The goal of this working group is to provide a comprehensive “tool book” of analysis techniques for ionospheric multi-satellite missions. The immediate need for this book is motivated by the upcoming ESA Swarm satellite mission, but the tools that will be described are general and can be used for any future ionospheric multi-satellite mission with comparable instrumentation. The title is intentionally chosen similar to the earlier ISSI book that was motivated by the ESA Cluster multi-satellite mission in the magnetosphere. In the ionosphere, a different plasma environment prevails that is dominated by interactions with neutrals, and the Earth’s main magnetic field clearly dominates the total magnetic field. Further, an ionospheric multi-satellite mission has different research goals than a magnetospheric one, namely in addition to the study of the immediate plasma environment and its coupling to other regions also the study of the Earth’s main magnetic field and its anomalies caused by core, mantle, or crustal sources. Therefore, different tools are needed for an ionospheric multi-satellite mission as compared to a magnetospheric one, and different parameters are desired to be determined with those tools. Besides currents, electric fields and plasma convection, such parameters include ionospheric conductances, Joule heating, neutral gas densities and neutral winds.
The book that will be the outcome of this working group will thus focus on techniques that are able to derive such local plasma parameters from the immediate multi-satellite measurements, and on techniques that can link these locally derived plasma parameters with observations made by other instruments in adjacent domains (including observations by other satellite missions, and ground-based observations), in order to determine the coupling between that domain and the ionosphere. In terms of the study of the Earth’s main magnetic field, this book will limit itself to tools that utilize the multi-satellite ionospheric observations in order to minimize errors in the main magnetic field modeling. It will thus not include techniques that are designed to determine core, mantle, or crustal magnetic anomalies itself from the main magnetic field model.