Secure Time delivery Military GPS receivers in challenged RF environments using existing wireless infrasructure

ABSTRACT: Echo Ridge and partner Rockwell Collins propose to quantify and demonstrate the value of existing tactical and commercial wireless communications signals in providing time aiding to MGUE. The primary results of the Phase I effort will be a comprehensive trade space analysis, off-air verification of absolute time-related statistics for selected signals, the development and demonstration of prototype algorithms showing achievable time accuracy and trustworthiness, and a preliminary design for supplying time aiding to a Rockwell Collins MGUE. The demonstration of the prototype algorithms and achievable time aiding accuracy will be based in part on prior funded research in using Signals of Opportunity (SoOPs) to improve PNT performance. This original work merges Simultaneous Localization and Mapping algorithms (SLAM) (modified to use RF landmarks) and vector tracking techniques with algorithms which synthetically synchronize imprecise and noisy disparate source/device clocks to generate PNT from non-navigation signals. We will extend this work to include not only relative time/frequency/range estimations, but also absolute (UTC) time as derived from one or multiple sources. BENEFIT: GPS receivers (including MGUE) are becoming ubiquitous in modern devices, systems and networks; including using their time output for synchronization in multiple applications. In many cases, GPS receivers operate in challenging environments where GPS operation/acquisition is impaired/denied. If accurate time could be supplied to the GPS receiver, it may be able to operate in the challenging environment including reducing the time to first fix and direct P(Y) acquisition. One approach to operation in challenging environments is time aiding produced from commercial and tactical communications infrastructures. Ideally, acceptably accurate and authenticated absolute time could be made available as a service. There are many advantages to this approach. In general, environments include multiple commercial and/or tactical communications signals, many of which have universal time broadcasts. This research will provide insight into the achievable absolute time transfer accuracy, and associated trust worthiness.