Accurate, Stable Clock for Small Low Power Anti-Jam GPS User Equipment

The development of a miniature, very-low power, rubidium clock specifically designed for integration into an airborne GPS receiver is described. The primary Phase I objective is to demonstrate the capability of an integrated Low-Power Precision Time Source (LPPTS) to minimize the Time-to-First Fix in a jamming environment. To accomplish this objective, Kernco proposes to fabricate, test and deliver a LPPTS which incorporates a Kernco coherent-population trapping (CPT) frequency standard, and a Receiver Interface Unit tailored to the timing requirements of a customer-specified airborne GPS receiver. The Interface Unit provides Time-of-Day input and output words over an RS-422 digital interface and precision 1 pulse-per-second input and output signals. Upon delivery of the LPPTS, Kernco will provide technical support for a joint USAF-Kernco evaluation of the Time-to-First Fix as a function of jamming power in accordance with the Guidelines for the "Global Positioning System (GPS) Receiver Applications Module (GRAM), March 1998" and the modernized "Technical Requirements Document for the Global Positioning System (GPS) Receiver Applications Module (GRAM-S/M), June 2005."