Dark current calibration method and device and storage medium

Abstract

The invention relates to the technical field of spectral measurement equipment, and discloses a dark current calibration method and device and a storage medium, and the dark current calibration method comprises the following steps: after sampling a certain number of bright frames, controlling a shading mechanism to shield a sampling light path, and sampling a dark frame; interpolation is carried out on the radiation values of the dark frames according to the sampling time of the bright frames, and the radiation value of the dark frame corresponding to each bright frame is obtained; and pairing the dark frame and the bright frame according to the sampling time, and calibrating the radiation value of the corresponding bright frame at the same moment by using the radiation value of the dark frame. According to the dark current calibration method, the detected dark current of the spectrum can be accurately deducted in real time, and the spectrum detection precision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of spectrum measurement equipment, and in particular to a dark current calibration method, device and storage medium. Background Art

[0002] The apparent optical parameters mainly include water-leaving radiance, normalized water-leaving radiance and remote sensing reflectance, etc. They are the basic physical quantities of ocean water color remote sensing and the optical manifestation of water pigment components. Accurate on-site acquisition of apparent optical parameters will be conducive to the development of bio-optical algorithms and atmospheric correction algorithms, and will be conducive to the radiation correction of satellite-borne remote sensors and the authenticity verification of their data. The measurement of optical parameters is to use a single spectrometer to measure multiple targets in time or multiple spectrometers to measure multiple targets simultaneously. The deduction of dark current when calculating the radiation value greatly affects the measurement accuracy. In the existing measurement method, the dark current is deducted by covering the light inlet with an opaque cover before or after measuring the target, measuring a dark baseline; or taking a section of dark pixel value in the spectrum (ultraviolet end or near infrared end) as the dark current value for deduction. The former requires manual on-site operation, which is inefficient and time-consuming, and cannot calibrate the detected spectrum in real time. The latter cannot accurately deduct the influence of dark current due to the inevitable differences between each pixel. For this reason, it is necessary to set up a new spectrum measurement scheme that can accurately calibrate the detected spectrum in real time. Summary of the invention

[0003] In order to overcome the deficiencies of the prior art, an object of the present invention is to provide a dark current calibration method, which can perform real-time high-precision dark current subtraction calibration on the detected spectral values, thereby improving the accuracy of spectral detection.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows: a dark current calibration method, comprising the following steps:

[0005] After sampling a certain number of bright frames, the shading mechanism is controlled to block the sampling light path and sample a dark frame;

[0006] Interpolate the radiation value of the dark frame according to the sampling time of the bright frame to obtain the radiation value of the dark frame corresponding to each bright frame;

[0007] The dark frame is paired with the light frame according to the sampling time, and the radiation value of the dark frame is used to calibrate the radiation value of the corresponding light frame at the same time.

[0008] Compared with the prior art, the beneficial effect of the present invention is that by controlling the shading mechanism to periodically block the sampling light path, dark frames can be automatically acquired regularly, and the dark baseline of the detection environment can be obtained from the dark frames. At the same time, by interpolating the radiation values ​​of the detected dark frames, the number of dark frames is matched with the number of bright frames, so that the dark current value corresponding to the bright frame at each sampling time can be obtained, so as to accurately deduct the dark current of each bright frame, realize real-time and accurate calibration of the spectrum value, and improve the accuracy of spectrum detection.

[0009] In the dark current calibration method described above, the step of interpolating the radiation values ​​of the dark frames according to the sampling time so that the number of dark frames matches the number of bright frames comprises:

[0010] Convert the radiation value of the sampled dark frame into engineering units;

[0011] Filtering removes spikes in the radiance values ​​of dark frames;

[0012] The radiance values ​​of the dark frames after filtering out the spikes are interpolated according to the sampling time so that the number of dark frames matches the number of bright frames.

[0013] In the above dark current calibration method, in the step of converting the radiation value of the sampled dark frame into engineering units, the radiation value of the dark frame is converted into engineering units by the following formula:

[0014] L DarkDat(λ) =(L CountsDarkDat (λ)-L CalDarkDat (λ))·a(λ)·ic(λ) / it

[0015] Where, L DarkDat(λ) is the radiation value of the dark frame in engineering units, L CountsDarkDat (λ) is the measured count value of the radiation value of the dark frame, L CalDarkDat (λ) is the average number of dark pixel counts that do not respond to the outside world, a(λ) is the correction coefficient, ic(λ) is the immersion coefficient, and it is the integration time used in the measurement.

[0016] The dark current calibration method described above, before the calibration step of pairing the dark frame with the bright frame according to the sampling time and using the radiation value of the dark frame to calibrate the radiation value of the corresponding bright frame at the same time, also includes:

[0017] Convert the radiance value of the sampled bright frame to engineering units.

[0018] In the dark current calibration method described above, in the step of converting the radiation value of the sampled bright frame into an engineering unit, the radiation value of the bright frame is converted into an engineering unit by the following formula:

[0019] L LightDat(λ) =(L CountsLightDat (λ)-LCalDarkDat (λ))·a(λ)·ic(λ) / it

[0020] Where, L LightDat(λ) is the radiation value of the bright frame in engineering units, L CountsLightDat (λ) is the measured count value of the radiation value of the bright frame, L CalDarkDat (λ) is the average number of dark pixel counts that do not respond to the outside world, a(λ) is the correction coefficient, ic(λ) is the immersion coefficient, and it is the integration time used in the measurement.

[0021] A storage medium stores a computer program, wherein the computer program implements the above-mentioned dark current calibration method when being executed and called by a processor.

[0022] A dark current calibration device comprises a processor and a memory, wherein the memory is electrically connected to the processor, and the processor implements the above-mentioned dark current calibration method by calling and executing a computer program stored in the memory.

[0023] A dark current calibration device includes: a sampling module, which is used to control a shading mechanism to block the sampling light path after sampling a certain number of bright frames, and sample a dark frame; an acquisition module, which is used to acquire the radiation values ​​of the sampled bright frames and dark frames; an interpolation module, which interpolates the radiation values ​​of the dark frames according to the sampling time of the bright frames, and acquires the radiation values ​​of the dark frames corresponding to each bright frame; and a calibration module, which is used to pair the dark frames with the bright frames according to the sampling time, and calibrate the radiation values ​​of the corresponding bright frames at the same time using the radiation values ​​of the dark frames.

[0024] The above-mentioned dark current calibration device also includes: a conversion module, which is used to convert the radiation values ​​of the sampled dark frames and bright frames into engineering units.

[0025] A spectrum measuring instrument comprises: the above-mentioned dark current calibration device; an optical coupling device for collecting light and coupling multiple light beams into an optical fiber; a shading mechanism, arranged on the optical path between the optical coupling device and the optical fiber, electrically connected to the dark current calibration device, and used for intermittently shielding the optical path between the optical coupling device and the optical fiber under the control of the dark current calibration device; a spectrometer, electrically connected to the dark current calibration device, with an input end connected to the output end of the optical fiber, and used for converting the radiation value of the light collected by the optical coupling device into an electrical signal; and a power module, used for supplying power to the dark current calibration device, the shading mechanism and the spectrometer.

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1is a flow chart of a dark current calibration method according to an embodiment of the present invention;

[0028] Figure 2 It is a structural schematic diagram of a spectrum measuring instrument according to a first embodiment of the present invention;

[0029] Figure 3 is a cross-sectional view of a spectrometer according to a first embodiment of the present invention;

[0030] Figure 4 is a cross-sectional view of a spectrometer according to a second embodiment of the present invention;

[0031] Figure 5 A schematic diagram of the internal structure of a spectrometer according to an embodiment of the present invention;

[0032] Figure 6 is a structural schematic diagram of a shading mechanism according to an embodiment of the present invention;

[0033] Figure 7 FIG. 4 is a schematic diagram of the structure of an optical splitter according to an embodiment of the present invention.

[0034] Description of Figure Numbers:

[0035] 100 watertight housing, 110 electrical connector, 120 coupling device housing, 130 back housing, 200 optical coupling device, 210 glass window, 220 sealing gasket, 230 incident hole, 240 cosine corrector, 300 optical fiber, 310 isolation column, 311 isolation sealing ring, 312 light-passing hole, 400 shading mechanism, 410 shading sheet, 420 shading motor, 500 control circuit board, 600 splitter, 610 bracket, 620 metal cover, 630 temperature sensor, 700 interface circuit board. DETAILED DESCRIPTION

[0036] The embodiments of the present invention are described in detail below. Figure 1 , an embodiment of the present invention provides a dark current calibration method, comprising the following steps:

[0037] After sampling a certain number of bright frames, the shading mechanism 400 is controlled to block the sampling light path and sample a dark frame; the bright frame refers to the measurement of external light without blocking, and the dark frame refers to the measurement of external light under blocking.

[0038] Interpolate the radiance values ​​of the dark frames according to the sampling time so that the number of dark frames matches the number of bright frames;

[0039] The dark frame is paired with the light frame according to the sampling time, and the radiation value of the dark frame is used to calibrate the radiation value of the corresponding light frame at the same time.

[0040] The dark current calibration method of the embodiment of the present invention controls the shading mechanism 400 to intermittently block the sampling light path, thereby obtaining a dark frame of the real-time measurement environment, so that the radiation value of the bright frame can be calibrated by the radiation value of the real-time dark frame, and the real-time dark current of the measured spectrum can be accurately deducted, thereby improving the accuracy of the real-time spectrum radiation value measurement. At the same time, the dark current calibration method of the present invention intersperses and detects a dark frame after sampling a certain number of bright frames, and after sampling, the radiation value of the sampled dark frame is interpolated according to the sampling time of the bright frame through an interpolation algorithm, so as to obtain the radiation value of the dark frame corresponding to each bright frame, so as to achieve accurate deduction of the dark current of each bright frame. This method uses an interpolation algorithm to interpolate the radiation value of the dark frame, which can avoid the frequent action of the shading mechanism 400 affecting the detection efficiency. At the same time, since the dark current is mainly caused by thermal excitation of the ambient temperature, the electrons in the detector material are excited to the conduction band due to thermal motion to form dark current, which is related to the ambient temperature and its change trend has a certain regularity. Therefore, the interpolation algorithm can be used to infer the radiation value of the dark frame corresponding to the bright frame sampling, thereby further improving the accuracy of dark current subtraction for the bright frame.

[0041] It is understandable that the sampling interval of the dark frame can be set according to actual needs, such as sampling one dark frame after sampling five bright frames, and the interpolation function can adopt interpolation polynomial, piecewise interpolation or triangular interpolation.

[0042] In this embodiment, for the convenience of engineering use, the radiation values ​​of the bright frame and the dark frame need to be converted into engineering units. The conversion formulas of the bright frame and the dark frame are shown in the following formulas (1) and (2), respectively:

[0043] L LightDat(λ) =(L CountsLightDat (λ)-L CalDarkDat (λ))·a(λ)·ic(λ) / it (1)

[0044] L DarkDat(λ) =(L CountsDarkDat (λ)-L CalDarkDat (λ))·a(λ)·ic(λ) / it (2)

[0045] Where, L LightDat(λ) is the radiation value of the bright frame in engineering units, L DarkDat(λ) is the radiation value of the dark frame in engineering units, L CountsLightDat (λ) is the measured count value of the radiation value of the bright frame, L CountsDarkDat (λ) is the measured count value of the radiation value of the dark frame, L CalDarkDat (λ) is the average number of dark pixel counts that do not respond to the outside world, a(λ) is the correction coefficient, ic(λ) is the immersion coefficient, and it is the integration time used in the measurement.

[0046] In some embodiments, in order to ensure the accuracy of the interpolated dark frame radiation value, before interpolation, the radiation value of the dark frame converted to the engineering unit needs to be filtered, and the peaks therein are filtered out, and then the radiation value of the dark frame after the peaks are filtered out is interpolated. In this embodiment, the peaks in the radiation value of the sampled dark frame are filtered out by first-order differential filtering. After interpolation is completed, L(λ)=L LightDat (λ)-L DarkDat(λ) The dark current of the bright frame at each sampling time is deducted to obtain the accurate radiation value L(λ) of each bright frame.

[0047] Based on the same inventive concept, an embodiment of the present invention further provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the above-mentioned dark current calibration method can be implemented.

[0048] In some possible embodiments, various aspects of the dark current calibration method provided by the present invention can also be implemented in the form of a program product, which includes a program code. When the program product is run on the device, the program code is used to enable the control device to execute the steps of the dark current calibration method according to various exemplary embodiments of the present application described above in this specification.

[0049] Based on the same inventive concept, an embodiment of the present invention also provides a device for implementing the above-mentioned dark current calibration method, including a processor and a memory, the memory is electrically connected to the processor, and the processor is used to execute the computer program stored in the memory to implement the above-mentioned dark current calibration method.

[0050] In one possible design, the processor may include one or more processing units, and the processor and memory may be implemented on the same chip or on separate chips. The processor may be a general-purpose processor, such as a central processing unit (CPU), a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, and may implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the dark current calibration method disclosed in the embodiments of the present application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0051] As a non-volatile computer-readable storage medium, the memory can be used to store non-volatile software programs, non-volatile computer executable programs and modules. The memory can include at least one type of storage medium, for example, it can include flash memory, hard disk, multimedia card, card-type memory, random access memory (Random Access Memory, RAM), static random access memory (Static RandomAccess Memory, SRAM), programmable read-only memory (Programmable Read Only Memory, PROM), read-only memory (Read Only Memory, ROM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, EEPROM), magnetic memory, disk, CD, etc. The memory is any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory in the embodiment of the present application can also be a circuit or any other device that can realize a storage function, for storing program instructions and / or data.

[0052] By designing and programming the processor, the code corresponding to the dark current calibration method described in the above embodiment can be fixed into the chip, so that the chip can execute the steps of the dark current calibration method of the embodiment shown in the present invention when running. How to design and program the processor is a technology well known to those skilled in the art and will not be described here.

[0053] Based on the same inventive concept, an embodiment of the present invention also provides another dark current calibration device, including a sampling module, an acquisition module, an interpolation module, a calibration module and a conversion module. The sampling module is used to control the shading mechanism 400 to block the sampling light path and sample a dark frame after sampling a certain number of bright frames. The acquisition module is used to obtain the radiation values ​​of the sampled bright frames and dark frames. The interpolation module interpolates the radiation value of the dark frame according to the sampling time of the bright frame to obtain the radiation value of the dark frame corresponding to each bright frame. The calibration module is used to pair the dark frame with the bright frame according to the sampling time, and calibrate the radiation value of the bright frame at the same time using the radiation value of the dark frame. The conversion module is used to convert the radiation values ​​of the sampled dark frames and bright frames into engineering units.

[0054] Reference Figure 2 and Figure 3Based on the same inventive concept, an embodiment of the present invention also provides a spectrometer, including the above-mentioned dark current calibration device, an optical coupling device 200, a shading mechanism 400, a spectrometer 600 and a power module. The optical coupling device 200 is used to collect light and couple multiple light beams into an optical fiber 300. The shading mechanism 400 is arranged on the optical path between the optical coupling device 200 and the optical fiber 300, and is electrically connected to the dark current calibration device, and is used to intermittently block the optical path between the optical coupling device 200 and the optical fiber 300 under the control of the dark current calibration device, so as to obtain dark frames in real time and obtain real-time dark current values. The spectrometer 600 is electrically connected to the dark current calibration device, and the input end is connected to the output end of the optical fiber 300, and is used to convert the radiation value of the light collected by the optical coupling device 200 into an electrical signal. The power module is used to power the dark current calibration device, the shading mechanism 400 and the spectrometer 600. Refer to Figures 2 to 4 In this embodiment, the dark current calibration device, the optical coupling device 200 , the shading mechanism 400 , the beam splitter 600 and the power module are all disposed in a watertight housing 100 .

[0055] Reference Figure 3 and Figure 4 It is understandable that the optical coupling device 200 selects a suitable coupling device according to different measurement signals, and may select a radiance coupling device or an irradiance coupling device. Figure 3 If a radiance coupling device is used, it includes a glass window 210 and a sealing gasket 220. The watertight housing 100 includes a coupling device housing 120 and a rear housing 130. A through hole for light to enter is provided at the front end of the coupling device housing 120. The glass window 210 is pressed on the through hole at the front end of the coupling device through a glass pressing block. A sealing gasket 220 is provided between the glass window 210 and the coupling device housing 120. Two incident holes 230 with different apertures are provided behind the glass window 210. The two incident holes 230 are coaxial with the through holes on the coupling device housing 120. The aperture value of the incident holes 230 can be controlled to obtain the required field of view angle. In this embodiment, the glass window 210 is made of a highly light-transmitting material such as sapphire or ultraviolet fused quartz.

[0056] Reference Figure 4 If an irradiance coupling device is used, the difference from the radiance coupling device is that it also includes a cosine corrector 240. The cosine corrector 240 has a Lambertian body property and is made of PTFE material in this embodiment. A cylindrical cavity is arranged in the middle. The cylindrical glass window 210 is embedded in the cavity of the cosine corrector 240. A sealing gasket 220 is arranged between the cosine corrector 240 and the coupling device housing 120. The cosine corrector 240 is pressed on the through hole at the front end of the coupling device housing 120 through a corrector pressing block.

[0057] It is understandable that the shading mechanism 400 may be a controllable shutter such as an electromagnetic shutter or a mechanical optical switch. Figures 4 to 6 In this embodiment, an isolation column 310 is provided at the connection between the coupling device housing 120 and the rear housing 130, and the optical fiber 300 is arranged in the isolation column 310. An end of the isolation column 310 close to the optical coupling device 200 is provided with a light hole 312 for light to pass through. The light hole 312 is coaxial with the through hole at the front end of the coupling device housing 120. The light entering the watertight housing 100 can pass through the light hole 312 on the isolation column 310 and be emitted to the input end of the optical fiber 300 inside. The shading mechanism 400 is arranged on the end surface of the isolation column 310 close to the optical coupling device 200, and includes a shading motor 420 and a shading sheet 410. The shading motor 420 is electrically connected to the dark current calibration device, and the shading motor 420 is arranged on one side of the light hole 312. The shading sheet 410 is connected to the output shaft of the shading motor 420, and can swing under the drive of the shading motor 420 to block or open the light hole 312, thereby intermittently blocking the light incident on the beam splitter 600. In this embodiment, the shading motor 420 is a hollow cup motor.

[0058] Reference Figures 3 to 5 In this embodiment, in order to further ensure the liquid tightness of the watertight housing 100, an isolation seal ring 311 is provided at the connection between the isolation column 310 and the rear shell 130 and the coupling device housing 120. A metal bracket 610 is provided at one end of the isolation column 310 close to the beam splitter 600, and the beam splitter 600 is connected to the isolation column 310 through the bracket 610. A control circuit board 500 is also provided on the bracket 610, and the processor and memory of the dark current calibration device are both provided on the control circuit board 500.

[0059] In this embodiment, the optical splitter 600 preferably uses the MMS series micro optical sensor module of Carl Zeiss. The optical splitter 600 uses an optical fiber 300 connector to guide light into the internal grating. The optical fiber 300 bundle includes about 30 quartz glass optical fibers 300 with a core diameter of 70 μm, which are linearly arranged to form an entrance slit. A flat-field holographic concave grating is used to simplify the optical path. The concave grating combines the functions of a plane grating and a concave mirror, greatly simplifies the optical path, reduces stray light, and at the same time, the diffraction efficiency of the concave grating using holographic blazing technology is also greatly improved, and the second and third order diffraction is weakened. The simplification of the optical path can achieve a smaller volume. The optical splitter 600 uses a photodiode array (PDA) as a detector, and its signal-to-noise ratio, dark current, temperature drift, repeatability, etc. are far superior to CCD.

[0060] Reference Figure 4 , Figure 5 and Figure 7, an amplifier circuit module is provided on the spectrometer 600, which is used to convert the charge output by the spectrometer 600 into a voltage signal, and is electrically connected to the processor through the amplifier circuit and analog-to-digital conversion chip provided on the control circuit board 500. A temperature sensor 630 is provided between the amplifier circuit module and the spectrometer 600, and the temperature sensor 630 is electrically connected to the processor on the control circuit board 500 to monitor whether the temperature of the spectrometer 600 is within a suitable operating temperature range, so as to avoid the decrease in sensitivity and resolution of the detector part of the spectrometer 600 due to excessively high or low temperature. The detector and the amplifier circuit module outer cover of the spectrometer 600 are provided with a metal cover 620 made of metal to form a shielding layer to shield external interference. In this embodiment, a tilt sensor is provided on the control circuit board 500, which is electrically connected to the processor in the dark current calibration device, and is used to provide auxiliary information for angle-sensitive irradiance measurement.

[0061] Reference Figure 2 and Figure 3 In this embodiment, an interface circuit board 700 is provided on the rear end cover of the rear shell 130. The power module is provided on the interface circuit board 700 to convert the external wide-range DC power into various voltages required by the internal circuit, and provide a stable voltage for the detector of the spectrometer 600 to ensure that the detector can accurately convert the optical signal into an electrical signal. A data transmission and communication module is also provided on the interface circuit board 700. The data transmission and communication module is electrically connected to the processor of the dark current calibration device, and is used to transmit the collected data to an external device, configure the collection frequency in response to an external instruction, collect data according to the instruction parameters, etc. An electrical connector 110 is provided on the outside of the rear end cover. The electrical connector 110 is electrically connected to the data transmission and communication module and the power module. The electrical connector 110 is used for the electrical connection between the optical spectrum measuring instrument and the external device, inputs the external voltage to the power module, transmits the external control instruction to the data transmission and communication module, and transmits the collected parameters output by the data transmission and communication module to the external device.

[0062] The present application is described with reference to the flowcharts and / or block diagrams of the methods, apparatus (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0063] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0064] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0065] It should be noted that in the description of the present invention, if there are any orientation descriptions, such as up, down, front, back, left, right, etc., the orientations or positional relationships indicated are all based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and cannot be understood as a limitation on the present invention.

[0066] In the description of the present invention, "several" means one or more, "more" means two or more, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0067] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0068] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A dark current calibration method, characterized in that: The steps include: After sampling a certain number of bright frames, the light shielding mechanism (400) is controlled to shield the sampling light path, and a dark frame is sampled; Interpolate the radiation value of the dark frame according to the sampling time of the bright frame to obtain the radiation value of the dark frame corresponding to each bright frame; The dark frame is paired with the light frame according to the sampling time, and the radiation value of the dark frame is used to calibrate the radiation value of the corresponding light frame at the same time.

2. The dark current calibration method according to claim 1, characterized in that: The step of interpolating the radiation values ​​of the dark frames according to the sampling time so that the number of dark frames matches the number of bright frames comprises: Convert the radiation value of the sampled dark frame into engineering units; Filtering removes spikes in the radiance values ​​of dark frames; The radiance values ​​of the dark frames after filtering out the spikes are interpolated according to the sampling time so that the number of dark frames matches the number of bright frames.

3. The dark current calibration method according to claim 2, characterized in that: In the step of converting the radiation value of the sampled dark frame into the engineering unit, the radiation value of the dark frame is converted into the engineering unit by the following formula: L DarkDat(λ) =(L CountsDarkDat (λ)-L CalDarkDat (λ))·a(λ)·ic(λ) / it Where, L DarkDat(λ) is the radiation value of the dark frame in engineering units, L CountsDarkDat (λ) is the measured count value of the radiation value of the dark frame, L CalDarkDat (λ) is the average number of dark pixel counts that do not respond to the outside world, a(λ) is the correction coefficient, ic(λ) is the immersion coefficient, and it is the integration time used in the measurement.

4. The dark current calibration method according to claim 1, characterized in that: Before the step of pairing the dark frame with the bright frame according to the sampling time and calibrating the radiation value of the corresponding bright frame at the same time using the radiation value of the dark frame, the method further includes: Convert the radiance value of the sampled bright frame to engineering units.

5. The dark current calibration method according to claim 4, characterized in that: In the step of converting the radiation value of the sampled bright frame into the engineering unit, the radiation value of the bright frame is converted into the engineering unit by the following formula: L LightDat(λ) =(L CountsLightDat (λ)-L CalDarkDat (λ))·a(λ)·ic(λ) / it Where, L LightDat(λ) is the radiation value of the bright frame in engineering units, L CountsLightDat (λ) is the measured count value of the radiation value of the bright frame, L CalDarkDat (λ) is the average number of dark pixel counts that do not respond to the outside world, a(λ) is the correction coefficient, ic(λ) is the immersion coefficient, and it is the integration time used in the measurement.

6. A storage medium storing a computer program readable by a computer, characterized in that: When the computer program is executed and called by a processor, the dark current calibration method according to any one of claims 1 to 5 is implemented.

7. A dark current calibration device, characterized in that: It comprises a processor and a memory, the memory is electrically connected to the processor, and the processor implements the dark current calibration method according to any one of claims 1 to 5 by calling and executing a computer program stored in the memory.

8. A dark current calibration device, characterized in that: include: A sampling module, used for controlling the shading mechanism (400) to shield the sampling light path after sampling a certain number of bright frames, and sampling a dark frame; An acquisition module, used to acquire the radiation values ​​of the sampled bright frame and dark frame; An interpolation module interpolates the radiation value of the dark frame according to the sampling time of the bright frame to obtain the radiation value of the dark frame corresponding to each bright frame; The calibration module is used to pair the dark frame with the light frame according to the sampling time, and calibrate the radiation value of the light frame at the same time using the radiation value of the dark frame.

9. The dark current calibration device according to claim 7, characterized in that: Also includes: The conversion module is used to convert the radiation values ​​of the sampled dark frame and bright frame into engineering units.

10. A spectrum measuring instrument, characterized in that: include: The dark current calibration device according to any one of claims 7 to 9; An optical coupling device (200) for collecting light and coupling multiple light beams into an optical fiber (300); A light shielding mechanism (400) is arranged on the optical path between the optical coupling device (200) and the optical fiber (300), is electrically connected to the dark current calibration device, and is used to intermittently shield the optical path between the optical coupling device (200) and the optical fiber (300) under the control of the dark current calibration device; A spectrometer (600) electrically connected to the dark current calibration device, with an input end connected to the output end of the optical fiber (300), and used for converting the radiation value of the light collected by the optical coupling device (200) into an electrical signal; A power supply module is used to supply power to the dark current calibration device, the light shielding mechanism (400) and the spectrometer (600).

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