Development of a Prelude Satellite Equipped with Electric Field and Plasma Measurement Sensors Based on Statistical Evaluation of Seismic Precursors Using Artificial VLF Radio Waves Obtained from In-Orbit Observations

Development of a Prelude Satellite Equipped with Electric Field and Plasma Measurement Sensors Based on Statistical Evaluation of Seismic Precursors Using Artificial VLF Radio Waves Obtained from In-Orbit Observations

Utah State University, Logan, UT

In this paper, we focus on the artificial VLF radio wave and show the result of the evaluation of the signal intensity decrease by the effect of ionospheric fluctuation, which is regarded as a sign phenomenon of earthquake occurrence. This paper also describes the mission design of Prelude (Precursor electric field observation CubeSat demonstrator) which is aiming at elucidation of the precursory mechanism of earthquake, and the development situation of hybrid sensor (electric field and plasma measurement) which is a mission instrument.

We focused on the artificial VLF wave, in which the electromagnetic wave itself does not affect the ionosphere, and examined the relationship between the degree of electric field intensity decrease by the artificial VLF wave and the magnitude of the earthquake. And, by using lightning data of WWLLN (World Wide Lightning Location Network), the relation between change of generation number and energy and earthquake was evaluated.

We have developed a CubeSat (6U Size) that is easy to mass-produce. However, the electric field measuring instrument and plasma measuring instrument mounted on the Demeter (130 kg large satellite) are each more than 1U in size. There are also no sensors for CubeSats that can be observed simultaneously. Therefore, we are working on the development of the hybrid sensor of 1U size or less which can measure electric field and plasma simultaneously on the orbit.