Design and Realization of High-Speed Acquisition System for Two Dimensional Fourier Transform Solar Spectrometer

Simultaneous or quasi-simultaneous multi-spectral solar imaging can be used to obtain the solar atmosphere's three-dimensional magnetic field and thermodynamic parameters, which is a key development direction of the focal plane terminal equipment for solar observations in the future. The Fourier transform spectrometer (FTS) has a wide bandwidth, high sensitivity and a high spectral resolution, but it is restricted by high frame rate and large area array detector. It has not been used for routine solar spectrum imaging yet. However, with the rapid development of CMOS image sensor technology, in the visible and near-infrared bands, the size and frame rate of the detector array have been qualitatively improved compared to traditional CCD detectors, making it possible to develop an area array, Fourier, solar spectrometer. Here in this paper, we introduce an area array, and high frame rate CMOS image sensor and design a set of high-speed data acquisition software and hardware systems for the scientific needs of area array Fourier transform solar spectrometers. It realizes the 10 kHz high-speed triggering, fast acquisition of 10 000 frames per second, 0.5 GB . s(-1) large data volume continuous, real-time storage and other functions. Combining with the above system and the existing point source FTS at the Huairou Solar Observing Station and targeting the visible light chromosphere line (H alpha 656.3 nm) and its nearby photosphere line, we set up a visible light experimental system and carried out surface source solar spectrum detection. We used the laboratory tungsten lamp and the sun as the light source, performed equal optical path difference interval sampling, and successfully obtained the area array interferogram. We obtained the narrow-band continuum spectrum and the solar chromosphere and photosphere line near 656.3 nm. Using the cross-calibration method, we compared our solar spectrum at the same resolution with the standard spectrum obtained by the National Solar Astronomical Observatory's NSO Fourier Spectrometer, and the results are the same, verifying the performance of the data acquisition system for the FTS of the plane array and the feasibility of area array Fourier Transform Solar Spectrometer in solar observation. This research lays a technical foundation for the wide-band solar FTS of the plane array in the visible region and at the same time, accumulates valuable experience for the subsequent extension of "The Infrared System for the Accurate Measurement of Solar Magnetic Field" (AIMS) from the line source to the plane source.