The EISCAT Scientific Association is currently building EISCAT_3D, the most advanced 3-dimensional imaging radar for atmospheric, ionospheric and near-Earth space investigations. EISCAT_3D is a European Strategy Forum for Research Infrastructures (ESFRI) Landmark in the Environment domain.

The fully steerable, tri-static, phased-array incoherent scatter radar is located in Skibotn (inland from Tromsø, Norway), Karesuvanto (Finland, north of Kiruna), and Kaiseniemi (Sweden, west of Kiruna). The transmit-receive array at Skibotn consists of about 10,000 aerials and ten 91-aerial outrigger receivers in the immediate vicinity. The receive-only arrays of Kaiseniemi and Karesuvanto consist of about 5,000 aerials each.

Construction of the facility began after the project kick-off in September 2017. First test measurements have been carried out with a single "antenna unit", which consists of 91 crossed-dipole aerials. The next step will be the so-called "PET-7" system, which consists of seven antenna units with full transmit and receive capabilities. PET-7, with 637 aerials with 1 kW power each, will allow for mono-static incoherent scatter radar measurements. Thereafter, EISCAT_3D will gradually expand to fully tri-static operations.

EISCAT_3D will eventually replace the EISCAT mainland radars, i.e. the 930-MHz UHF radar and the 224-MHz VHF radar at Tromsø, even though some overlap is foreseen not least for cross-calibration and comparison purposes. The remote receivers at Sodankylä (Finland) and Kiruna (Sweden) are already inoperable due to failures not feasible to repair.

The EISCAT Svalbard Radar (ESR) and the Ionospheric Heating facility at Tromsø will not be affected by EISCAT_3D becoming operational.

Here we give an overview of the current status and the road ahead.