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Question: What are currently the most promising approaches to non-GNSS PNT for applications that do not require high accuracy?
Answer: The DOD PNT strategy posits use of space-based, regional and local sources of information to ensure PNT resilience if GPS is disrupted. Resilience does not require GPS-quality accuracy but must enable service continuity for operations while GPS is unavailable. Local sources are viable for limited areas; however, regional sources are necessary for broader coverage. Enhanced Loran (eLoran) can be a viable and affordable backup to GPS. It broadcasts at a much higher power and at a different frequency than GPS, is virtually un-jammable over wide areas, is receivable underwater, and offers a communications channel. eLoran has been recommended as a critical infrastructure backup to GPS by the National PNT Advisory Board and directed by the U.S. Congress. Yet, lacking federal interest or resources, its infrastructure is heedlessly being dismantled — while Russia, China and Iran invest in their own Loran-based backups. What do they know that the United States does not?
Q: What reforms in GPS governance would help accelerate the modernization of the system?
A: Today, modernized GPS is not enough, though it remains the cornerstone of the national PNT Enterprise. Attention to the entire Enterprise is urgently needed. With GPS, the United States enjoyed a dominant GNSS position for nearly three decades. Absent PNT attacks or mishaps, a sense of ‘business-as-usual’ lethargy impedes GPS improvements and the adoption of complements. Leadership watches GPS modernization slide to the right while its complements and needed domestic critical infrastructure backups languish. Within DoD, GPS is no longer a discrete program, and there is no other joint program to command resources and bring urgency and coherence to resilient PNT efforts. Structural changes and experienced, competent acquisition managers are necessary to focus resources and deliver capabilities, and committed leadership is essential for continuity. They must acknowledge PNT as vital to our national security and economy — while our adversaries and competitors leverage its value and can exploit any unaddressed vulnerabilities.
<p>The post EAB Q&A: Promising approaches to non-GNSS PNT and modernizing the system first appeared on GPS World.</p>
