Aware of the potential for GPS and other signals being disrupted in the electromagnetic spectrum, the military has been researching ways to get location and navigation information when satellite signals are degraded. One possibility? A “pseudolite,” which is what it sounds like—a pseudo satellite that operates low to the ground, sending stronger signals than soldiers get from a satellite in orbit. Another possibility is using a Chip-Scale Atomic Clock, or CSAC, which can provide precise time to a GPS receiver when GPS signals are being jammed, in order to enable rapid signal reacquisition or to protect receivers from spoofing, according to a release from the Army’s Communications-Electronics Research, Development and Engineering Center’s Command, Power and Integration Directorate, or CERDEC CP&ID.They’re both part of CERDEC’s efforts to make sure that soldiers in the field have positioning, navigation and timing, or PNT, capabilities even when the usual signals, such as GPS, are being interfered with.