MAJIS resolution is better than 100km. This corresponds to JUICE w.r.t Io surface < 666500km
For each time window identified above, compute the fraction of illuminated disk k using the formula:

k= (1+ cos (phase angle))/2)

Whenever k>0.6 the opportunity for IO composition mapping is identified and a segment IO_MAJ_COMPOSITION is scheduled for the whole duration when those conditions are met.
Additional check ensures that Io is not in eclipse by Jupiter or by any other Galilean moon.