Doppler asymmetric spatial heterodyne spectroscopy (DASH) with its high stability and feasibility of synchronized calibration highly suit for the wind field observation. By applying the synchronized calibration, the thermal phase distortion of observation emission line could be corrected greatly based on the similarity of thermal effects between observation emission line and calibration line. While, the correction residual which could be called relative thermal phase distortion still influence the wind measurement precision significantly. In this manuscript, we discuss and analyze the relative phase distortion of DASH theoretically and practically based on the DASH retrieval theory and the experiment. Firstly, based on the retrieve theory of DASH, we analyze the relationship between the relative phase distortion and the precision of the wind measurement. It is found that 1.528mrad phase error equal to 1m/s wind measurement error for the DASH developed by our research group. Secondly, based on the DASH developed by our research group, laser of 632.8nm and Ne lamp are employed as input source to test relationship between relative phase distortion and internal temperature of interferometer. According to the experiment result, the relative phase distortion change weekly with the variation of temperature between 25.14°C and 25.67°C. While, the relative phase stability decrease rapidly in other else temperature range. Lastly, according to the experiment result, we analyze the major source of relative phase distortion which could make contribution to reducing the relative phase error, which could increase the wind measurement precision, in the future research.
Doppler asymmetric spatial heterodyne spectroscopy (DASH) is a new technology for measuring upper atmospheric winds by observing the Doppler shift of atmospheric emission lines from a satellite using a limb viewing geometry. The real-fringe DASH interferometer is a modification of conventional DASH interferometer; it keeps the advantages of the conventional one. Moreover, this interferometer will not need exit optics to image the superposed fringes onto the detector; it will be more compact and lightweight, making it suitable for space-based platforms. We describe the concept of the new interferometer and present the exact expression of spatial frequency and phase of the interferogram. We also describe design and simulation of a real-fringe DASH interferometer for observation of the O [<sup>1</sup>D] 630nm emission. The simulation results agree with the theory.
Spatial heterodyne spectrometers have been used in multiple scientific studies since their invention and early
development. Broadband spatial heterodyne spectrometers also have the advantages of large etendue, high spectral
resolving powers, and high data collection rates as traditional spatial heterodyne spectrometer. Basic theory, design and
performance parameters, breadboard experiment for a broadband, high-resolution spatial heterodyne spectrometer are
reported. The experimental spatial heterodyne spectrometer achieves a design resolution 0.39cm-1. Firstly, it is
demonstrated that broadband spatial heterodyne spectrometer have the advantages of wide spectral coverage and high
spectral resolving power simultaneously; secondly, the effects of optical defects on the system are discussed; thirdly,
Two dimension interference data procession also is mentioned.