Speaker
Description
The IHDEA working group “Identifying spacecraft relative location in heliospheric environments” started its activity this year (2026).
The motivation of this working group can be summarized in the following way. The plasma region-based location of a spacecraft is a key information for scientists working with in-situ measurements, both for supportive information and for data analysis. Coordinate systems are a standard way to locate spacecraft in space. However, due to the variability in time and space of plasma regions (interplanetary medium, plasmasphere, magnetospheric tail, …), coordinate systems do not suffice to locate the plasma region or the boundary layer (magnetopause, plasmapause, …) crossed by a spacecraft at any given time.
Region classifications are performed using three different approaches: data visualisation, model dependent, or machine-learning based. Classifications are performed for each kind of missions, in various environments (e.g., Cluster, Arase, Juno, ...).
The time needed to make the calibrated data available to the scientific community has improved greatly over the last decades. These data come with classical orbital information and at times with model predictions. However, the effective location (by regions) is not included in the data delivery plan of a scientific mission. The recent increasing number of region classification studies raises the question of a standard for these regions.
A unified, classified dataset will enable us to use the richness of data from missions all over the solar system to understand fundamental plasma physics: the localized nature of in-situ data in dynamic systems creates large uncertainties that can obscure processes signatures. Statistical studies on large datasets are essential to improve the signal-to-noise ratio and detect physical signatures indiscernible in single-event analyses.
The first results of the working group concerns the regions shall be included, how to identify, and to define these regions. The first level of classification is inside or outside the heliosphere. The second level of classification will include the interplanetary medium, magnetospheres, or cometary environments. The third level will include regions inside each of level 2 regions. At this stage we mainly focus on the definition of the transition region between inside and outside the heliosphere with the help of the NASA/Voyager spacecraft.