The Electric Field Detector on Board the China Seismo Electromagnetic Satellite—In-Orbit Results and Validation

Abstract

The aim of this work is to validate the China Seismo-Electromagnetic Satellite 01 (CSES-01) Electric Field Detector (EFD) measurements through the analysis of the instrument response to various inputs: (a) geomagnetic field variations, (b) plasma density depletions, and (c) electromagnetic signals from natural and artificial sources such as Schumann resonance and VLF (Very Low Frequency) antennas. The knowledge of the geomagnetic induced electric field vs×B (where vs is the satellite speed and B and the local magnetic field), and the plasma variations effect, described by the Orbit Motion Limited (OML) theory, are key parameters to determine the expected theoretical values of the EFD sensors potentials data. Based on the CSES on-board measurements of plasma parameters and geomagnetic field, a direct quantitative validation is presented. In addition, the electromagnetic signals detection capability is checked but only qualitatively confirmed, since the ionospheric complexity does not allow an accurate theoretical computation of waves modulation. The quantitative comparison highlights the very good agreement between observed and theoretical potentials values during average condition. Conversely, in case of strong electric fields, the OML theory shows partial inability in reproducing the actual space plasma conditions resulting in a reduced theoretical values reliability. Finally, both natural and artificial electromagnetic signals are satisfactorily identified showing a reliable sensitivity in different frequency bands.

Detection of electromagnetic anomalies over seismic regions during two strong (MW > 5) earthquakes

“…• the plasmaspheric hiss at ∼1 kHz (Malaspina et al, 2018;Tsurutani et al, 2018); • the first and second Schumann resonance, at ∼8 and ∼15 Hz respectively (Rodríguez-Camacho et al, 2022); • the signal due to the v × B field caused by the satellite motion into the geomagnetic field (Diego et al, 2021).…”

“…• ≈ 2 Hz (E y , E z ): these peaks are due to the v × B electric field present in the ELF band, caused by satellite motion into the geomagnetic field [see e.g., (Diego et al, 2021)]; • ≈ 8 and ≈15 Hz (E x , E y , E z ): first and second Schumann ionospheric resonances at CSES-01 orbit [see (Rodríguez-Camacho et al, 2022)]; • ≈ 1 kHz (E x ): signature of the plasmaspheric hiss (Malaspina et al, 2018;Tsurutani et al, 2018).…”

The August 2018 Geomagnetic Storm Observed by the High-Energy Particle Detector on Board the CSES-01 Satellite

“…The CSES-01 relies on the Chinese three-axis stabilized CAST2000 platform, and it is flying in a Sun-synchronous polar orbit at a ∼507 km altitude with a 97 • inclination and a five-day revisit time. Nine scientific payloads are present on board the satellite [22][23][24][25][26][27][28][29][30], among which is the HEPD particle detector, which was designed and built by the Ital-ian Limadou Collaboration. A schematic representation of the apparatus is reported in Figure 1.…”

Electric Field Multifractal Features in the High-Latitude Ionosphere: CSES-01 Observations

“…Thus, the selected ground magnetometer station permits confirmation of what is recorded by the instrument on board the DMSP and is reported in Figure 1. As a first step, we remove, from each component of the E, the motional electric field, E s = v s × B where v s is the satellite velocity, due to the spacecraft motion inside the geomagnetic field, B [28].…”