Table 1
Previous observations of EMIC waves in low earth orbit

Satellite Launch Mission lifetime Mass Orbit (perigee/apogee/inclination) Period Eccentricity Specifications EMIC observations
MAGSAT 1979 Oct 30 6 months 158 kg 351 km/578 km/ 96.74° 93.9 min 0.000574 16 samples/s, 1 nT resolution duskside, 58-60° latitudes, close plasmapause, during quiet time, switching polarizations between L and R modes
DE-2 1981 Aug 3 1.5 years 420 kg 309 km/1,012 km/89.99° 98 min 0.03 16 vectors/s, 1.5 nT, 0.1 mV/m resolution electron temperature enhancement accompanies with Pc1, caused by thermal electron acceleration
Viking 1986 Feb 22 535 kg 822 km/14,000 km/ 98.7° 270 min 0.477 53 vectors/s, 1 nT resolution Latitudinal width of Pc1 ~ 1°
Freja 1992 Oct 6 4 years 274 kg 601 km/1,756 km/63° 108.9 min 8 samples/s, 1 V/m Dispersive Pc1 bursts (peals), latitudinal width of Pc1 ~ 0.5°
CHAMP 2000 July 15 10 years 500 kg 450 km/87.18° 93.5 min 0.0007 50 Hz, RMS noise level of 0.05 nT Climatology of Pc1
SWARM A, B & C 2013 Nov 22 4 years 468 kg 460 km/87.4° 104 min 50 Hz, 0.01 nT resolution