Time Stability Quantities

 To measure the performance of a clock, its timing is compared to another reference clock. The performance of the various clocks are specified by two parameters, Timing Deviation (TDEV) and Maximum Time Interval Error (MTIE). Plots of TDEV and MTIE against sampling period are defined known as masks which the measured MTIE and TDEV has to lie below for all measurement intervals $\tau$. The masks are discussed in more detail in section 6.4. Both of the quantities are calculated from SPW data via the execution of code written in C/C++. TDEV and MTIE are parameters that can be derived from the time error function x(t). MTIE is an indication of the maximum time interval error over a period of time whereas TDEV can be thought of as a modified form of the standard deviation of the time interval error. TDEV is a measure of the underlying noise in a timing signal whereas MTIE is useful for estimating the level of phase transients. TDEV also provides information on the different noise components in a signal.