Most activity so far in the PNT community has centered around the questions of “Where am I?” and “Where am I going?” and “How fast am I going?” Positioning, navigation and timing. Seemingly that should about cover it. But no.
Mapping comes into the picture: “What fixed objects are in my environment?” This is actually a corollary of “Where am I?” though let’s not put too fine a point on it.
All this “I” business. To get to driverless cars and other autonomous vehicles, we will have to look beyond the first person singular, what some researchers call “the ego vehicle.” We must know, with a high degree of precision and certainty, “Where are other moving vehicles?” and “Where are they going?” and “How fast are they moving?” Another order of magnitude, if not several. PNT squared, as it were.
In the fast oncoming intelligent transportation systems (ITS), future driving (very much present and evolving now) will rely on accurate, reliable and continuous knowledge of the position of other so-called road participants. That’s not just cars, trucks, motorcycles and buses, but includes pedestrians and bicycles and who knows what else — skateboards?
The first approaches to this requirement use on-board ranging sensors such as camera/vision systems, radar, laser scanners and more. (Some of this “more” is explored in this May’s print cover story, “Look Around.”) This already calls for a significant level of integration with GNSS and inertial systems of the ego.
But it’s still not enough. A cooperative approach must develop, in which the other road participants actively support the continuous estimation of all relative positions. Not only must they have all the sensors the ego possesses, they must continually communicate all that data with the ego, and conversely. This is what’s called “connectivity.”
It’s almost as if vehicles are becoming sentient, expressive beings. A bit like us. Bringing new meaning to the expression “the automobile as an extension of the self.”
“Smart cartography” is the top theme at the 65th Cartography Conference, which will take place Sept. 26-28 in conjunction with Intergeo in Berlin, Germany. Numerous examples at the conference and trade fair will reveal smart cartography’s wealth of potential.
The latest smart maps are as far removed from their 2D relatives on paper as is the state-of-the-art GIS platform from the analog planning basics of bygone years. But just what is so smart about these cutting-edge maps? Here’s a handful of examples of smart cartography.
Smart maps are intuitive and attractive
Maps have always been used to represent relationships and make sense of our surroundings. More often than not, they achieve this far better these days than ever before. Maps have become more accessible to their target groups and more intuitively understandable. You rarely need instructions on how to read a map nowadays. A prime example of innovative design is the widely discussed and highly praised new plan of Berlin’s public transport network. Architect Jug Cerovic uses his own special standard to translate complex public transport systems into both functional and aesthetically appealing maps. (http://www.jugcerovic.com/maps/inat-metro-mapping-standard/)
Smart maps provide customized information
Smart maps provide customized information right where it is needed. This might be the optimum route for mountain bikers or hobby cyclists (www.bikemap.net) or for navigating stress-free through the city using whichever mode of transport you like (https://wego.here.com/). While in the past, maps flattened reality into 2D, nowadays 3D is the norm. Not only that, but the fourth dimension of time is becoming increasingly prominent in digital maps. (http://360.here.com/2017/03/28/4d-mapping-can-change-world/)
Smart maps capture the moment – right now
Today’s smart maps are a dynamic product. They don’t lead to dead-ends, but instead simply keep on evolving. In the Internet of Things, where vehicles, mobile objects and sensor data gather and network millions of items of information, companies are working on creating living maps that constantly display real-time status. These form the basis for the self-driving vehicles of the future, on the streets and in the air close overhead. (https://here.com/en)
Smart maps reveal new insights
Whether you’re interested in commuter flows or refugee accommodation (https://www.findingplaces.hamburg/), smart maps are the number-one tool for planners and are now being used by politicians and citizens alike as the basis for political debate. The ability to explore visual representations turns raw data into a practical basis for making decisions. In Hamburg, for example, smart maps have become a game-changer in the search for locations for refugee accommodation and also help plot the most suitable corridors for projected commuter flows.
Multi-sensory maps
Click on a street to see how it sounds, at goodcitylife.org
Acoustic maps have been able for some time to visually represent “soundscapes” or add sound with the aid of audio files (http://www.life-dynamap.eu/). What’s new is the addition of olfactory elements. Researchers at Goodcitylife are working on capturing the “smellscape” of cities. And their Happymaps offer a completely new slant on the city – for those who are not as much bothered about getting from A to B as “enjoying the ride”. (http://goodcitylife.org/index.html)
Virtual and augmented reality
No one can fail to have noticed the craze whipped up by the AR application Pokémon Go (http://www.pokemongo.com/de-de/). This plainly revealed the potential that lies in virtually embellished maps. VR and AR map applications now liven up tours of museums and churches (http://dom360.wdr.de/) and are being used as planning and information tools.
This month, we bring you a guest column on the 33rd Space Symposium in Colorado Springs, Colorado. Robin Wrinn, a communications professional based in Atlanta, gives her perspective on the premier annual space event, held in early April. Among her findings: new players in space race, new capabilities afforded by 3D printing and virtual reality, and insights into the GPS III program from Lockheed Martin’s VP for navigation systems.
— Alan Cameron, editor
Blue Origin spacecraft.
A host of new entrepreneurial and government players entering the space sector created an underlying sense of excitement that a new “space race” has begun. Visitors attending the 33rd annual Space Symposium first encountered the imposing, reusable Blue Origin spacecraft displayed prominently in front of the Broadmoor Hotel Exhibit Hall. It seemed to symbolically punctuate a statement that the space industry landscape is changing — and putting long-experienced government players and government contract monopolies on notice.
Hosted by the Colorado Springs-based Space Foundation, this year’s Symposium featured more than 180 exhibitors, including 38 new international partners and space, government and defense officials from more than 30 countries. In addition to the United States, other notable space nations attending included China, Germany, South Korea, Japan, high-level members of Russia’s ROSCOSMOS, and for the first time, the European GNSS Agency (GSA).
Space Recognized as a Security Asset
A primary theme throughout the speaker lineup was development of missions and programs to shore up national cyber and space security. Japan, for example, had previously banned all military use of space assets, but according to Shuzo Takada, director general of Japan’s National Space Policy Secretariat, the country has established new laws in part due to growing threats from countries such as North Korea.
Europe also has joined the club of providers of navigation services and has formally acknowledged the need to defend its member countries against cyber threats. In a keynote session, EU Commissioner for Internal Market, Industry, Entrepreneurship and SMEs, Elżbieta Bieńkowska, the first European Commissioner to address the Space Symposium, noted that Galileo, Europe’s GNSS, went live last December. In 2016, six Galileo satellites were launched building on the six the year before. Today, 17 leading chipset companies, representing more than the 95% of global supply, all produce Galileo-compatible products.
Bieńkowska also outlined a three-point space strategy for Europe that incentivizes innovation, including investment in R& D projects, but also prompts Europe to officially view space as a security asset. “We for the first time recognize that space is a strategic asset and a central element of Europe’s strategic autonomy. Europe must ensure its own security,” she said.
In his conference remarks, U.S. Congressman Jim Bridenstine welcomed addition of Galileo’s capabilities to the global satellite infrastructure, noting that GPS capabilities make it as important to our way of life as the electrical power grid. (Indeed, GPS actually enables key capabilities of the power grid through its precise timing, although Bridenstine did not mention this aspect.)
“There are very strategic risks to our satellite systems and we need to make sure the GPS, GLONASS and Galileo signals provide back0up to one another and are supported in bilateral ways. “
New Private Investment Sparks Change in Costs and Bidding
The growing presence of private investment in the space economy was very notable at this year’s Symposium. Jeff Bezos’ Blue Origin is among several entrepreneurial companies — Elon Musk’s SpaceX (Space Exploration Technologies) and Richard Branson’s Virgin Galactic, to name two others — that are challenging the traditional drivers. These new players are upsetting the standard government agency inclination to prefer longstanding relationships over price. Now the bid price gaps are too big to ignore.
Case in point: SpaceX has twice now in two years won bids to launch GPS III satellites, with price as a major factor. According to a March 2017 U.S. Department of Defense press release, SpaceX will provide the Falcon 9 launch vehicle production, mission integration and launch operation for support of the GPS III mission. The contract awards break a nearly 10-year monopoly held by United Launch Alliance, a joint venture of Lockheed Martin Space Systems and Boeing Defense, Space & Security.
Previously, Claire Leon, launch enterprise director for the Air Force Space and Missile Systems Center had been quoted as saying the service views the entrance of competition as a good step that will help the government over time. “You’ll see a lot of innovation between multiple contractors to invest in the rocket systems for the United States,” she said.
Lockheed Martin Touts Digital Tapestry Savings
Collaborative Human Immersive Laboratory (CHIL).
During the Symposium, Lockheed Martin Space Systems invited attending media to tour its expansive Littleton, Colo. campus where it is assembling and testing both the next-generation GPS III satellite constellation and the Orion spacecraft. Lockheed Martin is the prime contractor on the GPS III program and is under contract the U.S. Air Force to build eight position, navigation and timing satellites. The contract includes options for up to four more vehicles. In September 2016, the Air Force announced it had exercised the option for Lockheed Martin to build the ninth and tenth satellites, which will include additional hosted payloads to increase accuracy.
Throughout the tour, Lockheed Martin’s hosts emphasized the company’s cost and time efficiency innovations. We first saw the Collaborative Human Immersive Laboratory (CHIL), where Lockheed is using virtual reality (VR) technology to plan the design and manufacture of nearly all its aerospace components. In one of the largest VR laboratories of its kind, engineering teams review 3D models of product designs, tooling and facilities. Instead of paper, virtual prototyping enable Lockheed’s engineers to inspect holographs of the engineered designs, as well as become avatars to examine designs in virtual environments in full scale and in an immersive way. The lab also is used to conduct virtual dry runs of systems once products get to the shop floor.
Collaborative Human Immersive Laboratory (CHIL).
According to Darin Bolthouse, manager of the CHIL, Lockheed Martin began virtual prototyping in 2010 with an initial focus on the GPS III and the Orion space capsule programs. Now the company uses the CHIL across the enterprise for all programs. It also is looking for ways to shrink the large lab footprint with newer commercially available VR equipment to create more VR pods at other locations and a site-to-site VR environment network with other facilities, including Sunnyvale, Calif., Kennedy Space Center and Johnson Space Center.
Again, time and cost savings were emphasized with a primary narrative that “inserting virtual modeling and model-based engineering helps from the ground up.” Touted benefits included recouping an initial investment of $5 million per year since its construction in 2010 through cost avoidance in rooting out specific engineering problems in VR that otherwise would have been discovered on the shop floor. A specific example served up was using the CHIL to virtually redesign the top deck of the Orion spacecraft three times to work out human-machine ergonomic issues.
Parts made with a 3D printer.
In another leg of the tour, Lockheed Martin showcased how it uses 3D printing to make parts for both Orion and military satellites: tubing routings, bottles and attachments. This has reportedly reduced lead time to manufacture a single part from six months to 1.5 months, with assembly time reduced from 12 hours to just three. Another added benefit is accessibility and costs of replacement parts down the road. 3D printing provides the roadmap and means to recreate a part 20 years later even if Lockheed Martin or a sub-contractor should have ceased operation.
GPS III Vehicle Rundown
The highlight of the tour was Lockheed Martin’s top secret clean room, where the next-generation GPS III satellite constellation is being assembled and tested. The expansive space included areas for integrating the parts of each satellite vehicle, as well as environment testing chambers for acoustics and thermal vacuum, which simulate space conditions with extreme temperatures, including the near and far side of Earth solar temperatures. No phones, cameras or recorders were allowed, and even then parts of the satellite vehicles were draped off from visitors’ view.
3D printer.
Prominent placards gave the GPS III Program Production Status:
Space vehicle integration forecast completion – May 2017
Environmental testing to begin – May 2017
Available for launch – 2018
Vehicle 03
Navigation Payload forecast delivery – Spring 2017
Space vehicle integration – Fall 2017
Begin environmental testing – Early 2018
Available for launch – 2019
Vehicle 04
Navigation Payload forecast delivery – Fall 2017
Space vehicle integration – Early 018
Satellite Delays Resolved
According to Lockheed Martin spokesperson Chip Eschenfelder, who spoke with GPS World during the media tour, previously reported GPS III engineering delays related to the payload have been resolved.
Lockheed Martin’s GPS III clean room in Littleton, Colorado
Lockheed subcontractor Harris Corporation provides the critical mission data unit (MDU) and other components of the navigation payload, including atomic clock timing systems, radiation-hardened computers and powerful transmitters to deliver accurate, robust navigation signals for the GPS III constellation. Last year it was discovered that a ceramic capacitor had not been subjected to all the program’s required qualification tests. Once the issue was discovered, Harris deployed a dedicated team to complete the required tests by December 2016. The issue caused a delay of four months. The part was among the more than 28,000 used in the navigation payloads for the GPS III vehicles. The company announced in February 2016 that it plans to offer a fully digital navigation payload for the GPS III’s space vehicle 11 and beyond.
According to Harris Corp. spokesperson Ellen Mitchell, the company has so far delivered two full payloads to Lockheed Martin and has delivered some of the hardware for the third space vehicle.
Another potential GPS III delay presented itself in March 2017 when the U.S. Air Force opened a review of the propulsion systems used for Lockheed Martin’s GPS III and other military satellites, following a problem during an attempt to boost one into orbit. According to Eschenfelder, the review is a standard process and was out of an abundance of caution. Lockheed is“confident that this review will not delay the Air Force’s planned spring 2018 Initial Launch Capability (ILC).”
Further comments on the GPS III program came in a subsequent conversation I held with Mark Stewart, Lockheed Martin’s vice president for Navigation Systems:
Q: GPS III has extensive military applications. What differences will it bring to the civil, end-user experience as compared to today’s?
A: Millions of commercial and civilian users rely on GPS every day. GPS III begins a new era of improved Positioning, Navigation and Timing (PNT) performance for these civilian users in that it will be the first GPS satellite transmitting a new L1C civil signal designed to be compatible and interoperable with other international Global Navigation Satellite Systems (GNSS), like Galileo and QZSS. In the near future, civilian GPS receivers – like those found in smart phones — will be looking for L1C and compatible signals from satellites from multiple GNSS constellations, including GPS III. With more opportunities for GPS receivers to maintain “line-of-sight” L1C connections, civilian users will have much improved connectivity.
Q: What is the impact of the OCX/ground segment delay? Won’t that impact realizing GPS III’s full capabilities on time?
A: The first GPS III satellite, GPS III Space Vehicle 1 (GPS III SV01), was placed in storage on Feb. 27 and is now awaiting call up for launch from the Air Force. GPS III SV01 will need the Next Generation OCX Block 0 to launch. We are working closely with the Air Force and Raytheon to demonstrate GPS III SV01 operating on orbit as soon as possible. It is more appropriate for the U.S. Air Force and Raytheon to comment about OCX’s capabilities and what it will bring to the overall GPS III enterprise.
OCX Block 1 is the baseline program under development to command and control GPS III satellites. As a temporary gap-filler until OCX Block 1 is available, the Air Force placed Lockheed Martin under contract for “GPS III Contingency Operations” (COps), which will enable the current GPS Operational Control Segment (OCS) to checkout and operate GPS III satellites prior to the delivery of OCX Block 1. Lockheed Martin’s COps program successful completed a Critical Design Review in November 2016, on schedule for delivery in 2019.
Q: How do you see the future of GPS in a multi-constellation environment (considering that soon in addition to GPS and the Russian GLONASS, the European Galileo and the Chinese Baidoo will be fully operational)? And what does that mean for the civilian end-user?
A: Civilian multi-constellation users will significantly benefit from the new L1C signal, designed be compatible and interoperable with the Galileo E1 Open Service (OS) signal. In addition, GPS navigation messages include the GPS/GNSS-time offsets to enable a multi-constellation PNT solution.
Q: Galileo will be implementing a Commercial Service already in the first generation. Do you think that such a service could be implemented in the future on GPS?
A: Ultimately the capabilities of future GPS satellites will be determined by the Air Force. That said, Lockheed Martin’s GPS III was specifically designed to be flexible and modular so in the future the satellite could easily incorporate new missions if they are deemed necessary, and new technology as it becomes available.
Q: What were and are the technology challenges Lockheed Martin faced during the GPS-Ill development?
A: GPS III is the most powerful GPS satellite ever designed, with three times greater accuracy and up to eight times improved anti-jamming capability. That increased signal power comes from a revolutionary new navigation payload. Early in development our payload provider, Harris Corporation, had some design challenges. Those issues were eventually overcome and fully validated when GPS III SV01 successfully completed its Thermal Vacuum (TVAC) test in December 2015. We are excited to be bringing GPS III’s new capabilities to our warfighters soon.
Q: How do GPS III satellites compare with Galileo FOC satellite constellation? Achieve parity (Galileo 2 frequency, current GPS 1)? or leapfrogging over Galileo technology?
A: I cannot speak for Galileo’s capabilities but the U.S. Air Force’s Global Positioning System (GPS) has been the gold standard for PNT for more than 20 years. Lockheed Martin’s GPS experience includes more than 250 collective years of on-orbit operations for the 19 GPS IIR and IIR-M satellites that make up about 60 percent in today’s GPS constellation. With GPS III being the most powerful GPS satellite ever designed and built, I am confident GPS III will maintain that PNT gold standard ranking.
Q: There were clock anomalies in Galileo. What are you doing to avoid similar issues? Are GPS III clock’s different or the same?
A: GPS III Rubidium Atomic Frequency Standards (RAFS) have evolved from GPS IIR and IIR-M RAFS, which have collectively and reliably provided more than 250 years of on-orbit service, including significant time beyond their intended design lives. Our GPS III RAFS clocks undergo rigorous environmental qualification and life tests to assure performance over this next generation satellite’s 15-year design life. In addition, each GPS III SV includes multiple RAFS for redundancy. GPS III continually monitors the active RAFS to detect and mitigate clock anomalies. This is just one way that GPS III provides increased signal integrity for GPS users.
Galileo clocks utilize different suppliers than GPS III clocks. The GPS III clock supplier has produced reliable RAFS clocks for GPS satellites over the past several decades.
[end of Mark Stewart interview]
Ground Control
The GPS III satellite program is heavily dependent on the GPS Next Generation Operational Control System (GPS OCX), which according to government officials has experienced developmental issues and remains under General Accounting Office (GAO) scrutiny.
In assessing the implications, it’s important to note that OCX’s development is delivered in blocks, with Block 0 comprising the Launch and Checkout System required to take GPS III satellites into early orbit. Block 1 is built on Block 0 and will deliver the full OCX capability, allowing the Air Force to transition from its current GPS ground controls to the modernized and secure GPS OCX master control station.
According to the OCX prime contractor, Raytheon, all coding for Block 0 is complete and testing is wrapping up for delivery. Block 1 development is ongoing with the final iteration estimated to be completed in late 2018.
Findings in a recent GAO report are prompting examination of the reasons for the cost overruns and delays in military development programs. Meanwhile, the Air Force is looking at ways to modify the existing GPS control system to enable the operational use of the GPS III satellites until delivery of the OCX Block 1. Regardless, the Air Force may need to delay the launch of multiple GPS III satellites, according to the GAO.
Mr. Bezos, Mr. Musk, Mr. Branson … are you out there?
A fourth speaker has joined the panel of the free April 20 webinar, “From Flying Drones to Doing Business,” addressing UAVs in business applications. Francois Gervaix, product manager of surveying for senseFly, will address the business benefits of high precision GNSS, covering: high precision in photogrammetry drones, survey-grade accuracy, workflow flexibility and time/cost savings.
Webinar attendees will have the opportunity to ask direct questions of the speakers, both upon registration and during the live event. Register for free at env-gpsworld-integration.kinsta.cloud/webinar.
Gervaix joins a panel consisting of Gustavo Lopez, product manager GNSS solutions for UAV applications for Septentrio; Jan Leyssens, managing director of sales and business development for Airobot; and Zak Kassas, assistant professor in the Department of Electrical and Computer Engineering at the University of California, Riverside.
Other subtopics to be covered include the integration of various surveying and mapping sensors aboard a UAV platform; meeting safety demands for UAVs by providing intelligent safety components, specifically designed for drones, and in facilitating end-users’ success in completing their missions; and exploiting long-term evolution cellular signals for accurate and resilient autonomous vehicle navigation in the absence of clear GNSS signals.
Gervaix is a qualified geomatics engineer who has worked for Leica Geosystems and as a professor at the Technical University for Applied Sciences Western Switzerland. In 2010, he launched project R-Pod, Photogrammetry on Demand, before founding Easy2map, a drone-based photogrammetry service provider. He joined senseFly in February 2016. He is also president of the Swiss Society of Photogrammetry and Remote Sensing.
“It’s always been time.” That was the first answer out of the gate, given in Session 3 of the Munich Satellite Navigation Summit last month. Dominic Hayes, Spectrum Management and Policy for Galileo, EGNOS and Copernicus at the European Commission, was prompt off the mark. “GNSS is so good, so easy and so cheap, other means are falling out of use.” Therein lies the peril.
That emotion was seconded by every other speaker on the panel. But of course. Virtually no one in the GNSS community at large, let alone those attending the Munich Summit, thinks otherwise.
Thinking and action do not go hand-in-hand, however. GNSS back-up resembles the weather, in that everybody talks about it, yet … yet … nothing changes. As long ago as 2015, the U.S. Department of Transportation and the Deputy Secretary of Defense made noises about building an alternative system to GPS in case of disruption, and certainly there were hand gestures aplenty prior to that.
Do we have a back-up, presently?
No. The U.S. government is in such a hurry to protect its borders that it gives scant thought to protecting what’s inside: critical infrastructure.
Is it time?
It’s always been time.
Things are more like they are now than they ever have been, what with the cloud and all. We’re storing so much data in the cloud, with more and more of the world’s operations every day keyed to and driven by distributed database processing, in huge data servers around the world. This is according to John Fischer of Spectracom, who is in a position to know. Precise timing at the micro- and nanosecond level plays a huge role in connecting and synchronizing users. But again, he was preaching to the choir.
Guy Buesnel from Spirent Federal reiterated the new threat sprung from Pokémon Go: a community of gamers and enthusiastic coders, generating homespun spoofing mechanisms for fun. They will soon realize, if they haven’t already, that there’s profit to be made there as well.
“We have become too reliant on GNSS today,” stated Buesnel. Most interference warnings are low level, but 3 to 4 percent are serious enough to disrupt receiver operations. And that still means you have to take action in response. He stressed the importance of a balanced systems engineering approach, and invoked Brad Parkinson’s PTA mantra: protect, toughen and augment.
Hayes called for a European Radio Navigation Plan, similar to the U.S. Federal Radio Navigation Plan (FRNP). Later, in response to a follow-up question, he acknowledged that “radio” need not be part of all encompassed systems; the proposed name is a legacy of modeling after the FRNP.
So far, the FRNP itself is nothing but a model, a little architectural construct of what someday might be. But nothing’s been built, that particular someday is no closer, and meanwhile the threats loom larger.
Here’s a panorama in broad strokes across the range of GNSSs, garnered from top system spokespersons at the Munich Satellite Navigation Summit. It’s been several years since breaking news was aired at this annual late winter/early spring event, but it’s always good for a wide-ranging update, recalibrating levels, so to speak.
GPS. With 31 operational satellites (24 is baseline) and an estimated 3 billion receivers in use worldwide, what more needs to be said about the gold standard? Its best week ever for accuracy logged a signal-in-space performance average of 45.3 centimeter. The next-generation ground control system OCX “survived quite a struggle” and has emerged from Nunn-McCurdy breach, back on track and seemingly ready for future action. Or at least for future pre-certification tests. SV1 of the GPS III generation has completed all tests and is in storage, awaiting the first GPS III launch in spring 2018. SV02 and 03 are in assembly and integration, SV04 thru 08 are in box-level assembly, and 09 and 10 are on contract. Technical challenges with payload have been resolved.
(Click to enlarge.) Galileo satellite top-level block diagram. OHB Systems AG as prime contractor and Surrey Satellite Technology (SSTL) have teamed for production of the navigation satellites. OHB is responsible for the concept, the satellite platforms and the satellite-level inegration and test. SSTL supplies the satellite payloads and supports OHB on system level. OHB also supports the customers during launch preparation and in-orbit testing. (Image courtesy OHB)
Galileo. With 18 on-orbit satellites (15 operational), the European GNSS can be termed a coming thing. Performance statistics are based on only 11 of these satellites however; the four most recently launched in November 2016 are not yet included. Nevertheless, the system is logging 80-centimeter ranging accuracy. Eight more await launch: four in 2017, and four in 2018. The constellation is broadcasting the Open Service, the Public Regulated Service, and the Search and Rescue (SAR) signal. The SAR service will officially launch in early April — on April 6, because 406 MHz is the Emergency Position Indicating Radio Beacon frequency. Galileo has improved the historic SAR location performance from 3 hours to 10 minutes. The Commercial Service is still in preparation, and will be available in 2020. Spoofing is seen as a very real threat to GNSS overall by the Galileo authorities, as exemplified by the recent bloom of amateur spoofers encouraged by Pokemon go.
GLONASS. The Russian system will undertake three or four launches this year; one of them will be a triple-satellite launch. There have been several disruptions to efforts to decrease the offset between GLONASS system time and Universal Coordinated Time but the initiative perseveres. English versions of four system interface control documents (ICDs), to include the new CDMA signal, are promised for Q2 2017; Chinese versions are coming, too. Russian-language ICDs are available at glonass.aic.ru.
BeiDou. With the addition of three new satellites in the past year, China’s system is enjoying improved system performance. Hydrogen clocks are succeeding rubidium clocks, bring an order-of-magnitude improvement in timing accuracy. A BeiDou white paper was published last June, and a revised ICD appeared in November.
In the massive Chinese mass market, 30 percent of smartphones sold in China now have BeiDou capability; that’s out of a 700–800 million total. Huawei multi-function chip LX1101 is a key driver behind this. Unistrong has released a phone with RTCM input for professional use, blurring the line between mass and professional markets.
Six to eight satellites will be launched this year, and 10 to 12 in 2018. BeiDou is in a “very ambitious and aggressive race with time to complete the global system.”
ICG. The United Nations’ International Committee on Global Navigation Satellite Systems will meet in Japan in December of this year, in China next year, and in India in 2019. This can be interpreted as vigorous international interest and “a desire to advance and promote their respective systems’ visibility” worldwide. All pertinent documents can be found at unoosa.org.
EGNOS. The European Geostationary Navigation Overlay Service has two operational geosynchronous Earth-orbit satellites (GEOs) in operation, plus one in test and one in deployment, ready to swap in. It is extending its Ranging and Integrity Monitoring Stations (RIMS) to several new countries, notably Israel and the Ukraine. EGNOS.v3 is coming and will introduce dual-frequency (L1 and L5) service, and also Galileo with GPS, for multi-constellation corrections. The new system’s qualification is planned for 2022.
QZSS. This year, Japan’s Quasi-Zenith Satellite System will launch the second and third of the figure-eight inclined geosynchronous orbit (IGSO) satellites of the Michibiki type, to become operational in 2018. A GEO bird will also be launched. A seven-satellite system is the ultimate goal.
Among other announcements of note made during the course of the Summit, although not by the GNSS operators’ spokespersons:
(Click to enlarge.) Key features of the Galileo satellites.
• OHB, the Galileo satellite manufacturer, said its customer has decided to refurbish the clocks on eight satellites in preparation. “Satellite navigation is nothing but comparison of very precise clocks.”
• Airbus announced a new concept for train positioning integrity: “virtual valises” to correct train position that will replace or augment current trackside valises that are very expensive to build and maintain.
• Munich Aerospace (munich-aerospace.de), a public-private non-profit venture between DLR, the German space agency, Bauhaus Luftfahrt and two technical universities, will mount a Ph.D-level education and research program for 70 individuals, with candidates from 27 nations. This will be located in “the Bavarian Silicon Valley.” It will also undertake a global effort with several other organizations.
• One of the above technical universities, the Federal Armed Forces University in Munich, announced that it is investigating Lidar for potential use in an asteroid mining project for future space exploration. It also has underway initiatives concerning Lidar + GNSS and inertial + GNSS for autonomous vehicles.
In life, few things are certain. In family, love and friendship, fewer. Add more people — workplace, groups, associations, government, society, nations, war — and the complications multiply, the certainties become more scarce.
Some things, however, remain fixed, and true. We call them facts. They are not subject to denial or claims of fakery. They can sometimes be distorted, or their interpretation disputed, but at the end of the day they remain what they were at the beginning. Facts. True.
They do not require a majority to believe in them, nor even a powerful minority. They exist outside belief, heedless of the powers of persuasion, cajolery, hucksterism.
The facts do not always, to their detriment, speak for themselves. Reason does not always prevail. But the facts continue to exist, ruling the operations of the universe.
It has been said that journalism’s duty is to print the facts and raise hell (Chicago Times, 1861). I submit to you that it is a scientist’s duty — and an engineer is a scientist — to live and practice by the facts, to preserve the facts if necessary. To raise hell? That may be a matter of taste or personal style. But to see that the facts are known, shared, publicly available — that can be undertaken without uncomfortable or unpleasant hell-raising.
Guerrilla archiving and data rescues have mushroomed across the U.S., in response to fear that the U.S. government will remove facts it dislikes from its own websites. All-day hackathons are organized by volunteers; the events focus on downloading federal science data sets, particularly those related to climate change, from government websites and uploading them to a new site, datarefuge.org, an alternative source for data. They’re also feeding tens of thousands of government web pages into the Internet Archive, a nonprofit digital library with the mission of “universal access to all knowledge.” And of course someone has devised a custom-built app specifically for this purpose.
Climate-change data has a geospatial aspect, and much of it was collected with GPS equipment. Positioning coordinates lie at the heart of so much key information. So an attack on carefully assembled, scientifically overseen data can be interpreted as an attack on the validity of global positioning technology. Whether or not we take it personally, we should be wary of any attempt to deny or abolish any facts, anywhere.
We’ve seen this before, in other forms. The LightSquared episode in 2011–12 produced blatant denials of the physics of radio-frequency waveforms, for personal and institutional profit. We don’t yet know if this is happening again, whether government data has been erased or simply moved elsewhere.
Whether or wherever they appear or disappear, the facts continue to exist, and perhaps they deserve more respect than they’ve been getting.
Two documents of interest and importance to GNSS designers and manufacturers have been published, one from the Radio Technical Commission for Maritime Services (RTCM) and one from the U.S. Department of Homeland Security (DHS).
The latter document is the subject of a news story concerning receivers used in critical infrastructure, with an emphasis on timing receivers. It provides owners, operators, researchers, designers and manufacturers with information to improve the security and resilience of PNT equipment across the spectrum of equipment development, deployment and use. It makes specific recommendations.
The first-mentioned document is a white paper issued by the RTCM. It follows here, largely verbatim. It is titled “GNSS Community Benefit from Strong International Coordination and Cooperation,” and it addresses an important issue for GNSS receiver manufacturers and others concerning use of BeiDou signals. The authors believe that early publication and dissemination of the recommendation is needed to prevent possible confusion down the line.
GNSS Community Benefit from Strong International Coordination and Cooperation
Introduction
The ephemeris broadcast by China’s BeiDou Navigation Satellites do not directly provide unique identifiers that are similar to the GPS’s “Issue of Data, Ephemeris” (IODE) and “Issue of Data, Clock” (IODC) values. Special Committee #104 (SC-104) of the Radio Technical Commission for Maritime Services (RTCM) has been working with the China Satellite Navigation Office (CSNO) to ensure that equivalent BeiDou IODE and IODC values can be generated.
This paper presents the BeiDou IODE and IODC calculation algorithms that were developed by RTCM’s SC-104 and are being shared with the GNSS community in an effort to promote consistent BeiDou IODE and IODC computational approaches within the community.
Background
Most GNSS position and timing related algorithms need to know exactly where the satellite was at the moment the signal component of interest was transmitted. The signal sent from these satellites also contain messages, which contain parameters used to calculate the position and clock errors of that satellite for a moment of interest within the validity period of those orbital parameters. Because this validity period is relatively short (e.g., +/-4 hours of the current time), the satellites are periodically broadcasting new orbital parameters. These orbital parameters are often referred to as the satellite broadcast ephemeris. Plots from the different broadcast ephemeris for the same satellite do not directly overlay each other because there are forces acting on those satellites (such as solar wind, ionospheric drag, and gravitational anomalies) that do not permit long term exact prediction of orbits and clocks.
Many differential correction services require both the correction generator system (e.g., reference station and reference networks) and the correction consumer (e.g., GNSS rover receivers) know and use the exact same orbital parameters. That is, the consumer of the corrections needs to apply those corrections using the exact same orbital parameters as those used to create the corrections. Failure to do so results in errors and biases for reasons earlier described. In such correction services, the correction message contains information enabling the consumer to uniquely identify the orbital parameters used by the generator.
Correction services need a mechanism to uniquely identify the orbit parameters used by the correction generator system. The GPS Broadcast ephemeris messages are uniquely identified for a certain period of time by what are known as the “Issue Of Data, Ephemeris” (IODE) and the “Issue of Data, Clock” (IODC). Other GNSS constellations have similar concepts, or at least other parameters that can be used for similar purposes. Unfortunately, the 2011, 2012 and 2013 BeiDou Signal-In-Space Interface Control Documents (BDS-SIS-ICD) have offered no information enabling one to develop some mechanism for such a unique identification.
In 2013 RTCM SC-104 created the BeiDou Working Group (BDS WG). Since then, the BDS WG has worked closely with the China Satellite Navigation Office (CSNO) to ensure proper inclusion of BeiDou in RTCM standards and recommendations. As part of this effort, RTCM SC-104 and the CSNO explored several avenues concerning equivalent BeiDou values of IODE and IODC. Ultimately an approach was selected by the CSNO. The selected approach stems from a ground-segment based approach which does not require a change to the BeiDou broadcast message format. However, it does then require that the users of BeiDou needing IODE and/or IODC values ensure that they employ the exact same algorithm to compute those values from the data available in the broadcast ephemeris.
In May 2016, Kendall Ferguson (RTCM SC-104 Chair), Shaowei Han (Wuhan Navigation and LBS, Ltd. and Chair of the RTCM SC-104 BDS WG), and Dr. Hui Liu (Wuhan University /Wuhan Navigation and LBS, Ltd. and co-Chair of the RTCM SC-104 BDS WG) met with the Deputy Director of the CSNO. In that meeting, the CSNO Deputy Director indicated that a soon to be release BDS-SIS-ICD would provide information that would enable calculation of equivalent BeiDou IODE and IODC values. In November 2016, the CSNO released the BDS-SIS-ICD, Version 2.1, and that ICD contains the needed information.
The language in the new BDS-SIS-ICD indicates that the normal ephemeris update (i.e., with new ephemeris parameters) will occur every hour on the hour when everything is normal. If new parameters are needed for whatever reason, they will occur on 12 minute slots within the hour. Any parameter that is changed in a broadcast ephemeris that is related to toc will result in a new toc (coincident with the 12-minute slot of the hour). Likewise, any parameter that is changed in a broadcast ephemeris that is related to toe will result in a new toe (coincident with the 12-minute slot of the hour). Whenever toc changes so will toe. There will be no repeated toc or toe values within a week.
On February 3, 2017, RTCM SC-104 formally approved algorithms for BeiDou ephemeris unique identifiers that can be computed by both message generators and message consumers. The reason for announcing this approval is to proactively prevent a wide variety of BeiDou IODE/IODC algorithms from emerging throughout the GNSS community.
These RTCM BeiDou IODE and IODC algorithms are:
BDS IODC=mod (toc / 720, 240)
BDS IODE=mod (toe / 720, 240)
The modulo 240 gives an 8-bit IODE (and an 8-bit IODC) that provides 2 days of uniqueness and which offers the smaller bit size needed for correction messages. The values from 240 to 255 thus offer some future expansion should additional cases be needed.
Unlike the relationship between the GPS IODE and GPS IODC, the BDS IODC may not be equal to the BDS IODE. The BDS IODC may be updated much more often than BDS IODE. However, whenever the BDS IODE is changed, the BDS IODC is also changed at the same time. Thus, RTCM will be using the BDS IODC as the unique ephemeris identifier in its messages.
Conclusions
Special Committee #104 (SC-104) of the Radio Technical Commission for Maritime Services (RTCM) has been working with the China Satellite Navigation Office (CSNO) seeking methods where by BeiDou equivalents of the GPS IODE and IODC might become available. The BDS-SIS-ICD, Version 2.1, released November 2016, provides information about the constellation allowing computation of IODE and IODC values from its broadcast ephemeris. In February 2017, RTCM SC-104 approved the algorithms it will use to compute unique ephemeris identifiers that will be contained in its messages, thus allowing the recipients of RTCM BeiDou related messages to identify the ephemeris used by the sender of such messages. RTCM is announcing these algorithms in an effort to prevent a variety of such algorithms from emerging and thus causing community confusion.
Micro-Technology for Positioning, Navigation, and Timing towards PNT everywhere and always; slide from a 2014 DARPA presentation to the Space-Based Positioning, Navigation and Timing National Advisory Board (Image: Robert Lutwak, DARPA Micro-Technology Office). Click to enlarge.
The U.S. Defense Advanced Research Projects Agency (DARPA) has initiatives underway with a dizzying number of technologies, all seeking to reduce reliance on GNSS in challenged environments. Using cold atom interferometry and other techniques to reduce the size, weight and power consumption (SWAP) as well as cost of inertial sensors, employing other signals of opportunity (SOI), chip-scale atomic clocks (CSAC), micro-electro-mechanical systems (MEMS) and more, the Micro-Technology Office (MTO) and the Adaptable Navigation Systems (ANS) projects press relentlessly forward to provide U.S. forces with PNT “everywhere and always.”
DARPA’s ANS initiative explores tools to enable use of the many sensors available to warfighters and first reponders. “Over the past two decades, the field of robotics has done a lot for extracting features out of imagery and tracking those features as the robot moves through a given environment,” said Lin Haas says, program manger at the Strategic Technology Office. “We’ve been building upon those capabilities and using the capabilities for the purposes of navigation.”
ANS seeks to provide GPS-quality PNT to military users regardless of the operational environment. It addresses three basic challenges through its Precision Inertial Navigation Systems (PINS) and All Source Positioning and Navigation (ASPN) efforts:
better inertial measurement units (IMUs) that require fewer external position fixes;
alternate sources to GPS for those external position fixes;
new algorithms and architectures for rapidly reconfiguring a navigation system with new and non-traditional sensors for a particular mission.
PINS is developing an inertial measurement unit (IMU) that uses cold atom interferometry for high-precision navigation without dependence on external fixes for long periods of time. Atom interferometry involves measuring the relative acceleration and rotation of a cloud of atoms within a sensor case, with potentially far greater accuracy than today’s state-of-the-art IMUs.
A company called AOSense has applied cold-atom interferometry to IMUs and demonstrated sensors that support system drifts of 5 meters per hour, by using quantum physical properties to measure the relative acceleration and rotation of a cloud of laser-cooled atoms. The next challenge is shrinking the lasers to microsystem size, because the concept requires three lasers generating five beams to cool and move the atoms through interferometers to determine movement and rotation of the device.
Because even long-duration IMUs require an eventual position fix, the ASPN effort is developing sensors that use signals of opportunity — non-navigation signals from sources like television, radio and cell towers, and satellites, as well as natural phenomena, such as lightning.
“Our navigation systems tend to be finely tuned, and as a result they are fairly brittle in terms of accepting new sensors without a lot of hands-on time to make it work,” said Haas.
Flexible Combinations. Integrating and tuning these diverse sensors, maps and other components into a navigation system is expensive and slow, producing platform and mission-specific solutions. The ASPN effort is also developing new fusion algorithms and plug-and-play processing architectures for rapid integration and near-real-time reconfiguration or upgrading of sensors, IMU devices, maps and databases on a navigation system. With flexible combinations of existing and new navigation sensors, ASPN can produce improvements in accuracy, robustness and cost of navigation systems across a range of platforms, environments and missions.
PINS is working towards a final subsystem demonstration in fiscal year 2017. ASPN has completed multiple field demonstrations on air, land and sea platforms, with final demonstrations scheduled in fiscal 2017.
Chip-Scale Atomic Clocks. Meanwhile, last year DARPA launched the Atomic Clocks with Enhanced Stability project under the direction of Robert Lutwak (recipient of GPS World’s Leadership Award for Products in 2012). “If ACES is successful, virtually every Defense Department system will benefit,” Lutwak said.
ACES seeks to create palm-sized, battery-powered atomic clocks that perform up to 1,000 times better than the current generation, employing experts and techniques from atomic physics, optics, photonics, microfabrication and vacuum technology. “All of our modern communications, navigation and electronic warfare systems as well as our intelligence, surveillance and reconnaissance systems depend on accurate time-keeping,” Lutwak added.
Pseudolites. In other, non-DARPA initiatives around the Department of Defense, the Command and Control Directorate of the Army’ Communications-Electronics Research, Development and Engineering Center (CERDEC) is “very concerned about what happens when we lose GPS,” according to Paul Olson. CERDEC is developing vehicle-based, dismounted and anti-jam antenna pseudolite systems.
The pseudolites have completed feasibility testing and entered acquisition for transmitters, receivers and command-and-control. Rockwell International and L-3 are developing the transmitters. The effort seeks to use current military GPS receivers with software modified to accept pseudolite signals.
This article draws on interview quotes that appeared in Signal magazine of the Armed Forces Communications and Electronics Association.
Robots are way cool. Anyone three or older knows that. And agricultural robots were among the first envisioned civilian applications of GPS. When Brad Parkinson went to Stanford in 1984, one of the earliest demonstrations he and his bright new students conducted was fully automatic GPS control of farm tractors on a rough field to an accuracy of 2 inches. Now it’s a bazillion global industry. See “Agriculture robots market projected to reach US$5.7 billion by 2024” for a few figures on that.
The market report underpinning that story contained a couple unquantified yet provocative assertions. Here’s one: Rural flight to the cities is a big force in this market’s growth.
“Progress . . . has primarily driven a growing number of people towards the urban areas and the suburbs. . . . This, in turn, has caused a twofold need for the incorporation of agriculture robots in several countries. Firstly, the growing global population — a lot of it being urban — is pressuring countries to increase food production while steadily reducing the hands available for the agriculture industry. Secondly, the overall land slotted for agriculture in nearly all countries is reducing, thanks to the burgeoning industrial sector and residential construction projects.”
I find this a bit chilling, a bit 1984-ish, and goodness knows we’ve got enough of that going on already. Will our future trips through the countryside, the shrinking countryside, take us through landscapes populated by nothing by smoothly chuffing engines? Will the term “bucolic” lose all meaning?
A second factor driving the agricultural robots market is “the increasingly accepted modes of corporate farming.” Now, I know that multitudes must be fed. Still, personally, I buy my food from small, local farmers as much as possible. It simply tastes better. That is indisputable. Arguments rage about whether it’s better for you; I believe that it is.
I hope the small farmers that my family and neighbors depend on benefit from GPS even though they don’t have huge expensive pieces of equipment. I’ll have to ask them next time I go on a visit. Meanwhile if any GPS and/or robotics manufacturers supply products to the artisanal, shall we say, as opposed to the corporate side of farming, I’d like to hear from you.
We have a finite number of pages to bring you each month, one might say a tightly controlled number. That number has never easily accommodated the quantity of fresh, relevant GNSS and PNT news and technical material that emerges each month. The pace of your developments is too fast with which to keep up!
2017 GPS World Receiver Survey (PDF).
This month, a case in point. Most importantly, driving the whole issue is the latest, greatest version of that long-running industry resource and guide, the GNSS Receiver Survey: 24 data-packed pages of it!
There is a major GNSS milestone to report, one which I have personally awaited since the year 2000 — and I know many others have also. When I signed on at this publication, my first assignment was getting its little sister magazine out the door: the summer 2000 issue of Galileo’s World. For four years we published that optimistic quarterly. There was plenty of content for it, but the constellation itself, and the market to support it, were slower in developing. No longer. With the Declaration of Initial Services, reported in the System of Systems section, Galileo is truly and fully open for business.
This month, we also report a momentous satnav development that is not GNSS in the traditional sense, but does come from a globally orbiting constellation. Adding signals from ranging satellites in low-Earth orbit to those from GNSS satellites in medium-Earth orbit provides just the kind of augmentation and backup that many applications critically need. The advantages come primarily in the timing realm, but there is potential for significant positioning benefits, especially once you many innovators out there get your hands on it and combine it with inertial. A true PNT powerhouse.
I haven’t even gotten to this month’s cover story yet: a technical advance in multipath mitigation that has the potential to amp the power, so to speak, of GNSS receivers in many applications. Correlator beamforming is an intriguing new development. Scientists at the Air Force Institute of Technology put it through its paces, and report good results.
At the risk of giving short shrift to any of these essential stories, not to mention the multiple new products, partnerships, application advances and technology updates that appear in smaller bites, we have opted not to omit any, but to cram them all into the one knowledge-laden issue.
We may not be the New York Times, nor can we approach that venerable publication’s mission, reproduced here. But we have our own — All the News That Fits!
Letter to the Editor
My November column began with Jimi Hendrix, drifted into GPS jamming, touched on a mock presidential plebiscite conducted during ION GNSS+, and concluded by reverting to Hendrix’s Purple Haze: “The real [election] results may already be known by the time you read this … Is it tomorrow, or just the end of time?”
Brian in Oklahoma sent me a four-word email in response. “The end of time,” he wrote.
It has been a good year for all global navigation satellite systems (GNSS), as the chief executives of each system testify here. Alternative positioning, navigation and timing (PNT) also thrives. In this roundup of the latest highlights from the past year and forecasts for the future, 2017 augurs very well indeed! Let’s look at the newest alternative-PNT offerings first, followed by forecasts from the chief executive officers (CEOs) of each of the conventional GNSS.
Alternative PNT grows and expands
Two new entrants to the positioning, navigation and timing (PNT) marketplace offer key capabilities to fill in the gaps left by GNSS. A new satellite timing and location (STL) service from low-Earth orbit satellites, provided by Satelles and Orolia, gives a strong signal capable of penetrating buildings.
Satellite Time and Location (STL) Service. Pursuant to a recent announcement of new PNT solutions independent of GPS/GNSS signals, provided via the Iridium constellation, GPS World talked with Jean-Yves Courtois, CEO of Orolia. Orolia has partnered with Satelles to bring new PNT products and services to the global market, with a focus on military, and defense, government and commercial customers worldwide.
Jean-Yves Courtois, CEO of Orolia.
“We are a manufacturer and integrator of timing equipment,” Courtois said. Orolia is the parent company of GPS/GNSS product and service providers Spectracom, McMurdo and Spectratime. “This new STL service is not fully commercialized yet, but it’s operational and it can be tested. Receivers are available and can be integrated into our equipment.
“The timing signal is very accurate and close enough to GPS for most timing applications, although the positioning accuracy is lower than what GPS users are used to. It is an augmentation for timing primarily, and secondarily for positioning.
“In terms of timing accuracy, it provides on the order of tenths of microseconds in accuracy, and this covers a lot of timing applications, very familiar to us and to our customers. This is an ideal timing backup or augmentation of GPS. As number 2 worldwide in high-precision timing, we know this market and its applications very well.”
Correlator beamforming. The Locata Corporation announced a patented correlator beamforming technology to stem multipath mitigation. The new technique’s performance under rigorous testing by the U.S. Air Force Institute of Technology will be detailed in the January 2017 issue. Look for it! Here are a series of snippets as a preview of that lengthy technical article appearing in Richard Langley’s Innovation column.
“Unlike conventional or traditional beamsteering technology, the new correlator beamforming approach combines RF signals received by any number of individual antenna elements into a single switched-RF signal. This time-multiplexed signal is then downconverted and digitized by a single RF front-end. The correlator beamforming design will should offer cost savings because the resulting data stream is processed using a single correlator channel per beam. This markedly reduces the complexity when compared to the traditional beamsteering methodology.
“The correlator beamforming technique performs antenna array signal processing to form beams as part of a receiver’s correlation process. The complete explanation of this technology can quickly get complex, even for the seasoned RF engineer. To describe this process more simply, we will assume noiseless signals and no multipath (except as noted), as well as equal noise figures for all front-end processing chains. To further simplify our explanation, modulation on the carrier and switching losses will be ignored.”
“To evaluate the performance of correlator beamforming as fairly as possible compared to traditional beamsteering and single-element processing, AFIT set up its data collection such that all three approaches could be implemented in a software receiver. Additionally, a seven-element Naval Air Systems Command GPS Antenna System 1 (GAS-1) antenna was used for this experiment. The antenna was mounted on a 51-inch (130-centimeter) diameter rolled-edge ground plane provided to the ANT Center by the MITRE Corporation.”
“The testing focused on demonstrating an easily modified GNSS receiver to potentially deliver a low-cost solution for mitigating multipath — specifically targeting short delay and carrier multipath. The results presented here show that the multipath rejection performance nearly equals that of a traditional beamsteering GNSS receiver. Applications that can significantly benefit from this technology include stationary GNSS monitoring installations such as those used in satellite-based and ground-based augmentation systems and GNSS receivers for autonomous vehicles and UAVs in high multipath areas such as urban canyons.”
GPS III ready, steady
Col. Steve Whitney, Director, U.S. Air Force GPS Directorate
“The [GPS III] program is working to solve several technical challenges as we progress to completion,” Col. Steve Whitney, director of the U.S. Air Force GPS Directorate, wrote in GPS World’s December issue. “SV-01 testing uncovered electro-magnetic interference between a payload component and a hosted payload. Testing also uncovered electron impact issues on the L-band antenna elements. In partnership with Lockheed Martin, the program developed corrective action and design mitigations for both of these issues and is implementing these steps within our production flow for all the SVs.”
“In the coming year, SV-02, the second GPS III satellite, will also be progressing towards completing production. Currently, all of the SV-02 sub-assemblies have been received by Lockheed Martin and are being integrated into the spacecraft. The next major step in the production flow for SV-02 will be to mate it with its propulsion core.
“Recently, we completed negotiations with Lockheed Martin to extend the production line with purchases of SV-09 and SV-10. These satellites will be technically equivalent to SV-01 through SV-08. This $395 million purchase of two satellites marks a significant affordability milestone for the procurement of GPS III satellites.
“Looking ahead, we are analyzing how to acquire satellites beyond SV-10. We are executing a phased strategy which starts first with determining the viability of a GPS III production design existing beyond the current contractor. We awarded an initial phase of contracts to the Boeing Company, Lockheed Martin Space Systems Company, and Northrop Grumman Aerospace Systems in May 2016 to provide a feasibility assessment of the readiness of their satellites designs. In this phase, the contractors will provide a GPS III production design, manufacturing plans and a navigation payload brassboard test report, along with manufacturing/production processes and facilities maturity.”
Galileo coming on strong
Director of the Galileo Programme Paul Verhoef of the European Commission wrote in that same issue of the magazine, “The production of the satellites continues to maintain a steady rhythm, with a production line stretching from suppliers across Europe to OHB and SSTL and then to ESA’s ESTEC Test Centre in the Netherlands for acceptance testing, based on a wide range of simulated space tests.”
Paul Verhoef, director of the Galileo Programme and Navigation-related Activities, European Space Agency.
“The acceptance of the next satellites to launch is scheduled for this year’s end,” continued Verhoef. “Along with the two more Ariane 5 launches to come — one in the second half of 2017 and another in 2018 — the current plan is to commission further launch services as well as additional satellites in order to have Galileo fully operational by 2020. For these launches, Galileo may be the first customer of the new Ariane-6 launch vehicle.
“2017 will see the upgrade of various elements of the Galileo Ground Segment to reinforce its robustness, including updated releases to the Galileo Control Segment overseeing the satellites and the Galileo Mission Segment, overseeing the navigation signals. A new release of elements of the Galileo Security Facility, for security monitoring of the system, as well as the secure Public Regulated Service, will be deployed at the two Galileo Security Monitoring Centres.
“The Galileo Ground Segment will gain a sixth tracking telemetry and control facility, for monitoring the satellite platforms in Papeete, Tahiti, and additional processing chains for increased redundancy will be deployed across the Uplink Stations in Kourou, Reunion and Noumea used to update the navigation message information. Similar redundant chains will be finalized for all 15 current Galileo Sensor Stations, which perform continuous collection of Galileo signals to identify the tiniest clock error or satellite drift.”
EGNOS. “Along with the progress of Galileo, contracts are planned to cater for the further development of the ESA-designed European Geostationary Navigation Overlay Service, Europe’s first navigation system. EGNOS was certified for safety-of-life aviation use in 2011, and is managed by the European Commission through a contract with operator the European Satellite Services Provider, based in France. ESA will support the technical evolution of EGNOS version 3, intended as multi-constellation in nature, again through the Horizon 2020 framework.”
GLONASS looks forward to a new signal: CDMA!
Sergey Karutin, GLONASS Chief Designer, wrote “On the threshold of the first GLONASS-K2 launch, new GLONASS reference documents were published in October 2016, describing the family of code-division multiple-access (CDMA) radionavigation signals. The draft GLONASS Open Service Performance Standard has been developed. The GLONASS User Information Support System continues to evolve.”
From left: Sergey Karutin, GLONASS designer general; Nicolay Testoedov, director general, SC Information Satellite Systems; and Andrey Tulin, director general, SC Russian Space Systems.
“The system transmitting CDMA navigation signals is referred to in four interrelated interface control documents containing general information on signals and the detailed description of signal structures and digital message data. The new signals make it possible to include 63 satellites in the constellation, not only in circular medium-Earth orbit but also on geostationary and high-Earth orbits.
“The transition to the flexible string-type structure of the message data produces 2-second periodicity of integrity information delivery to users. The increased number of digits occupied by the ephemeris and clock parameters contributes to a better orbit and clock broadcast accuracy. The ephemeris broadcast precision improves from 0.4 to 0.001 meters. Time-stamp length in CDMA signal has increased to 30 bits, compared to 12 bits of frequency-division multiple-access signals.”
BeiDou approaches full regional services
Li Wang
“In 2017, three to four launches of BeiDou satellites will occur,” wrote Li Wang, Director of the International Cooperation Center in China’s Satellite Navigation Office. “BDS will provide basic services to the countries along the Belt and Road region by 2018, and possess global service capability by 2020.”
“BDS will keep improving its nationwide reference station network and steadily enhance its service performance. The dense reference stations for the nationwide frame network will be constructed by 2018, providing meter and decimeter level real-time location services for users in China, even centimeter level service in some areas.
“BDS will carry out the design, validation and construction of SBAS in accordance with international civil aviation standards. The first GEO satellite of BDSBAS will be launched in around 2018. The satellite-based augmentation services covering China and surrounding regions will be provided from 2020, to provide CAT-I services to civil aviation users.
“China will promote construction of a national comprehensive positioning, navigation and timing (PNT) system based on BDS, and strive to establish such a national PNT system with a united benchmark, no-gap coverage, security and effectiveness by 2030, as well as to upgrade capabilities to provide time and space information.”
I haven’t even gotten to 
