Research On CE-1 Imaging Interferometer (IIM) Spectral Information Extraction Technology

Research on CE-1 Imaging Interferometer (IIM) spectral information extraction technology is implemented. The instrument is developed by Xi'an Institute of Optics and Precision Mechanics to analyze mineral contents and distribution of different types and draw rock distribution map on lunar surface. Data optimization technology is discussed firstly and the Photometric correction and reflection inversion is researched then. At last, the mineral information distraction technology on lunar surface is analyzed.Data optimization technology is discussed. Aiming at the striping noise existing in IIM data, the Fourier transform algorithm and the linear interpolation algorithm are experimentally utilized for strip noise removal in IIM images. A modified linear interpolation algorithm is proposed, which combines low rank algorithm with high rank algorithm. After noise location, high rank interpolation or linear interpolation is used by judging whether the pixel difference between the upper and lower lines goes up to the threshold. Comparison of mean values and standard deviations as well as the IQ (Image Quality) factor shows that this modified method is evidently superior to the linear algorithm.Hyperspectral images transformed from Interferogram obtained by IIM contain information on reflectance, light condition, terrain and so on. Reflectance is the main factor to analyze mineral type on lunar surface. Therefore, interference caused by terrain and light condition should be removed. By summarize the advantages and disadvantages of several kinds of method of Photometric correction and reflection inversion, empirical formula of Brown University is used on photometric correction. Both the Flat-Field method and the method which utilize the solar radiation spectrum are used on reflectance, inversion in order to transform radiant brightness image into reflectance, image. Results show that the absolute reflectance, curves obtained by both two methods are basically identical.The spectrum data obtained by IIM is actually mixed spectrum of various materials due to instrumental resolution, mixed lunar soil, and so on. Therefore, pixel unmixing is essential to distraction information on mineral type. Different kinds of algorithms of pixel unmixing are discussed and compared. The minimum distance and spectrum angle mapper method are chosen as analyzing model for IIM data. Results show that the mineral distribution in the image is basically identical to the theory known to people in nowadays.