5:15 PM - 6:45 PM
[PPS01-P03] High-Frequency part of the Radio & Plasma Wave Investigation (RPWI) aboard JUICE: toward the Lunar-Earth flyby in Aug 2024
Keywords:Jupiter, JUICE, RPWI, Lunar and Earth flyby
This talk provides a summary of the initial operations of Radio & Plasma Wave Investigation (RPWI) aboard JUpiter ICy moons Explorer (JUICE) launched in April 2023, in the view for its high frequency radio observation capability in 80k – 45MHz.
RPWI provides a unique and first opportunity in this huge mission. The RPWI will investigate electromagnetic fields and plasma environment around Jupiter and icy moons with passive and active soundings by 4 Langmuir probes (LP-PWI; 3-axis E-field -1.6 MHz by four 10 cm diameter probes on the 3-m booms) and a search coil magnetometer (SCM; 3-axis B-field -20 kHz) + a tri-dipole antenna system (RWI; 3-axis E-field 0.08-45 MHz, 2.5-m tip-to-tip length) on the long MAG-Boom with JMAG. All antennas were successfully deployed just during the week of JpGU 2023.
In lower frequency, RPWI enables to investigate electric field and electromagnetic interactions governing Jupiter - moon systems, cold plasmas in the ionospheres of icy moons for investigations of surfaces and salty conductive sub-surface oceans., and cold micrometeorite impacts.
The high frequency part of this system, i.e., Preamp of RWI and its High Frequency Receiver (HF) is procured by the RPWI Japan team with the colleagues in Austria, France, Poland, and Sweden. This part enables the characterization of Jovian radio emissions (including gonio-polarimetry), passive radio sounding of the ionospheric densities of icy moons, and passive sub-surface radar measurements. The HF part of RPWI has an enough capability to detect Jovian radio emissions from magnetosphere (aurora etc.), atmosphere (lightning), and icy moons. Direction and polarization capabilities are first enabled in the Jovian system, to identify their source locations and characteristics. RPWI with other instruments covers the survey of harsh environment around Jupiter, environments and interaction with icy moons, and their surface and subsurface characteristics.
The most key parts of the HF part is the sensing of the ionospheres, surface, and subsurface of icy moons during the flybys and on the orbit around Ganymede. We will do unique remote observations of the ionospheres below the spacecraft orbit by the radio occultation and reflection of Jovian radio signals. In this talk, we introduce the emulation results for those. (1) “The occultation capability” of Jovian auroral radio waves is for the investigation of icy moons’ ionospheric density profiles. It enables to detect the ionospheric density not only in usual status but also episodic plume ejections triggered by expected crustal activities. For this emulation, we utilized the data observed by the Galileo spacecraft during the Ganymede and Calisto flybys. (2) “the reflection capability” of Jovian auroral radio waves is for the characterizing of icy moons’ surfaces and subsurfaces. It is challenging to try the passive subsurface radar (PSSR) concept which sounds the icy crusts of Galilean satellites by the reflections of penetrated Jovian radio emissions (HOM/DAM). For this emulation, we reanalyzed the data observed by the Kaguya spacecraft on the Moon orbit. Quantitative and qualitative discussion including the practical limitation will be discussed.
Those observations require the low electric noise environment from the spacecraft. Unfortunately, during Near Earth Commission Period in May-July 2023, we identified that large line noises as a harmonics of 200 kHz and wide-band noise in 4-10 MHz. Those potentially suffers the observational capability, so we are now testing to mask some of them by onboard processes. This effect will be tested during the Lunar Earth flyby of JUICE in Aug. 2024. During this period, we also do some operational tests for lcy moons with Lunar flyby and for Jovian radiation with Earth flybys (including the simultaneous observations with JAXA Arase spacecraft in 20kHz – 10MHz range). This talk will summarize those effects and plans with the expected performance Jupiter and icy moon system in 2030s
RPWI provides a unique and first opportunity in this huge mission. The RPWI will investigate electromagnetic fields and plasma environment around Jupiter and icy moons with passive and active soundings by 4 Langmuir probes (LP-PWI; 3-axis E-field -1.6 MHz by four 10 cm diameter probes on the 3-m booms) and a search coil magnetometer (SCM; 3-axis B-field -20 kHz) + a tri-dipole antenna system (RWI; 3-axis E-field 0.08-45 MHz, 2.5-m tip-to-tip length) on the long MAG-Boom with JMAG. All antennas were successfully deployed just during the week of JpGU 2023.
In lower frequency, RPWI enables to investigate electric field and electromagnetic interactions governing Jupiter - moon systems, cold plasmas in the ionospheres of icy moons for investigations of surfaces and salty conductive sub-surface oceans., and cold micrometeorite impacts.
The high frequency part of this system, i.e., Preamp of RWI and its High Frequency Receiver (HF) is procured by the RPWI Japan team with the colleagues in Austria, France, Poland, and Sweden. This part enables the characterization of Jovian radio emissions (including gonio-polarimetry), passive radio sounding of the ionospheric densities of icy moons, and passive sub-surface radar measurements. The HF part of RPWI has an enough capability to detect Jovian radio emissions from magnetosphere (aurora etc.), atmosphere (lightning), and icy moons. Direction and polarization capabilities are first enabled in the Jovian system, to identify their source locations and characteristics. RPWI with other instruments covers the survey of harsh environment around Jupiter, environments and interaction with icy moons, and their surface and subsurface characteristics.
The most key parts of the HF part is the sensing of the ionospheres, surface, and subsurface of icy moons during the flybys and on the orbit around Ganymede. We will do unique remote observations of the ionospheres below the spacecraft orbit by the radio occultation and reflection of Jovian radio signals. In this talk, we introduce the emulation results for those. (1) “The occultation capability” of Jovian auroral radio waves is for the investigation of icy moons’ ionospheric density profiles. It enables to detect the ionospheric density not only in usual status but also episodic plume ejections triggered by expected crustal activities. For this emulation, we utilized the data observed by the Galileo spacecraft during the Ganymede and Calisto flybys. (2) “the reflection capability” of Jovian auroral radio waves is for the characterizing of icy moons’ surfaces and subsurfaces. It is challenging to try the passive subsurface radar (PSSR) concept which sounds the icy crusts of Galilean satellites by the reflections of penetrated Jovian radio emissions (HOM/DAM). For this emulation, we reanalyzed the data observed by the Kaguya spacecraft on the Moon orbit. Quantitative and qualitative discussion including the practical limitation will be discussed.
Those observations require the low electric noise environment from the spacecraft. Unfortunately, during Near Earth Commission Period in May-July 2023, we identified that large line noises as a harmonics of 200 kHz and wide-band noise in 4-10 MHz. Those potentially suffers the observational capability, so we are now testing to mask some of them by onboard processes. This effect will be tested during the Lunar Earth flyby of JUICE in Aug. 2024. During this period, we also do some operational tests for lcy moons with Lunar flyby and for Jovian radiation with Earth flybys (including the simultaneous observations with JAXA Arase spacecraft in 20kHz – 10MHz range). This talk will summarize those effects and plans with the expected performance Jupiter and icy moon system in 2030s