Software-type Wave–Particle Interaction Analyzer on board the Arase satellite

Yuto Katoh, Hirotsugu Kojima, Mitsuru Hikishima, Takeshi Takashima, Kazushi Asamura, Yoshizumi Miyoshi, Yoshiya Kasahara, Satoshi Kasahara, Takefumi Mitani, Nana Higashio, Ayako Matsuoka, Mitsunori Ozaki, Satoshi Yagitani, Shoichiro Yokota, Shoya Matsuda, Masahiro Kitahara, Iku Shinohara

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


We describe the principles of the Wave–Particle Interaction Analyzer (WPIA) and the implementation of the Software-type WPIA (S-WPIA) on the Arase satellite. The WPIA is a new type of instrument for the direct and quantitative measurement of wave–particle interactions. The S-WPIA is installed on the Arase satellite as a software function running on the mission data processor. The S-WPIA on board the Arase satellite uses an electromagnetic field waveform that is measured by the waveform capture receiver of the plasma wave experiment (PWE), and the velocity vectors of electrons detected by the medium-energy particle experiment–electron analyzer (MEP-e), the high-energy electron experiment (HEP), and the extremely high-energy electron experiment (XEP). The prime objective of the S-WPIA is to measure the energy exchange between whistler-mode chorus emissions and energetic electrons in the inner magnetosphere. It is essential for the S-WPIA to synchronize instruments to a relative time accuracy better than the time period of the plasma wave oscillations. Since the typical frequency of chorus emissions in the inner magnetosphere is a few kHz, a relative time accuracy of better than 10 μs is required in order to measure the relative phase angle between the wave and velocity vectors. In the Arase satellite, a dedicated system has been developed to realize the time resolution required for inter-instrument communication. Here, both the time index distributed over all instruments through the satellite system and an S-WPIA clock signal are used, that are distributed from the PWE to the MEP-e, HEP, and XEP through a direct line, for the synchronization of instruments within a relative time accuracy of a few μs. We also estimate the number of particles required to obtain statistically significant results with the S-WPIA and the expected accumulation time by referring to the specifications of the MEP-e and assuming a count rate for each detector.[Figure not available: see fulltext.].

Original languageEnglish
Article number4
Journalearth, planets and space
Issue number1
Publication statusPublished - 2018 Dec 1


  • Magnetosphere
  • Radiation belts
  • Wave–particle interactions
  • Whistler-mode chorus

ASJC Scopus subject areas

  • Geology
  • Space and Planetary Science


Dive into the research topics of 'Software-type Wave–Particle Interaction Analyzer on board the Arase satellite'. Together they form a unique fingerprint.

Cite this