Solar Surface Stereoscopy with Solar Orbiter's Polarimetric Helioseismic Imager (SO/PHI)

A compound method for a stereoscopic analysis of the height variations in the solar photosphere is presented. This method allows to estimate relevant quantities (i.e. the Wilson depression) and to study structures in the solar photosphere and within sunspots. We will demonstrate the feasibility of the method using simulated Stokes I continuum observations derived from a radiative transfer model using the plasma properties of a MHD simulation of the solar surface. The large scale variations in our method are estimated by shifting and correlating two signals of the same region as observed from two different view directions. This result is then introduced as an initial height estimate in a least squares optimization algorithm in order to reproduce smaller scale structures. This method has been developed to be applied to the high resolution images of the PHI instrument on board Solar Orbiter or similar instruments on other Sun-observing spacecraft. It will allow to perform direct stereoscopic studies of solar surface observations in different wavelengths of the solar spectrum. Preliminary results, advantages and limitations, applications and particular considerations for PHI data will be discussed.