Table 2 EISCAT_3D radar coverage and location requirements for different science topics, together with suggestions for complementary instruments

Mesoscale electrodynamics and flows (including BBFs)

As wide as possible (30° elevation with all azimuths)

Within auroral oval

20 × 20; multi-static meas.

Magnetometers, optical equipment, tomography radio receivers, SuperDARN

Small-scale (auroral) dynamics

100 km in the F region, 33 km in the E region

Within the auroral oval

30 in N-S, 10 in E-W; Multi-static meas.

Optical equipment, rockets

– “–

– “–

– “–

– “–

Fine-scale auroral structures

5 km in the E region, within 10–20 km from magnetic zenith in the F region

Within the auroral oval

5–7 N-S, 1–7 E-W; multi-static meas., interferometric studies

Optical equipment, rockets

– “–

– “–

– “–

– “–

Ion outflow (natural and heater-induced)

~100 km curvature of field line

Within the auroral oval

N-S fan of 5–10 beams

Optical equipment, rockets

NEIALs (aperture synthesis imaging)

40 km × 40 km at 700 km

Within the auroral oval

Spreading the beam in the F-A direction; plasma lines ±6 MHz

Optical equipment, rockets

Ionospheric irregularities

As wide as possible

Within the auroral oval

20 × 20

GPS scintillation measurements, rockets

Topside composition (O⁺, He⁺, H⁺)

N/A (field line tracing)

Fan, enough to cover field line curving

Optical equipment, rockets

Transition region composition (NO⁺/O₂ ⁺ vs. O⁺)

N/A

One; heater ion-cyclotron freq. gives additional information

Optical equipment, rockets

High-energy particle events (SEPs, etc.)

As wide as possible

Oval and just equatorward of the oval

20 × 20

VLF, riometers, MF radar, satellites (POES, GOES, LANL, etc.), rockets

– “–

– “–

Atmosphere-ionosphere coupling (AGW, winds)

As wide as possible

Auroral oval and at the edge of the polar vortex

20 × 20

MST radar, MF radar, meteor radar, lidar, airglow imager, FPI, sounding rockets, heater (API)

Mesosphere-stratosphere-troposphere (MST) small-scale dynamics

As wide as possible

Location inside the polar winter vortex favourable for some questions

20 × 20 (M), one (ST); additional low-power TX mode, dual frequency (200–1000-kHz separation) for interferometric distance determination

MST radar, MF radar, meteor radar, lidar, airglow imager, sounding rockets, heater

D region phenomena

As wide as possible

Oval and just equatorward of the oval

20 × 20

Riometer, VLF, MF radar, rockets, heater

PMSE, PMWE

As wide as possible

20 × 20

MST radar, additional ISR at higher frequency, lidar, sounding rockets, heater

Meteoroids and their effects on the background (Es, PMSE, etc.), high-power mode

Fattened beam or multiple beams

Tracking mode (20 × 20 piggyback), fan for receiver beams, multi-static measurements for trajectory

Meteor radar, MST radar, optical networks

Planets and asteroids

Low elevation look direction to the south, at least 25°

As far south as possible

One; arbitrary polarisation TX and RX, hydrogen maser clocks

Other IS radars, optical instruments

Interplanetary scintillation

Low elevation with all azimuths, particularly to the south

One; BW > 20 MHz, minimal RFI and ability to clip out individual narrow-frequency bands prior to integration over the bandwidth

Other radio receiver networks, including LOFAR and e-MERLIN

Heating experiments

20° zenith angle

Auroral oval

10 × 10

MST radar, airglow imager, FPI, sounding rockets

Heating experiments, aperture synthesis imaging

20° zenith angle

Fatten the beam or multiple beams (10 × 10)

MST radar, airglow imager, FPI, sounding rockets

Space debris monitoring and satellite tracking

25° elevation with all azimuths

North for satellite tracking

N/A; multi-static meas. for trajectory, multiple overlapping receiver beams for interferometric angle determination, dual freq. (200–1000-kHz separation) for interferometric distance determination

Meteoroid monitoring (piggyback and low-power mode)

N/A

N/A

Meteor radar, MST radar, optical networks