Volpe Center GPS Expert Testifies Before Congressional Subcommittee
Ms. Karen Van Dyke is the Volpe Center's National Expert on Global Positioning System (GPS), and is also serving as the Acting Director for Positioning, Navigation and Timing in the U.S. DOT's Research and Innovative Technology Administration (RITA). A leading DOT authority on this topic, Ms. Van Dyke was recently asked to testify before the National Security and Foreign Affairs Subcommittee of the House Committee on Oversight and Government Reform in response to a GAO report on potential GPS availability gaps beginning in two years.
Karen Van Dyke, National Expert on Global Positioning System. (
Volpe Center photo)
Ms. Van Dyke's testimony focused on the topic of the criticality of GPS to civilian users. She discussed the importance of GPS positioning, navigation and timing (PNT) services and the need to ensure the sustainment of the GPS constellation. The technology enhances public safety by preventing transportation accidents and reducing the response time of emergency services. It allows agriculture operations to continue through low visibility field conditions to apply chemicals precisely, reducing environmental impact while also reducing production costs. Of particular importance to the U.S. DOT is the operation of the FAA's NextGen Air Transportation System which requires the precise navigation and surveillance capabilities based on GPS.
Ms. Van Dyke also stated that the U.S. DOT is confident that the Department of Defense will continue to operate GPS at or above the minimum GPS Performance Standard commitment and will find innovative methods to extend the life of the GPS satellites to prevent any gaps in availability. However, GPS is vulnerable to interference that can be reduced, but not eliminated. The Volpe Center issued the “Vulnerability Assessment of the Transportation Infrastructure Relying on the Global Positioning System” in 2001. This assessment indicated that, due to the reliance of transportation on GPS signals, it is essential that threats be mitigated and alternative back-ups be available, and the system be hardened for critical applications.
Potential back-up capabilities to GPS are being explored as part of a National PNT Architecture study. The overarching goal of the architecture, with GPS as its cornerstone, is intended to overcome identified capability gaps, and achieve an evolutionary path to providing integrated space-based, terrestrial, and autonomous solutions in the 2025 time period that will ensure the continuity of government-provided PNT services.
