During the measurement interval, the IMS accumulators are active for a period of 12 msec. The RIMS instrument continued to return usable data until the end of the DE mission in March 1991. The anomaly disappeared on day 73 or 74 of 1982. The Z heads show spin variation primarily at low altitudes in cold, dense plasmas at high spacecraft velocities. One MAF record is 5624 bytes in size.
Data quality is, in general, excellent.
Data are not always recorded at altitudes down to the DE-1 perigee of 675 km. At the lower altitudes, the plasma density can be quite high and the RIMS instrument is generally shut off to protect the particle detecting CEMs from excessive counting rates. However, on occasion, saturation of the detecting CEMs may be seen in the radial head data during low altitude-high density passes. Detection of very low-energy ions is made difficult by the presence of floating spacecraft potentials. By preventing measurement of the coldest plasma components, this potential can mask out an isotropic background plasma or, when the potential is sufficiently high, can give the appearance that no cold plasma exists in a region.