For a detailed description see Galperin et al., Annales de Geophysique, v.38, N 5, 1982.

Particle detector RIEP-2802 was developed and built in Russia. It is a large geometric factor 4-channel electrostatic spectrometer with spectral resolution (deltaE)/E ~ 0.2. Two detector channels were for electrons, two channels for ions, all working in parallel.

The combined Soviet-French ONCH-TBF onboard instrument had in memory modes the data only from several filter-banks in the range from 10 Hz to 16 kHz (while in the real-time telemetry modes, the measurements included 5-component wave-form data in the range 10 Hz - 1.5 kHz for 3 magnetic and 2 electric field components, or a wide-band mode in the range 10 Hz - 15 kHz, and several filter banks).

The combined Soviet-French TRAC experiment was aimed to measure magnetic field variations due to auroral field-aligned currents. The signals ofthe onboard magnetic field detector for attitude restitution were read and treated by the TRAC device in a way of a "zoom". Each of the three magnetic components measured, once in 43 seconds, was digitized to 12 bits, and these values, together with the difference analog signal (currently measured value minus the last digitized) were given to telemetry.