System tolerance analysis of dual-advantage spectrographic system based on coded aperture

Traditional dispersive spectrographic systems based on single slits cannot achieve dual advantages simultaneously and statically. A novel dual advantages system model for dispersive spectrographic system appears and the traditional entrance slit is replaced by a coded aperture based on orthogonal independent column codes. The extended aperture lets more energy enter the system and the independence of the codes helps to avoid degradation of the spectral resolution. On the basis of the derivation of system model, this paper emphasizes on system tolerance analysis, to find out the key factors which affect the realization and performance of the system model. First, the influences of inaccurate system adjustment and calibrations on system performance were studied. The standard methods for system adjustment and calibrations were represented. Then, simulations were carried out to study the influence of several abnormal situations of the coded aperture on system performance, which includes the existing of error fabrication and imperfect illumination of the coded aperture. The analysis result shows that the system can still function normally when the coded aperture has a fabrication error rate of 30% or severe imperfect illumination of the coded aperture.