Fig. 2

Schematic diagram of cross-correlation leading to incremental index-shifts δi. The RF signal was recorded at different wall-clock times T. One frame consists of multiple scanlines that were subdivided in half-overlapping intervals of six wavelengths along the axial direction (left). Cross-correlation was calculated between the same axial intervals on the same scanlines recorded at different times (middle) resulting in the incremental index-shifts (right)