Spatial Coregistration

Landsat-8/9 and Sentinel-2A/B images are resampled to 30 m resolution in the Military Grid Reference System. The use of the European Space Agency’s (ESA) Sentinel-2-based Global Reference Image (GRI) in the production of Level-1 Sentinel-2 and Landsat-8/9 data substantially improves the geolocation accuracy of both data streams. As a result, HLS v2.0 no longer uses the ad-hoc in-house geolocation images and Automated Registration and Orthorectification Package (AROP) as in HLS v1.4.

Spectral resampling methods used in coregistration:

– Sentinel-2 10 m bands are resampled to 30 m using a simple average;

– Sentinel-2 20 m bands are resampled to 30 m using an area-weighted average;

– Sentinel-2 60 m bands are resampled to 30 m by replication;

– Landsat-8/9 bands are reprojected and resampled using cubic convolution.