Professor Last was one of the first members of the foundation and had served on its International Advisory Council since its inception. He perished in the crash of a small plane he was piloting on the Nov. 25, 2019.
The foundation and three of its members have begun the drive with pledges totaling $24,000.
The fund will be administered in the United Kingdom and is envisioned to pay student expenses for attendance at navigation-related conferences and symposia.
Individuals and organizations wishing to contribute to the scholarship fund should contact the foundation at [email protected]. Donations can also be made through the foundation’s website.
UPDATE: The search was called off on Tuesday afternoon. Additional information is available in this Evening Standard article.
David Last (Photo: @harriethallphoto via Dana Goward)
Just before 13:00 GMT on Nov. 25, a private plane piloted by David Last, former president of the Royal Institute of Navigation, disappeared from radar and hit the sea approximately two miles off the coast of Wales.
On-going search and rescue efforts have recovered pieces of wreckage and personal effects.
“Last was one of the most respected and well-loved figures in the worldwide positioning, navigation, and timing community. His loss creates a hole that cannot be filled,” said Dana Goward, president of the Resilient Navigation and Timing Foundation. “David was a close personal friend. Our grieving will not be brief.”
According to BBC News, the search for the missing plane and its pilot off the Welsh coast resumed on Nov. 26. North Wales Police said the light aircraft was flying from Caernarfon Airport to the Great Orme, Llandudno, and back on Monday when it disappeared. There were no other passengers and officers were supporting the missing pilot’s family.
The Maritime and Coastguard Agency said the search has resumed around Puffin Island, near Penmon, Anglesey. A plane carrying a sonar technology camera is searching the area as well as a lifeboat, helicopter and coastguard teams on foot.
David Last was a U.K. consultant engineer specializing in radio navigation and communications systems, professor emeritus at the University of Bangor, Wales, and past president of the Royal Institute of Navigation.
He also was a member of the expert panel and co-author of the January 2018 Blackett Report.
That is, in the People’s Republic of Boulder, Colorado. To those of us who live in Colorado, Boulder is known by this seemingly timeless but absolutely accurate appellation. This stunningly beautiful city located in the foothills of the Rocky Mountains, known as the Flatirons, is where the National Space-Based Positioning, Navigation and Timing Advisory Board (PNTAB), which provides independent advice to the National Executive Committee on Space-Based PNT (EXCOM) from outside the U.S. government, chose to meet in the waning days of October 2015. Ironically, they chose the same week as a Republican presidential candidates debate, which took place at the University of Colorado just a couple of miles away. The PNTAB was also concomitant with the ICG, the Tenth Meeting of the International Committee on GNSS (ICG-10), held Nov. 2-5, 2015. Both the PNTAB and ICG were held at the Boulder NCAR/UCAR facility, University Corporation for Atmospheric Research Center Green Conference facility.
PNTAB
The PNTAB serves a vital purpose. Board memberse advise the highest levels of the U.S. government (USG) concerning all matters relating to PNT. This open-ended charter covers a multitude of sins, and as the new PNTAB Chairman John Stenbit, stated clearly, it is important to focus on the doable, even if it seems difficult, but not to tilt at windmills. I have known and worked with John Stenbit for more than 25 years, especially during his two stints in the Pentagon, and I find him to be extremely knowledgeable and ethical. He is certainly well-spoken and gregarious, but he does not suffer fools, and is known to be resolute, which is a pseudonym for stubborn and hardheaded, but in a good way. I look forward to his chairmanship.
PNTAB Members at 16th Meeting in Boulder. New Chairman John Stenbit is center of last row. (Courtesy of gps.gov)
You can view the PNTAB presentations at the www.gps.gov website. While there, you will note there were more than 25 presentations, and most were excellent. Only a couple required the audience to consume copious amounts of caffeine to remain coherent.
In the end, the PNTAB adopted courses of action (COA) on which to formulate recommendations for the EXCOM. For our purposes, the pertinent COAs centered around two main subject areas: Spectrum protection and eLoran. The spectrum protection issues are fraught with equal parts litigious danger and tedium. Not coincidently, the World Radiocommunication Conference 2015 (WRC-15) kicked off in Geneva, Switzerland, on Nov. 2, just two days after the end of the PNTAB. Several of the PNTAB members attended the closing Saturday night PNTAB dinner and flew from Denver direct to Geneva Sunday morning, just in time for some minor jet lag adjustments, and then attended the opening ceremonies of WRC 2015 in snowy Switzerland.
I have had the dubious privilege of observing several International Telecommunication Union (ITU)-sponsored WRC sessions in the past, and it is certainly a critical spectrum decision-making body. (Seriously, folks, 26 days of talking and wrangling about spectrum? Praise the Lord the Swiss know how to brew strong coffee.) WRC 2015 wraps up on Nov. 27. In this regard, Ann Ciganer, who serves as an official PNTAB representative and the executive director of policy for the GPS Innovation Alliance (GPSIA, formerly the U.S. GPS Industry Council), is my hero. She has been working spectrum issues for more than 20 years. She has the fortitude of FDR and the patience of Job.
Since the spectrum and spectrum-protection issues are still being coldly debated in Geneva, let’s take a look at the PNTAB’s second major topic, eLoran. While eLoran was discussed ad nauseam, there was one definitive standout presentation given by my old friend and colleague Professor David Last. David is Professor Emeritus at the University of Wales (Bangor) and former president of the Royal Institute of Navigation (RIN). As he is wont to do, David held forth, with that wonderful, attention-arresting British public school accent, on eLoran matters before an appreciative audience. David presented his topic with equal parts passion and credibility. You can view his presentation material in its entirety (the PowerPoint slides, anyway) at www.gps.gov, but you will not have the wonderful experience of having him present it personally with all the attendant persuasion, and dry British humor and wit.
eLoran European Style
David immediately makes the point early on in the historical portion of his presentation that the U.S. first committed to Loran-C more than 75 years ago, and as recently as 2010 upgraded a majority of the sites to eLoran status only to have the current administration shut down Loran just after officially assuring the United Kingdom the U.S. would keep Loran up and running. Now the U.S. is in the position of looking for a backup and major terrestrial augmentation to GPS (GNSS) and is once again considering eLoran.
Professor David Last at 16th PNTAB
Professor David Last at the 16th PNTAB meeting. (Photo: Don Jewell)
Professor Last explained the difference between our viewpoints. “I see it from a British perspective, and a European perspective. I watch administrations in other parts of the world grappling with the same decisions the U.S. faces. The U.S., of course, is in a unique position: it is the source of GPS, the world standard in satellite navigation. And over the nearly 40 years since the first satellite was launched, the U.S. has taken the lead in learning to understand the role of GPS, from its military-only origins, through when it was a novelty with its first civil applications, through a period of hubris in which it was to replace every other means of navigation on land, sea and air, to its present role, so deeply embedded in your national life as to form a critical component of national infrastructure. The U.S. was first to recognize the vulnerabilities of GPS, to understand the threat they posed to your nation and to seek ways of mitigating them. That topic came to dominate technical conferences first in the U.S. and now around the world. And it has led to a policy debate of quite exceptional difficulty, one that is shared by all governments.”
The Message
What David did not come right out and say, although I maintain it was implied by his tone of voice and body language, is that this discussion is at times both energized and denigrated by those that refuse to acknowledge GPS or GNSS vulnerabilities and those that would be happy to see it revert to a military-only system — the proverbial ostrich syndrome. David made it clear that GPS vulnerability discussions must take place publicly in the U.S. because they are, in fact, global discussions. “All space-based PNT systems today are similar to GPS in concept and technology, and referred to by most users as GPS,” he said. “Very few bother or even know about Galileo, GLONASS and BeiDou. To them, it is all simply GPS.”
David went on to make his point by describing the ubiquity and pervasiveness of GPS and GNSS. “Now there is no area of transportation, commerce, industry or telecommunications in your country or mine that does not employ satellite navigation.”
Indeed, David described how other GNSS systems came about due to national pride, and yet they had no choice but to mimic GPS both technically and officially, since they must for safety-of-life concerns reside in the same regimes and crowded radio bands.
David stated, “Soon, these new GNSS became invested with immense national pride. Their vast cost had to be justified by claims of technical superiority. In reality, engineers know that their designers had no choice but to make them compatible with GPS, since GPS was decades ahead and the world standard. These new systems also had to squeeze alongside GPS in the narrow radio bands allocated internationally to navigation. Not surprisingly, indeed happily, all our new GNSS turned out to look very like GPS: versions of the same technology — with just a hint of garlic here, a whiff of curry there. This similarity is obvious to engineers and to navigators, though rarely to politicians.”
DOT Volpe GPS Jamming Report
Professor Last referred to the U.S. provider and user communities as groups that, prior to the important 2001 Volpe Report, failed to acknowledge that GPS had any serious vulnerabilities. That report was a watershed event for the future of GPS, and for me as a journalist. Among other jamming incidents around the country, a major jamming occurrence in San Diego harbor affected GPS-dependent systems (mostly those dependent on accurate timing) and users for miles around. It became a wakeup call for GPS and GNSS users globally; I wrote a Defense PNT column on it in this space in 2007.
David put it in perspective. “To understand the perceptions of those governments, wind back the U.S. story to before the Volpe Report on GPS vulnerability with its recommendations that led to your [PNT Advisory] Board’s policy of ‘Protect, Toughen, and Augment’. Despite the growth of jamming and even attacks by one sovereign nation on its neighbor, despite the appearance of low-cost spoofing, there has never been a Volpe Report anywhere outside the United States. The pre-Volpe culture of the denial of vulnerability is alive and well and living in Europe.”
“Thirty-seven years after the launch of the first GPS satellite, there is still little recognition by the world’s governments of how essential resilient position, navigation and timing have become to the critical infrastructure of their nations,” Last said.
After the Volpe Report came an industry report chaired by the Father of GPS, Professor Bradford Parkinson (Col, USAF, Ret), describing eLoran as the only cost-effective method of backup to GPS. The report was published globally, and then the United States completely failed to implement the transition from Loran-C to eLoran. At the time it failed politically, the Loran-C to eLoran conversion was 85 percent complete and only needed a small amount of funding for the future. Luddites within the U.S. OMB (Office of Management and Budget) managed to kill the program just short of completion. Unfortunately, the message to the world of GPS users was the U.S. had categorically rejected eLoran as a complimentary PNT system.
David presented the European point of view: “The Volpe Report, an FAA study, proposed and demonstrated Enhanced Loran (eLoran). GPS-like digital techniques were applied to the obsolete Loran-C low-frequency system. The result were astounding: it met the accuracy, integrity, availability and continuity standards of certain aircraft instrument approaches plus the very demanding port-entrance requirements of shipping, and it delivered precise timing to support telecomms. Brad Parkinson’s high-level study group of industry leaders said this was the only cost-effective GPS substitute for U.S. needs.
“The world outside the U.S. watched the Department of Homeland Security announce eLoran as the U.S. national backup to GPS and then completely fail to implement it! That message, that the U.S. does not need a complementary system and has rejected eLoran, is the current understanding of U.S. policy in many countries.”
Professor Last maintains the same eLoran drama is now being played out in Europe in real time. The UK developed its own eLoran system from the North of Norway to the South of France which, while it only officially achieved initial operational capability on Oct 31, 2014, has in fact been running flawlessly 24/7 for three years.
The message to the world, especially Europe, should be that the eLoran concept proposed by the U.S. FAA (Federal Aviation Administration) really works and is easy to implement. It has been, in fact, implemented and maintained in the UK by a mere handful of personnel.
However, according to David, the European eLoran system may never reach FOC (full operational capability) because currently Western Europe lacks any coordinated plan to respond to the vulnerabilities of GPS and all other PNT systems. Many have yet to embrace or even recognize the Volpe Report.
Indeed, several European countries are planning to shut down their eLoran systems supposedly since that is what we (the U.S.) did and it seems to be working for us.
David explains that “this [proven] system may never reach Full Operational Capability. Western Europe lacks any coordinated plan to respond to the vulnerability of GPS — why, who needs that when Europe has Galileo and EGNOS! The governments who control the Loran stations in Norway and France, observing that mariners no longer want Loran-C, plan to close down the transmissions just nine weeks from now, and demolish the infrastructure. After all, they say, that is what the U.S. did.”
Service Alternative
To paraphrase Winston Churchill, this was indeed not our finest hour. However David maintains there is a realistic commercial alternative: provide eLoran as a service. This is exactly what some in the United Kingdom and Europe are considering. It is a totally viable alternative, but David asserts that what would really help “is a positive signal from the United States.”
Continuing in the same vein, David posits “all is not lost. Responding to the future — indeed, the present — needs of the telecomms and broadcasting industries, and driven from the U.S., there is a commercial plan to take over and operate that European Loran infrastructure and sell its services to government and industrial users. If governments struggle to seize the initiative in this area, let the market — and good old greed — provide the mechanism for realizing the multiple benefits, paying the costs and making a profit. But I believe that this initiative will only succeed in Europe, if there is a positive signal from the U.S. The world listens to signals from the U.S., from the EXCOM, from this board.”
Unique Organizations
Historically, relationships between multi-GNSS systems are confrontational at best; however, David states clearly that Europeans realize the PNTAB and EXCOM are unique and unprecedented around the world. “These official government entities recognize and advocate for resilient PNT that is of major importance to critical infrastructures of the U.S. and other nations as well.”
In actuality, the U.S. has faced up to these vulnerabilities thanks to the PNTAB and EXCOM, two truly unique organizations. Undeniably, there is an incalculable polyphonic argument to be made concerning the vulnerabilities of space-based PNT systems such as GPS and how to mitigate them, but globally beyond the PNTAB and EXCOM, no one is officially having these critical discussions.
In the end, according to Professor Last, over the next nine weeks the immediate future of PNT really comes down to one critical question: “Will global PNT with eLoran be a global system or a nationally unique system?”
David supports his cogent argument for eLoran by giving excellent examples of GPS and multi-GNSS jamming supporting his insightful adage, “Space-based PNT systems live and die together.” They are all subject to the same vulnerabilities.
Wrapping up his refreshingly insightful presentation, Professor Last posed two questions to the PNTAB:
Does the U.S. see a role for eLoran as a complement to resilient GPS?
Does the U.S. recognize and encourage the move to GNSS receivers that take advantage of multiple constellations?
As one PNTAB pundit opined, “The critical issue for the U.S. government is we have to break the mold. The current administration is too often technologically controlled by Luddites and held hostage by low-level bureaucrats within OMB.”
Professor Last appropriately has the last word: “The bottom line for the PNTAB, EXCOM and USG is that the United Kingdom, nee Europe, is asking for support on eLoran.”
Until next time, happy navigating and don’t forget your GPS when you head over the bridge and through the woods to Grandma’s house. Happy Thanksgiving!
Despite being an avowed Anglophile since my first visit to the United Kingdom, somewhere around 50+ years ago, I just could not help myself. Professor David Last, Professor Emeritus at the University of Wales (Bangor) and former president of the Royal Institute of Navigation (RIN) was holding forth, with that wonderful, attention-arresting public school accent, on weighty PNT (position, navigation and timing) matters before an awestruck audience.
Professor Emeritus David Last.
And what did I do? I just could not stop myself reminding him and everyone within earshot that the American Institute of Navigation (ION) predated the British Royal Institute of Navigation by more than two years. The point being, of course, that while two years actually makes little difference in the scheme of things, actuarially speaking we yanks rarely have the opportunity to make such a claim where our stiff upper-lipped Red Coat cousins are concerned. So, when the opportunity presents itself, as it typically does at ION GNSS+, then in my opinion, we former colonists just have to jump in with both feet — or one if by land and two if by sea, and all that.
An even more compelling argument for being first revolves around GPS versus Galileo operational satellites. The first GPS operational launch occurred in 1978, while Galileo has yet to launch a non-R&D operational PNT satellite, into a useable orbit that is. Now, before you accuse me of being smug, I am actually making a case for increased cooperation between the United States Air Force (USAF) and our European counterparts (ESA) where precision positioning, navigation and timing (PNT) schemes are concerned. For when it comes to satellite navigation and PNT, we yanks can definitely declare “been there, done that” mistakes and successes. What better place to “crow,” or rather, impart our considerable knowledge and network with fellow PNT aficionados, than at ION GNSS+.
ION GNSS+
All vocal eloquence jealousies and juvenile kidding aside, in many respects the ION GNSS+ event is actually the epitome of international cooperation in the PNT and GNSS (Global Navigation Satellite System) arena. This annual premiere event is described as “the world’s largest technical meeting and showcase of GNSS technology, products and services,” and I wholeheartedly agree. Indeed, the 2014 event, which took place from September 8-12 at the Tampa Convention Center in Tampa, Florida, had the stated goal of bringing together international leaders in GNSS and related positioning, navigation and timing fields to present new research, introduce new technologies, discuss current policy, demonstrate products and exchange ideas. It was a networking paradise in a wonderful, albeit somewhat steamy, venue, which you can review in two excellent videos concerning the event at the ION website.
This ION conference improves every year in content and attendance, and this year was no exception. Congratulations to Lisa Beaty and her whole team for a great conference, year after year. My favorite events are the annual GPS World Leadership Dinner and the prestigious annual ION Kepler award luncheon. Notice a trend?
GPS World Leadership Dinner
This much ballyhooed event becomes more and more of a draw each year. Tickets are coveted (as scare as hen’s teeth as Granny used to say) and competition is fierce. Every year we have about twice as many people wanting to attend as we have room to accommodate them. So the competition is never boring. This year was special in that one of our own GPS editors was nominated for an award and was overwhelmingly elected to receive it.
The Leadership Award winners this year were Javier Benedicto Ruiz, the Galileo Project Manager from the European Space Agency (ESA), who won in the Satellites category, while an old friend Sherman Lo, who is a senior research engineer and associate investigator (APNT) at Stanford University, won in the Signals category. Our own Eric Gakstatter, contributing editor for Survey and GIS from GPS World, won in the Services category; and finally Oliver Montenbruck, who is head of the GNSS Technology and Navigation Group, from DLR, the German Space Operations Center, won in the Products category.
GPS World 2014 Leadership Trophies.
The invited guests, and there was not an empty seat in the house, heard various perspectives from sponsors Lockheed Martin, Exelis, Raytheon, and Braxton Technologies, as well as visions of GNSS progress from our four award winners.
This event will be covered in much more depth in our December issue, but suffice it to say it was as usual a great event. I wonder from year to year how we will ever top the previous year’s entertainment, which always involves audience participation, but Alan Cameron just keeps coming up with outrageous ideas that seem to always pan out. Hope to see you there in Tampa next year.
The Kepler Award
This year, the highly prestigious ION Kepler Award was won by Dr. Pratap Misra. Even though I am happy to say that through the years many of my friends and colleagues have won this coveted award, I can honestly say, in my opinion, there has never been a more deserving award winner than Professor Pratap Misra.
[Correction: The newsletter summary of this article misspells Pratap Misra’s name. We apologize for the error.—Editors]
Pratap Misra, 2014 Kepler Award recipient.
I have had the good fortune to know Professor Misra for many years, and frankly erroneously assumed, along with many others, that since he is so obviously deserving he had previously won the Kepler Award.
The Kepler Award is presented annually by ION in recognition of an individual’s unparalleled, sustained and significant contributions to the development of satellite navigation. It is the highest honor bestowed by ION’s Satellite Division. Professor Pratap from Tufts University meets and exceeds all of these qualifiers and more. He is simply self-effacing and polite as he quietly goes about being the best in all he endeavors.
Throughout the years, I have found Pratap to be extremely dedicated to his work, and more recently to his students. These are key attributes. Academically, I can honestly say that the authoritative tome Global Positioning System: Signals, Measurements and Performance that he coauthored with, another friend and colleague, Professor Per Enge of Stanford University, is among the most dog-eared in my PNT library. This widely praised volume is often described as a “comprehensive introduction to GPS: the system, signals, receivers, measurements, and algorithms for estimation of position, velocity, and time.” And while it was originally intended as a textbook for senior or graduate-level engineering courses, it also serves remarkably well as a self-study guide for practicing engineers and as a reference tool for writers and researchers. I consider it to be one of the three PNT bibles that are a must-have in every PNT subject-matter expert’s (SME) library. (The other two are Global Positioning System: Theory and Applications, Volumes 1 and 2, by Bradford W. Parkinson and James J. Spilker, and Understanding GPS: Principles and Applications, Second Edition, by Elliott Kaplan and Christopher Hegarty.)
Revised Second Edition by Pratap Misra and Per Enge.
In recent years, Pratap Misra has been honored as both an ION and IEEE Fellow and has served as a past chairman of the ION Satellite Division. He has held numerous volunteer positions within ION, but most recently he has focused on something near and dear to his heart, the support of student programs. This is where Professor Pratap Misra is without peer. Frankly it is obvious that his students adore him, and it is due in no small part to his single-minded dedication to and concern for them.
Every time we meet, the majority of his words and thoughts concerns his students. Their welfare is always uppermost in his priority list. Inevitably, while we are attempting to conduct a quiet and private conversation or interview, we are constantly being interrupted by well-meaning students, past and present, who just want to thank Pratap for his help and support. I could fill up several pages with the technical accomplishments of Professor Pratap Misra, but none of those accomplishments, recognitions or awards mean as much to him as the love, support and success of his students. It is so obvious to anyone who pays attention that he wholeheartedly thinks of his students as and treats them just like family.
I am sure, or at least hope, we all have past professors or teachers in our lives that we remember fondly, and then there are the few or perhaps only the one that changed the course of our lives for the better. Professor Pratap Misra is one of those rare latter individuals, so deserving of the appellation — a professor that made a difference in the lives of his students. I am so proud that he deservedly won the Kepler Award and am deeply honored that I can call him my friend.
GPS-IRT Update
The Global Positioning System Independent Review Team (GPS-IRT) is now officially part of the Independent Strategic Assessment Group (ISAG) under the auspices of the Institute for Defense Analyses (IDA). For 19+ years, the GPS-IRT was a separate team within IDA that researched GPS matters with the “goal of insuring both the military and civilian communities would benefit from new GPS/PNT capabilities and services.”
As a result of this organizational change, Air Force Space Command (AFSPC) chose to formally recognize the GPS-IRT’s 19+ years of effort in support of GPS modernization.
Last Thursday, General John Hyten (USAF), the commander of Air Force Space Command, presented a commemorative plaque to Mr. Kirk Lewis, the executive director at IDA, for both the GPS-IRT and the ISAG. The plaque will be displayed with the GPS satellite on permanent display at AFSPC headquarters, in the James V. Hartinger building on Peterson Air Force Base, Colorado. The plaque contains the names of the four prestigious chairmen who led the GPS-IRT over the last 19 years, as well as the names of the members of the IRT over that same time period. Sadly, two of the chairmen and five of the members are no longer with us, but we can only hope they are looking down upon us fondly and giving us guidance of a different sort.
Until next time, happy navigating, and remember: GPS is brought to you courtesy of the United States Air Force.
Threat Development Parallels Information/Communication Technology
Headshot: Oscar Pozzobon
By Oscar Pozzobon
The GNSS interference session this year at the ION-GNSS conference in Nashville was one of the most crowded, confirming the need of all sectors of the community to understand the threats in GNSS and how they can be mitigated. In that context I received one of the most challenging questions of my career: “Can we predict the future of GNSS security?” What is the status of civil and commercial GNSS security today? Which are the threats and risks and how they are mitigated? Where are we going and what shall we expect from the future?
I decided to tackle this topic carefully, using as a basis and inspiration the history of information and communication technology (ICT) security: from the first threats and attacks of the 1980s to a glance at what technology offers today.
Secondly, to obtain different perspectives — and shift the blame to someone else if one day these predictions should prove to be wrong — I solicited the opinions of three other experts and colleagues in the domain of GNSS and security: Logan Scott, Todd Humphreys, and David Last.
Snapshots from History
The Internet was officially born in 1969 when the U.S. Defense Advanced Research Projects Agency (DARPA) crated the Advanced Research Projects Agency Network (ARPANET). A short 11 years later, the 414 Gang, a computer-hacking organization (the term hacking was coined at the Massachusetts Institute of Technology as early as the 1960s) performed one of the first attacks and frauds upon computer systems. In 1983 the first computer virus was discovered. In 1988 the Computer Emergency Response Team (CERT) was created to report and disseminate information on the threats, and AT&T Bell Labs created the first concept of firewalls. Some readers may recall the 1983 movie War Games, which found Hollywood hard at work on cyber-attacks, denial, and deception to computer systems at a time when we had only six GPS satellites in orbit. One year later, Steven M. Bellovin published a paper on the possibility of performing a transmission control protocol/internet protocol (TCP/IP) Spoofing attack.
Six years after that paper, in 1995, the Computer Incident Advisory Committee (CIAC) reported the first TCP/IP spoofing attack to a system. In another four years, the first denial of service (DoS) attack to computer networks was reported by the CERT. A DoS attack consists of several computer systems sending unsolicited requests to the target, causing a saturation of network and computer resources. In terms of objectives, it could be compared to what jamming causes in GNSS systems.
Between 1984 and 1986, Dorothy Denning and Peter Neumann researched and developed the first model of a real-time intrusion detection system (IDS). This prototype was initially a rule-based expert system trained to detect known malicious activity. I like to think that this could be compared to today’s jamming detection and localization systems.
In the 1990s, the need for guidelines to provide general outlines as well as specific techniques for implementing security became a pressing one for all organizations. The first standard, originally published by the British Standards Institution (BSI) in 1995 was the BS 7799, was later adopted by the International Organization for Standardization (ISO) as the ISO/International Electrotechnical Commission (IEC) 27000 series.
Information technology today can be security-evaluated via the Common Criteria (CC) standard (ISO/IEC 15408), which allows computer-systems certification. CC is a framework in which computer system users can specify their security functional and assurance requirements. The Federal Information Processing Standard (FIPS) 140 is an alternative standard for cryptographic modules, developed by the U.S. Federal Information Processing Standards.
The Nessus Project, started by Renaud Deraison in 1998, set as its objective the provision of an open-source vulnerability-assessment tool. Since 2000, Nessus has become one of most popular tools for computer-network security and vulnerability assessment, used by more than 75,000 organizations worldwide.
ICT security today is assured in a lifecycle composed by CERT managing the threats notifications, ISO/IEC 27000 managing the processes, and CC/FIPS 140 defining the security requirements for the system and vulnerability assessment tools to certify the robustness.
Now, Where Are We in GNSS?
Radio-frequency interferences (RFI) or jamming cases can hardly be tracked, as they are difficult to detect and have a long history in the military domain. Recent incidents such the one at Newark International Airport show that the threat is increasing and demonstrate the need for mitigation strategies. GNSS signal falsification frauds, or spoofing, seems to as yet have no evident cases in the civil domain.
The Volpe Report of September 10, 2001 is one of the first government public announcements of GNSS threats, including jamming and spoofing. More than 10 years, later the unmanned aerial vehicle (UAV) experiment coordinated by Todd Humphreys at the University of Texas proved that such attacks are feasible.
In GNSS, jamming detection (and sometime mitigation) are nowadays commercial options for some professional and mass-market GNSS receivers. Spoofing detection has been available in commercial prototype receivers since 2008 (among others, the Trusted GNSS Receiver (TIGER) funded by the European GNSS Agency. In 2012 we have seen the presentation of the first civil GNSS security testbed. For examples of the latter, see the University of Texas TEXBAT initiative, mentioned on page 37, and the GNSS Authentication and User Protection System Simulator (GAUPSS) project, which involved the development of software and algorithms that were integrated and tested in the radio navigation laboratory of the European Space Agency/ European Space Research and Technology Centre (ESA/ESTEC) in Noordwijk, the Netherlands.
I will make the assertion that compared to ICT security, civil GNSS security seems to be reliving the early days of the 1980s: first publication of attack concepts, first publicly known attacks, no standards, and only prototype mitigation strategies. With a gap of almost 30 years, at least four mid-Earth orbit GNSS systems becoming operational in the next few years, and an annual 10 percent growth rate of GNSS applications, the era of civil GNSS security begins now.
The Question Why
Logan Scott is a consultant specializing in radio-frequency signal processing and waveform design for communications, navigation, radar, and emitter location. His opinion on the future threat leaves no doubts:
“In assessing security threats, an important starting question is ‘Why would someone do that?’ If there is no motivation, chances are, there won’t be an attack. Over the last five years or so, the combination of ubiquitous, low-cost communications systems and satellite navigation has moved civil GNSS positioning and timing into use domains where there are stronger motivations for an attack. Specifically, widespread use in asset monitoring and tracking encourages jamming attacks and so, we are seeing more such attack. As GNSS becomes more deeply embedded into societal infrastructure, we can expect to see more attacks of increasing sophistication. Motivation will be there.”
David Last is a consultant engineer and expert witness specializing in radio-navigation and communications systems. He operates in the domain of covert tracking and law enforcement,, an area where interference can be tempting. As expert in the field, and to the best of his knowledge, he believes that “although there are some cases of jamming, we have seen no events of spoofing — so far. To date, all we have seen from criminals are crude jamming attacks. Attacks by technically sophisticated aggressors who understand GNSS vulnerability have yet to start. They will be much more serious.
“Furthermore, when the receiver stops receiving data in a court case, we can’t say it’s jamming: we can mention that is one of the things that stops the signal. Law enforcement is now beginning to use receivers that can perform jamming detection.”
David Last’s opinion on the issue of potential low-cost spoofers appearing in the near future was also provocative: “Criminals don’t buy things, they steal them.”
The Time is Right, Now
An ICT security standard arrived about 10 years after the first publication and case reports of attacks. Are we at the right time, now, to consider security certification of GNSS receivers?
Logan Scott’s opinion is that receivers should be certified in order to provide awareness of the attacks:
“Today, essentially all houses and buildings have smoke alarms. Smoke alarms don’t put out fires but they do alert the occupants to the probability that there is a problem. Similarly, GNSS receiver situation awareness regarding jamming and spoofing is a first step towards militating against attacks on GNSS components. As civil receivers stand today, many don’t discriminate between loss of lock due to signal attenuation and loss of lock due to jamming. This needs to change.
“Fairly simple algorithms can detect most types of jamming and spoofing. Jammers and simple spoofers almost invariably affect automatic gain control gain settings. They are easy to detect. More sophisticated spoofers have difficulty covering apparent direction of arrival and can be detected using some simple antenna techniques.
“The problem for the user community at large is in knowing whether or not a receiver maintains adequate situational awareness. This is where test-based receiver certification can play a role.”
Awareness is indeed needed to notify to the application the security and authentication state. GNSS authentication integrated in the system still lies far off.
Not only is implementing authentication without compromising user cost and simplicity challenging, but the impact on the ground and space segment in GNSS to maintain legacy signals compatibility is also considerable.
We believe that user-based authentication will be the Plan B for the next 5–10 years. This requires the development of receiver techniques and the use of security testbeds as the baseline for vulnerability assessment, in the same way the Nessus tool was used in the 1990s for computer network assessment.
On the test approach, Logan Scott stresses that “Using a series of canned scenarios, GNSS receivers can be tested to determine how well they maintain situational awareness. Do well enough, and the receiver can be stamped as certified, much like an Underwriters Laboratory (UL) label. The test process can be automated and conducted by an independent third party, similar to the way cellular equipment is certified.
“Additional certifications might include cyber security aspects such as accepting only digitally-signed software updates and maps, providing attestation capabilities, and use of authenticatable GNSS signals.
“The benefit for the non-expert user community is that they have a basis for selecting GNSS receivers, secure in the knowledge that they meet minimum performance standards.”
Testing, Testing
Ringing in my third fellow expert, I asked Todd Humphreys, assistant professor in the Department of Aerospace Engineering at the University of Texas at Austin, for his opinion regarding the future of GNSS security testing.
“A testbed capable of simulating realistic spoofing attacks is needed so that the efficacy of proposed civil GPS signal authentication techniques can be experimentally evaluated. A generic testbed capable of evaluating all known authentication techniques would be prohibitively expensive; for example, it would require a large anechoic chamber for evaluating receiver-autonomous antenna-oriented techniques. But if the scope of evaluation is limited to receiver-autonomous signal-processing-oriented techniques and networked techniques, then it is possible not only to develop an inexpensive testbed but to share the testbed’s data component so that the tests can be replicated in laboratories across the globe.
“In October, we released the Texas Spoofing Test Battery (TEXBAT), a set of six high-fidelity digital recordings of live static and dynamic GPS L1 C/A spoofing tests conducted by the Radionavigation Laboratory of the University of Texas at Austin. National Instruments is hosting TEXBAT on cloud servers so that anyone can download it.
“The battery can be considered the data component of an evolving standard meant to define the notion of spoof resistance for civil GPS receivers. According to this standard, successful detection of or imperviousness to all spoofing attacks in TEXBAT, or a future version thereof, could be considered sufficient to certify a civil GPS receiver as spoof-resistant.
“This is a spoofing-specific version of the ‘not stupid’ certification that Logan Scott has suggested for GNSS receivers. In my July congressional testimony, I advocated requiring a ‘spoof resistance’ certification for GNSS devices that are used in critical infrastructure.”
Looking into the Future
Now I turn and attempt to answer the final question: Can we predict the future of civil GNSS security?
I believe that we can predict that, unfortunately, attacks will increase, and new attacks will be discovered. For example, we have been talking about deception jammers (also known as intelligent, PRN, or gold code jammers) only in the last few years, as an emerging threat. We will see certification and standards for security in GNSS, and we expect them to come in the next five years. Tools for GNSS security testing are already available commercially, for example the Qascom GNSS Security testbed (GST). As ICT has CERT for notification of threat, we will also see the raising of a GNSS emergency response team — possibly called a GERT.
In conclusion, whether my predictions turn out to be correct or not, the good news is that GNSS security also has a history in Hollywood’s annals: the 1997 James Bond movie Tomorrow Never Dies narrates a spoofing attack on the GPS navigation system of a submarine, performed via a GPS encoder that modifies the time.
Again, 007 anticipated the future, and he did it 15 years before a handful of world renowned GNSS security experts.
I have not yet seen the 2012 James Bond film Skyfall. I wonder what it portends?
Oscar Pozzobon is the director and co-founder of Qascom S.r.l., based in Bassano del Grappa, Italy. He received a Masters degree in telecommunication engineering from the University of Queensland, Australia, and is the Italian contact for the Civil Global Positioning System Service Interface Committee (CGSIC).
Across transportation, agriculture, industry, commerce, and finance, GPS has replaced earlier technologies, opened up innovative applications, and led to new ways of doing old things. GPS now plays a key role in the critical infrastructures of all industrialized nations, from the most sophisticated telecommunications system to the production of a simple loaf of bread.
Wheat is the world’s second staple food, and bread its main product. Bakers have been around for 30,000 years. GPS, among its manifold other duties, now also helps bring us our breakfast toast and midday sandwich.
British farmers sow 2 million hectares (5 million acres) of wheat per year, harvest 8 tonnes per hectare (3.6 U.S. tons per acre) and sell it at £150 a tonne ($214 per U.S. ton), making their harvest worth £2.5 billion ($3.9 billion). Nearly a billion pounds-worth ($1.6 billion) goes to make bread.
We use Britain as an example because we are British, but this same truth holds, at much grander scale, when you consider the United States, Russia, and many other European nations.
A vital value chain wends its way from farm to mill to bakery to store to home: in the UK, 99 percent of households buy bread, 99 percent of which is made in this country, 80 percent of it from domestic flour. This relatively closed value chain lets us see how GPS is used, and that its loss would increase the price of a loaf and translate into inflation.
GPS serves as the basis of the precision agriculture, cutting fuel costs and enabling selective and variable rate optimized application of fertilizers. It lets farmers use less manpower, reduces soil compaction, and even minimizes operator fatigue. Farmers now spend much more time on yield monitoring and within-paddock zone management than leaning on gates chewing straws. Though the capital cost of precision agriculture is high, the annual benefits are comparable with the investment. Losing GPS-based precision agriculture would increase the price of bread by at least 2 percent.
Transport logistics is the glue that joins our value chain together. GPS in fleet management optimizes routings, accelerates dispatching, prevents theft, improves driver behavior, and delivers fuel efficiencies. Loss of GPS in the transport links in our chain would increase fuel costs alone by 13 percent.
On top of all this, GPS is the ultimate source of precision timing supporting telecommunications links at every stage of the value chain, from wheat futures trading and banking transactions to voice, data, and Internet traffic.
The sudden loss of GPS in farming, transportation, communications, business management, and retail distribution, would substantially raise the price of bread, hit every household, and impact the national economy.
What applies to a traditional and at first glance low-technology product like bread applies across the board. The recent report on GNSS vulnerabilities by the Royal Academy of Engineering says that GPS and other satellite navigation services have applications so pervasive that there is now a real threat to global security if the systems should fail — or be interfered with. The signals are used by almost every industry: rail, road, aviation, space, maritime, agriculture, energy, surveying, construction, law enforcement and communications.
Dependence on GNSS connects many otherwise independent services into a so-called accidental system — with a single point of failure, the satellite signal. And a satellite signal, says the report, is a weak foundation for important services, since it can fail in dozens of ways.
GPS is no longer the only GNSS, of course, as many nations, recognizing its political and economic value, have developed their own systems, and augmentations to enhance accuracy and integrity. Over the next few years, the number of navigation satellites may approach 150. This will help reduce vulnerability to the loss of GPS and so will be a benefit in the short term.
But the long term is a very different matter. All these systems now use, or shortly will use, essentially the same technology. And, crucially, the same radio frequency bands.
In those frequency bands, GNSS is threatened by rising levels of radio interference. This threat has several strands that are being recognized separately and handled individually, but which taken together will determine the future of GNSS.
We face a Triple Whammy!
The First Threat
The first component of the Triple Whammy comes from the new satellite systems themselves. Each satellite transmitting in the GPS frequency band increases the noise level there. Satellite navigation receivers must find and lock onto the extremely weak signal that reaches the Earth, digging it out from the background noise of the cosmos. And the other GPS satellites add to the noise level.
Günther Hein of the European Space Agency shows this remarkable diagram (Figure 1): as the number of systems increases and the number of satellites heads for that 150, up rises the noise they make, the blue-green line. More than about 70 of them, and satellite noise exceeds the cosmic noise floor in red and becomes the main source of noise. The more satellites, the worse the reception as GNSS interferes with itself. Too many satellites, and you’d pick up none at all! The first threat of the triple whammy is self-inflicted.
Chart: David Last and Sally Basker
Figure 1. The first threat of the Triple Whammy: new satellite systems. Source: Günther Hein.
The Second Threat
Conflicts between nations as their new GNSSs compete for radio spectrum also threaten GNSS viability.
The frequency bands available to satellite navigation are essentially L2, L5, and the principal one we use currently, L1. On L1, the European Galileo system and the Chinese Compass system occupy the same areas. Now, that’s very desirable if the two systems are to share receivers. But they also compete for that spectrum, and there is conflict between Compass and Galileo.
This battle for spectrum is a highly complex engineering problem. But chiefly, the spectrum wars are political, even emotional.
Chinese satellites fly across American skies broadcasting signals that interfere with European receivers. Spectrum wars have everything to do with relationships between nations and little to do with battles between engineers. They are developing into a classic tragedy of the commons: a situation in which self-interest determines how a limited resource — here the radio spectrum — is to be shared in a regime in which regulation is weak. The International Telecommunication Union sets standards and registers claims. The UN Office for Outer Space Affairs seeks to mediate. But neither is a policeman; sovereign governments may sometimes be penniless, but they are very powerful.
The second threat of the Triple Whammy is also self-inflicted.
The Third Threat
Communications systems compete with GNSS for spectrum: witness the current LightSquared case of a powerful new broadband system. For existing receivers, including those in government systems and aviation, it seems there is no fix for its devastating interference. LightSquared is driven by rich and powerful commercial forces; it could well win this fight.
Communication technologies will continue to press upon the satellite navigation spectrum. LightSquared will likely erode spectrum gaps between communications and navigation services, the so-called guard bands.
Satellite navigation has become highly political. The intense use of GNSS across our economies makes them vulnerable. GNSS is threatened by a Triple Whammy, by jamming, and by spoofing. These increase the risks to our security and our economies, both in probability and impact. The solution of detecting jammers and making ownership illegal will help with local problems in local areas. But the Triple Whammy threats are not local; they are national and international, world-wide.
Today’s spectrum wars affect us all. That the loss of GPS would increase the price of a loaf — the very trigger for the French Revolution — brings this down to earth.
These are not technical issues, they determine the price of our food! They constitute a real and present danger to our societies — down to the mundane yet very real level of our daily bread.
David Last is a past-president of the Royal Institute of Navigation, a consultant and expert witness on radio-navigation and communications systems to companies, governmental and international organizations, and criminal investigators.
Sally Basker, former director of research and radionavigation at the General Lighthouse Authorities of the UK and Ireland, has opened Traxis Ltd: management, business, and technology advice with expertise in navigation service provision. See www.traxis.co.uk.
This article is adapted from a presentation at the European Navigation Conference, London, November 2011. A longer version of the talk appears in the Royal institute of Navigation News.
A range of unrelated events in September show that GPS, the world’s preeminent GNSS, remains a work in progress.
The first in a series of deviations from normal GPS signal broadcasts during September was noted by researches at the University of New Brunswick, among others around the globe, who found that normal signals from the L1 and L2 transmitters on the GPS satellite PRN01/SVN49 were unavailable for more than two hours on the morning of September 4.
The satellite did not transmit useful signals on L1 and L2 from about 12:00 to 14:11 UTC, as reported by International GNSS Service stations in Europe. The L5 test signal continued to be tracked by some receivers but not others.
One possible explanation for the inability to track PRN01 is that the satellite rejected an upload and automatically went into non-standard mode, resulting in GPS receivers being unable to track the L1 and L2 signals. In other words, the L1/L2 transmitters were still on but transmitting a non-standard signal.
“It is not known for sure what actually happened with the satellite, but perhaps it is related to the ongoing issues with the signal reflections on the satellite and that the GPS Wing was conducting further tests,” said Richard Langley, GPS World’s Innovation editor and professor at the University of New Brunswick. “Luckily, the problem was short lived.” As to why some receivers continued to track the L5 signal but others did not, Langley speculates that some receivers may need to acquire and track the L1 signal before they can track the L5 test signal.
HDOP Warning. On September 10, the U.S. Coast Guard Navigation Center (USCG NavCen) issued a high dilution of precision (DOP) warning for certain locations in the U.S., Asia, and Oceania, reporting that GPS users might experience a temporary degradation in GPS reception in parts of the southwest and central United States from 13:02 UTC to 13:23 UTC on September 11.
“The warning is based on a best-four satellite scenario: what the DOPs would be if we only used the best four satellites (the combination providing the lowest DOP value) of all the satellites in view at a particular location,” said Langley.
“However, most civil receivers these days track eight or 10 or all satellites in view. I contacted the Coast Guard about this, and they did another analysis and confirmed DOP spikes for all-in-view users too. Prompted by that, I did my own analyses and found that with PRN31 out of action for the delta-V and PRN01 not yet declared healthy, only five satellites above 5 degrees elevation angle (and almost colinear in the sky) will be visible at the stated locations and times, resulting in GDOP spikes approaching 100!
“So, in this case, the warning is for all users in the affected areas, not just receivers with only four channels.”
Although a window stretching from 00:30 to 15:00 UTC had been allocated for the PRN31 delta-V maneuver, prompting the high DOP alert, the GPS Wing avoided any problem to users by delaying the start of the operation until 01:27 UTC and completing it in little more than one hour. The satellite was back on line by 02:37 UTC.
Sat Moves. After 22:00 UTC September 12, system operators began transitioning satellite SVN25 (PRN25) into the broadcast almanac for all satellites. Meanwhile, they moved satellite SVN24 (PRN24) out of the almanac.
The current GPS operation control system (OCS), known as AEP, cannot handle 32 satellites. However, the recent move gave rise to speculation that the maximum number of operable satellites has now been reduced from 31 to 30, for some reason. Apparently, the military cannot allow more than 30 space vehicles to be in active service at any one time. So when a new SV is activated, one must be deactivated. SVN24 will be placed in caretaker status, ready to be brought back on line should the situation change or the 30 SV limit be overcome.
Recent pronouncements by GPS Wing personnel on the benefits of the next operating system, OCX, have stated that it will be able to handle many more satellites, as many as 60. This figure now appears in doubt.
Russian Vision. Grigory Stupak and Mark Shmulevich reported Russia’s plans to restore a full GLONASS constellation of 30 space vehicles, laying out a road map leading to full interoperability with GPS. They envisaged a world orbited by 117 navigation satellites, with GLONASS operating alongside GPS, Galileo, and China’s COMPASS, supported by a further 29 augmentation satellites. That would certainly mitigate many of the vulnerabilities of GNSS due to propagation effects — but not those from interference in the frequency bands they will all share.
Solutions Sought to GNSS Vulnerabilities
Baska conference report by David Last
The second conference on GNSS Vulnerabilities and Solutions, September 2–5 in Baska, Croatia, focused on GNSS vulnerability to space weather, unintentional interference, jamming, and multipath propagation.
The conference was a joint venture by the Royal Institute of Navigation, London, and Nottingham University’s Institute of Engineering Surveying and Space Geodesy. Sixty-four delegates, mostly European, came from 21 countries.
Nearly half the papers focused on space weather and ionospheric and tropospheric propagation, taking in long-term and short-term solar effects, scintillation, signal attenuation, tropospheric delay variations, meteorological influences, and even gravity waves. The approach of the physicists was: Understand these things and maybe you can mitigate your vulnerability to them.
GNSS vulnerability can threaten safety-critical and mission-critical systems, including navigation in the air, maritime automatic identification systems, and the transportation of nuclear waste and other dangerous materials on land. Mitigations include EGNOS (the European WAAS) and GBAS (ground-based augmentation systems.)
Road Tolling. An unexpectedly hot topic was the enthusiasm of European governments to deploy road-user charging schemes based largely on GNSS technology. Some say road pricing is a rare and novel case of GNSS users who are hostile to the technology and seeking to exploit its vulnerability to the maximum. To enforce charges through the legal system may require levels of integrity approaching those of aircraft instrument-approach systems.
Suggestions for jamming defenses came mostly from Germany: Ulrich Engel and Angelika Hirrle proposed exciting new mathematical techniques to help separate GNSS signals from noise and interference, while Michael Felux sought refuge in low-cost inertial systems.
Hank Skalski of the U.S. Department of Transportation laid out U.S. government plans to detect and track down sources of GPS jamming. The SETS (Space Event Tracking System) will deploy aircraft, vans, fixed-base units, and trained technicians.
The U.S. Federal Aviation Administration (FAA) has certified Honeywell’s Smartpath precision-landing system for airport installations. As this magazine went to press, neither the FAA nor the Department of Transportation had issued an official release, but industry contacts were notified in mid-September.
The ground-based augmentation system provides aircraft with precise navigation data for CAT I approaches and landings, enabling closely spaced parallel and curved path approaches to increase airport capacity. It asserts improved navigation accuracy over instrument landing systems (ILS), using differential GPS and broadcasting both pseudorange corrections for each satellite in view as well as approach path information in a digital broadcast.
According to Honeywell, most current-production Airbus and Boeing aircraft now carry GBAS avionics or offer it as an option. Future Smarpath upgrades include the ability for CAT III approaches.
Arctic Passage Traversed by Merchant Ships
Two German merchant ships traversed the Northeast Passage from South Korea, leaving in late July, to Siberia, and plan to continue their journey to Rotterdam in the Netherlands.
A sea lane traditionally blocked by heavy ice floes or solid sheet ice, this route has opened because of to global warming. In 2007, Arve Dimmen, director of maritime safety for Norway’s Coastal Administration, told the U.S. National Space-Based Positioning, Navigation, and Timing Advisory Board that disappearing ice across the Arctic poses potential threats: 25 percent of undiscovered oil resources lie in that region, and the route could now be used by supertankers and large container ships, as it is more economical and less time-consuming.
Precision navigation faces more challenges north of the Artic Circle, from atmospheric affects in polar regions and the low elevation of SBAS satellites at those latitudes. A June 2009 study on GNSS use in the high Arctic by Richard Langley, however, found that conventional horizontal (marine) navigation works well north of the Arctic Circle. Still, others held that “this is another reason why eLoran is so important: someone at USCG/State/Commerce needs to use this as a wake-up call!”
Created from nearly 200 Envisat scenes, this Arctic mosaic reveals that the most direct route of the Northwest Passage (the orange line) across northern Canada is fully navigable. The blue line traces the Northeast Passage along the Siberian coast, which is only partially obstructed by ice; see story, page 16. Envisat advanced synthetic aperture radar mosaic produced by the Danish National Space Center.
The most widely used of all GPS devices are in-car navigators. When vehicles carrying navigators are used for criminal purposes, records contained in the devices may be examined. Such investigations rely on newly developed forensic techniques that employ a combination of computer expertise and navigation knowledge, yielding valuable data for crime investigators.
Evidence from GPS-based tracking systems now fitted to a wide range of vehicles can be of even greater value. These installations, many of them covert, provide a history of vehicle movements. Forensic analysis of such records can provide evidence of considerable value in crime detection.
Whilst the principal purpose of vehicle-tracking systems is generally to provide real-time information for efficient fleet control, they also serve an important security function. By continuously displaying up-to-date location information and identifying vehicles that deviate from planned routes or cross specific boundaries, they help protect assets that include the vehicles themselves and their high-value contents. Vehicle-tracking systems now constitute one of the most important GPS applications for our society.
The recent appearance of readily available, low-cost GPS jamming devices presents a real and immediate threat to all such tracking and security systems. Criminals now employ jammers that can block both GPS reception and GSM in Europe, and U.S. and other mobile phone systems throughout the world, rendering vulnerable the use of GPS in critical security applications. Other global satellite navigation systems (GNSS) in development will likely share that vulnerability. While not yet deployed for criminal purposes, spoofers that mimic GNSS signals will pose an even greater threat to vehicle security than jammers.
Alternative technologies, including enhanced Loran (eLoran), for vehicle navigation and tracking are not vulnerable to these threats, and promise a degree of protection to vehicle-tracking and recovery systems. These solutions will likely play an increasing role as GNSS jamming and spoofing activity increases.
Vehicle Navigators
Vehicle navigators often contain large numbers of records created by their users. These may show where they have been, how they got there, and a great deal more of value to investigators.
The destinations stored in car navigators can be extracted, listed, and plotted. It is now possible to do this for virtually all makes and models of device, whether after-market installations or built in by the manufacturer. Such examinations must be conducted with great care, to maintain high forensic standards so the evidence will stand up in court. It is also essential to preserve that evidence. This requires screening receivers from incoming satellite signals during the examination; this can be very difficult to achieve given the exceptionally high sensitivity of current GPS receivers!
Some car navigators disclose a great deal of information: who owns them; multiple addresses; a home address plus favorite addresses; destinations visited most frequently or most recently; the language spoken by the user, and other preferences; whether the user travels abroad; and occasionally telephone calls made and received. Some units even contain a detailed record of journeys stretching back over months, each point timed and dated (see Figure 1). These can provide compelling evidence of criminal activity.
Figure 1. Detailed tracks of routes travelled by a vehicle, each point dated and timed.
Tracking systems
Probably the most impressive forensic evidence involving GPS comes from the tracking systems now fitted to increasing numbers of trucks, trailers, delivery vans, and rental cars. Each vehicle carries a receiver that records its location and sends it at intervals to a tracking center via mobile phone data services. The tracking center may store, process, and display the data on a map, and raise an alarm if a high-value cargo deviates from its planned route or if a rental car is about to be exported illegally. Many of these tracking installations are covert and very difficult to discover.
When the police seize a tracking record, a forensic expert must audit the data in various ways, shown in blue in Figure 2. These focus on the many parts of the system the tracking company does not control. Tracking companies generally do not check the quality and accuracy of GPS at the time, and in the place, of a crime. A navigation professional, accustomed to dealing with high-integrity safety-of-life systems, can bring valuable experience to examining tracking records.
Figure 2. Vehicle tracking system with checks (in blue) to establish quality of evidence.
It is also often necessary to estimate the accuracy of GPS fixes. Doing so may require analysis of complex situations. An example would be the GPS receiver in a covert tracking system, with its antenna hidden deep inside the vehicle, perhaps behind the dashboard. The vehicle itself might be surrounded by tall buildings that block and reflect satellite signals. This is a novel and fascinating area where navigation and forensic science meet!
GPS Jamming
The use of GPS jammers, long foreseen in navigation circles, has become a reality as criminals employ them to overcome tracking systems and steal vehicles. These low-powered transmitters (see photo), readily available over the Internet for as little as $150, can block GPS reception in a vehicle’s vicinity.
GNSS satellites transmit no more power than a car headlight, yet must illuminate nearly half the Earth’s surface from 20,000 kilometers above it. Signals reaching a receiver are easily swamped by even a thousandth of a watt of jamming signal radiated near by.
Figure 3 shows the spectrum of the signal radiated by the low-power jammer in the photo above it, plotted across a 100 MHz frequency range centred on the GPS L1 frequency at 1575.42 MHz. The total power this jammer radiates is only about one tenth of a milliwatt, yet that is sufficient to block commercial GPS receivers over a few meters range — all the criminals need.
Low-power GPS jammer.Figure 3. Signal spectrum radiated by low-power jammer.
GPS/Phone Jammers
If a vehicle is to be completely screened from electronic tracking, not only must GPS be disabled in its vicinity, so must mobile phones as well. If not, they can be used to call for assistance; they can also be tracked using cell-site analysis methods. To prevent that, a jammer (see adjacent PHOTO) can block not only GPS reception but also that of all the mobile phone bands used in the area. The spectra of the jamming signals radiated by this device are designed to cover the frequency bands in which European 900 MHz, 1800 MHz, and 3G base stations transmit, so preventing mobiles from receiving them and establishing communications.
Recently, much more powerful jammers have appeared on the market (see adjacent photo). These radiate approximately two watts on each frequency, a power level some 20,000 times greater than the low-power jammer — and more powerful than the transmitter employed recently in official UK tests of effects on shipping of jamming GPS over a sector of the North Sea up to 30 kilometers from the jammer. A two-watt jammer could interfere over a substantial area.
Other GNSS
The spectrum in Figure 3 of the jamming signal of the simple low-power device extends from approximately 1563 MHz to 1600 MHz. Towards the center of this band is the civil GPS signal, approximately 2 MHz wide. The jammer also covers the 20-MHz-wide military P/Y signal, the yellow block. The slightly wider blue block represents L1 signals planned for Galileo, so this device would serve as a Galileo jammer, too. Its spectrum covers only the low end of the (purple) GLONASS bands, but other similar devices on the market jam that as well.
It is often argued that, since Galileo will use more than one frequency band, simply jamming L1 would not prevent Galileo reception. However, the bottom photo shows a jammer that has recently come onto the market, with two transmissions: one covering L1; the other, at a higher power, covering the L2 band. Adding L5 would be trivial. These are the frequency bands in which present and planned GNSS operate.
The jammers presented here are relatively simple and crude, but highly effective in preventing the operation of civil GPS receivers. They are readily available and are certainly being sold and being used. They render our GNSS-based security systems vulnerable to attack.
More seriously, I believe that it is now technically feasible, though apparently not yet within the capabilities of criminals, to spoof GPS. When that happens, it will allow criminals to hi-jack and divert a vehicle whilst the tracking system shows it still following its planned route — no alarm will be raised. Vehicles will also be able to avoid purely GNSS-based road-user pricing systems.
From left: Jammer for GPS, GSM (900MHz), DCS (1800MHz), and 3G mobile bands; high-power jammer for GPS and mobile phone bands; L1 and L2 jammer.
Mitigation
All is not lost! In many countries, vehicle-tracking systems such as Datatrak are deployed that do not depend on GNSS. There are also vehicle recovery systems such as Tracker with its LoJack technology installed in police cars and helicopters. These systems are immune to GNSS jamming and spoofing. Of course, like all radio systems, they can be jammed. But they are orders of magnitude less vulnerable than GNSS, and jammers that targeted them would be easier to detect.
Dead-reckoning can also mitigate GNSS jamming. Many cars with built-in navigators carry heading sensors and wheel-rotation counters to cope with loss of GPS in tunnels and urban canyons. They are immune to jamming, at least for short periods and distances. But they would not necessarily be immune to GNSS spoofing.
Enhanced Loran, or eLoran, offers a complete alternative navigation technology. Built into a GNSS receiver, it can take over seamlessly when GNSS is jammed, and replace precise GPS timing that currently keeps most of our telecommunications systems and the Internet running. There is great interest in this cost-effective insurance policy worldwide.
Conclusions
Legal and forensic aspects of GNSS grow ever more important, and their role more vital and successful in reducing crime. We must plan our responses to the vulnerability of our current and future GNSS-based security systems, which are now under attack. We must recognize these threats and encourage open and full discussion of them and of solutions to the dangers they pose.
DAVID LAST is the immediate past-president of the Royal Institute of Navigation, a consultant and expert witness on radio-navigation and communications systems to companies, governmental and international organizations, and criminal investigators.
