The GPS Timing Unit operates on the civilian L-band (1575.42MHz) utilizing C/A (Coarse Acquisition) code transmissions to monitor time and frequency data from the Navstar satellite constellation. 

The unit automatically acquires and tracks satellites based on health status and elevation angle. In the Stationary mode, time and frequency monitoring requires only one satellite, once accurate position data has been acquired or entered, although the receiver will use as many satellites as available. In “AUTO” mode, and the “Dynamic” mode, a minimum of four satellites are required for the GPS Timing unit to do three dimensional (latitude, longitude, and altitude) position fixes.

The basic GPS Timing Unit configuration includes the GPS Main Module, an antenna/preamp and a coaxial cable for interconnection. A corrected 1pps output signal and a 10MHz Sine Wave are provided. An RS-232 I/O Port is also provided in the basic configuration which can be used to control the unit as well to get data from the unit. The basic unit has an LCD Display and a keyboard. It generates IRIG B Serial Time Code, and has the capability of measuring the time interval difference between the GPS 1pps and an externally input 1pps (or it can measure an external frequency input – Models ET6000 and ET6010 only). It contains an RS-232 printer port.