摘要:The software-type wave–particle interaction analyzer (S-WPIA) is an instrument package onboard the Arase satellite, which studies the magnetosphere.The S-WPIA represents a new method for directly observing wave–particle interactions onboard a spacecraft in a space plasma environment.The main objective of the S-WPIA is to quantitatively detect wave–particle interactions associated with whistler-mode chorus emissions and electrons over a wide energy range (from several keV to several MeV).The quantity of energy exchanges between waves and particles can be represented as the inner product of the wave electric-field vector and the particle velocity vector.The S-WPIA requires accurate measurement of the phase difference between wave and particle gyration.The leading edge of the S-WPIA system allows us to collect comprehensive information, including the detection time, energy, and incoming direction of individual particles and instantaneous-wave electric and magnetic fields, at a high sampling rate.All the collected particle and waveform data are stored in the onboard large-volume data storage.The S-WPIA executes calculations asynchronously using the collected electric and magnetic wave data, data acquired from multiple particle instruments, and ambient magnetic-field data.The S-WPIA has the role of handling large amounts of raw data that are dedicated to calculations of the S-WPIA.Then, the results are transferred to the ground station.This paper describes the design of the S-WPIA and its calculations in detail, as implemented onboard Arase.