The FSP3 situation criterion

That part of the FSP1 time interval, which corresponds to the magnetic conjugations of the any couple of the 4 considered spacecraft: INTERBALL TAIL PROBE, INTERBALL AURORAL PROBE (or MAGION 5) or CLUSTER(ESA/NASA), POLAR (NASA), and GEOTAIL (NASA, ISAS).
The value of the relative geocentric angular distance between magnetic field line footprints is considered during FSP3 situation selection. The mentioned angular distance value less then 5 deg is used as a criterion of the FSP3 situation. During magnetic mapping Tsyganenko 87 (Kp=2) + IGRF95 magnetic field models are used. The magnetic field line stop trace altitude (km) is 110.