Image reference system — WGS 84.

• World Geodetic System 1984 is the global coordinate/datum standard.
• Defined relative to a set of globally-distributed ground stations.
• Reference surface: a spheroidal reference ellipsoid (the WGS 84 ellipsoid).
• Origin: the Earth’s center of mass, accurate to within about 2 cm.
• Used by GPS/GNSS and nearly all modern remote-sensing products — including all Landsat and Sentinel Level-1/Level-2 products.