Scratch and dig analysis for Metis mirrors surfaces defects evaluation

The presented paper aims to theoretically analyze the possibilities, advantages and drawbacks of standard methods used for the assessment of optical surface defects (the so-called Scratch and Dig analysis). Based on the acquired knowledge, we design and apply a process of SaD analysis suitable for the evaluation of optical surfaces of mirrors of the space coronagraph Metis, whose manufacturing was successfully implemented within the Centre Toptec in the past period.