Temperature correction method, device and equipment for distributed optical fiber temperature measurement system and medium

Abstract

The invention relates to the technical field of distributed optical fiber temperature measurement system temperature correction, and discloses a distributed optical fiber temperature measurement system temperature correction method, device, equipment and medium, and the method comprises the steps: extracting a first signal intensity value set and a second signal intensity value set, setting a direct current bias according to the first signal strength value set and the second signal strength value set, and adding the direct current bias to the first signal strength value set to obtain a third signal strength value set; a system temperature is calculated based on the third set of signal strength values and the second set of signal strength values. The method has the beneficial effects that the systematic improvement of the signal-to-noise ratio of the signal is realized by continuously adjusting the direct current bias and correcting the time domain dislocation, gain deviation and transmission loss difference of the Raman scattering light signal, the measurement accuracy can be improved, different environmental conditions can be adapted, and the measurement accuracy is improved. And the stability and the accuracy of the system can be kept under various working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature correction of a distributed optical fiber temperature measurement system, and in particular to a method, device, equipment and medium for temperature correction of a distributed optical fiber temperature measurement system. Background Art

[0002] The spontaneous Raman scattered light intensity in the distributed fiber temperature measurement system (DTS) is very weak, even only 10% of the incident light intensity. -9 During the transmission and acquisition process, it is easily contaminated by noise from hardware systems such as lasers and photodetectors and other scattered light, which can submerge useful signals, affect the signal-to-noise ratio, and ultimately reduce temperature accuracy and transmission distance. Summary of the Invention

[0003] Based on this, it is necessary to address the problem of temperature correction in the existing distributed optical fiber temperature measurement system, and propose a method, device, equipment and medium for temperature correction in a distributed optical fiber temperature measurement system.

[0004] A method for temperature correction of a distributed optical fiber temperature measurement system, the method comprising:

[0005] Collecting the periodic pulse signal emitted by the laser;

[0006] extracting a first signal intensity value of a first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal to form a first signal intensity value set, and extracting a minimum value of a second Raman scattered light signal at each preset sampling point in the periodic pulse signal as a second signal intensity value to form a second signal intensity value set;

[0007] Setting a DC offset according to the first signal strength value set and the second signal strength value set, and adding the DC offset to the first signal strength value set to obtain a third signal strength value set;

[0008] determining whether the third signal strength value set meets a preset requirement; if so, outputting the third signal strength value set; otherwise, calculating a strength ratio set between the third signal strength value set and the second signal strength value set, and resetting a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement;

[0009] A system temperature is calculated based on the third set of signal strength values ​​and the second set of signal strength values.

[0010] Furthermore, the step of calculating a strength ratio set between the third signal strength value set and the second signal strength value set, and resetting a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement includes:

[0011] Calculating the ratio of each of the preset sampling points to obtain a ratio set, and calculating the standard deviation of each of the ratio sets;

[0012] Calculating a second DC bias according to the standard deviation;

[0013] Determining whether a difference between the second DC bias and the DC bias is within a preset range;

[0014] If it is not within the preset range, the second DC bias is recorded as the DC bias, and the second DC bias is recalculated until the difference between the second DC bias and the DC bias is within the preset range. It is then determined that the third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirements.

[0015] Furthermore, the step of determining whether the third signal strength value set meets a preset requirement includes:

[0016] Obtaining a current third signal strength value set and resetting a set number of DC bias times;

[0017] If the set number of times is greater than or equal to the preset number of times, it is determined that the preset requirement is met; otherwise, it is determined that the preset requirement is not met.

[0018] Furthermore, the step of resetting the DC bias based on the intensity ratio set includes:

[0019] The standard deviation is calculated according to the formula f = std(ξ), where ξ is the set of intensity ratios, f is the standard deviation, and std(.) is the standard deviation calculation formula;

[0020] The reset DC offset is calculated according to the formula offset1=offset-η×grad(f), where offset is the last set DC offset, offset1 is the current set DC offset, η is the number of times the DC offset is reset, and grad(.) is a vector-valued function.

[0021] Furthermore, the step of extracting the minimum value of the second Raman scattered light signal in the periodic pulse signal at each preset sampling point as the second signal intensity value to form a second signal intensity value set includes:

[0022] Extracting the minimum value of the preset second Raman scattered light signal corresponding to each preset sampling point in the periodic pulse signal;

[0023] Determine whether the minimum value is 0;

[0024] If the minimum value exists and is 0, then the minimum value of 0 is added to the set minimum value to form a new second signal strength value set.

[0025] Furthermore, one of the first Raman scattered light signal and the second Raman scattered light signal is a Stokes Raman scattered light signal, and the other is an anti-Stokes Raman scattered light signal.

[0026] Furthermore, the step of calculating the system temperature based on the third signal strength value set and the second signal strength value set includes:

[0027] Measuring the temperature value of each of the preset sampling points;

[0028] Selecting, from the preset sampling points, a first sampling point having a temperature value of a preset first temperature value and a second sampling point having a temperature value of a preset second temperature value according to the temperature value;

[0029] calculating a first target intensity ratio of the first sampling point and a second target intensity ratio of the second sampling point;

[0030] According to the formula Calculate the system temperature, where R1 is the first target intensity ratio, R2 is the second target intensity ratio, and T m is the system temperature, k B is the Boltzmann constant, E is the difference in molecular excitation energy levels, h is the Planck constant, and Δv is the Raman frequency shift.

[0031] The present invention also provides a device for temperature correction of a distributed optical fiber temperature measurement system, the device comprising:

[0032] An acquisition module is used to acquire the periodic pulse signal emitted by the laser;

[0033] an extraction module, configured to extract a first signal intensity value of a first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal to form a first signal intensity value set, and to extract a minimum value of a second Raman scattered light signal at each preset sampling point in the periodic pulse signal as a second signal intensity value to form a second signal intensity value set;

[0034] a first calculation module, configured to set a DC offset according to the first signal strength value set and the second signal strength value set, and add the DC offset to the first signal strength value set to obtain a third signal strength value set;

[0035] a determination module, configured to determine whether the third signal strength value set meets a preset requirement, and if so, output the third signal strength value set; otherwise, calculate a strength ratio set between the third signal strength value set and the second signal strength value set, and reset a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement;

[0036] A second calculation module is configured to calculate a system temperature based on the third signal strength value set and the second signal strength value set.

[0037] A computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the following steps:

[0038] Collecting the periodic pulse signal emitted by the laser;

[0039] extracting a first signal intensity value of a first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal to form a first signal intensity value set, and extracting a minimum value of a second Raman scattered light signal at each preset sampling point in the periodic pulse signal as a second signal intensity value to form a second signal intensity value set;

[0040] Setting a DC offset according to the first signal strength value set and the second signal strength value set, and adding the DC offset to the first signal strength value set to obtain a third signal strength value set;

[0041] determining whether the third signal strength value set meets a preset requirement; if so, outputting the third signal strength value set; otherwise, calculating a strength ratio set between the third signal strength value set and the second signal strength value set, and resetting a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement;

[0042] A system temperature is calculated based on the third set of signal strength values ​​and the second set of signal strength values.

[0043] A computer-readable storage medium stores a computer program, which, when executed by a processor, causes the processor to perform the following steps:

[0044] Collecting the periodic pulse signal emitted by the laser;

[0045] extracting a first signal intensity value of a first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal to form a first signal intensity value set, and extracting a minimum value of a second Raman scattered light signal at each preset sampling point in the periodic pulse signal as a second signal intensity value to form a second signal intensity value set;

[0046] Setting a DC offset according to the first signal strength value set and the second signal strength value set, and adding the DC offset to the first signal strength value set to obtain a third signal strength value set;

[0047] determining whether the third signal strength value set meets a preset requirement; if so, outputting the third signal strength value set; otherwise, calculating a strength ratio set between the third signal strength value set and the second signal strength value set, and resetting a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement;

[0048] A system temperature is calculated based on the third set of signal strength values ​​and the second set of signal strength values.

[0049] The beneficial effects of the present invention are as follows: by continuously adjusting the DC bias, the time domain misalignment, gain deviation and transmission loss difference of the Raman scattered light signal are corrected, and the signal-to-noise ratio is systematically improved. This not only improves the measurement accuracy, but also can adapt to different environmental conditions, ensuring that the system can maintain stability and accuracy under various working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] in:

[0052] Figure 1 is a schematic diagram of a distributed optical fiber temperature measurement system according to one embodiment;

[0053] Figure 2 A flow chart of temperature correction of a distributed optical fiber temperature measurement system according to one embodiment;

[0054] Figure 3 A schematic diagram of the relationship between an uncalibrated Raman scattered light signal and the optical fiber length according to an embodiment;

[0055] Figure 4A schematic diagram of the relationship between uncalibrated temperature and optical fiber length according to an embodiment;

[0056] Figure 5 A schematic diagram of the relationship between the Raman scattered light signal and the optical fiber length after calibration according to an embodiment;

[0057] Figure 6 A schematic diagram of the relationship between temperature and optical fiber length after calibration according to an embodiment;

[0058] Figure 7 It is a structural block diagram of a device for temperature correction of a distributed optical fiber temperature measurement system in one embodiment;

[0059] Figure 8 FIG. 1 is a structural block diagram of a computer device in one embodiment. DETAILED DESCRIPTION

[0060] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0061] Figure 1 FIG. 1 is a schematic diagram of a distributed optical fiber temperature measurement system according to an embodiment of the present invention. Figure 1 ,

[0062] The distributed optical fiber temperature measurement system mainly consists of a laser 1, an avalanche photodiode 5 (APD), a wavelength division multiplexing 2 (WDM) and a data acquisition card 6. The structure is as follows: Figure 1 As shown in the figure, the laser emits a pulse signal which is transmitted to the sensing fiber 3 via the wavelength division multiplexing 2. The reflected Raman scattered light of two different wavelengths is converted into an electrical signal by the avalanche photodiode 5. Finally, the data is extracted and processed by the acquisition card 6 and uploaded to the terminal 7.

[0063] The Distributed Fiber Temperature Measurement System (DTS) combines optical time domain reflectometry (OTDR) and Raman scattering to achieve continuous temperature monitoring and precise positioning along the optical fiber. When the temperature changes at a certain point along the optical fiber, the intensity of the Raman scattered light signal at that point will fluctuate. Raman scattering is an inelastic scattering, which will produce frequency shift when transmitted in the optical fiber, generating Stokes light P s and anti-Stokes light P as .

[0064]

[0065] Among them, P0 is the power of incident light, K s and K as are the correlation coefficients of the scattering cross sections of Stokes light and sub-Stokes light, α0, α s and α as are the attenuation coefficients of the incident light, Stokes light, and anti-Stokes light during propagation along the optical fiber, v s and v as are the propagation speeds of Stokes light and anti-Stokes light, R s (T) and R as (T) are the temperature modulation functions of Stokes light and anti-Stokes light, respectively.

[0066] Under constant temperature conditions, in order to correct the measurement error caused by the attenuation coefficient, when the system is not disturbed by other factors, it is assumed that the attenuation loss of the two signal lights is uniform along the fiber and does not change with time. The attenuation coefficient is constant in both time and length directions. The Stokes light and anti-Stokes light at a certain position in the fiber can be simply expressed as:

[0067] P s =A1e -αL

[0068] P as =A2e -αL

[0069] Among them, A1 and A2 are the initial intensities of Stokes light and anti-Stokes light respectively, and α is the attenuation loss coefficient. At this time, the ratio of the two beams of light at L is a constant, ξ = A2 / A1, and the demodulated temperature signal is a straight line. However, in actual applications, the attenuation of the two scattered light beams is different, and the difference in the ratio of the two beams of light intensity gradually increases with the increase of the optical fiber length. At the same time, the intensity of the two scattered light signals is also affected by the APD DC bias and shows different gain sizes and changes with the ambient temperature. A slight fluctuation in the DC bias can lead to a large change in the final demodulation temperature. The DC bias can be reduced by certain technical means, such as using TEC to control the temperature of the APD to reduce the APD temperature drift [5], but the temperature control effect of a single TEC is not good (the multi-layer design greatly increases the cost). Combined with the influence of the attenuation and DC bias of the two optical signals on DTS demodulation, the formula P s 、P as can be re-expressed as:

[0070] P s =A1e -αL +D1

[0071] P as =A1e -αL +D2

[0072] Where D1 and D2 are the DC biases of the Stokes signal and the anti-Stokes signal, respectively. Under this condition, if the demodulated temperature signal is to remain constant with distance changes, the following conditions must be met:

[0073]

[0074] At this point, in order to continue to satisfy the two-way light ratio ξ = A2 / A1 at L as a constant and keep the demodulated temperature signal as a straight line, we can fix any value of D1 and D2 and find another D value to make ξ constant, that is, to minimize the standard deviation of ξ.

[0075] like Figure 2 As shown, in one embodiment, a method for temperature correction of a distributed optical fiber temperature measurement system is provided. This method can be applied to both a terminal and a server. This embodiment uses the server as an example for illustration. The method for temperature correction of a distributed optical fiber temperature measurement system specifically includes the following steps:

[0076] S1: collects the periodic pulse signal emitted by the laser;

[0077] S2: extracting a first signal intensity value of a first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal to form a first signal intensity value set, and extracting a minimum value of a second Raman scattered light signal at each preset sampling point in the periodic pulse signal as a second signal intensity value to form a second signal intensity value set;

[0078] S3: Setting a DC offset according to the first signal strength value set and the second signal strength value set, and adding the DC offset to the first signal strength value set to obtain a third signal strength value set;

[0079] S4: Determine whether the third signal strength value set meets a preset requirement; if so, output the third signal strength value set; otherwise, calculate a strength ratio set between the third signal strength value set and the second signal strength value set, and reset a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement;

[0080] S5: Calculate system temperature based on the third signal strength value set and the second signal strength value set.

[0081] As described in step S1 above, the periodic pulse signal emitted by the laser is collected, that is, converted into an electrical signal by the avalanche photodiode 5, and finally the data is collected by the acquisition card 6. The pulse signal is a periodic laser pulse, usually a high-intensity, short-wavelength laser, which propagates through the optical fiber and excites the molecules or materials along the line, triggering Raman scattering. Raman scattering is a phenomenon caused by the interaction between photons and molecules.

[0082] As described in step S2 above, the first signal intensity value of the first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal is extracted to form a first signal intensity value set. Furthermore, the minimum value of the second Raman scattered light signal in the periodic pulse signal at each preset sampling point is extracted as a second signal intensity value to form a second signal intensity value set. The captured pulse signal is analyzed to extract the first Raman scattered light signal, i.e., the first signal intensity value set. Simultaneously, the minimum intensity value of the second Raman scattered light signal appearing in the pulse signal is extracted as the second signal intensity value set. The preset sampling points are pre-set sampling points.

[0083] As described in step S3 above, a DC bias is set based on the first signal strength value set and the second signal strength value set, and the first signal strength value set is added to the DC bias to form a third signal strength value set. The DC bias is set based on an empirical value set based on the first signal strength value set and the second signal strength value set. That is, a correspondence table between the first signal strength value set and the second signal strength value set and the DC bias can be pre-established, and then the corresponding DC bias can be obtained from the correspondence table. It should be noted that the initially set DC bias generally does not directly meet the preset requirements and requires subsequent adjustment. Therefore, the DC bias here can also be set arbitrarily.

[0084] As described in step S4 above, it is determined whether the third signal strength value set meets the preset requirement. If so, the third signal strength value set is output. Otherwise, an intensity ratio set of the third signal strength value set and the second signal strength value set is calculated, and a DC bias is reset based on the intensity ratio set until the third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement. The preset requirement is an arbitrarily set requirement. For example, the number of iterations can be set, or the standard deviation of the calculated intensity ratio set no longer decreases. These can be considered to meet the preset requirement. The specific determination method will be described in detail later and will not be repeated here. When the requirement is not met, the DC bias needs to be re-iterated until the preset requirement is met. The design of this iterative process enables the system to dynamically adjust and eliminate errors that may be caused by changes in the signal background. By continuously adjusting the DC bias, the time domain misalignment, gain deviation, and transmission loss difference of the Raman scattered light signal are corrected, thereby achieving a systematic improvement in the signal-to-noise ratio. This not only improves the measurement accuracy, but also adapts to different environmental conditions, ensuring that the system can maintain stability and accuracy under various working conditions.

[0085] As described in step S5 above, the system temperature is calculated based on the third signal intensity value set and the second signal intensity value set. The current temperature is calculated using the obtained third signal intensity value set and the second signal intensity value set. The calculation can be implemented using a relationship model between Raman scattering signal intensity and temperature. Common models include those based on Boltzmann distribution or other statistical models. On this basis, the system will use the intensity ratio, usually the ratio of the third signal intensity to the second signal intensity, to derive the corresponding temperature value. In this way, the temperature value finally obtained can reflect the actual temperature state of the measured material or environment.

[0086] In one embodiment, step S4 of calculating a strength ratio set between the third signal strength value set and the second signal strength value set, and resetting a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement includes:

[0087] S401: Calculating the ratio of each of the preset sampling points to obtain a ratio set, and calculating the standard deviation of each of the ratio sets;

[0088] S402: Calculating a second DC bias according to the standard deviation;

[0089] S403: Determine whether the difference between the second DC bias and the DC bias is within a preset range;

[0090] S404: If it is not within the preset range, the second DC bias is recorded as the DC bias, and the second DC bias is recalculated until the difference between the second DC bias and the DC bias is within the preset range. It is then determined that the third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement.

[0091] As described in steps S401-S404 above, the ratio between the third set of signal strength values ​​and the second set of signal strength values ​​is calculated at each preset sampling point. This ratio is essentially calculated by dividing the third signal strength value by the second signal strength value. By calculating this ratio, the system can determine the relative strength variations at each sampling point, thereby better analyzing the relative relationships between signals. The system also calculates the standard deviation of all ratios, a statistical measure used to measure the dispersion of these ratios. After successfully calculating the standard deviation of the ratios, the system sets the second DC offset based on this standard deviation. The second DC offset is adjusted based on the standard deviation to effectively compensate for errors caused by signal fluctuations. The difference between the newly calculated second DC offset and the currently used DC offset is evaluated to check whether the difference is within a preset range. The preset range is based on a threshold defined during system design, typically to limit the magnitude of DC offset adjustment to ensure system stability. If the difference is within the preset range, it indicates that the adjustment is reasonable and effective. If it is not within the range, further adjustment is required, and the second DC offset calculation is performed again, and the difference is recalculated and monitored based on the previous standard deviation. During this cycle, the system needs to detect the difference and repeat the above calculation until the difference is finally within the preset range, thereby finding the appropriate offset value.

[0092] In one embodiment, step S4 of determining whether the third signal strength value set meets a preset requirement includes:

[0093] S411: Obtain a current third signal strength value set, and reset a set number of DC bias times;

[0094] S412: If the set number of times is greater than or equal to the preset number of times, it is determined that the preset requirement is met; otherwise, it is determined that the preset requirement is not met.

[0095] As described in steps S411-S412 above, the current third set of signal strength values ​​is obtained and the number of times the DC bias needs to be reset is determined. The third set of signal strength values ​​is the signal strength values ​​previously calculated by the system after adding the DC bias. The set number of times the DC bias needs to be reset refers to the number of times the system updates the DC bias to optimize signal quality during the dynamic adjustment process. This counter increments after each adjustment to monitor the adjustment process and ensure that the system does not endlessly attempt to adjust the DC bias, thereby affecting measurement stability and efficiency. By recording the set number of times, the system can subsequently determine whether an acceptable number of adjustments has been reached and whether further adjustments need to be stopped. The set number of DC bias adjustments is compared with a preset maximum number of times. If the current set number of times is greater than or equal to the preset number of times, the current third set of signal strength values ​​is determined to meet the preset requirements. Conversely, if the set number of times is less than the preset number of times, the system determines that the preset requirements are not met and further iterations are required.

[0096] Reference Figure 3-Figure 6 , Figure 3 This is the schematic diagram of the original signal before calibration. Figure 4 This is a schematic diagram of the temperature demodulation signal before calibration. Figure 5 This is the signal diagram after 500 iterations. Figure 6 The figure shows the temperature demodulation signal after 500 iterations. Compared with the value before optimization, the overall intensity of the Stokes light signal has decreased by a certain value. At this time, the demodulated temperature remains basically constant. Figure 4 and Figure 6 It can be seen that the temperature difference in the first half of the optical fiber at 1 km, 5 km and 10 km lengths is very small after calibration, and the temperature at the tail end 10 km is only 3.8°C lower than the temperature at 1 km.

[0097] In one embodiment, the step S4 of resetting the DC bias based on the intensity ratio set includes:

[0098] S421: Calculate the standard deviation according to the formula f=std(ξ), where ξ is the intensity ratio, f is the standard deviation, and std(.) is the standard deviation calculation formula;

[0099] S422: Calculate the reset DC offset according to the formula offset1=offset-η×grad(f), where offset is the last set DC offset, offset1 is the current set DC offset, η is the number of times the DC offset is reset, and grad(.) is a vector-valued function.

[0100] As described in steps S421-S422 above, the DC bias is reset to satisfy iterative calculation, thereby finding the optimal DC bias. Specifically, the standard deviation is first calculated, and then the DC bias is reset based on the standard deviation. It should be noted that each time the DC bias is reset, the number of times needs to be counted, and then the coefficient of the vector-valued function is set, so that subsequent adjustments will gradually decrease, avoiding subsequent excessive adjustments that fail to achieve a better DC bias.

[0101] In one embodiment, the step S2 of extracting the minimum value of the second Raman scattered light signal in the periodic pulse signal as the second signal intensity value set includes:

[0102] S201: Extracting the minimum value of the preset second Raman scattered light signal corresponding to each preset sampling point in the periodic pulse signal;

[0103] S202: Determine whether the minimum value is 0;

[0104] S203: If the minimum value exists and is 0, then the minimum value of 0 is added to the set minimum value to form a new second signal strength value set.

[0105] As described in steps S201-S203 above, the minimum value of the second Raman scattered light signal corresponding to each preset sampling point is extracted from the periodic pulse signal. After acquiring the signal, each sampling point is analyzed to find the minimum value of the signal intensity within a specific time window. This minimum value usually represents the lowest point of the background noise or signal level, rather than the actual Raman signal intensity. These extracted minimum values ​​will constitute a set, namely the second signal intensity value set. Check whether there is a case where the extracted minimum value is 0. If there is a minimum value of zero, then meaningless situations will occur when the logarithmic function is subsequently calculated. Therefore, in order to avoid the situation of being 0, the value of the extracted minimum value of 0 can be added to a set minimum value to form a non-zero signal intensity value. The set minimum value is set according to the characteristics of the system and the experimental conditions. Usually, a constant that is small enough but still reflects the background noise or measurement capability is selected.

[0106] In one embodiment, one of the first Raman scattered light signal and the second Raman scattered light signal is a Stokes Raman scattered light signal, and the other is an anti-Stokes Raman scattered light signal.

[0107] In this embodiment, that is, in one embodiment, the first Raman scattered light signal is a Stokes Raman scattered light signal, and the second Raman scattered light signal is an anti-Stokes Raman scattered light signal. In another embodiment, the first Raman scattered light signal is an anti-Stokes Raman scattered light signal, and the second Raman scattered light signal is a Stokes Raman scattered light signal.

[0108] In one embodiment, the step S5 of calculating the system temperature based on the third signal strength value set and the second signal strength value set includes:

[0109] Calculate the intensity ratio of each point in the third signal strength value set and the second signal strength value set, and calculate the average of the intensity ratios as the target intensity ratio:

[0110] According to the formula Calculate the system temperature, where R is the target intensity ratio, T is the system temperature, and k B is the Boltzmann constant, and E is the difference in molecular excitation energy levels.

[0111] S501: measuring the temperature value of each of the preset sampling points;

[0112] S502: Selecting, from the preset sampling points, a first sampling point having a temperature value of a preset first temperature value and a second sampling point having a temperature value of a preset second temperature value according to the temperature value;

[0113] S503: Calculate a first target intensity ratio of the first sampling point and a second target intensity ratio of the second sampling point;

[0114] S504: According to the formula Calculate the system temperature, where R1 is the first target intensity ratio, R2 is the second target intensity ratio, and T m is the system temperature, k B is the Boltzmann constant, E is the difference in molecular excitation energy levels, h is the Planck constant, and Δv is the Raman frequency shift.

[0115] As described in the above steps S501-S504, the calculation of the system temperature is realized, that is, the intensity ratio of each point of the third signal strength value set and the second signal strength value set is calculated, and the average of the intensity ratios is calculated as the target intensity ratio, and then the system temperature is calculated according to the formula, thereby realizing the calculation of the system temperature. It should be noted that the preset second temperature value is preferably set to the ambient temperature.

[0116] Reference Figure 7 The present invention also provides a device for temperature correction of a distributed optical fiber temperature measurement system, the device comprising:

[0117] The acquisition module 902 is used to acquire the periodic pulse signal emitted by the laser;

[0118] an extraction module 904 configured to extract a first signal strength value of a first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal to form a first signal strength value set, and to extract a minimum value of a second Raman scattered light signal at each preset sampling point in the periodic pulse signal as a second signal strength value to form a second signal strength value set;

[0119] a first calculation module 906 configured to set a DC offset according to the first signal strength value set and the second signal strength value set, and add the DC offset to the first signal strength value set to obtain a third signal strength value set;

[0120] a determination module 908, configured to determine whether the third signal strength value set meets a preset requirement; if so, output the third signal strength value set; otherwise, calculate a strength ratio set between the third signal strength value set and the second signal strength value set, and reset a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement;

[0121] The second calculation module 910 is configured to calculate the system temperature based on the third signal strength value set and the second signal strength value set.

[0122] In one embodiment, the determination module 908 includes:

[0123] a ratio set calculation submodule, configured to calculate the ratio of each of the preset sampling points to obtain a ratio set, and calculate the standard deviation of each of the ratio sets;

[0124] a second DC bias calculation submodule, configured to calculate a second DC bias according to the standard deviation;

[0125] a second DC bias determination submodule, configured to determine whether a difference between the second DC bias and the DC bias is within a preset range;

[0126] The second DC bias marking submodule is used to record the second DC bias as a DC bias if it is not within a preset range, and recalculate the second DC bias until the difference between the second DC bias and the DC bias is within a preset range, and then determine that the third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement.

[0127] In one embodiment, the determination module 908 includes:

[0128] A third signal strength value set acquisition submodule, configured to acquire a current third signal strength value set and reset a set number of DC biases;

[0129] The set times determination submodule is used to determine that the preset requirement is met if the set times are greater than or equal to the preset times, and otherwise, determine that the preset requirement is not met.

[0130] In one embodiment, the determination module 908 includes:

[0131] The standard deviation calculation submodule is used to calculate the standard deviation according to the formula f=std(ξ), where ξ is the intensity ratio set, f is the standard deviation, and std(.) is the standard deviation calculation formula;

[0132] The DC bias reset submodule is used to calculate the reset DC bias according to the formula offset1 = offset-η×grad(f), where offset is the last set DC bias, offset1 is the current set DC bias, η is the number of times the DC bias has been reset, and grad(.) is a vector-valued function.

[0133] In one embodiment, the extraction module 904 includes:

[0134] a minimum value extraction submodule, configured to extract the minimum value of the preset second Raman scattered light signal corresponding to each preset sampling point in the periodic pulse signal;

[0135] A minimum value judgment submodule, used to judge whether the minimum value is 0;

[0136] The second signal strength value set forming submodule is configured to add a set minimum value to the minimum value of 0 to form a new second signal strength value set if the minimum value is 0.

[0137] In one embodiment, one of the first Raman scattered light signal and the second Raman scattered light signal is a Stokes Raman scattered light signal, and the other is an anti-Stokes Raman scattered light signal.

[0138] In one embodiment, the second calculation module 910 includes:

[0139] A temperature value measurement submodule, used to measure the temperature value of each of the preset sampling points;

[0140] A sampling point selection submodule, configured to select, from the preset sampling points according to the temperature value, a first sampling point having a temperature value of a preset first temperature value and a second sampling point having a temperature value of a preset second temperature value;

[0141] an intensity ratio calculation submodule, configured to calculate a first target intensity ratio of the first sampling point and a second target intensity ratio of the second sampling point;

[0142] System temperature calculation submodule, according to the formula Calculate the system temperature, where R1 is the first target intensity ratio, R2 is the second target intensity ratio, and T m is the system temperature, k B is the Boltzmann constant, E is the difference in molecular excitation energy levels, h is the Planck constant, and Δv is the Raman frequency shift.

[0143] Figure 8 FIG1 shows an internal structure diagram of a computer device in an embodiment. The computer device can be a terminal or a server. Figure 8 As shown, the computer device includes a processor, a memory, and a network interface connected via a system bus. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program. When the computer program is executed by the processor, the processor can implement the method for temperature correction of the distributed optical fiber temperature measurement system. The internal memory may also store a computer program. When the computer program is executed by the processor, the processor can implement the method for temperature correction of the distributed optical fiber temperature measurement system. Those skilled in the art will understand that Figure 8 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0144] In one embodiment, a computer device is provided, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the following steps:

[0145] Collecting the periodic pulse signal emitted by the laser;

[0146] extracting a first signal intensity value of a first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal to form a first signal intensity value set, and extracting a minimum value of a second Raman scattered light signal at each preset sampling point in the periodic pulse signal as a second signal intensity value to form a second signal intensity value set;

[0147] Setting a DC offset according to the first signal strength value set and the second signal strength value set, and adding the DC offset to the first signal strength value set to obtain a third signal strength value set;

[0148] determining whether the third signal strength value set meets a preset requirement; if so, outputting the third signal strength value set; otherwise, calculating a strength ratio set between the third signal strength value set and the second signal strength value set, and resetting a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement;

[0149] A system temperature is calculated based on the third set of signal strength values ​​and the second set of signal strength values.

[0150] By continuously adjusting the DC bias and correcting the time domain misalignment, gain deviation, and transmission loss differences of the Raman scattered light signal, a systematic improvement in the signal-to-noise ratio can be achieved. This not only improves measurement accuracy but also adapts to different environmental conditions, ensuring that the system can maintain stability and accuracy under various operating conditions.

[0151] In one embodiment, a computer-readable storage medium is provided, storing a computer program. When the computer program is executed by a processor, the processor performs the following steps:

[0152] Collecting the periodic pulse signal emitted by the laser;

[0153] extracting a first signal intensity value of a first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal to form a first signal intensity value set, and extracting a minimum value of a second Raman scattered light signal at each preset sampling point in the periodic pulse signal as a second signal intensity value to form a second signal intensity value set;

[0154] Setting a DC offset according to the first signal strength value set and the second signal strength value set, and adding the DC offset to the first signal strength value set to obtain a third signal strength value set;

[0155] determining whether the third signal strength value set meets a preset requirement; if so, outputting the third signal strength value set; otherwise, calculating a strength ratio set between the third signal strength value set and the second signal strength value set, and resetting a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement;

[0156] A system temperature is calculated based on the third set of signal strength values ​​and the second set of signal strength values.

[0157] By continuously adjusting the DC bias and correcting the time domain misalignment, gain deviation, and transmission loss differences of the Raman scattered light signal, a systematic improvement in the signal-to-noise ratio can be achieved. This not only improves measurement accuracy but also adapts to different environmental conditions, ensuring that the system can maintain stability and accuracy under various operating conditions.

[0158] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchl ink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0159] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0160] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for temperature correction of a distributed optical fiber temperature measurement system, characterized in that: The method comprises: Collecting the periodic pulse signal emitted by the laser; extracting a first signal intensity value of a first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal to form a first signal intensity value set, and extracting a minimum value of a second Raman scattered light signal at each preset sampling point in the periodic pulse signal as a second signal intensity value to form a second signal intensity value set; Setting a DC offset according to the first signal strength value set and the second signal strength value set, and adding the DC offset to the first signal strength value set to obtain a third signal strength value set; determining whether the third signal strength value set meets a preset requirement; if so, outputting the third signal strength value set; otherwise, calculating a strength ratio set between the third signal strength value set and the second signal strength value set, and resetting a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement; A system temperature is calculated based on the third set of signal strength values ​​and the second set of signal strength values.

2. The method for temperature correction of a distributed optical fiber temperature measurement system according to claim 1, characterized in that: The step of calculating a strength ratio set between the third signal strength value set and the second signal strength value set, and resetting a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement includes: Calculating the ratio of each of the preset sampling points to obtain a ratio set, and calculating the standard deviation of each of the ratio sets; Calculating a second DC bias according to the standard deviation; Determining whether a difference between the second DC bias and the DC bias is within a preset range; If it is not within the preset range, the second DC bias is recorded as the DC bias, and the second DC bias is recalculated until the difference between the second DC bias and the DC bias is within the preset range. It is then determined that the third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirements.

3. The method for temperature correction of a distributed optical fiber temperature measurement system according to claim 1, characterized in that: The step of determining whether the third signal strength value set meets a preset requirement includes: Obtaining a current third signal strength value set and resetting a set number of DC bias times; If the set number of times is greater than or equal to the preset number of times, it is determined that the preset requirement is met; otherwise, it is determined that the preset requirement is not met.

4. The method for temperature correction of a distributed optical fiber temperature measurement system according to claim 1, characterized in that: The step of resetting the DC bias based on the intensity ratio set comprises: The standard deviation is calculated according to the formula f = std(ξ), where ξ is the set of intensity ratios, f is the standard deviation, and std(.) is the standard deviation calculation formula; The reset DC offset is calculated according to the formula offset1=offset-η×grad(f), where offset is the last set DC offset, offset1 is the current set DC offset, η is the number of times the DC offset is reset, and grad(.) is a vector-valued function.

5. The method for temperature correction of a distributed optical fiber temperature measurement system according to claim 1, characterized in that: The step of extracting the minimum value of the second Raman scattered light signal in the periodic pulse signal at each preset sampling point as the second signal intensity value to form a second signal intensity value set includes: Extracting the minimum value of the preset second Raman scattered light signal corresponding to each preset sampling point in the periodic pulse signal; Determine whether the minimum value is 0; If the minimum value exists and is 0, then the minimum value of 0 is added to the set minimum value to form a new second signal strength value set.

6. The method for temperature correction of a distributed optical fiber temperature measurement system according to claim 1, characterized in that: One of the first Raman scattered light signal and the second Raman scattered light signal is a Stokes Raman scattered light signal, and the other is an anti-Stokes Raman scattered light signal.

7. The method for temperature correction of a distributed optical fiber temperature measurement system according to claim 1, characterized in that: The step of calculating the system temperature based on the third signal strength value set and the second signal strength value set comprises: Measuring the temperature value of each of the preset sampling points; Selecting, from the preset sampling points, a first sampling point having a temperature value of a preset first temperature value and a second sampling point having a temperature value of a preset second temperature value according to the temperature value; calculating a first target intensity ratio of the first sampling point and a second target intensity ratio of the second sampling point; According to the formula Calculate the system temperature, where R1 is the first target intensity ratio, R2 is the second target intensity ratio, and T m is the system temperature, k B is the Boltzmann constant, E is the difference in molecular excitation energy levels, h is the Planck constant, and Δv is the Raman frequency shift.

8. A device for temperature correction of a distributed optical fiber temperature measurement system, characterized in that: The device comprises: An acquisition module is used to acquire the periodic pulse signal emitted by the laser; an extraction module, configured to extract a first signal intensity value of a first Raman scattered light signal when a Raman scattered light signal appears at each preset sampling point in the periodic pulse signal to form a first signal intensity value set, and to extract a minimum value of a second Raman scattered light signal at each preset sampling point in the periodic pulse signal as a second signal intensity value to form a second signal intensity value set; a first calculation module, configured to set a DC offset according to the first signal strength value set and the second signal strength value set, and add the DC offset to the first signal strength value set to obtain a third signal strength value set; a determination module, configured to determine whether the third signal strength value set meets a preset requirement, and if so, output the third signal strength value set; otherwise, calculate a strength ratio set between the third signal strength value set and the second signal strength value set, and reset a DC bias based on the strength ratio set until a third signal strength value set obtained by adding the reset DC bias to the first signal strength value set meets the preset requirement; A second calculation module is configured to calculate a system temperature based on the third signal strength value set and the second signal strength value set.

9. A computer-readable storage medium, characterized in that A computer program is stored, and when the computer program is executed by a processor, the processor is caused to perform the steps of the method for temperature correction of a distributed optical fiber temperature measurement system according to any one of claims 1 to 7.

10. A computer device, characterized in that: The device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the method for temperature correction of a distributed optical fiber temperature measurement system according to any one of claims 1 to 7.

Images