In addition to HAARP, the United States has operated two other ionosphere research sites in recent years, one in Puerto Rico, near the Arecibo Observatory, and the other (known as HIPAS) in Alaska near Fairbanks. Both of these facilities were built with both active and passive radio instrumentation similar to those at the HAARP facility. Interest in the ionosphere is not limited to the US: a five-country consortium operates the European Incoherent Scatter Radar site (EISCAT), a premier ionosphere research facility located in northern Norway near Tromso. Facilities also are located at Jicamarca, Peru; near Moscow, Nizhny Novgorod (“SURA”) and Apatity, Russia; near Kharkov, Ukraine and in Dushanbe, Tadzhikistan. All of these installations have as their primary purpose the study of the ionosphere, and most employ the capability of stimulating to a varying degree small, localized regions of the ionosphere in order to study methodically, and in a detailed manner what nature produces randomly and regularly on a much larger scale.