Key Parameters for the Magnetometer investigation are
computed within the ISTP/CDHF for a week of data at a time.
Generally Key Parameter availability lags real time by about
14 days.
Parameters derived on a routine basis are proton velocity,
number density, and temperature (most probable thermal
speed). Those parameters are obtained from a non-linear,
least-squares fit to the observed fluxes using a convected,
isotropic Maxwellian model.
Key Parameters for the Plasma instrument are computed at MIT
using Level Zero data that are staged to the ISTP/CDHF
approximately two weeks after being received on Earth. Thus
the plasma instrument's Key Parameters lag real time by
something greater than 2 weeks, but less than four.