While farmers work on growing and gathering their crops in the most efficient ways possible, other people key to the agriculture industry are hunters. These hunters seek the most efficient and groundbreaking ways to carry out such tasks as plowing, planting, fertilizing, weeding and, finally, gathering.
This month, among other machine-control applications, we focus on using GNSS technology to improve agricultural efficiency. According to research firm MarketsandMarkets, the precision farming market is estimated to be $7 billion in 2020 and is projected to reach $12.8 billion by 2025, growing 12.7% every year between.
Factors driving growth include increasing farm mechanization in developing countries, rising labor costs, increasing strain on the global food supply, substantial cost savings associated with smart farming techniques, and government initiatives to adopt modern agricultural techniques. For a look at today’s technology, see our cover story.
James Litton
Sadly, this month we also say goodbye to a pioneer in the precision ag field. James D. Litton founded NavCom Technology in 1995 with three partners, Ron Hatch, KT Woo and Jalal Alisobhani.
Litton’s career began at Magnavox in the early days of GPS, where he worked on the original proposal for GPS Phase I and helped develop new and advanced commercial navigation and survey receivers for both the Navy’s TRANSIT system and the Air Force’s GPS.
In 1992, Litton opened a consulting firm, and in 1994, he and his partners founded NavCom with Litton as CEO. Under contract, NavCom developed a single-frequency WAAS-capable GPS aircraft navigation receiver.
“His work transformed agriculture into a data-driven, technological industry.” — Brad Parkinson
NavCom also began a relationship with Deere & Company, supporting more efficient and productive agriculture. This relationship was so successful that Deere, which recognized GNSS tech as a smart investment, purchased NavCom in 1999.
Litton continued to lead the company and serve as part of Deere’s senior management team for eight more years.
Among his many contributions to the GNSS field, his impact on global agriculture might well have been his greatest, according to Brad Parkinson, the original chief architect for GPS and Editorial Advisory Board member.
“His work transformed agriculture into a data-driven, technological industry that was incredibly more efficient,” Parkinson said. “The cost savings and increases in productivity have impacted billions around the world.”
Litton also authored several articles for GPS World.
New Technology, New Applications, New Science from the Stanford Symposium
Headshot: James D. Litton
By James D. Litton
The sixth annual Stanford PNT Symposium in November brought together a select group of experts to share insights from the latest research, developments, and proposals, GNSS and non-GNSS, that show promise for the international community. Among other noteworthy presentations, we heard Brad Parkinson’s suggested incremental system changes to significantly improve signal availability and accuracy, a comprehensive update on China’s Compass system, and the latest in spoofing and proposed proofs of location.
GNSS in General
The budget realities of U.S. GNSS development, and the need to maintain the systems at the high levels of performance upon which so many critical and commercially beneficial applications now depend, were analyzed by two men with industry-household names, Brad Parkinson and Gaylord Green.
Nibbles. Professor Parkinson gave a very sophisticated, nuanced presentation entitled “Nibbles,” in which he outlined feasible and productive technical steps to ensure the preservation of what he described as “the three As:” availability, affordability, and accuracy. Rather than do radical surgery on accuracy or availability in order to preserve affordability, he identified so-called nibbles at requirements, incremental improvements enabled by use of current technology advances, for example, vector (Spilker) receivers, power-conversion efficiency improvements, antenna gain and steering modifications, weight reduction for multiple launch capability, and use of sensor fusion for more robust receivers with greater jam resistance.
It was a high-level but quantitative system design approach aimed at improving affordability and interference resistance while maintaining and improving availability and accuracy. He made the salient point that affordability with a given level of performance is enhanced by availability, that is, maintaining 30+ satellites on orbit brings multiple benefits that improve affordability. The estimates of gain from the nibbles struck me as conservative, at least for those with which I had some quantitative feel.
Alternative Architectures. Col. Gaylord Green addressed the same subject with a different approach, in a presentation entitled “GPS Alternative Architectures.” His motivation for alternative architectures was to provide the needed PNT capability at an affordable cost. He pointed out that GPS satellites have increased in dry weight from 334 to 2,100 pounds, and that the cost of the IIA, IIF, and III satellites have gone from $100 million on orbit to $400 million on orbit. Colonel Green indicated that starting a new development with the same signals cost more than continuing with GPSIII. (The Congressional Budget Office has recommended consideration of using IIF satellites to maintain the constellation and bypassing GPS III.)
The reduced capability satellites are called NavSats. He suggested that a mixed constellation of NavSats (with minimal ancillary payloads and frequencies) such as 15 GPSIII and 15 NavSats would enable a constellation of 30 satellites; the minimum necessary to assure sky-challenged users of satisfactory coverage. He recommended that design of satellite power conversion to be set by start-of-life, not end-of-life goals. Colonel Green identified the signal priorities in terms of their functions (L-5, L-2, L1C, and four military signals requiring crypto). Like Parkinson, he identified technology changes in antennas and signal architecture to reduce costs, necessitating a demonstration program. He also indicated that advantage could be taken of other GNSS constellations for civil signal purposes, alleviating the demands on GPS satellites. Colonel Green identified satellite constellation arrangements which would be more cost effective (multiple launch) and provide adequate coverage. He pointed out that such a NavSat program would require a new start and would necessarily constrain GPS modernization funding. In short, such a “GPS Alternative Architecture approach” would combine continuation of GPS III as planned with the addition of simpler, lighter satellites with reduced diversity of signals to replace the aging GPS satellites now on orbit beyond their design life.
Compass. Professor Jingnan Liu of the GNSS Research Center of Wuhan University gave what most observers thought was the first comprehensive and data-intensive description of Precise Positioning results with the COMPASS (Beidou) system. He showed that the Beidou regional system, from which he presented copious data, can currently provide standard positioning service with <10M horizontal and <20M vertical accuracies at 95% confidence level. He also showed that results with Beidou plus GPS are 10-20% better than GPS alone. He provided results for surveying, for ground-based augmentation, for RTK, PPP, clock stability, orbital statistics, wide area differential and many other metrics of PNT. Professor Parkinson noted, in appreciating the presentation, that it was the first detailed release of so much technical data on COMPASS performance. The results noted above were obtained with 4GEO+5 IGSO+2MEO satellites. The constellation is expected to grow to 5GEO+5IGSO+4MEOs by the end of 2012 and to 5GEOs+3IGSOs+27 MEOs by 2020 for a global service. The amount of data and the diversity (application and instrumentation) of the data were truly impressive.
GPS Modernization. Dr. Keoki Jackson of Lockheed Martin presented a comprehensive review of GPS Modernization with charts which described the evolution of GPS from Block I to Block III. He depicted the program as on schedule for delivery of the first GPS III vehicle in May, 2014, with a 2015 launch. Most of this material was the same as reported from the AFCEA GC-12 program in GPS World earlier this year. A matrix comparing the attributes of GPS III with GPSII and beneficial outcomes from “Back-to-Basics Investments” were key takeaways.
Ground Control. Ray Kolibaba of Raytheon presented a detailed overview of the OCX program, the next generation Operational Control System. This presentation also emphasized improvements in program management, simplification of development practices, extensive use of commercial development methods and predicted on-time delivery with all of the attributes needed for both GPS III and the existing constellation.
Military User Equipment. Col. Bernie Gruber, Director of the GPS Directorate, gave an update on current activities with emphasis on progress in Military User Equipment (MGUE) development. This material was somewhat further advanced in schedule than the equivalent May 2012 time frame in which the same subject was presented in much detail at the AFCEA GC-12 meeting at the Directorate. The currently ‘hot’ topics of jamming and spoofing threats, countermeasures and affordability were prominent in the presentation. Some of the key achievements for 2012 listed were the release of BAAs (Broad Agency Announcements) for NavSat studies and the completion of a Congressional Report on ‘Cost Effective GPS). Launch of GPS IIF-3 and delivery of GPS IIF-4, 5,6 & 7 were also noted. Security Certification for MUE cards was a very noteworthy achievement, which will make future MGUE development and utilization much easier for the challenging jamming and spoofing environment which is expected. The themes of affordability and jamming and spoofing threats were dominant in this review, as well.
General PNT
Norvald Kjerstad is a professor of Nautical Science at Aalesund University College and a long-time professional navigator in academic, geophysical, and shipping communities. His paper vividly depicted the risks brought about by climate change, by increased commercial interest in shipping and mineral resource exploration in the Arctic region, and by the very limited navigation infrastructure and limited communications assets.
Arctic Navigation. Both DGPS and SBAS systems are quite limited in the arctic, magnetic compass systems are less accurateat the very high latitudes ( and their errors propagate into navigation radar, collision avoidance and other systems). Auroral effects limit the availability of GNSS at times (Glonass improves GPS because of the higher orbital inclinations) and hydrographic charts of the arctic are frequently quite wrong, due to changes in water depth and to limited surveying frequency. Increased tourism, shipping and resource interest intensify the consequences of the increased risk to seafarers.
The advent of Galileo and Compass, integrated with GPS-Glonass will greatly improve the reliability of GNSS signals. However, navigation through the ice, at places thin and navigable and at random places deep and massive (ice ridges) is much more than knowing where one is with respect to the center of the earth. Radar helps with detection and avoidance of ice ridges but the sinking and grounding of icebreakers and commercial vessels demonstrate that much better knowledge of the environment is needed to avoid future disasters. The thousand-kilometer shorter route over the Pole can be very expensive and not necessarily the fastest one. However the increased activity in the Arctic is going to continue, and it is mandatory that safety factors be given greater attention by the International Maritime Organization (satellite compasses are reliable where magnetic ones are not, but the IMO has not approved them) and by the hydrographic services of the affected areas.
From Farm to Front Office. Jim Geringer, former governor of Wyoming, now a director of ESRI and a member of the GPS Excom gave, as usual, a very entertaining presentation (“GPS/GNSS From the Farm to the Front Office”) with highly interesting examples of the very broad and deep impact of GNSS on society, including financial statistics and object lessons in the misuse or inaccurate use of geospatial data. Geringer was an engineer before he went into politics and that came through clearly in the presentations, even though he was very self-effacing concerning his technical credentials. He gave amusing examples, not all from Apple, of the effects of combining current and historical geospatial data, such as airport runways shown in topography layers obtained before leveling the airport areas, and a road running across the valley filled by Hoover Dam.
Geringer critiqued an attitude on the part of GNSS professionals in which their attention is more devoted to the how of obtaining the information than to the effects that future changes might have on the users. He discussed policy challenges presented by the FCC mandate to find 500MHz of spectrum for high speed wireless data, by affordability, by the potential for jamming and spoofing. It was good to be reminded of the awesome realized economic benefits of GNSS, the manifold applications which GNSS systems enable and the ease with which this potential can be limited or actually damaged by pursuit of other worthwhile objectives which are politically favored or which bring short term revenue into the treasury at the expense of GNSS system requirements in bandwidth. The less obvious but equally or more beneficial economic benefits of high accuracy GNSS and the impact of actual lives lost or resources untappedwere illustratedand quantified in Geringer’s broad presentation. One hopes that this presentation will be or has been seen at High GSA and policy levels in the FCC and NTIA.
Geringer’s presentation provides a nice segue into a presentation by:
LightSquared Lessons Learned. Rich Lee of Greenwood Telecommunications Consultants, LLC and iPosi. Entitled Lessons Learned from the GPS-LightSquared Proceeding, it was an assessment of the opportunities missed and damage done in the drive to enable the use of spectrum adjacent to GNSS frequencies for 4G LTE wholesale services through high power Auxiliary Terrestrial Components (ATCs) using MSS spectrum reallocated (or repurposed) to the purpose under a conditional waiver by the Chairman of the FCC, Julius Genachowski, on a recommendation by the International Bureau of the FCC. According to Lee, Greenwood was called in to solve, “if solutions exist” the problem of the ‘spectrum collision’ between the LSQ design and GPS, after the collision occurred. He likened the role of Greenwood to that of a tow truck operator called in to clear up a collision after the impacts. Lee served on the TWG (Temporary Working Group) as head of the cellular subgroup and headed the NTIA/Excom cellular tests. The presentation was very good, technically, in both its detailed and more strategic aspects but both the history described and the lessons learned (see below) were, understandably, from the perspective of a party which was unable, in this particular instance, to achieve the goals desired by their sponsors. This failure was for reasons of basic spectrum policy conflicts between GNSS applications and those mooted to become transcendent- mobile high speed data for consumer and industrial applications.
Lee depicted the lack of a requirement in history for regulation of receiver standards, as opposed to transmitter standards, to the inability to anticipate the crowded spectrum (for example, his statement that spectrum was regarded as “free” and minimizing interference was the key objective, a burden placed on the transmitters). Now that spectrum is seen as scarce and underutilized in many U.S. government applications and inadequately conserved in many civil applications, the concept of receiver standards for avoiding interference and the use of advanced filterand antenna technology in receivers as well as in transmitterswould enable easier, less confrontational and more lucrative use of this 21st century El Dorado.
Parenthetically, Pierre de Vries (University of Colorado, and a member of the FCC’s Technical Advisory Committee) and others recently testified to a House of Representatives panel, recommending that harm claim thresholds be established with which to manage the trade-offs between intrinsic receiver protection requirements and transmitter power distribution, so that instead of just adding the specification requirement to receivers, a flexible system approach be adopted. They noted that it was very difficult to anticipate the receiver design needs for all applications. The failure to understand the requirements of precision GNSS receivers and the simplistic concept of fences was a large driver in the collision between LightSquared and GNSS.
Lee’s lessons learned summary is:
Upper 10: candidate for ground augmentation? The upper 10 MHz (1545-1555 MHz) of spectrum was originally allocated to LightSquared through its acquisition of TerraSat. During the 2012 conflict months, LightSquared publicly abandoned operating in the Upper 10.
Question: sound alternatives for this band? (Including as a good GNSS guard band)
Consider: sub-microwatt uses for short range augmentation, such as Department of Transportation Intelligent Transport Systems (ITS)-TWG findings. Given very low effective isotropically radiated power (EIRP), ample compatibility with precision GPS nearby.
Precision GPS: –82 dBm worst case Upper 10 susceptibility (–1 dB C/NO)
1 uW EIRP transmitter is about 13 dB below at 1 meter
Seems suitable for high availability in urban areas; provides urban in-fill, redundancy such as ITS
At 100-mETER range: Signals ~-135 dBm incident power at an ITS receiver antenna
Band continues as a space-to-earth downlink, shared with geostationary Earth orbit-mobile satellite services, including carriage of GPS/GNSS corrections (OmniSTAR, StarFire)
Lee contested the FCC chairman’s assertion that the LightSquared-GPS matter was an anomaly, saying instead that it was “foreseeable.”
However, foreseeable anomalies such as singularities exist in predictions of scientists. I believe that this anomaly was clearly foreseeable, but a hedge-fund mentality, financial engineering, and a long-held attitude toward GPS in the FCC were the drivers of these benighted decisions.
The gold rush is still on for finding underutilized spectrum. Some systems, including GNSS, utilize bandwidth that needs protection for purposes other than the usual communications requirements. It is vital to honor the homesteads of GNSS and protect the noise floors. Receiver standards must be considered very carefully because communications receivers and high precision GNSS receivers are very different systems.
Scientific Subjects
Some presentations grouped under this topic are available in ION publications from GNSS 2012.
Atom Interferometry. Mark Kasevich of Stanford presented his paper on precision navigation sensors based upon atom interferometry. While application of these sensors in general awaits many highly difficult engineering advancements, the outcome would be a great boon to navigation, were the outcome comparable to the evolution of chip-scale atomic clocks.
Andrei Shkel reprised his paper entitled “Precision Navigation, Timing, and Targeting enabled by Microtechnology: Are we there yet?”
Gravity. Tom Murphy of the University of California, San Diego, gave a fascinating paper of fundamental importance to understanding gravity by laser ranging to retroreflectors left on the moon by various Apollo and Russian missions. A highly contrived initialism for the project is APOLLO, for Apache Point Laser Observatory Lunar Laser-Ranging Operation. The work is a product of a seven-university/research center consortium.
The system of APOLLO for measuring the range of the moon relative to the earth at Apache Point is a marvel of experimental ingenuity and advanced instrumentation in collecting the few photons that get back from the laser shots at the moon. Laser light is caught by the retroreflectors and returned to the telescope at Apache Point. A very sensitive gravimeter system at the observatory enables compensation for the Earth’s crustal motions, and orbital deviations are compensated. Precisions of a few millimeters in range to these devices on the moon are achieved, almost good enough to be useful in testing the “Strong” Equivalence Principle of General Relativity.
From an engineering point of view, the timing, motion compensation, detection sensitivity (a few photons per shot), and several other features of the system are truly impressive, and the potential for improving our understanding of general relativity, so-called dark matter or energy, and more, are exciting aspects of this work. To have much better precision through placing laser transceivers on the moon to increase the number of reflected/transponder photons in the samples would appear to be quite valuable and relatively simple NASA missions for future work, even though the data may eventually be sufficient to enable theoretical advancements without such added signal-to-noise benefit. This paper was an example of excellent engineering in the service of important science.
Vulnerabilities and Limitations
Charles Schue of UrsaNav gave a very detailed and comprehensive paper on wide-area timing, navigation, and data using low-frequency technology. He provided data for timing, location, and data transmission over distances greater than 125 nautical Mmiles.
eLoran. He made the point and showed examples to demonstrate that the technology for these systems exists today, is highly affordable, and can represent a major strengthening of the nation’s critical infrastructure. The systems and hardware he presented are very attractive and seemingly very mature.
Schue was preaching to the choir, as far as I can tell; there is, in the PNT community, no controversy about the need for eLoran. Further, there is a sense of disappointment and wonder that so little money was saved at the expense of great risk to our critical PNT infrastructure, particularly in view of the vulnerability to jamming and spoofing of GPS and the other GNSS systems for civil use; a vulnerability analysis which informed the balance (two) of the papers in this summary report.
Spoofing. Dennis Akos presented data on spoofing tests conducted at Lulea, Sweden, near a low-density commercial airport with limited road traffic and a restricted Swedish Air Force weapons test area, and in Kaohsiung, Taiwan, near a very busy airport with dense roadway traffic. The incidence of radio-frequency interference (RFI) in the latter case was great and in the former case negligible, until the team introduced their jamming and spoofing equipment.In both cases, a simple automatic gain control (AGC) monitoring design, which was computationally efficient, was able to detect and measure the RFI from the jammer-spoofer.
Using all commercial off-the-shelf (COTS) hardware, the jammer was identified and located with time-of-arrival and power-difference-of-arrival. The researchers showed that using a controlled reception pattern antenna (CRPA) like the Stanford four-element CRPA and all-COTS equipment, jammers could be indentified and located efficiently through AGC processing. A large amount of detailed data were presented with screen shots and plots of the effects of the jamming on the receivers.
Proof of Location. Logan Scott of LS Consulting gave a paper on proof of location. He projected the need for location proof in several applications, ranging from system control and data acquisition intrusions that would affect industrial control systems to bogus Mayday calls, the response to which is very expensive, and he provided many examples of data security applications. He also provided several schemes, ranging from cryptographic GPS RF signal structures to the use of overlapping systems, like Galileo and GPS, to enable verification of location.
Scott identified the massive security threat represented by millions of smart phone and tablet users who can store millions of bytes of information, such as maps of sensitive locations. An authorized user of such a map, GNSS-enabled, on a tablet or smart phone, should be able to access the restricted information if the user is in the right location. However, a user, authorized or not, outside of the restricted area would find that area of the map blank if he tries to access it externally, a kind of location need-to-know control.
Scott anticipates the use of temporary keys for weapons usage; such keys would require that the user be in a location authorized for such use. He provides block diagram descriptions of systems that would be feasible to achieve these location proofs for high-value and dangerous operations. These block-diagram level descriptions are accompanied by quantitative assessments of the difficulties and benefits of such system modifications.
It was a compelling tour de force on the subject. We do not have time or space to cover it well but the material has gradually been built up from earlier available publications by Scott at ION conferences and in GNSS journals and magazines. Both the need for such systems and the means by which they may be practically achieved are well worth studying by those responsible for policy and programmatic decisions, and by technologists seeking new product ideas and applications.
And More
A few interesting presentations do not fit into the above categories. Stan Honey, founder of the company Sportvision (the creator of the first-down yellow-line overlay in televised American football, and many other broadcast enhancements for sporting events) and considered sailing’s master navigator, gave a wonderful dinner talk about the PNT technology being utilized in the America’s Cup TV graphics, umpiring, and race management. Honey reflected upon how competitive sailing, unlike other professional sports, has fully adopted the use of advanced PNT technology in how the sport is umpired and managed.
Jason Wither of Microsoft presented a paper on spatialized data for mixed reality, which was very informative in how various types and layers of data are combined to create mixed-reality systems.
Ron Fugelseth of Oxygen productions showed his very entertaining video entitled “A Toy Train in Space.” The video was posted on YouTube a few months ago and immediately went viral. It is a fine example of the use of GPS technology.
James D. Litton heads the Litton Consulting Group and previously played key executive roles at NavCom Technology and Magnavox.
This year’s GPS Partnership Council provided among other highlights a discussion of the tensions between commercial off-the-shelf (COTS) receiver systems used in tactical combat operations versus official military GPS user equipment (MGUE), and an enthralling warfighters’ panel that revealed much of those COTS/MGUE dilemmas. The event, held May 1–2 in El Segundo, California, drew an enthusiastic and involved audience, including many GPS veterans. I was struck by the graying of the clan as well as the practiced and confident presentations of current civilian and military program staffs.
Keynote speaker Brig. Gen. Martin Whelan, Director of Requirements, Headquarters Air Force Space Command, emphasized that ideas for improvement of the system would be hard sells under current budget realities, but good ideas for lower cost would be welcome. Referring to the three segments — space, ground, and user — he recommended that the segments should talk with each other and challenge requirements. In effect, he implied that the separate segments could reduce overall costs, rationalize requirements, and cooperate better in optimizing the resilience and flexibility of the system, including — this is my interpretation — taking advantage of the “competitive” GNSSs to effect user satisfaction.
According to Whelan, resiliency of the space segment is a top priority; smaller satellites, hosted payloads, and net-centric designs were highlighted. He commented that multiple GNSSs should be employed in such a way that the user does not know the difference.
Regarding the upcoming budget, he told us that Department of Defense will be cut by 22 percent, the Air Force will drop 9 percent — but the AF space budget only 1.5 percent. A notable exception to the generally favorable overview was his comment that the MGUE segment, from a distance, looked uncoordinated. Much more along this line came up later during both days of the Council.
Widespread COTS. There was an air of defensiveness about the user segment, and many comments on both the success and the risks associated with the widespread use of COTS user equipment. We heard further commentary on the very infrequent use of SAASM keys, due to the difficulty of procedures to obtain and employ them, and due to the perception of very low risk of jamming and spoofing threats in current combat deployments.
A session on “The Future Military Receiver” enlisted two panels of government experts and contractors from Deere-NavCom, Garmin, IEC, Johns Hopkins Applied Physics Labs, Raytheon, and Rockwell-Collins. Although the unclassified nature of the presentations limited the level of detail, it clearly emerged that many tactical, in-combat deployments of COTS GPS receiver systems had occurred and continue to occur.
A video compared the jamming resistance of a Garmin receiver with that of approved GPS User equipment receivers. It showed a screen of the Garmin receiver losing satellites at greater distances from the jammer and losing lock at closer distances. Directorate employees and officers made several references to the risks from dependence upon COTS receivers, and related with considerable candor the difficulties with large, expensive, power-hungry MGUE, both mobile and platform-mounted, models of which were held up during the presentations — often to laughter from some in the audience.
More on this followed in Day Two’s dramatic warfighters’ panel, which many people felt was by itself worth the price of admission. These experienced users of GPS under fire — from Coast Guard search and rescue to Air Force forward controllers calling in air strikes within range of small-arms fire — related direct personal experience in a broad array of critical applications. They clearly knew how to use COTS equipment to good advantage and described the operational protocols developed from hard and sometimes painful experience.
Manipulation of multiple screens in a heavy device, which requires initialization or synchronization before dismounting, was often simply not an option. Translation of such experience into qualified requirements is a major challenge for the Air Force and Army. Overdependence on the anecdotal but very valid combat experiences would weaken a design against an enemy with even rudimentary jamming and spoofing capability.
An astute questioner asked “Have you seen any evidence that the enemy (in Afghanistan) has changed tactics because of our technology?”
The answer came “Not yet,” with a comment that the enemy’s early warning systems are very sophisticated and the target of a mission to capture a high-value individual (HVI) frequently knows that such a mission is underway; his support network spirits him away and attacks the mission with the advantage of surprise denied to our forces, abetted by the advantage of favorable terrain and numbers accruing to the enemy.
The Puck. The Army-led MGUE program status was described as being at technology readiness level (TRL) 6.0; the request for proposals was released on April 16. The key to the success across platforms of this “system of systems” was said to be the Common GPS Module (CGM), also referred to as the Puck. This module is M, P, and C/A code-capable and SAASM-capable but has flexible interfaces and “emulates commercial.” The module itself is a system-on-chip (SoC) that can be integrated across many platforms. Depending upon the level of integration employed, it can be as small as chips found in smartphones or somewhat larger.
The program schedule was defended as having only been funded two years ago and having very complex security and platform interfaces. This program presentation drew a large number of questions and commentary from the audience, much of it politely skeptical and showing impatience with the bureaucratic aspects of the program. Well-informed former military field-grade officers in the audience questioned its real availability. The answer that it would be available in quantity sometime in 2017 did not please the questioners.
In short, procurement regulations appeared to be the highest barrier to a rapid, flexible program for a net-centric, open-architecture system development.
Currently, the circuit boards for the MGUE are classified secret, but it is hoped to have these at a confidential or unclassified level for deployment by handling the encryption exclusively in software. The leader of this presentation indicated that software receivers were the ideal but were not available, so reduction in size, power consumption, and complexity in hardware was the goal.
Trumping Military. One almost nostalgic comment hearkened back to the time when military systems were regarded as the height of technological excellence, whereas it is now generally perceived that commercial systems trump the military in sophistication. Garmin claimed to have developed SAASM receivers in the lab but found little interest from business leaders at that time.
The CEO of Mayflower Communications, which makes and sells miniaturized SAASM receivers, pointed out that anybody could make a SAASM receiver employing a Sandia crypto-chip approved by the U.S. National Security Agency (NSA) but pointed out, as did several others, that the availability of certifications and authorizations was very limited, and that volume drove cost. Implicitly, NSA’s requirements and protocols got blamed for the limited distribution and use of SAASM receivers.
Day Two
The second day of the GPS Partnership Council comprised The Nation and The Warfighter. In the latter group came an outline of the Army’s COTS vision and — the hit of the entire conference — the Warfighter panel with a keynote introduction by a USAF colonel warrior now at the GPS Directorate.
The Nation. Tony Russo, director of the National Coordination Office for Space-Based Positioning, Navigation, and Timing, disabused those who thought that the apparent demise of the LightSquared threat had eliminated that subject from his agendas; he still deals with it often. He provided entertaining and informative examples of non-obvious and valuable applications of GPS, from assessing rugby players’ game performance through detection of clandestine underground nuclear tests to a social application of matching available part-time and temporary workers with jobs when labor demand surges and a roster shows where the closest qualified candidates are.
John Merrill of the Department of Homeland Security (DHS) identified 18 critical infrastructures that depend upon GPS integrity and showed the cascading effect of taking out sites like SCADA (Supervisory Control and Data Acquisition) systems. He related a threat-illustrative story of a DHS agent who required constant contact via his agency smart phone but who could not get reception while attending mass in church. The pastor later and very proudly showed him the mobile phone jammer in the sacristy; he had given up on asking parishioners to turn off their cell phones off during services.
James Miller of the National Aeronautics and Space administration noted that only 5 percent of space missions lie outside the GPS coverage envelope (3,000 kilometers to geostationary altitude of 35,800 kilometers is the space service volume). Reducing the burden on spacecraft tracking networks is a highly profitable application for GPS.
Warfighters Panel. These real-life experiences from combat and other vital operations could easily justify an entire article of their own. The following examples will illustrate the life-saving force multiplication of GPS, particularly the ubiquitous civil GPS technology in the current combat environment.
• An Air Force Special Operations Major described a mission to snatch an HVI, giving great detail on battlefield terrain, combat conditions, and how he worked between a COTS GPS receiver and a COTS handheld computer with Google Earth-like facilities to bring JDAMs (GPS-equipped smart munitions) onto an ambush mounted by defenders of the HVI, who were alerted to the raid by their extensive and sophisticated early-warning network consisting of sympathizers with cell phones. His description of the heroics of individual forward controllers, their injuries and fatalities, and the symbiosis of man and machine in a relatively benign electromagnetic interference but relatively malign electromagnetic propagation environment, and overtly and covertly hostile indigenous population, was dramatic and compelling.
Clearly, unsophisticated and easily-available high-power jammers rapidly alter such situations to reduce our technological advantages. Also clear was the need to design user equipment, not just to reject interference but to minimize time and the inevitable ambiguities in actual combat situations.
• A Coast Guard lieutenant described the search-and-rescue missions he flies out of local airports to Pacific Ocean sites. Again, COTS equipment, aided by the near-ubiquity of commercial GPS equipment, along with VHF marine radio on boats and ships, enhances these mission results over those flown with standard USCG-issued navigation equipment.
• An Air Force tanker pilot major now attached to the GPS Directorate described three personal experiences. He once had to ask his boom operator to retrieve the Garmin receiver issued in the survival kit in order to navigate the tanker for rendezvous with tactical aircraft needing fuel when the tanker’s standard equipment failed.
When tasked to fly into an airport in Afghanistan with unreliable navaids, under suddenly occurring zero-zero conditions, the onboard GPS enabled him to land safely.
In a third instance in Iraq, he observed a downed airman being approached by gunmen. The gunmen with AK-47s were being targeted by drone operators. The major was able to discern that these gunmen were friendly forces moving to rescue the downed airman and avert a friendly-fire disaster. The downed airman’s ability to send his exact coordinates were key to the ability of the observer to get close enough to direct rescue efforts and to avoid a fatal error.
• A Navy surface warfare lieutenant commander and a CWO Riverine or small boat skipper cited instances in which GPS was essential to missions and ways in which user equipment design could improve their operations — for example, by making it float.
All the veterans repeated, during or after their accounts of ways in which GPS saved lives or enabled missions, “thank you for what you do,” addressed to the audience, the presenters, and their leaders. Going into denied territory places a high premium on user friendliness, battery life, robustness, size, and weight. In the future, inevitably, jam and spoof resistance will be an object of gratitude, as well.
Final Review. We all know these things, intuitively and by doctrine, but hearing reports from people in harm’s way or retrieving comrades from harm’s way was a great addition to the usual program and technology descriptions by the development teams.
I was particularly impressed with the very articulate, sophisticated, and focused presentations of these combat veterans. It is highly incumbent on the industry and the government GNSS leaders to translate these experiences into design requirements quickly, so that future systems are less dependent on individual ingenuity and on commercial gap-fillers.
Much of this progress depends on truly incorporating the applications focus of commercial product development and on use of other GNSS systems for robustness, flexibility, and affordability — often quoted as mission goals by the leaders of this enterprise.
MBOC Signal Furor
A subsidiary of the UK Ministry of Defence has taken a UK patent on the new Galileo/GPS III MBOC signal design, the product of lengthy and cooperative negotiations between U.S. and European scientists. The patent, in the names of two UK engineers who participated in the project, is being used by a legal firm to demand royalty fees from receiver manufacturers, causing considerable controversy.
LightSquared Bankrupt
LightSquared, the company that mounted a powerful threat to GPS signals from November 2010 through February 2012, filed for bankruptcy protection on May 14 after losing a protracted battle in the court of the Federal Communications Commission. The war is not over, however. Exploding sprectrum demand for mobile data use makes it likely that future challenges to GPS and GNSS spectrum will emerge.
Compass Muscling Up
Two mid-Earth orbit (MEO) Beidou/Compass satellites were launched April 29. Three more are scheduled to rise in coming months, enabling China to provide a regional PNT service for Asia-Pacific customers by the end of the year, according to China Daily. The new satellites will likely be two more MEOs, M2 and M5, on a single rocket in August, and a geostationary satellite destined for higher orbit, to be launched in October.
This month we present a guest column by James D. Litton, who attended the 2012 GPS Partnership Council, jointly sponsored by the Armed Forces Communication and Electronics Association and the U.S. Air Force GPS Directorate. The key topic of this year’s council quickly emerged as the tension between commercial off-the-shelf GPS receivers and official military issue; the two are used side-by-side in active military theaters.
By James D. Litton
This year’s GPS Partnership Council provided among other highlights a discussion of the tensions between commercial off-the-shelf (COTS) receiver systems used in tactical combat operations versus official military GPS user equipment (MGUE), and an enthralling warfighters’ panel that revealed much of those COTS/MGUE dilemmas. The event, held May 1–2 in El Segundo, California, drew an enthusiastic and involved audience, including many GPS veterans. I was struck by the graying of the clan as well as the practiced and confident presentations of current civilian and military program staffs.
Keynote speaker Brig Gen Martin Whelan, Director of Requirements, Headquarters Air Force Space Command, emphasized that ideas for improvement of the system would be hard sells under current budget realities, but good ideas for lower cost would be welcome. Referring to the three segments — space, ground, and user — he recommended that the segments should talk with each other and challenge requirements. In effect, he implied that the separate segments could reduce overall costs, rationalize requirements, and cooperate better in optimizing the resilience and flexibility of the system, including — this is my interpretation — taking advantage of the “competitive” GNSSs to effect user satisfaction.
According to Whelan, resiliency of the space segment is a top priority; smaller satellites, hosted payloads, and net-centric designs were highlighted. He commented that multiple GNSSs should be employed in such a way that the user does not know the difference.
Regarding the upcoming budget, he told us that Department of Defense will be cut by 22 percent, the Air Force will drop 9 percent — but the AF space budget only 1.5 percent. A notable exception to the generally favorable overview was his comment that the MGUE segment, from a distance, looked uncoordinated. Much more along this line came up later during both days of the Council.
Widespread COTS. There was an air of defensiveness about the user segment, and many comments on both the success and the risks associated with the widespread use of COTS user equipment. We heard further commentary on the very infrequent use of SAASM keys, due to the difficulty of procedures to obtain and employ them, and due to the perception of very low risk of jamming and spoofing threats in current combat deployments.
A session on “The Future Military Receiver” enlisted two panels of government experts and contractors from Deere-NavCom, Garmin, IEC, Johns Hopkins Applied Physics Labs, Raytheon, and Rockwell-Collins. Although the unclassified nature of the presentations limited the level of detail, it clearly emerged that many tactical, in-combat deployments of COTS GPS receiver systems had occurred and continue to occur.
A video compared the jamming resistance of a Garmin receiver with that of approved GPS User equipment receivers. It showed a screen of the Garmin receiver losing satellites at greater distances from the jammer and losing lock at closer distances. Directorate employees and officers made several references to the risks from dependence upon COTS receivers, and related with considerable candor the difficulties with large, expensive, power-hungry MGUE, both mobile and platform-mounted, models of which were held up during the presentations — often to laughter from some in the audience.
More on this followed in Day Two’s dramatic warfighters’ panel, which many people felt was by itself worth the price of admission. These experienced users of GPS under fire — from Coast Guard search and rescue to Air Force forward controllers calling in air strikes within range of small-arms fire — related direct personal experience in a broad array of critical applications. They clearly knew how to use COTS equipment to good advantage and described the operational protocols developed from hard and sometimes painful experience.
Manipulation of multiple screens in a heavy device, which requires initialization or synchronization before dismounting, was often simply not an option. Translation of such experience into qualified requirements is a major challenge for the Air Force and Army. Overdependence on the anecdotal but very valid combat experiences would weaken a design against an enemy with even rudimentary jamming and spoofing capability.
An astute questioner asked “Have you seen any evidence that the enemy (in Afghanistan) has changed tactics because of our technology?”
The answer came “Not yet,” with a comment that the enemy’s early warning systems are very sophisticated and the target of a mission to capture a high-value individual (HVI) frequently knows that such a mission is underway; his support network spirits him away and attacks the mission with the advantage of surprise denied to our forces, abetted by the advantage of favorable terrain and numbers accruing to the enemy.
The Puck. The Army-led MGUE program status was described as being at technology readiness level (TRL) 6.0; the request for proposals was released on April 16. The key to the success across platforms of this “system of systems” was said to be the Common GPS Module (CGM), also referred to as the Puck. This module is M, P, and C/A code-capable and SAASM-capable but has flexible interfaces and “emulates commercial.” The module itself is a system-on-chip (SoC) that can be integrated across many platforms. Depending upon the level of integration employed, it can be as small as chips found in smartphones or somewhat larger.
The program schedule was defended as having only been funded two years ago and having very complex security and platform interfaces. This program presentation drew a large number of questions and commentary from the audience, much of it politely skeptical and showing impatience with the bureaucratic aspects of the program. Well-informed former military field-grade officers in the audience questioned its real availability. The answer that it would be available in quantity sometime in 2017 did not please the questioners.
In short, procurement regulations appeared to be the highest barrier to a rapid, flexible program for a net-centric, open-architecture system development.
Currently, the circuit boards for the MGUE are classified secret, but it is hoped to have these at a confidential or unclassified level for deployment by handling the encryption exclusively in software. The leader of this presentation indicated that software receivers were the ideal but were not available, so reduction in size, power consumption, and complexity in hardware was the goal.
Trumping Military. One almost nostalgic comment hearkened back to the time when military systems were regarded as the height of technological excellence, whereas it is now generally perceived that commercial systems trump the military in sophistication. Garmin claimed to have developed SAASM receivers in the lab but found little interest from business leaders at that time.
The CEO of Mayflower Communications, which makes and sells miniaturized SAASM receivers, pointed out that anybody could make a SAASM receiver employing a Sandia crypto-chip approved by the U.S. National Security Agency (NSA) but pointed out, as did several others, that the availability of certifications and authorizations was very limited, and that volume drove cost. Implicitly, NSA’s requirements and protocols got blamed for the limited distribution and use of SAASM receivers.
Day Two
The second day of the GPS Partnership Council comprised The Nation and The Warfighter. In the latter group came an outline of the Army’s COTS vision and — the hit of the entire conference — the Warfighter panel with a keynote introduction by a USAF colonel warrior now at the GPS Directorate.
The Nation. Tony Russo, director of the National Coordination Office for Space-Based Positioning, Navigation, and Timing, disabused those who thought that the apparent demise of the LightSquared threat had eliminated that subject from his agendas; he still deals with it often. He provided entertaining and informative examples of non-obvious and valuable applications of GPS, from assessing rugby players’ game performance through detection of clandestine underground nuclear tests to a social application of matching available part-time and temporary workers with jobs when labor demand surges and a roster shows where the closest qualified candidates are.
John Merrill of the Department of Homeland Security (DHS) identified 18 critical infrastructures that depend upon GPS integrity and showed the cascading effect of taking out sites like SCADA (Supervisory Control and Data Acquisition) systems. He related a threat-illustrative story of a DHS agent who required constant contact via his agency smart phone but who could not get reception while attending mass in church. The pastor later and very proudly showed him the mobile phone jammer in the sacristy; he had given up on asking parishioners to turn off their cell phones off during services.
James Miller of the National Aeronautics and Space administration noted that only 5 percent of space missions lie outside the GPS coverage envelope (3,000 kilometers to geostationary altitude of 35,800 kilometers is the space service volume). Reducing the burden on spacecraft tracking networks is a highly profitable application for GPS.
Warfighters Panel. These real-life experiences from combat and other vital operations could easily justify an entire article of their own. The following examples will illustrate the life-saving force multiplication of GPS, particularly the ubiquitous civil GPS technology in the current combat environment.
• An Air Force Special Operations Major described a mission to snatch an HVI, giving great detail on battlefield terrain, combat conditions, and how he worked between a COTS GPS receiver and a COTS handheld computer with Google Earth-like facilities to bring JDAMs (GPS-equipped smart munitions) onto an ambush mounted by defenders of the HVI, who were alerted to the raid by their extensive and sophisticated early-warning network consisting of sympathizers with cell phones. His description of the heroics of individual forward controllers, their injuries and fatalities, and the symbiosis of man and machine in a relatively benign electromagnetic interference but relatively malign electromagnetic propagation environment, and overtly and covertly hostile indigenous population, was dramatic and compelling.
Clearly, unsophisticated and easily-available high-power jammers rapidly alter such situations to reduce our technological advantages. Also clear was the need to design user equipment, not just to reject interference but to minimize time and the inevitable ambiguities in actual combat situations.
• A Coast Guard lieutenant described the search-and-rescue missions he flies out of local airports to Pacific Ocean sites. Again, COTS equipment, aided by the near-ubiquity of commercial GPS equipment, along with VHF marine radio on boats and ships, enhances these mission results over those flown with standard USCG-issued navigation equipment.
• An Air Force tanker pilot major now attached to the GPS Directorate described three personal experiences. He once had to ask his boom operator to retrieve the Garmin receiver issued in the survival kit in order to navigate the tanker for rendezvous with tactical aircraft needing fuel when the tanker’s standard equipment failed.
When tasked to fly into an airport in Afghanistan with unreliable navaids, under suddenly occurring zero-zero conditions, the onboard GPS enabled him to land safely.
In a third instance in Iraq, he observed a downed airman being approached by gunmen. The gunmen with AK-47s were being targeted by drone operators. The major was able to discern that these gunmen were friendly forces moving to rescue the downed airman and avert a friendly-fire disaster. The downed airman’s ability to send his exact coordinates were key to the ability of the observer to get close enough to direct rescue efforts and to avoid a fatal error.
• A Navy surface warfare lieutenant commander and a CWO Riverine or small boat skipper cited instances in which GPS was essential to missions and ways in which user equipment design could improve their operations — for example, by making it float.
All the veterans repeated, during or after their accounts of ways in which GPS saved lives or enabled missions, “thank you for what you do,” addressed to the audience, the presenters, and their leaders. Going into denied territory places a high premium on user friendliness, battery life, robustness, size, and weight. In the future, inevitably, jam and spoof resistance will be an object of gratitude, as well.
Final Review. We all know these things, intuitively and by doctrine, but hearing reports from people in harm’s way or retrieving comrades from harm’s way was a great addition to the usual program and technology descriptions by the development teams.
I was particularly impressed with the very articulate, sophisticated, and focused presentations of these combat veterans. It is highly incumbent on the industry and the government GNSS leaders to translate these experiences into design requirements quickly, so that future systems are less dependent on individual ingenuity and on commercial gap-fillers.
Much of this progress depends on truly incorporating the applications focus of commercial product development and on use of other GNSS systems for robustness, flexibility, and affordability — often quoted as mission goals by the leaders of this enterprise.
We have been reading with much interest the Innovation column, “GNSS Antennas and Humans” (Innovation, February issue). As the interaction with the human body is something many companies designing GPS into their products do not consider, it is great to see this topic being given some recent attention. We do feel, however, that we should comment on some issues we see in the article, especially as one of our antennas has been used as part of the testing.
As rightly mentioned in the article, many of the products using GPS where performance close to the body is potentially an issue are consumer products. These typically are of small size or at very least have major space constraints placed on those designing them. As such it is very unlikely that they would use either a large active patch antenna or in fact an active antenna from Sarantel. In the vast majority of consumer applications, either smaller patch antennas (12 × 12 millimeters, maximum) will be used with smaller ground planes or even small chip or planar inverted-F antenna (PIFA) style antennas.
From a Sarantel perspective, we would recommend our smallest antenna, the passive SL1300, for these types of applications. In terms of how this would then affect the results of the test described in the article, our extensive testing of various antennas would suggest that with smaller patch antennas and linear antennas like chip and PIFA types, the impact of the body on antenna performance is greater than you would typically see with a large patch with a large ground plane. In addition, one of the reasons we would recommend our smaller antenna for this kind of application is because the ceramic material used has a much higher dielectric value than our larger products and as such is affected much less by the body or other interfering aspects of a product design.
As I mentioned, we have done extensive testing of various antennas, much of which is available through the Application Centre section of our website. Further information can be shared if it would be of interest to your readers.
— Chris Muir Director of Sales, Sarantel Limited
Spectrum Swap
I read with interest your article today (Latest News, February 1) concerning LightSquared looking at a possible spectrum swap in the current Aeronautical Mobile Telemetry band, used heavily by both the DOD and commercial side, primarily for aircraft and missile testing. I found it more interesting that the DOD MIDLANT Area Frequency Coordinator had been contacted concerning the same.
First let me say that both the DOD and civil aviation and defense industries guard these bands quite strongly as individual users and via the Aerospace Flight Test Radio Coordinating Council (AFTRCC). AFTRCC is also the recognized non-government coordinator for these bands and resists any encroachment in these bands, while additionally allowing some temporary sharing when feasible.
Secondly, I would add the the DOD has seven total Area Frequency Coordinators geographically spread across the United States, so contacting one would serve little purpose. Additionally, the coordinators are members of the DOD Frequency Management Group who one would say is the DOD equivalent of AFTRCC and believe me, both organizations are on the same sheet of music when it comes to defending AMT for flight-test purposes and even meet jointly twice a year to do just that. Combined with the DOD and if one looks at the member companies of AFTRCC any attempt to wrest any portion ATM spectrum away from the aerospace industry and DOD would be an expensive and lengthy process.
This email does not constitute a response from either DOD or AFTRCC but that of a private citizen.
— Wayne Morris
Greenville, Texas
Privacy Matters
Good editorial (“When the Gavel Comes Down,” February issue). The three or four bases for the unanimous ruling in the instant case show a diversion of philosophy on this matter that is dangerous for resolution only through case and constitutional law.
You are dead right, legislation is needed at the federal level before a hodgepodge of states and other jurisdictions make up their own policies for a global utility with manifold applications affecting privacy and personal and intellectual property, for good and for evil; morally neutral technology, as always….not just GNSS but as in most instances, GNSS enhanced.
It would not be popular with the federal legislature, but I think some European Union deliberations on these subjects would be instructive for the U.S. Congress to heed in writing legislation. I wish that the White House and an interagency group like EXCOM could first take a non-political look at the trades and lead Congress, but that is unlikely to happen. Look at what nearly happened with the Software Owners Protection Act (SOPA) because of the lobbying power of media interests.
Truly we live in interesting times, also from the stress on our constitutional concepts which often use tortured analogies to keep the law inside the four corners of the constitution.
— James D. Litton
President/CEO, Litton Consulting Group, Inc.
