The Visible Spectro-Polarimeter (ViSP) for the Advanced Technology Solar Telescope

It is an echelle spectrograph designed to measure three different regions of the solar spectrum in three separate focal planes simultaneously between 380 and 1600nm. It will use the polarimetric capabilities of the ATST to measure the full Stokes parameters across the line profiles.

By measuring the polarization in magnetically sensitive spectral lines the magnetic field vector as a function of height in the solar atmosphere, along with the associated variation of the thermodynamic properties can be obtained. The ViSP will have a spatial resolution of 0.04 arc seconds over a 2 minute field of view (at 600nm). The minimum resolving power for all the focal planes is 180,000.