Abstract: Sona Hosseini will report on progress toward development of a tunable spatial heterodyne spectrometer (TSHS) at the fixed focus of the Coudé Auxiliary Telescope (CAT) in the Shane Telescope at Lick Observatory (Khayyam). Spatial Heterodyne Spectrometer (SHS) instruments are a class of interferometric sensor capable of providing a combination of large étendue, high resolving power (R=λ/dλ~ 105) and wide field of view (FOV~0.5 degree) at Optical and NUV wavelengths in a compact format.
The TSHS implementation addresses the bandpass limitation of the basic SHS through controlled rotation of pilot mirrors in the interferometer. The use of a single grating as both a dispersing and beam-splitting element in the all reflective SHS greatly relaxes the precision required in the alignment of the other optical elements relative to a more typical scanning Fourier Transform Spectrometer and allows the TSHS implementation to be accomplished with low cost commercial rotation stages. The new design builds on a previous design originally tested in 2007, and will address several issues identified with the input beam, output imaging, and grating efficiency. Here she will discuss the design considerations going into this new system and the initial results of the installation and testing of the TSHS and the future plans.
Following completion of the ground based TSHS version (Khayyam), the longer term goals of the TSHS project are to provide in flight testing on a sounding rocket platform that Sona’s research group is developing and then ultimately a translation to satellite applications.