Recently, the upper atmosphere wind field has attracted increasingly attention of the researchers. The history, status and the future of temporal phase-stepping measurement methods used for upper atmosphere measurement(UAM) are introduced. The traditional four intensities method which is field-widened, achromatic, temperature compensation wind imaging is presented comparatively. This paper mainly expounds the principle and method for three arbitrary phase-stepping measurement methods. Analysis and calculation of the wind temperature and velocity are described emphatically. The more terse and precise measurement method has scientific significance and practical value for physical geography, atmospheric science, environment protection, national defense and national economic construction.
The theoretical operation and experimental demonstration of a Fourier-transform Stokes imaging spectropolarimeter are presented. It is composed of two birefringent crystal retarders with equal thickness (the frontal retarder is rotatable) and a Fourier-transform spectrometer based on Savart polariscope. The polarized light enters the spectrometer to create three sets of interferograms, where the spectral Stokes parameters can be calculated and acquired. Compared with previous instruments, the significant advantages of the described sensor are no spatial aliasing in the polarized spectra and it can be used in wider spectral coverage with low cost, ultra-compact size and a simpler common-path configuration.