The LL-3760 is a very precise GPS Timing Receiver. The unit outputs 10 Mhz and 1 pulse per second (1 pps) synchronized to the Navstar GPS System.
Originally the unit was designed to provide time and frequency to Spirent Pseudolite Simulators GSS6100P (Galileo). Three capabilities to shift the system time independently could be used to build up a test time and to steer the GSS6100(P) simulator.
UTC time scale, based on a receiver that is synchronized to the United States NAVSTAR GPS allows precise time synchronization with an accuracy in the single digit ns range. The United States NAVSTAR GPS is a satellitebased radio-positioning, navigation, and timetransfer system. It was installed by the United States Department of Defense and is operated by the US Naval Observatory.
GPS time Scale started on 6 January 1980 and is autonomous and differs from UTC by the integer number of leap seconds that have occurred since the GPS time scale began. Although timing specification for the GPS system accuracy to UTC is 1 microsecond, the last years the accuracy is in a range of < +/-25ns to UTC(USNO), typically +-2 ns.