Instrument forward model of the modified Sagnac interferometer for atmospheric wind measurement

The instrument forward model of the modified super-wide-Sagnac imaging interferometer based on liquid crystals on Silicon (MSASII-LCoS) is developed as an integrated code package with Matlab language to simulate the images of satellite observations. There are five sub-models in the forward model including radiation model of O(1S), orbit attitude, filter, interferometer and array detector. The principle of each sub-model is described separately and then the overall forward model equation is derived. The four simulation images are obtained. Based on the integrated signal level for the daytime observations, the apparent measurement error of wind is less than 3 m/s and the signal noise ratio (SNR) is greater than 194 with a binning of 2 × 25 pixels at the tangent height range of 70–190 km.

Research Highlights
► The modified Sagnac imaging interferometer based on LCoS is described.
► We derive the overall forward model equation which considers five sub-models.
► An integrated code package of the instrument forward model is developed.
► We obtain four simulation images based on the integrated code package.
► We calculate apparent measurement error of wind and SNR.