pLEO Positioning, Navigation, and Timing

GPS is an integral part of American life. Its lead architect has called our dependence upon his invention America’s “largest unaddressed critical infrastructure problem”. It has also been called a “single point of failure” by DoD officials. Across the DoD, efforts are underway to develop robust alternatives to GPS for PNT. Caliola is developing one such GPS alternative for PMW/A-170. Our Satellite Communications [SATCOM] Antenna Pointing for Positioning (SCAPP) solution leverages the pointing vectors and ranging measurements produced by the Navy Multiband Terminal while tracking DoD satellites in geosynchronous orbit for positioning and navigation. Using live DoD terminal data, we have shown that 20-meter positioning accuracy is feasible for stationary terminals with two satellites in view. In this SBIR effort, Caliola is evolving our SCAPP positioning and navigation solution for use with commercial proliferated low Earth orbit and medium Earth orbit constellations. We are focused primarily on the OneWeb constellation since it is transponded and therefore compatible with future Navy capabilities. Critically, a future tranche of OneWeb satellites will support the optical crosslinking required for time transfer. In Phase I, we used high-fidelity modeling and simulation to show that 40-meter positioning is feasible for SCAPP when using pointing vectors from OneWeb. We also showed that 20-ns time transfer is feasible via the standard Two-Way Satellite Time Transfer (TWSTT) protocol. In the proposed Phase II effort, we will evolve SCAPP to work with OneWeb. The Base effort will culminate with a demonstration of the SCAPP positioning code at a fixed site with an Intellian OneWeb terminal as the pointing source. In Option 1, a two-site fixed demonstration will show the ability to calibrate the satellite ephemeris from one site and use that data to fix the position of a second. In Option 2, the GPS-denied site will be mobile and use an advanced antenna from Kymeta. In parallel, we will develop and demonstrate a TWSTT solution. Following an initial over-the-air demonstration in the Base effort, we will demonstrate TWSTT over OneWeb in fixed (Option 1) and mobile (Option 2) settings.