An optical coherence tomography scanner for recording sub-surface scans of an object, wherein the optical coherence tomography scanner comprises: - an interferometric system configured for projecting a probing beam onto the scanned object and recording sub-surface data at different probing beam positions on the scanned object; - a position encoder pattern arranged in the path of the probing 2. beam; - a computing system comprising a non-transitory computer readable medium on which algorithms are stored as instructions and a data processing unit for executing the instructions of the algorithms, where the algorithms are configured for: - generating a sequence of A scans from the recorded sub-surface data; - detecting the position encoder pattern in said sequence of said A scans; - deducing based on the detected position encoder pattern the probing beam position and/or inclination for at least one A scan of said sequence of A scans; and - generating a sub-surface scan of the object based on the sequence of A scans taking into account the deduced probing beam position and/or inclination, characterized in that the position encoder pattern comprises a substrate on which a patterned anti-reflective coating layer is defined, and wherein the position encoder pattern is at least partly formed by a plurality of first regions of a first transmissivity and a plurality of second regions of a second transmissivity, where the first transmissivity is higher than the second transmissivity. - an interferometric system configured for projecting a probing beam onto the scanned object and recording sub-surface data at different probing beam positions on the scanned object; - a position encoder pattern arranged in the path of the probing 2. beam; - a computing system comprising a non-transitory computer readable medium on which algorithms are stored as instructions and a data processing unit for executing the instructions of the algorithms, where the algorithms are configured for: - generating a sequence of A scans from the recorded sub-surface data; - detecting the position encoder pattern in said sequence of said A scans; - deducing based on the detected position encoder pattern the probing beam position and/or inclination for at least one A scan of said sequence of A scans; and - generating a sub-surface scan of the object based on the sequence of A scans taking into account the deduced probing beam position and/or inclination, characterized in that the position encoder pattern comprises a substrate on which a patterned anti-reflective coating layer is defined, and wherein the position encoder pattern is at least partly formed by a plurality of first regions of a first transmissivity and a plurality of second regions of a second transmissivity, where the first transmissivity is higher than the second transmissivity. - generating a sequence of A scans from the recorded sub-surface data; - detecting the position encoder pattern in said sequence of said A scans; - deducing based on the detected position encoder pattern the probing beam position and/or inclination for at least one A scan of said sequence of A scans; and - generating a sub-surface scan of the object based on the sequence of A scans taking into account the deduced probing beam position and/or inclination,