Virtual instrument is a set of data obtained from one instrument or the result of data processing which can be presented as a sequence of data records associated with a time sequence. For example: magnetic field vector or ion energy spectra (array) along with the time of measurements.

Each real instrument can be divided into several virtual instruments. For example: CORALL ion energy spectra and plasma parameters calculated from CORALL data are two different virtual instruments.

Auxiliary data (orbit, attitude, magnetometer offsets, calibration coefficients (time dependent) are virtual instruments as well.