Calibrating Optical Distortions In The Solar Orbiter Spice Spectrograph

The Spectral Imaging of the Coronal Environment (SPICE) instrument on SolarOrbiter is a high-resolution imaging spectrometer operating at extremeultraviolet (EUV) wavelengths from 70.4-79.0 nm and 97.3-104.9 nm. Asingle-mirror off-axis paraboloid focuses the solar image onto the entranceslit of the spectrometer section. A Toroidal Variable Line Space (TVLS)grating images the entrance slit onto a pair of MCP-intensified APS detectors.Ray-tracing analysis prior to launch showed that the instrument was subject toa number of small image distortions which need to be corrected in the finaldata product. We compare the ray tracing results with measurements made inflight. Co-alignment with other telescopes on Solar Orbiter will also beexamined.