Inertial Compensated Crystal Oscillator for High A/J UTC GPS/Inertial Operation

Under previous research efforts, we have developed a high A/J UTC approach, termed FCTRACK, which optimally processes all of the signal codes broadcast by the GPS satellites. Since all of the codes broadcast by the same satellite are coherent in phase,this approach allows the combined signal power of all of the GPS codes to be leveraged for anti-jam protection. By applying data-aiding, it is also possible to extend the coherent integration interval beyond the 20 msec data bit period, which allows J/Slevels approaching 100 dB to be theoretically possible. Our previous research has shown that to achieve these high A/J protection levels, both the inertial and the clock phase prediction error must be kept small during the integration period. Under thisproposed SBIR effort we plan to develop an Inertial Compensated Crystal Oscillator (ICXO) that will allow the clock phase variations to be predicted and compensated within the UTC processing. This will allow the UTC coherent integration period to beextended further improving the A/J protection possible using ultra-tightly-coupled GPS/inertial systems.Under Phase I, we will develop a design for the ICXO and evaluate its performance in a UTC solution using generic missile and target models to be provided. This effort will demonstrate by simulation that the design technique provides significant anti-jamimmunity and robustness to vehicle dynamics. Under the Phase II effort, we will integrate and test the ICXO with our GPS/INS UTC test-bed. The Phase II and III effort on this SBIR is visualized to produce perhaps the highest anti-jam GPS receiver built to date, yet the design allows for this to be built at a very low marginal cost relative to existing or future GPS receivers. It is proposedto apply this technology first to Cruise Missiles, low flying UAV's, air to ground weapons and other platforms that must approach close to jammers or must linger over the battle space. Any military application that requires anti-jam immunity androbustness to vehicle dynamics will benefit from this development.