The Sondrestrom Upper Atmospheric Research Facility was an ionospheric and atmospheric research facility situated about 15 km (9.3 mi) west of Kangerlussuaq, Greenland.

The ionospheric radar was first constructed by SRI International at Stanford, California, then moved to Chatanika, Alaska, where it was operational from November 1971 to March 1982.

[1] It was operated by SRI International for the U.S. National Science Foundation and the Danish Meteorological Institute.

This facility hosted more than 20 instruments, the majority of which provided unique and complementary information about the arctic upper atmosphere.

The centerpiece instrument of the facility was an L band incoherent scatter (IS) radar with a 32 m (105 ft) fully steerable antenna.