  The Galactic dwarf spheroidal galaxies (dSphs) provide valuable insight into
dark matter (DM) properties and its role in galaxy formation. Their close
proximity enables the measurement of line-of-sight velocities for resolved
stars, which allows us to study DM halo structure. However, uncertainties in DM
mass profile determination persist due to the degeneracy between DM mass
density and velocity dispersion tensor anisotropy. Overcoming this requires
large kinematic samples and identification of foreground contamination. With
1.25 deg$^2$ and 2394 fibers, PFS plus pre-imaging with Hyper Suprime Cam will
make significant progress in this undertaking.
