“The Obama administration believes we must protect existing GPS users from disruption of the services”
What is the mandate of National Coordination Office for Space-Based PNT?
The mandate for the National Coordination Office (NCO) is detailed in United States (U.S.) National Policy. Our primary role is to support the National Space-Based PNT Executive Committee which convenes at the Deputy Secretary level to advise and coordinate on Space-Based PNT issues affecting multiple departments and agencies. The NCO does not make decisions or create policy. Rather, we serve as the Executive Committee’s Secretariat and execute tasks as directed by them. Specific responsibilities include interagency coordination, consensus development and issue resolution for all matters presented to the Executive Committee. As Director, I represent the Executive Committee on space-based PNT matters within the Government, the public sector, and with representatives of foreign governments and international organizations.
Would you like to explain the updates in US PNT policy?
President Obama’s 2010 National Space Policy includes specific language related to Global Navigation Satellite Systems (GNSS). It provides an overarching goal statement calling for the United States to maintain our leadership in the service, provision, and use of GNSS. It left other elements of U.S. PNT Policy, including the structure of the Space-Based PNT Executive Committee and its Coordination Office intact. Specifically it directs the federal agencies to:
a. Provide continuous worldwide access to the Global Positioning System (GPS) free of direct user charges for peaceful civil uses.
b. Engage with our international partners to encourage GNSS compatibility and interoperability, service transparency, and market access
c. Continue to operate and maintain GPS to satisfy civil and national security needs consistent with our published standards. In addition, the United States may consider use of foreign PNT services to augment and strength resiliency of GPS
d. Invest in domestic capabilities and support international activities to detect, mitigate and increase resiliency to harmful interference to GPS. As necessary, the United States will implement redundant and backup systems or approaches to protect critical infrastructure, key resources and mission-essential functions.
What is new in GPS?
There is always something new in GPS. As I was writing this, another GPS IIF satellite completed verification testing and is now operational. The IIF generation of satellites improves accuracy through more advanced atomic clocks. The IIF family of satellites has a longer design life than the previous generation of GPS satellites and it transmits a third civil signal. The new L5 signal is in the protected Aeronautical Radionavigation Services (ARNS) band and is more robust than L1 C/A due to its higher transmission power, wider bandwidth and longer spreading codes. When the constellation is fully populated with L5 capable satellites, it will improve performance for aviation, other safety-of-life and all civil users worldwide.
Just a few weeks ago, the Department of Defense completed the expansion of the GPS constellation into what is called the “Expandable 24” configuration. This was a two-phased operation that took 18 months to complete. The result is better geometry providing more coverage to GPS users. The new configuration increases robustness of satellite availability and overall signal in space performance.
In addition to continuing to modernize the satellites, we are simultaneously improving the command and control segment of GPS by replacing the legacy Operational Control Segment with the GPS Advanced Control Segment (OCX). The OCX ground system will bring more automation and will double the capacity to command and control satellites. It will be able to handle all the new civil signals coming on line with the GPS IIF and the GPS III programs.
Meanwhile we continue to expand and upgrade our GPS augmentation systems to further enhance Space-Based PNT services. For example, use of the FAA’s Wide Area Augmentation Service (WAAS) has now expanded to the point that “Local Performance with Vertical Guidance” (LPV) approaches more than double the number of Instrument Landing System (ILS) approaches. WAAS-enabled LPV approaches do not require ground-based transmitters at airports and eliminate the need for critical area limitations associated with an ILS. New WAAS users are emerging at a rate of more than 1,000 per month. Meanwhile, a WAAS software upgrade in November will provide even greater resiliency to ionospheric distortions, once again improving the space-based PNT service for all of our users.
Even a successful program like GPS has its share of challenges. Recently, our analysts noticed one of our older GPS satellites, SVN-30, had a malfunctioning clock and therefore was not performing up to our published standards. We take our claim of being the world’s “gold standard” seriously, so we decided to activate one of the three residual satellites we maintain as on-orbit spares to replace the malfunctioning satellite. This is exactly why we keep residual satellites on-orbit, but fortunately this is only the second time in 25 years we have had to use one of them.
It is said that GPS signals across the US are threatened by a new wireless Internet network being established by LightSquared. What is your comment on this?
This is an issue still under review by the Federal Communications Commission (FCC), an independent U.S. government agency charged with regulating commercial interstate and international communications in the 50 states, the District of Columbia and U.S. possessions. Our office has worked extensively on the GPS interference aspects of this problem with the FCC and the National Telecommunications and Information Administration (NTIA), the Executive Branch agency responsible for advising the President on telecommunications issues, and the manager of the federal government’s use of spectrum. I can assure your readers the U.S. Government is carefully considering the concerns of our GPS users as they evaluate LightSquared’s proposals. Mr. Genachowski, Chairman of the FCC, has promised to protect the use of GPS and also promised a fact-based, engineering approach to the evaluation.
The Obama administration believes we must protect existing GPS users from disruption of the services they depend on today and ensure innovative new GPS applications can be developed in the future. At the same time, recognizing the President’s instruction to identify 500 MHz of spectrum for new mobile broadband services, we will continue our efforts at more efficient use of spectrum. Therefore, the U.S. government will participate in further testing required to establish whether there are any mitigation strategies that can enable LightSquared operation in the lower 10MHz of the Mobile Satellite Services band. We also encourage commercial entities with interests to work with LightSquared toward a possible resolution, though any proposed mitigation must be subjected to full testing. The challenge of meeting the President’s goal also depends on long-term actions by Federal agencies in the area of research and development, procurement practices that encourage spectrally-efficient applications, and new policy development.
There is a thought that there is too much dependence on GPS? What is your view on the ‘said back ups’ like Loran?
The continuing growth of services based on the Global Positioning System presents both opportunities and risks to U.S. national, homeland, and economic security. The widespread and growing dependence on the Global Positioning System of military, civil, and commercial systems and infrastructures has made many of these systems inherently vulnerable to an unexpected interruption in positioning, navigation, and/or timing services. For this reason, our national policy specifically calls for backup capabilities to ensure continued service for growing national, homeland and economic security requirements, for civil requirements and to meet commercial and scientific demands.
Although Policy is clear in the direction to have backup capabilities, it does not mandate any specific solution like Loran. The Department of Transportation, in coordination with the Secretary of Homeland Security, has primary responsibility to develop, acquire, operate and maintain backup PNT capabilities for critical transportation, homeland security and other critical civil and commercial infrastructure.
The Department of Homeland Security, with input from across the Federal Government, is nearing completion of a comprehensive National Risk Assessment focused on civil GPS services, which should provide us greater insight into our dependency and our need for additional backup capabilities.
What are your ideas in addressing the issues like jamming?
I undertook the task of addressing the proliferation of GPS jamming devices as my top priority when I took over as Director of the NCO. I took on this task because this is very serious problem that has been getting worse over the last several years. There are now companies whose sole line of business is manufacturing devices that purposefully and illegally cause harmful interference to GPS. In just in the past year, low-cost devices produced overseas have negatively impacted civil aviation, surveying, cell phones, law enforcement and other PNT services in our country. The Executive Committee has devoted significant time and attention to this issue. They have asked for new threat and risk assessments, a review of the legal regime, engagement with our international partners, new jamming test procedures and improved measures to detect, identify, locate and mitigate sources of interference. Our colleagues at the FCC have stepped up enforcement against the owners of these devices and against the companies that manufacture and sell them. We have introduced a proposal for action at the International Committee on GNSS to address this issue as it affects all GNSS systems and cuts across international borders.
With many new GNSS systems on horizon, how do you position the US GPS vis-à-vis them? Don’t you think that such a GNSS race is not in the interest of the US?
I disagree with the premise of your question. We do not see any GNSS race. If there ever was such a race, it was over long ago. We recognize we are in a multi-GNSS environment today and new players will continue to emerge in the future. This is not a threat to us. In fact, it may be an opportunity as numerous studies show using signals from multiple national systems can improve availability and enhance performance of certain applications. The emergence of other GNSS services complements U.S. provision of GPS services, and does not need to be seen as competition.
We expect that people around the world will continue to want to use GPS, either by itself or in combination with other GNSS. GPS has performed outstandingly well. It has never failed to meet its promised capabilities and has exceeded them every year of its operation. We have decades of reliable performance, a complete transparency with respect to our published standards and interface control documents, supportive policies consistent across decades of political leadership, and stable, multi-year funding. We have exciting new capabilities coming on line in the next few years as we continue to modernize both our satellites and our ground stations.
US offers free GPS signals, still many countries want to have their own GNSS systems? What could be the reasons?
I think that would be a good question to ask those countries. We have made a commitment to the world to provide free GPS signals for peaceful uses to anyone that wants them. We have demonstrated over several decades our good faith in keeping that commitment. GPS has remained available and reliable for global civilian use despite U.S. involvement in multiple wars and anti-terrorism activities, even during and after the attacks of September 11, 2001. However, each nation has to make these decisions for itself based on its own strategic interests and I certainly respect that. The United States welcomes other GNSS providers and our National Policy supports using new GNSS services to augment and strengthen the resiliency of GPS, although we will always maintain our own core GPS capabilities.
What challenges you feel are there in international collaborations in the field of GNSS?
While we have made great strides in areas like frequency deconfliction, additional international collaboration is still needed to fully realize mutual goals of compatibility and interoperability. I also believe there is further work we can do to ensure the new providers support transparency and open market access. One of the common challenges ahead is a worldwide demand for more bandwidth and t increasing pressure on the GNSS frequency bands. In our discussions with FCC and NTIA on the LightSquared issue, we have seen how complex it can be to maximize efficiency of spectrum use, while still supporting critical GNSS services. This problem will not be unique to GPS and I expect the issue of increasing spectrum efficiency to be one that gets a lot of discussion in future multi-lateral GNSS fora. I also expect the issue of GNSS interference, both intentional and unintentional, will be a growing international issue and a common challenge for all GNSS providers.