Research Of Solar Hyperspectra Resolution Imaging Methods Of Observation Based On Sodium Atom Frequency Discrimination

Atomic frequency discriminator (AFD) as an optical frequency discriminator based on atomic energy levels transition, is characterized by ultra-narrow bandwidth and stable central wavelength, thus it has a unique advantage in the field of photoelectric detection which needs optical filtering and frequency discriminating.High spectral resolution imaging technique based on atomic frequency discriminator can achieve the observation of the top of photosphere and the bottom of chromosphere of solar atmosphere. It can also offer high spectral resolution raw data for the research and application of solar physics and has important significance to solar activity monitoring and space weather forecasting.This dissertation focuses on the research of high spectral resolution imaging observation methods of the Fraunhofer sodium D2 line so that the imaging of the top of photosphere and the bottom of chromosphere in solar atmosphere can be achieved. The main contributions of this dissertation are listed as follows:First of all, taking advantage of the characteristic that the central working wavelength of center peak transmission atomic frequency discriminator is exactly corresponding to the solar Fraunhofer sodium D2 line, long-term and stable observation on solar was carried out, and the detailed information on the solar atmosphere at the top of photosphere and the bottom of chromosphere was obtained;Secondly, the core component -center peak transmission atomic frequency discriminator for high spectral resolution imaging observation of solar was successfully developed. The transmission spectrum was measured by using a narrowband laser, and the result was compared to the theoretical computation result;Thirdly, the solar imaging observation system based on the center peak transmission atomic frequency discriminator was constructed, including the tracking unit, atomic frequency discriminating unit and the image acquisition unit;Finally, the full-disk solar image observation with high spectral resolution was carried out by using the constructed system, and the preliminary observation results of the solar atmosphere at the top of photosphere and the bottom of chromosphere was obtained.