Energetic electron injection signatures observed by GPS at high magnetic latitudes

Energetic particle measurements continue to be expanded on the GPS constellation with the commissioning of two new instruments on recent GPS launches ns41 and ns54. These new instruments (CXD, BDD-IIR) now measure energetic electrons from ~ 100 keV to several MeV, which make the lower energy channels sensitive to the range of energies commonly associated with substorm injections ( ~ 20 -- ~ 300 keV). We report here on the first measurements of energetic electron injection signatures (> 100 keV) with these instruments, many of which occur outside the trapping boundary for these energies. We investigate the relationship of these high latitude injections to other injection observations on the LANL geosynchronous satellites, POLAR and CLUSTER, and to other traditional indicators of substorm activity.