A low cost GPS Time sensor is proposed to be developed which will be suitable for power system fault detection and control. GPS provides a highly precise time reference which allows data to be synchronized to within 100 nanoseconds between substations and control centers. Applications of precise time in power control include data logging, relay testing, fault isolation and phase angle measurements. Failures can be isolated in a grid to a precision of 100 meters by measuring the relative time of arrival of a fault at two stations. Phase angle measurements can be determined to a precision of 40 micro-rad. As part of this effort, a simulation will be performed on the network state estimation performance improvement possible using these precise time measurements. Currently, the least expensive GPS timing receivers cost over $10,000. Such equipment would be very expensive to install at tens of thousands of substations throughout the electric power grids. It is proposed under this effort to develop a low cost precise time synchronization GPS sensor for use in electric power system monitoring. The proposed sensor will provide a highly reliable, time reference accurate to 100 nanoseconds for a cost of less than $1,000.