Curlometer Technique and Applications

We review the range of applications and use curlometer, initially developed to analyze Cluster multi-spacecraft magnetic field data; but more recently adapted other arrays spacecraft flying in formation, such as MMS small-scale, 4-spacecraft configurations; THEMIS close constellations 3–5 spacecraft, Swarm 2–3 configurations. Although gradients require knowledge separations field, structure electric current density (for example, its relative spatial scale), any temporal evolution, limits measurement accuracy. Nevertheless, many magnetospheric regions curlometer is reliable (within certain limits), particularly under conditions time stationarity, or with supporting information on morphology when geometry large scale expected). A number large-scale have been covered, as: cross-tail sheet, ring current, layer at magnetopause field-aligned currents. Transient smaller structures (e.g., reconnected flux tube dipolarisation fronts) energy transfer processes. The method able provide estimates single components vector density, even if there are only two three satellites within region, can be case a highly irregular configuration. computation topology general includes rotation analysis various least squares approaches, well indeed added inclusion plasma measurements extension larger considered.