Recap of the 57th meeting of the U.S. Civil GPS Service Interface Committee

The 57the meeting of the U.S. Civil GPS Service Interface Committee was held September 25-26, 2017 at the Oregon Convention Center in Portland, OR in conjunction with the Institute of Navigation’s Global Navigation Satellite System (GNSS)+ conference. For readers who were unable to attend a synopsis of the meeting and presentations is provided below. The full agenda and presentations are available for download from the website.

The meeting of the CGSIC is an annual event, free and open to the public, conducted to provide official updates from U.S. GPS program officials and ensure effective information exchange between the U.S. government and civil GPS users. The two-day meeting is hosted by the U.S. Department of Transportation (DOT) and the Coast Guard Navigation Center (NAVCEN). DOT serves as the civil lead for the GPS and chairs the CGSIC in this capacity. NAVCEN is assigned duties as deputy chair and executive secretariat for the CGSIC.

The four subcommittees of the CGSIC (Timing, State and Local Government, International Information, and Survey, Mapping, and Geosciences) held focused discussions on specific GPS topics and contained a variety of interesting user applications. Summaries of these meetings were presented to the CGSIC Plenary Session by the Subcommittee Chairs on September 26th.

The keynote speaker for this year’s plenary session was Dr. Keith Conner, Senior Engineer, Science and Technology First Responders Group, U.S. Department of Homeland Security. He spoke of resilience as the ability to prepare and adapt to changing conditions and withstand and recover rapidly from disruptions, deliberate attacks, accidents or naturally occurring events. He reminded us that GPS is a 20th century technology with receivers that are inherently radios designed to trust the source of their signals with little regard for interference sources. The 21st century is bringing to GPS receivers a need to “Trust but Verify” and be wary of signals that are “too good.” The DHS Science and Technology (S&T) component is actively engaging the community of interest to address the constantly changing nature of the threats to GPS security and resiliency through information sharing, cooperative research and development as well as testing and evaluation. Three Best Practices documents relating to GPS receiver resiliency have been published that are available to the public at S&T has hosted multiple “Live Threat” events for the community including a First Responder electronic jamming exercise as well as testing for GPS receivers used in critical infrastructure. S&T and the National Institute of Science and Technology (NIST) are working towards a compliance program that will collaborate with multiple industry groups, leverage existing standards and specifications, and include best practices and testing procedures that address both hardware and software device components.

Presentations during the Plenary session focused on the operational status and modernization of the GPS constellation and ground control system, U.S. Space-Based Positioning, Navigation, and Timing (PNT) policy, GPS augmentation systems, U.S. engagement with other international GNSS providers, as well as a variety of topics related to the status and progress of ongoing GPS programs in the U.S. government.

If you have suggestions for topics to include in upcoming CGSIC meetings, would like to present a topic, or if you found information from past meetings useful and would like to hear more, please contact us via our Navigation Center “contact us” form. Please be sure to select “Civil GPS Service Interface Committee (CGSIC)” from the pull-down menu.

From a GPS operational perspective, civilian non-aviation users can submit GPS-related inquiries or report signal interference or degradation to the U.S. Coast Guard Navigation Center online at: or to the 24 hour watch desk at 703-313-5900.

Civil aviation users within the United States should contact the Federal Aviation Administration for GPS user support. The GPS Operations Center at Schriever Air Force Base, Colorado, is the lead in the Department of Defense for operational issues and questions concerning military use of GPS.