Precision Time Protocol Trilateration for Planetary Navigation
Ron Murdock, John Mackay

Progeny Systems

Abstract

To support extended planetary operations, precision localization and route mapping is required for planetary EVA, manned rovers and surface mobility units. Under a Phase II SBIR contract with NASA Glenn Research Center, Progeny Systems has developed a working prototype planetary navigation system recently tested on a large scale at a Nevada desert test site. The IEEE 1588 Precision Time Protocol (PTP) timing standard applied to a wireless network allows time synchronization based range measurement for point to point ranging during communications. Trilateration processing coupled with the use of wireless PTP can yield localization precision comparable to terrestrial GPS. Trilateration provides positional estimates based on absolute path delay between points. PTP determines path delay intrinsically within the timing protocol. Individual path delays between fixed points (nodes) and mobile nodes can be interpreted as spheres. The position solution is obtained by solving for the intersection points between the resulting spheres as is done with GPS. The innovation is the establishment of a fault tolerant, field scalable, precision navigation system that can and support size, weight, and power (SWaP) goals by integrating mature technologies to provide an innovative navigation system while naturally supporting data and voice communications on the same network. Perhaps most importantly, this system is bidirectional such that position information is provided to both the base and the mobile units. Such a system provides a precise and reliable navigation backbone to support traverse-path planning systems and other mapping applications and establishes a core infrastructure for long term occupation. The test results from the Nevada large scale test are complete and very encouraging.

Presented at ISDC 2011 - Huntsville. Paper and presentation charts are not available.