Small-Footprint LF Solutions
UrsaNav and its select collaborative partners have developed a small footprint, rapidly deployable, easily transportable, and cost-effective Low-Frequency-based Position, Navigation and Timing (PNT) system. Our team of experts has taken the idea of a small footprint system through the design, integration, proof-of-concept and successful field-test stages. This system is completely self-contained and can be deployed in an area as small as 160’ x 160’. It consists of a portable antenna array, a self-contained shelter or cargo truck, and a power generator. The system can be set up and operable in less than one day.
Although the focus of field-test efforts was on enhanced-Loran (eLoran), the technology can be applied to other LF systems appropriate for various Position, Navigation, Timing and Data (PNT&D) solutions, particularly when GPS is degraded or unavailable. A small footprint LF system is capable of supporting multiple missions (e.g., eLoran, emergency/data communications, subsurface/submarine broadcast) multiple modes (e.g., aviation, maritime, land mobile, location-based time and frequency) and multiple signal formats (e.g., Pulse Position Modulation, Supernumary Interpulse Modulation, and Intrapulse Frequency or Amplitude Modulation). UrsaNav has proven that this technology works and, consequently, has inspired additional research efforts. Such research includes investigating alternative waveforms (Binary Phase Shift Keying and Raised Cosine) that may result in applying our techniques to improving LF service.
Potential Uses and Scenarios
There are many potential uses for a small footprint eLoran- or LF-based Terrestrial Positioning System (TPS) as a means to augment and back up GPS, provide PNT&D services where GPS is corrupted or unavailable, or present PNT&D services to users who require GPS independence. Prospective uses include:
- Military operations subject to GPS unavailability (e.g., triple canopy, jamming scenarios, and mountainous terrain;
- Critical infrastructure protection for ports, harbors, airports, key assets, etc.;
- High-profile events, such as the Olympic Games;
- Interference-enabled crime fighting (e.g., car theft, border crossing, tracking felons, and toll “cheating); and
- Wide-area or localized timing source providing +/- 30 ns to UTC (Stratum 1).
Testing demonstrated that it takes minimal time, effort, and cost to assemble a small footprint LF system. Increasing the signal coverage area is a straightforward task that adds an alternative means of obtaining PNT&D services independent of GPS.