Terahertz time-domain spectroscopy rapid scanning data processing method

Abstract

The invention relates to a terahertz time-domain spectroscopy rapid scanning data processing method, which relates to the field of signal processing, and comprises the following steps: inputting first signal data, detecting a signal peak value position, and recording the signal peak value position as S0; inputting second signal data, detecting a signal peak value position, and recording the signal peak value position as S1; s0 and S1 are compared, if S0 is smaller than S1, data of S1-S0 are cut off from the starting part of the second signal, and the data of S1-S0 are added to the tail part of the second signal; if S0 is larger than S1, data of S0-S1 are cut off from the tail of the second signal, and the data of S0-S1 are added to the starting part; carrying out arithmetic averaging on the processed data; carrying out weighting processing on the signal after arithmetic averaging; the method has the advantages that the signal-to-noise ratio of the terahertz time-domain spectrum rapid scanning data is increased, and a foundation is laid for subsequent application of the signals.

Description

Technical Field

[0001] This invention relates to the field of signal processing technology, and in particular to a method for rapid scanning data processing of terahertz time-domain spectrometers. Background Technology

[0002] Typically, data processing methods for rapid scanning delay lines in terahertz time-domain spectroscopy mainly involve arithmetic averaging within a set scanning range to improve the signal-to-noise ratio (SNR). However, due to variations in the repeatability accuracy of delay lines and atmospheric flow within the terahertz wave transmission space causing loss and optical path fluctuations, signal repetition stability fluctuates. Therefore, simply performing blind averaging within the set scanning range can actually reduce the SNR. The key issue is how to effectively process data to improve the SNR and lay a solid foundation for subsequent data applications. Currently, the common practice is only to perform simple arithmetic averaging in the time or frequency domains, without further advanced terahertz time-domain spectral rapid scanning data processing methods.

[0003] Therefore, to address the above shortcomings, a rapid scanning data processing method for terahertz time-domain spectroscopy is needed. Summary of the Invention

[0004] (a) Technical problems to be solved The technical problem to be solved by this invention is to address the current lack of more effective methods for rapid scanning data processing of terahertz time-domain spectroscopy.

[0005] (II) Technical Solution To address the aforementioned technical problems, this invention provides a method for rapid scanning data processing of terahertz time-domain spectroscopic data, comprising the following steps: I. Input the first signal data, detect the peak position of the signal, and record it as S0; II. Input the second signal data, detect the peak position of the signal, and record it as S1; III. Compare S0 and S1. If S0 = S1, do not process the second signal data. If S0 < S1, truncate the second signal from the beginning by removing the data from S1 to S0 and add the data from S1 to S0 to the end. If S0 > S1, truncate the second signal from the end by removing the data from S0 to S1 and add the data from S0 to S1 to the beginning. Input each scan data in sequence and perform an arithmetic average of the processed data. IV. If the signal quality varies greatly after arithmetic averaging, the weighting factor for the poor signal is set to 0; if some signal intervals are similar and others are very different, the weighting factor for each interval is set to 1 / N, where N is the number of signals. V. Input each data in sequence and perform the above processing to finally obtain a processed signal.

[0006] As a further explanation of the present invention, preferably, the magnitude of the quality difference is determined by the difference in the time domain width, peak-to-peak value, and noise between the signals.

[0007] As a further explanation of the present invention, preferably, before data processing, it is necessary to reset the delay line to zero at each scan to determine the zero position of the reference value.

[0008] (III) Beneficial Effects The above-described technical solution of the present invention has the following advantages: This invention designs a method for statistical processing based on the quality of the signal, which improves the signal-to-noise ratio of rapid terahertz time-domain spectral scanning data and enhances the data quality for subsequent applications. Attached Figure Description

[0009] Figure 1 This is a first type of schematic diagram illustrating the relationship between signal amplitude and pulse width in this invention; Figure 2 This is a second type of schematic diagram illustrating the relationship between signal amplitude and pulse width in this invention. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] A method for rapid scanning data processing of terahertz time-domain spectroscopy includes the following steps: I. The delay line is required to be reset to zero at each scan to determine the reference zero position. Considering that this operation is time-consuming, it can be performed once after a complete averaging scan. This is to avoid the problem that the grating ruler of the delay line cannot eliminate the fluctuation of the signal in absolute position.

[0012] II. Input the first signal data, detect the signal peak position, i.e. the data sequence number, and use it as the reference and record it as S0; input the second signal data, detect the signal peak position, and record it as S1.

[0013] III. Compare S0 and S1. If S0 = S1, the repeatability is excellent, and the second signal is left unprocessed. If S0 < S1, truncate the beginning of the second signal by removing the data from S1 to S0 and add the data from S1 to S0 to the end. The data amplitude can be copied from the last S1 to S0 data of the original second signal. If S0 > S1, truncate the end of the second signal by removing the data from S1 to S0 and add the data from S1 to S0 to the beginning. The data amplitude can be copied from the beginning S0 to S1 data of the original second signal. Continue this process, inputting each scan data sequentially. Finally, perform an arithmetic average of the processed data to effectively improve the signal-to-noise ratio.

[0014] IV. Based on step III, after unifying the peak positions of each signal, compare the lengths of the delay line positions between peak-to-peak values ​​to see if they are consistent. Inconsistency will also worsen the arithmetic averaging effect. The processing principle is: compared to the original signal, the processed signal pulse should have a narrower time-domain pulse width, a larger peak-to-peak value, and lower noise. A narrower time-domain pulse results in a wider signal spectrum after Fourier transform to the frequency domain. A larger peak-to-peak value and lower noise improve the signal-to-noise ratio.

[0015] When it appears Figure 1 In the situation shown, the blue signal, which has better signal quality, will have a wider pulse width and a smaller peak value, resulting in a deterioration in signal quality. The simplest solution is to set the weighting factor for the yellow signal to 0, i.e., delete the yellow signal as shown in the diagram, and set the weighting factor for the blue signal to 1.

[0016] When it appears Figure 2 In the scenario shown, the arithmetic average of the signals (with a larger pulse width than the blue signal and a lower amplitude than the yellow signal) cannot retain the advantages of both original signals, so weighting is necessary. Normally, averaging two very similar signals results in a weighting factor of 0.5, while averaging three very similar signals results in a weighting factor of 1 / 3.

[0017] In the portions t1~T1 and T2~t2, the weighting coefficient for the yellow signal is 0, and the weighting coefficient for the blue signal is 1. In the portion T1~T2, the weighting coefficients for both the yellow and blue signals are 0.5.

[0018] V. Similarly, input each data point in sequence and perform the above processing to finally obtain a processed signal.

[0019] As a further explanation of the present invention, preferably, the magnitude of the quality difference is determined by the difference in the time domain width, peak-to-peak value, and noise between the signals.

[0020] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for rapid scanning data processing of terahertz time-domain spectroscopic data, characterized in that: Includes the following steps: I. Input the first signal data, detect the peak position of the signal, and record it as S0; II. Input the second signal data, detect the peak position of the signal, and record it as S1; III. Compare S0 and S1. If S0 = S1, do not process the second signal data. If S0 < S1, truncate the second signal from the beginning by removing the data from S1 to S0 and add the data from S1 to S0 to the end. If S0 > S1, truncate the second signal from the end by removing the data from S0 to S1 and add the data from S0 to S1 to the beginning. Input each scan data in sequence and perform an arithmetic average of the processed data. IV. If the signal quality varies greatly after arithmetic averaging, the weighting factor for the poor signal is set to 0; if some signal intervals are similar and others are very different, the weighting factor for each interval is set to 1 / N, where N is the number of signals. V. Input each data in sequence and perform the above processing to finally obtain a processed signal.

2. The terahertz time-domain spectral rapid scanning data processing method according to claim 1, characterized in that: The magnitude of the quality difference is determined by the differences in the time domain width, peak-to-peak value, and noise between the signals.

3. The method for rapid scanning data processing of terahertz time-domain spectroscopic data according to claim 1, characterized in that: Before data processing, it is necessary to reset the delay line to zero on each scan to determine the zero position of the reference value.

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