1. Current plans for future systems should be revisited in light of the multiple phenomenology vectors. For example, space-based PNT is and will remain a cornerstone of the PNT architecture, but the Architecture should envision adding to the current GPS construct as technology evolves, as some terrestrial PNT systems have limited utility for some transportation modes or do not fit with perceived needs for 2025. Subsequent review and revision of PNTsystems willbeneededasthecurrentvectorsandrecommendationsbegin to improveUSPNTcapabilities. 11. Ensure critical infrastructure precise time and time interval users have access to and take advantage of multiple available sources
2. National PNT needs, synergies, and decisions on the national architecture would benefit from a long-term, national PNT coordination process extending beyond space-based PNT. The US should identify and organize the nation's expertise to develop a National PNT Coordination Process. The process could address PNT needs analysis, programassessments, and costestimation;advise and encouragegovernmentscienceandtechnologyinvestments, as well as commercial research and development, in key PNT-related technologies; and perhaps provide system engineeringand integrationsupportto PNTprogramoffices, serviceproviders, and customers. 18. Identifyand leverage centers of excellence for PNTphenomenologyandapplications
3. The National PNT Coordination Process could focus the national effort on science and technology, ensuring sufficientbreadth anddepthwith efficientuse ofnationalresources. For example, the process could offer knowledge resources touser equipmentdevelopersregarding theperformance and costofalternativetechnologies. 19. Define, develop, sustain,and manageaPNTmodelingandsimulation coreanalyticalframework