Multiple spacecraft measurements have obvious
    advantages over a single spacecraft observation
    (left).

    Three cases below illustrate how data from four
    spacecraft can be used to differentiate between areas
    of plasma uniformity, spatial gradients and regions of
    vorticity where a single spacecraft may return similar
    observations in all cases.
 
 
 
 
 
 
 
 
 
 
 

below: Uniformity: four spacecraft measurements can show uniform plasma flow conditions over an extended region of space (right), rather than a single point measurement (left)

 

below: Gradients: Four spacecraft can observe differences in plasma flow over the region of space covered by the satellites (right). Again, a single spacecraft (left) can only observe one point in the plasma flow.

below: Vorticity: A single spacecraft can record the direction of the plasma flow at its position (left), but 4 spacecraft observations (right) can describe a feature such as the vortex shown

 

Images by Andrew Fazakerley and Chris Owen- please do NOT reproduce without permission
Last updated on 07/08/00 by Sarah Szita