, find the corresponding spatial resolution value by comparing the spatial frequency, find the minimum unit pattern that can be seen clearly, and thus determine the spatial resolution value of the infrared thermal imaging instrument 7 under test.
[0023] The calculation formula for spatial frequency in step 4 is: (1) In the formula, d is the target bar width of the four-bar target, l is the relative distance between the infrared thermal imaging instrument under test and the target plate, is the spatial frequency.
[0024] Example 1 This embodiment provides an infrared thermal imaging instrument field optical performance detection system and method, such as Figure 1 As shown, it includes a bracket 1, a target plate 2, a target 3, a level 4, a small portable black body 5, a portable power supply 6 and a measured infrared thermal imaging instrument 7; the target 3 is fixed on the front of the target plate 2, the level 4 is fixed directly above the target plate 2, the small portable black body 5 is fixed on the back of the target plate 2, and the small portable black body 5 is located directly behind the target 3. The target plate 2 and the small portable black body 5 are supported by the bracket 1, and the portable power supply 6 supplies power to the small portable black body 5. At a certain distance, the measured infrared thermal imaging instrument 7 is used to image the target 3 on the target plate 2.
[0025] The detection method based on the detection system includes the following steps: Step 1: Determine the relative distance between the infrared thermal imaging instrument under test and the target plate according to the spatial resolution index value of the infrared thermal imaging instrument under test. l ; Step 2: Based on the relative distance determined in the previous step lSelect an open and flat location to build the bracket and target plate, install the target and small portable black body, and connect the portable power supply and the small portable black body; Step 3: Set the relative distance between the target plates l The infrared thermal imaging instrument to be tested is set at the position, and after being turned on, the infrared thermal imaging instrument to be tested is aimed at four-bar targets with different spatial frequencies on the target plate for imaging; Step 4, the operator observes the four-bar target patterns of different spatial frequencies on the target plate through the infrared thermal imaging instrument under test. When a clearly visible target pattern is observed, the operator finds the corresponding spatial resolution value by referring to the spatial frequency lookup table, that is, observes the four-bar target pattern and finds the smallest unit pattern that can be seen clearly, thereby determining the spatial resolution value of the infrared thermal imaging instrument under test.
[0026] The detection environment can be either day or night, and during the detection process, the infrared thermal image field of view should be kept away from the influence of other heat sources as much as possible.
[0027] like Figure 2 The following is a schematic diagram of the smallest unit structure of the target, which is a four-bar target with a length-to-width ratio of ( L : d ) is 7:1, and a positive four-bar target with a light-transmitting middle strip target and opaque surrounding parts is used to produce a target image. The width of the light-transmitting strip target and the opaque four-bar target is the same.
[0028] like Figure 3 As shown, it is a schematic diagram of the target pattern on the target board. Multiple groups of four-bar targets with different spatial frequencies and different directions can be distributed on the target board. The widths of the four-bar targets are different, representing their different spatial frequencies. The wider the width, the smaller the spatial frequency. Targets with different spatial frequencies can be replaced according to the detection needs of the infrared thermal imaging instrument being tested.
[0029] As shown in Table 1, the spatial frequency of the target is selected to represent the schematic diagram. l Represents the relative distance between the infrared thermal imaging instrument under test and the target plate, and the spatial frequency represented by the four-bar target The calculation formula is: (1) in, d is the target bar width of the four-bar target, l is the relative distance between the infrared thermal imaging instrument under test and the target plate. l The spatial frequency, that is, the spatial resolution capability of the infrared thermal imaging instrument under test can be calculated based on the target rod width of the smallest unit pattern that can be seen clearly in the test results.
[0030] Table 1 Target spatial frequency selection table
[0031] Example 2 This embodiment provides an infrared thermal imaging instrument field optical performance detection system, such as Figure 1-3 As shown, it includes a bracket 1, a target plate 2 is connected to the bracket 1, a target 3 is connected to the front surface of the target plate 2, a level 4 is connected to the top of the target plate 2, a small portable black body 5 is connected to the back surface of the target plate 2, and the small portable black body 5 is connected to a portable power supply 6; it also includes a measured infrared thermal imaging instrument 7, which is used for imaging the target 3.
[0032] Example 3 On the basis of Example 2, the bracket 1 has telescopic adjustment capability and can adjust the height of the target plate 2; the level 4 is fixed directly above the target plate 2, and the bracket 1 is adjusted to be perpendicular to the ground; the target 3 is a four-rod target in the directions of 0° and 90°, the thickness of the target 3 is not less than 0.5 mm, and the geometric dimension deviation is less than 3%.
[0033] Example 4 On the basis of Example 3, the length-to-width ratio of the target bars in the four-bar target 3 is 7:1, and the width of the light-transmitting strip target and the opaque four-bar target is the same; the side of the target 3 facing the infrared thermal imaging instrument 7 to be tested is coated with a film layer with an emissivity of not less than 95%, and the side facing the small portable black body 5 is coated with a film layer with a reflectivity of not less than 90%; Example 5 On the basis of Example 4, the weight of the small portable black body 5 does not exceed 5kg, the temperature resolution is less than 10mK, the absolute temperature range is not less than +15°C~+35°C, the emissivity is not less than 96%, and the uniformity is not greater than ±20mK.
[0034] Example 6 This embodiment provides an out-of-field optical performance detection method for an infrared thermal imaging instrument, which is specifically implemented by the following steps: Step 1: Determine the relative distance between the infrared thermal imaging device 7 and the target plate 2 according to the spatial resolution index value of the infrared thermal imaging device 7 under test. l ; Step 2: Based on the relative distance determined in step 1 l Select an open and flat location to build the bracket 1 and the target plate 2, and install the target 3 on the target plate 2, and connect the portable power source 6 and the small portable black body 5; Step 3: The target plate 2 is spaced at a relative distance l The infrared thermal imaging device 7 to be tested is arranged at the target plate 2, and after being turned on, the infrared thermal imaging device 7 is aimed at the target 3 with different spatial frequencies on the target plate 2 for imaging; Step 4, observe the target 3 patterns of different spatial frequencies on the target plate 2 through the infrared thermal imaging instrument 7 under test. When a clear target pattern can be observed, find the corresponding spatial resolution value by comparing the spatial frequency, find the minimum unit pattern that can be seen clearly, and thus determine the spatial resolution value of the infrared thermal imaging instrument 7 under test.
[0035] The calculation formula for spatial frequency in step 4 is: (1) In the formula, d is the target bar width of the four-bar target, l is the relative distance between the infrared thermal imaging instrument under test and the target plate, is the spatial frequency.
[0036] In summary, the infrared thermal imaging instrument outdoor optical performance detection system and method of the present invention can realize the instant and rapid detection of its spatial resolution and other performance by setting up a target plate in an outdoor environment and using the infrared thermal imaging instrument to observe the target, thereby improving the convenience and detection efficiency of the infrared thermal imaging instrument performance detection.
Claims
1. Infrared thermal imaging instrument field optical performance detection system, characterized in that: The invention comprises a support (1), the support (1) being connected to a target plate (2), the front surface of the target plate (2) being connected to a target (3), the top of the target plate (2) being connected to a level (4), the back surface of the target plate (2) being connected to a small portable black body (5), and the small portable black body (5) being connected to a portable power source (6); Also included is an infrared thermal imaging instrument (7) to be tested, wherein the infrared thermal imaging instrument (7) to be tested is used for imaging the target (3).
2. The infrared thermal imaging instrument outfield optical performance detection system according to claim 1, characterized in that: The support (1) has telescopic adjustment capability and can adjust the height of the target plate (2); the level (4) is fixed directly above the target plate (2) to adjust the support (1) to be perpendicular to the ground.
3. The infrared thermal imaging instrument outfield optical performance detection system according to claim 1 is characterized in that: The target (3) is a four-bar target in the 0° and 90° directions, the thickness of the target (3) is not less than 0.5 mm, and the geometric dimension deviation is less than 3%.
4. The infrared thermal imaging instrument outfield optical performance detection system according to claim 3 is characterized in that: The length-to-width ratio of the target bars in the target (3) is 7:1, and the light-transmitting strip target and the opaque four-bar target have the same width.
5. The infrared thermal imaging instrument outfield optical performance detection system according to claim 3 is characterized in that: The target (3) has a surface facing the infrared thermal imaging instrument (7) to be measured coated with a film layer with an emissivity of not less than 95%, and a surface facing the small portable black body (5) coated with a film layer with a reflectivity of not less than 90%.
6. The infrared thermal imaging instrument outfield optical performance detection system according to claim 1, characterized in that: The weight of the small portable black body (5) does not exceed 5 kg, the temperature resolution is less than 10 mK, the absolute temperature range is not less than +15°C to +35°C, the emissivity is not less than 96%, and the uniformity is not greater than ±20 mK.
7. A method for detecting the optical performance of an infrared thermal imaging instrument in the field, characterized in that: The infrared thermal imaging instrument outdoor optical performance detection system according to any one of claims 1 to 6 is implemented in the following steps: Step 1: determining the relative distance between the infrared thermal imaging device (7) under test and the target plate (2) according to the spatial resolution index value of the infrared thermal imaging device (7) under test l ; Step 2: Based on the relative distance determined in step 1 l Select an open and flat location to build a support (1) and a target plate (2), install a target (3) on the target plate (2), and connect a portable power source (6) and a small portable black body (5); Step 3, the target plates (2) are spaced at a relative distance l An infrared thermal imaging device (7) to be tested is arranged at the target plate (2), and the infrared thermal imaging device (7) to be tested is turned on and aimed at targets (3) of different spatial frequencies on the target plate (2) for imaging; Step 4, using the infrared thermal imaging device (7) to observe the target (3) patterns of different spatial frequencies on the target plate (2), and when a clear target pattern can be observed, the corresponding spatial resolution value is found by comparing the spatial frequency, and the smallest unit pattern that can be seen clearly is found, thereby determining the spatial resolution value of the infrared thermal imaging device (7) to be tested.
8. The method for detecting the outfield optical performance of an infrared thermal imaging instrument according to claim 5, characterized in that: The calculation formula for the spatial frequency in step 4 is: （1） In the formula, d is the target bar width of the four-bar target, l is the relative distance between the infrared thermal imaging instrument under test and the target plate, is the spatial frequency.