Infrared interferogram reconstruction method

Abstract

The invention discloses an infrared interferogram reconstruction method, wherein a laser interference signal and an infrared interference signal which are generated through light splitting by a Michelson interferometer exist. The method comprises the steps of simultaneously performing oversampling on the laser interference signal and the infrared interference signal by means of the same sampling rate; according to the requirement in an actual condition, setting the same interpolation factor for performing interpolation operation on two signals after oversampling; acquiring laser zero-crossing information from the laser interference signal after interpolation, and performing resampling on the infrared interference signal after interpolation according to the laser zero-crossing information, and finally obtaining an infrared interferogram with equal light path difference after reconstruction. According to the method of the invention, sampling and interpolation operation on the two signal are performed simultaneously, thereby ensuring time consistency and simplifying extraction to the zero-crossing information of the laser interference signal. The method according to the invention reduces data processing complexity.

Description

technical field [0001] The invention belongs to the field of infrared signal acquisition and processing, and in particular relates to an infrared interferogram reconstruction method. Background technique [0002] In the FTIR spectrometer, the beam splitter in the Michelson interferometer divides the light emitted by the light source into two beams, one of which is reflected by the beam splitter to the fixed mirror of the interferometer, and the other beam is transmitted to the dynamic interferometer by the beam splitter. mirror. Then they are reflected back to the beam splitter along their respective original optical paths and split by the beam splitter, finally generating interference signals. Since the sampling position of the interference signal is very sensitive to the movement speed of the moving mirror in the interferometer, a small change in the movement speed will cause serious deviations in the interferogram, thereby affecting the accuracy of the restored spectrum....

AI Technical Summary

Problems solved by technology

Due to the limitations of the Nyquist sampling theorem, the laser trigger method has low sampling frequency and high requirements for instruments and hardware

The sampling method proposed by "Brault" uses an asynchronous counter to record the laser and infrared signals. The asynchronous sampling increases the delay in the two signals, which leads to the need to correct the delay in subsequent processing, and in this method The use of hardware increases the complexity of the instrument structure and reduces the adaptability to the surrounding environment

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