Landsat-8 and Sentinel-2 data are registered to the same reference image per tile, using the Automated Registration and Orthorectification Package (AROP) (Gao et al. 2009). The NIR band (B5 for OLI and B8A for MSI) is used for the cross-correlation analysis with the referencde images, which are Sentinel-2 B8A images not severely contaminated by clouds.

Spectral resampling methods used in coregistration:

– S10 from input up to and including L1C v02.00-03 are resampled with a cubic convolution method;

– S30 10m bands for L1C v02.04 and later are re-sampled to 30m using a simple average;

– S30 20m bands for L1C v02.04 and later are re-sampled to 30m using an area-weighted average;

– S30 60m bands for L1C v02.04 and later are supersampled to 30m by replication;

– L30 are re-sampled using AROP polynomial equations and a cubic convolution resampling method. Thermal infrared
bands from TIRS are included in the L1T product already supersampled
from 100m to 30m. Here they are treated as any other 30m band.