GPS World

Tag: GNSS Design & Test Newsletter

  • User location data could support satellite launches

    User location data could support satellite launches

    Let’s look through the other end of the telescope this month. The satellites are nattering along, lining up in orderly fashion at the rocket pad, extending their solar arms smoothly in space once they arrive on orbit. The constellations accrue and new signals inch closer to maturity.

    The only blips on the horizon come from Ligado’s terrestrial impulse and a looming gap in GPS ground control. Just possibly, the latter might coincide with activation of the full European constellation and Galileo could come to the rescue of suitably equipped users who hunger for greater accuracy. This has been Galileo’s raison d’etre for two decades now, and it may actually be on the cusp of coming true.

    At any rate, back to the telescope’s other end. What might that be? Facebook.

    FB_Location-W“When you think back to the beginning of online advertising, this is what advertisers have been waiting for.” That is Facebook’s director of monetization product marketing — an actual job title, and a powerful one in time to come.

    All this — what advertisers have been waiting for — is made possible by GPS. Soon, by all GNSS. And by your smartphone.

    From a GNSS Design & Test point of view, this means we are about to see some real money come available for constellations. Fast-multiplying applications of position, navigation and timing data have always shaped GNSS evolution, to some degree. Making this latest development different by a degree of magnitude is its potential to alter the way GNSS policy is shaped and the way GNSS funding is provided.

    Facebook will soon roll out a new Store Visits metric for business clients: location data and purchases correlated to Facebook ad performance. Partnerships with point-of-sale systems like Square and Marketo will “prove” (let’s use that word loosely for now) who bought what after seeing Facebook ads.

    The way the company tells it, “While people use mobile in 45 percent of all shopping journeys, more than 90% of sales still happen in brick-and-mortar businesses.”

    Even if you don’t buy something, Facebook will know that you — assuming, and this is a big jump, that you are a Facebook user — visited a store by aligning GPS, beacon, Wi-Fi and other radio-frequency signals and cell-tower locations with brick-and-mortar coordinates. You may not be a Facebook user, but I’ll bet one of your loved ones is.

    With the new feature, instead of having to (gasp!) leave Facebook to visit an unfamiliar website for a store locator, users can view the address, hours, phone number and estimated travel time without exiting the social network.

    Cleveland_on_Facebook

    I know people who rarely or never leave Facebook. Do you? This is a plus for them.

    Facebook, one of the new corporate mega-giants, duels with Google, Apple and Microsoft over various pieces of digital turf. One of the most hotly contested treasures — the Holy Grail, in marketing execs’ terms — is the capture and use of user data. It is getting more than a little bit creepy.

    To date, the even-bigger giant that is advertising has used metrics such as ad views and clicks to measure effectiveness: how much an ad actually inspires purchase or response to other calls to action. I know this because I use these metrics, or someone in my organization does. Such metrics are now deemed “flimsy” by the standards of aligning GPS, beacon, Wi-Fi data and so on as outlined above.

    Facebook is not alone in exploring the fertile ground. Google recently launched ads that show maps of nearby locations, and the others surely do not lag far behind. For the moment, these massive integrators aggregate and anonymize the data to protect privacy, but that’s not to guarantee they would always do so. Currently, there’s no specific opt-out other than turning off location services for the app on the user’s device, which people might be reluctant to do if it degrades other app functionality.

    Let’s shield our eyes from the dark side for the moment, and consider what this means for GNSS.

    We, you and I, those of us in the PNT industry, have known for some time how integral to critical infrastructure GPS is and GNSS soon will be. But the vast public does not. And lawmakers, bless their little hearts, largely do not either. That will change when the desperate craving of large companies to reach billions of buyers enters the PNT arena.

    We can envision mega-marketing bolstered by alliance with the transportation industry, both ground and air, as driverless vehicles and drones become more commonplace. With powerful lobbying interests behind it, GPS might finally get some respect, and other systems around the world with it. Modernization might proceed more smoothly and quickly, without funding hiccups and capability gaps. That’s the bright side of all this.

    It reminds me of nothing so much as an old rock’n’roll song. In “Top of the Pops,” the Kinks sang:

    Now my agent called me on the telephone
    He said, son your record’s just got to number 1
    And you know what this means?

    This means you can earn some real money.

  • Galileo Space-Borne, Industry Land-Bound

    Galileo Space-Borne, Industry Land-Bound

    Galileo’s latest pair of full operational capability (FOC) satellites now orbit proudly in space, “performing beautifully.” The first two FOC birds may soon shift their focus from navigation to gravity experiments instead.

    Meanwhile, as the European Space Agency tries to fly, European industry seeks firmly grounded support in the form of an industrial policy and economic stimuli, expressing concern that the current situation “might jeopardize the achievement of the main objections of the European GNSS programmes.”

    Alba and Oriana (aka Galileo satellites 9 and 10), launched on Sept. 11, are drifting towards their target orbital positions. Thruster firings will resume around the end of October to stop their drift and achieve fine positioning in orbit. Their control now rests in the electronic hands of the Galileo Control Centre in Oberpfaffenhofen, Germany.

    Gravity Probe. The two satellites launched last September have not fared so well. Injected into the wrong orbit by a faulty Soyuz rocket, they were moved to a “usable” orbit in December 2014, reducing orbit eccentricity and avoiding the high radiation doses in the Van Allen belts, but still not high enough to function fully as navigation satellites. The European Commission (EC) and ESA remain convinced that Doresa and Milean (satellites 5 and 6) will be able to contribute in some limited fashion to Galileo’s PNT solutions, but they are also preparing alternate roles for the pair.

    Together with Sytèmes de Référence Temps Espace (SYRTE, or Time-Space Reference Systems department) of the Observatoire de Paris and the Center of Applied Space Technology and Microgravity (ZARM) at the University of Bremen, ESA has explored taking advantage of the combination of Dorena’s and Milesa’s eccentricity (about 0.15 in the corrected orbits), the passive hydrogen maser (PHM) on-board clocks’ high accuracy-stability (~10−14 per day), and high orbital precision to perform a measurement of the gravitational redshift. The redshift or Einstein shift is a process by which electromagnetic radiation originating from a source that is in a gravitational field is reduced in frequency, or redshifted, when observed in a region of a weaker gravitational field. The three organizations believe that the two satellites can help measure this effect with a superior accuracy compared to today’s state of the art, based on Gravity Probe A, an experiment performed in 1976.

    These tests are noted to have a high scientific relevance, as many alternative theories of gravitation predict violations of the Einstein Equivalence Principle at some level of accuracy. Two parallel research activities, with SYRTE and ZARM, will be launched by ESA to assess this potential in greater detail.

    See What the Future Brings. Two further Galileo satellites are scheduled for launch by end of this year. Next year the deployment of the Galileo system will be boosted by the entry into operation of a specially customized Ariane 5 launcher that can double, from two to four, the number of satellites that can be placed into orbit by a single launch.

    GalileoMustSucceed

    We Want What They Got. Earlier this month, the 29-company Galileo Services association, made up of European chipset and receiver suppliers and associated service providers, issued a position paper calling for “a coordinated industrial policy to support the European economy,” specifically that portion of the economy based on satellite positioning, navigation and timing. The companies jointly complain that in the United States, Russia, China and Japan, dedicated national strategies, including “massive funding” for both R&D and manufacturing, support GNSS downstream industries — but in Europe, no such backing exists. The un-level playing field imperils European commercial activity.

    “As things stand, in a few years, it will be difficult or nearly impossible for European industry to survive in the highly competitive GNSS global market,” the position paper reads. “Unless an effective and long-term strategy is put in place during the Galileo early services exploitation phase (2016–2020), the window of opportunity for European industry to benefit from the current GNSS market boom will soon be closed.”

    “Europe Must Succeed in the Global Navigation Market Race” (the full document is available here) calls upon European governments to devise and adopt a strategic plan to support Galileo’s downstream suppliers and manufacturers. The desired strategy connotes money and favorable regulations.

    Europe governmental hands may be a bit tied by a U.S.-European agreement that neither will put up barriers discriminating against each other’s satnav systems. China and Russia have not signed the agreement and so are not bound by its restrictions; the two countries can freely make “massive procurements equivalent to several billions of euros from the public sector, as anchor customer, which radically boosts private investment,” according to the Galileo Services paper. Further, the United States can step around the agreement’s terms via military contracts to U.S. manufacturers, leveraging their commercial ventures.

    Thirty-three or Bust. The report continues to reference the magic number 33 percent, the traditional European global market share in any high-tech sector. European industry partners estimate they hold 20 percent of the worldwide satnav currently, if even that, and, ominously, they see that share declining. They cast U.S. manufacturers in the dominant role: “80 percent of well-established market owners are of U.S. origin.” This is not the same as an 80 percent market share, but it still sounds scary to European ears. Meanwhile, “the size and growth of Chinese industry, which has already in just a few years outperformed European industry in the field of telecommunications, is particularly worrying” to satnav concerns.

    Section Two of “Europe Must Succeed” defines the strategic plan that the industry partners would like to see:

    • quantitative objectives in terms of market share, revenue, and job creation;
    • clear support actions in terms of public procurement and regulations;
    • key performance indicators to assess progress towards set milestones.

    Section Three lays out a series of recommended key support actions for public institutions to undertake, and Section Four proposes a Galileo Services Forum, a permanent and formal arena for discussions between the European Commission, the European GNSS Agency, and the European Space Agency on the one hand, and European GNSS downstream industry on the other.

    Interestingly, while the report in an earlier section calls out a number of promising application and service markets — basically all the usual suspects, from connected vehicles to offshore infrastructure — it singles out one, “the leading position of Europe in GNSS security and resilience,” for particular attention. It “should be strengthened, as it is critical for today’s and tomorrow’s markets.”

    The report also makes a pointed allusion to European industry’s “strong reputation for quality and reliability.” This note is not sounded elsewhere in the paper, suggesting a fear that price trumps quality in today’s marketplace. A well-founded fear.

    Galileo Services represents more than 180 members. Its most active and representative GNSS players include: Airbus Defence & Space, Ansaldo STS, CGI, European Satellite Services Provider (ESSP), Eutelsat, France Developpement Conseil, Fugro, GMV, Guide, Hertz Systems, Honeywell, Indra, Ineco, JAVAD GNSS, Kayser-Threde, Kongsberg, M3 Systems, NavCert, NLR, NovAtel, Nottingham Scientific Limited, OHB, QinetiQ, Septentrio, Catapult, Sogei, Spirent, Thales and Veripos.

     

  • To L2C or Not to L2C? That Is the Operational Question.

    Half of the GPS constellation now transmits the new civil signal, L2C. In a matter of weeks, that number will crest into the majority of the constellation when IIF-10 is set active and operational to users. By the end of the year or early 2016, look for 18 usable satellites transmitting L2C. That could be considered a nominal initial operating capability (IOC), though it is unlikely to be declared as such by the Air Force. We can anticipate a full operating capability (FOC) within five years. Many high-precision GPS receivers currently embody L2C signal processing capability.

    As Oscar Colombo, research scientist at NASA, noted in a recent CANSPACE contributed note, “This seems like a moment to start seriously thinking about using L2C as much as possible.”

    This month’s newsletter presents an amalgam, a panel discussion in virtual print, on several aspects and viewpoints stimulated by his posting,

    Some readers may want to peruse this U.S. government bulletin for a general description of L2C; others who feel sufficiently informed may skip directly two paragraphs down to “Three issues might be in the way of that being a practical proposition.”

    “L2C is the second civilian GPS signal, designed specifically to meet commercial needs. Its name refers to the radio frequency used by the signal (1227 MHz, or L2) and the fact that it is for civilian use. There are also two military signals at the L2 frequency. When combined with L1 C/A in a dual-frequency receiver, L2C enables ionospheric correction, a technique that boosts accuracy. Civilians with dual-frequency GPS receivers enjoy the same accuracy as the military (or better). For professional users with existing dual-frequency operations, L2C delivers faster signal acquisition, enhanced reliability, and greater operating range. L2C broadcasts at a higher effective power than the legacy L1 C/A signal, making it easier to receive under trees and even indoors. The Commerce Department estimates L2C could generate $5.8 billion in economic productivity benefits through the year 2030. The first GPS IIR(M) satellite featuring L2C launched in 2005. Every GPS satellite fielded since then has included an L2C transmitter.”

    Oscar Colombo’s CANSPACE note continues:

    “Three issues might be in the way of that [using L2C as much as possible] being a practical proposition, and I would appreciate comments on some or all of them:

    “(1) The fact that the new L2C navigation code (CNAV) is being transmitted, but flagged as pre-operational by the USAF, indicating that this organization is not yet ready to guarantee its fitness for use.

    “(2) The quarter-wave phase difference with the heritage signal L2.
    This one is important to know when fixing the ambiguities of differential observations (double differences and first order differences between satellites) combining L2C data from IIR-M and IIF satellites with those with only L2 (IIR and IIA). Some high-end commercial receivers correct for this phase difference, some don’t.  The latest RTCM document I’ve seen that touched on this issue came out in 2013 (RTCM Standard 10403.2, Paragraph 3.1.8, Table 3.1-5), and listed the choices , at that time, by nine leading manufacturers on this matter. The list does not include all of present-day manufacturers of high-end receivers, a list that changes over time.

    “(3) There is no proper place for L2C in files in the widely used Rinex 2.11 format.
    In principle, this can be taken care of by using data files in the Rinex 3 format. However, the use of Rinex 3, that has some major departures from 2.11, is not universal yet.

    “Does anyone  know of an up-to-date, reliable and comprehensive list of receiver manufacturers showing those that correct and those that do not correct for the quarter-wave phase shift?”

    GPS World contributing editors Eric Gakstatter (Geospatial Solutions) and Don Jewell (Defense) had a private conversation about the above, which I now make public.

    Don Jewell: “I can address this from a policy and operational perspective but you [Eric] have a better feel for the users perspective.

    “With two more successful IIF launches there will then be 18 L2C SVs broadcasting that signal, and that is considered by the government to be nominal IOC, an initial operating capability. Regardless of where you are on the Earth, shy of 60 deg N and 60 deg S, you should always have at least one or more L2C SVs in view.

    “We are probably looking at 2023 (8 more years) before the L2 carrier phase is in jeopardy of shifting without notice. If indeed that ever happens.

    “So from an operational and providers (HQ AFSPC, 50SW and 2SOPS) perspective, certainly the L2C signal should be useful and reliable. Just not normally guaranteed until FOC or full operational capability is declared, usually with 24 SVs broadcasting L2C. With no premature losses that will be halfway through the GPS III launch schedule ~ 2019-20.

    “Schedules are dynamic and always subject to change of course.”

    [Editor’s note: The L2 carrier isn’t going to go away or shifting to another frequency. What might go away is the P(Y) modulation on the L2 carrier if the DoD considers the P(Y) signals redundant once the M-code is fully embraced. If the P(Y) signal on L2 is no longer transmitted, then civil receivers currently using the P(Y) signal to obtain L2 carrier-phase measurements will no longer be able to do this.]

    Eric Gakstatter replied, “I’ve heard that some manufacturers say they are taking advantage of L2C when there are IIRM or IIFs in view and maybe some of the receivers I’m using are doing so. I’ve not paid attention to it.

    “It could be helpful in areas where users are trying to work in difficult environments such as near and under tree canopy.

    “In the case of RTK, I would think the reference station would have to broadcast L2C data.”

    A CANSPACE reader provided the following useful reference, which although it dates from 2012, still contains much immutable data: “The most recent view on the situation I have with L2C can be found here.”

    This links to the presentation slides from an American Geophysical Union 2012 Fall Meeting paper, “The Effects of L2C Signal Tracking on High-Precision Carrier Phase GPS Positioning: Implication for the Next Generation of GNSS Systems,” by Frederick Blume, Henry Beglund, and Lou Estey of UNAVCO, a non-profit university-governed consortium, facilitates geoscience research and education using geodesy.

    Oscar Colombo and other CANSPACE subscribers have contributed several further notes t the L2C discussion string.  To read them, it’s possible to access the archives here.
    Or you can more simply and elegantly subscribe to CANSPACE; see instructions here.

    Last month, Richard Langley and Oliver Montenbruck jointly communicated the following interesting aspect of the U.S. Federal Radionavigation Plan to CANSPACE readers:

    “in the new version of the FRP is a new phrasing of the earlier statement on guaranteed availability of the P(Y) signal only up to 2020:

    “The [U.S. Government (USG)] commits to maintaining the existing GPS L1 C/A, L1 P(Y), L2C, and L2 P(Y) signal characteristics that enable codeless and semi-codeless GPS access until at least two years after there are 24 operational satellites broadcasting L5. Barring a national security requirement, the USG does not intend to change these signal characteristics before then. Twenty-four satellites broadcasting the L5 signal is estimated to occur in 2024. This will allow for the orderly and systematic transition of users of semi-codeless and codeless receiving equipment to the use of equipment using modernized civil-coded signals. Note that it is expected that 24 operational satellites broadcasting L2C will be available by 2018, enabling transition to that signal at this earlier date. Civilian users of GPS are encouraged to start their planning for transition now.”

    Finally, Richard Langley notes that “I have a student looking into which Precise Point Positioning engines can currently process L2C observables, but his report is not yet available. Also, we are looking into adding an optional L2C processing capability to the University of New Brunswick PPP software, GAPS (GPS Analysis and Positioning Software), but that’s a month or so away.”

    As a postscript, there is a trending discussion at the LinkedIn group, GNSS R&D, Using C\A acquisition products to acquire L2C long code.

  • eLoran Progresses Toward GPS Back-Up Role in U.S., Europe

    eLoran Progresses Toward GPS Back-Up Role in U.S., Europe

    eLoran-restart-W
    (fFrom left) Congressman LoBiondo, UrsaNav CEO Chuck Schue and Harris Division President Pam Drew. (hoto Credit: Andrei Grebnev, UrsaNav)

    As of June 19, eLoran is on the air in the United States. The low-frequency signal emanates from a single station, a former U.S. Coast Guard Loran Unit in Wildwood, N.J., which sports a 625-foot signal mast that has been out of action for five years. The signal is receivable at distances of up to 1,000 miles.

    The facility began generating eLoran pulses at the press of a command button by Congressman Frank LoBiondo (R, N.J). Present for the ceremonial start of a 12-month demonstration and research program under the aegis of the Department of Homeland Security were project participants Charles Schue, CEO of UrsaNav; Pam Drew, president of Harris Information Systems; and Dana Goward, president of the Resilient Navigation and Timing Foundation.

    Brief remarks delivered at the turn-on collectively made the key points that:

    • GPS services are essential to national and economic security, yet are vulnerable to disruption.
    • The eLoran navigation and communications signal has  features that are complementary to GPS, making it difficult to disrupt; further, it could be an important part of enabling UAVs to fly safely in our airspace.
    • The U.S. Federal Radionavigation Plan cites not being critically dependent upon a single system for positioning, navigation, and timing as a national policy objective. The plan specifically identifies eLoran testing as an important step toward reaching that objective.

    The two engineering companies, UrsaNav, a supplier of eLoran technology, equipment, and services, and Harris (which recently acquired Exelis), provide funding and technology for the tests supported by the U.S. Coast Guard, Department of Defense, Department of Homeland Security and other federal agencies under a Cooperative Research and Development Agreement (CRADA) announced in May.

    The team will evaluate eLoran as a potential complementary system to GPS, exploring the capabilities and use methods of eLoran in depth to identify all strengths, capacities, and potential vulnerabilities of the technology. One goal of the CRADA is to reduce the size, weight, cost, power needs and other aspects of Loran, similar to what has evolved with GPS.

    “This is a phoenix arriving. We have the opportunity to add 2015 technology to the older idea,” said Schue of UrsaNav, once Coast Guard commanding officer at the former Loran station. “A prudent mariner always has two systems to navigate.”

    Dana Goward, also a retired Coast Guardsman whose non-profit Resilient Navigation and Timing Foundation is working on the project, stated that eLoran can attain positioning accuracy of six meters or better.

    “We will explore many places eLoran can be deployed where GPS isn’t available such as deep canyons, through buildings, in foliage and under water,” added Harris Corp.’s Drew. “We’re involved with unmanned aerial drones, and eLoran could be key. There are applications for civilian and military uses.”

    In this GPS World exclusive video, Admiral Thad Allen, former commandant of the U.S. Coast Guard, discusses PNT alternatives to GPS for navigation, including eLoran and the activation this week of the signal on the eLoran tower in New Jersey.

    eLoran in Europe

    Matters have moved a little further along in Europe. In 2013, the General Lighthouse Authorities of the UK & Ireland (GLA) established prototype eLoran Initial Operating Capability (IOC) in the United Kingdom, where eLoran now delivers PNT data at the 10-meter level from a network of high-power, low frequency, terrestrial transmitters.

    “To get high accuracy from eLoran requires accurate calibration of Additional Secondary Factor (ASF) through measurement,” according to paper delivered at the Institute of Navigation’s 2015 Pacific PNT meeting. “Can eLoran Deliver Resilient PNT?” was authored by Nick Ward, Chris Hargreaves, Paul Williams, and Martin Bransby of the GLA.

    The older Loran-C system suffered from significant positioning bias errors due to a number of radio frequency signal propagation delay factors, they write. “The Primary Factor (PF) is due to the signal travelling slower in air than free-space, the Secondary Factor (SF) is due to the presence of the Earth’s surface and the electrical properties of the oceans. Additional Secondary Factor (ASF) is due to the additional electrical resistance encountered by non-seawater terrain, land, mountains, deserts, and so on. PF and SF can be modeled, but to get high accuracy from eLoran requires accurate calibration of ASF through measurement.

    “To do this,” they continue, “ASF surveying and mapping has been conducted along the port approach channels at Aberdeen; along the Firth of Forth; Middlesbrough; Hull and the Humber Estuary Traffic Separation Scheme (TSS); Harwich and Felixstowe; The ports of London, Medway and the approaches past the London Array wind-farm and also through the Dover Straits.

    “To complement these services, seven differential-Loran (DLoran) Reference-Stations, one located close to each of these survey areas have been established. These stations monitor the time of arrival of the received eLoran signals, and generate differential-corrections that are broadcast via the Anthorn Loran Data Channel (LDC), to account for temporal variations in these ASF maps.

    “Making use of these ASF maps, combined with the locally-produced differential corrections, can allow a maritime user of eLoran IOC to obtain position accuracy of the order of 10m (95%), within a radius of 30 to 50 km of the DLoran reference station.”

    See also “Back-up to Vulnerable GPS Signals Required for Busy Shipping Lanes.”

    The GLA authors conclude that:

    1. eLoran can deliver Resilient PNT and this has been demonstrated on several vessels.
    2. Seamless handover from primary (GPS) to secondary (eLoran) positioning source has been successfully implemented.
    3. Surveying and mapping of ASF has been carried out for several major ports and the required levels of performance demonstrated.
    4. DLoran reference stations to correct for short-term, temporal variations have been installed and commissioned.
    5. Good levels of performance have also been demonstrated for coastal voyage phase away from the ASF surveyed areas.

    eDLoran in Rotterdam. The July 2014 issue of GPS World presented a cover story showing results of a newer version, enhanced differential Loran (eDLoran), yielding position accuracies of approximately 5 meters.

    vw-W

    eDLoran: The Next-Gen Loran

    Potential GNSS Back-up Improves to GPS-Level Accuracy

    A new enhanced differential Loran system demonstrates 5-meter accuracy not achievable by the current DLoran system, and requires less expensive reference stations. A prototype tested in Rotterdam’s Europort area uses standard mobile telecom networks and the Internet to reduce correction data latency — a key source of error — by one to two orders of magnitude.

    By Durk van Willigen, René Kellenbach, Cees Dekker, and Wim van Buuren

    Figure 12. The large ship symbol (grey) is derived from the GPS-RTK receiver of the Rotterdam pilots. The width of the ship symbol is 10 meters and the speed-over-ground was 11 kts. The red triangle is generated by the eDLoran receiver and remains between the required ± 5 meter limits for eDLoran.
    Figure 12. The large ship symbol (grey) is derived from the GPS-RTK receiver of the Rotterdam pilots. The width of the ship symbol is 10 meters and the speed-over-ground was 11 kts. The red triangle is generated by the eDLoran receiver and remains between the required ± 5 meter limits for eDLoran.
    Figure 13. The red track is based on raw eLoran data without any corrections. The transparent blue line is made by GPS-RTK and is widened to 10 meters giving the required ± 5 meter limits of eDLoran. The white line is output from the eDLoran receiver which stays within the borders of the 10 meter wide transparent blue line.
    Figure 13. The red track is based on raw eLoran data without any corrections. The transparent blue line is made by GPS-RTK and is widened to 10 meters giving the required ± 5 meter limits of eDLoran. The white line is output from the eDLoran receiver which stays within the borders of the 10 meter wide transparent blue line.

    The GLA authors from the UK give a perspective on the Rotterdam project, as follows:

    “A compatible system (eDLoran) has been developed for operation by ships’ pilots on the Europort approach to the Port of Rotterdam.

    “However, Loran is a regional system dependent on international collaboration. The 9 transmitters in northern Europe are operated by Denmark, France, Germany, Norway and the UK.

    “Both Norway and France have declared an intention to cease Loran transmissions at the end of 2015. Moreover, France intends to dismantle its Loran infrastructure in 2016. Arrangements for the commercial operation of the infrastructure are being investigated, but this depends on some form of regional agreement. The European Union appears to have no policy for resilient PNT, the European Radio Navigation Plan having twice been drafted but never published. The view seems to bee that the introduction of Galileo will achieve resilient PNT, which it will not.”

    And Elsewhere

    South Korea is implementing a national eLoran service, and it is understood that similar plans are being considered in Russia and China.

    Meanwhile, the U.S. Army is interested in eLoran PNT for the warfighter.

  • Galileo Update, Ionospheric Model Shared at ENC

    This year’s European Navigation Conference (April 7–10 in Bordeaux, France) got underway with “Good news from up there .…”

    Galileo’s seventh and eighth satellites launched successfully in late March, the European Space Agency (ESA) plans four more satellites to reach orbit in 2015, and space maneuvers for Galileo 5 and 6 have been completed, with a recovery plan currently under study. ESA also happily confirms that satellites 7 and 8 are in good position, under control, and behaving very well.

    Fiammetta Diani, deputy head of Market Development for the European GNSS Agency (GSA) followed her keynote opener with “ . . . some good news also from down here.”

    Photo: European GNSSThe GSA has just published a new document on the NeQuick Ionospheric Model, used to compensate ionospheric errors on Galileo and other GNSS signals. The document, titled “European GNSS (Galileo) Open Service Ionospheric Correction Algorithm for Galileo Single Frequency Users,” and downloadable, contains detailed description and results from years of intense research.

    Ionospheric Model

    The NeQuick model improves accuracy levels globally when using single-frequency services, even during hyperactive periods of the 11-year solar cycle, according to the GSA.

    (Last year, authors from the European Space Research and Technology Centre (ESTEC) at the European Space Agency (ESA) published an article in GPS World magazine, “Innovation: the European Way,” as the Innovation column edited by Richard Langley. From Langley’s introduction to the article: “The ionosphere is a dispersive medium for radio signals, so by making measurements simultaneously on two frequencies transmitted by a satellite, most of the effect of the ionosphere can be removed. However, single-frequency devices such as most vehicle navigation and handheld receivers don’t have the luxury of dual-frequency correction. These devices must rely on a single-frequency correction model. The coefficients for such a model are included in the navigation messages transmitted by all GPS satellites. Known as the Ionospheric Correction Algorithm or Klobuchar Algorithm, it removes at least 50 percent of the ionosphere’s effect.

    “The Galileo satellites also include the parameters of an ionospheric algorithm, called NeQuick G, in their navigation messages. In this month’s column, the Galileo system design team describes the novel European way for modeling the ionosphere for single-frequency users and compares its performance to the current GPS approach.”

    The online version of the Innovation column contains an extensive Further Reading list, including resources on the GPS (Klobuchar) ionospheric model.)

    Receivers operating in single-frequency mode may use a single-frequency ionospheric correction algorithm,which is given in the report in the form of two equations, to estimate the ionospheric delay on each satellite link. The Effective Ionisation Level, Az, is determined from three ionospheric coefficients (broadcast within the navigation message) and the Modified Dip Latitude (MODIP) at the location of the user receiver. MODIP is expressed in degrees and a table grid of MODIP values versus geographical location is provided together with NeQuick G model. The receiver then calculates the integrated Slant Total Electron Content along the path using NeQuick G and converts it to slant delay using a stated equation for ionosphere group delay (delay on the pseudo-range or signal code phase), neglecting higher order terms.

    A further section of the report describes practical guidelines for the implementation of the single-frequency ionospheric model within Galileo user receivers, with sub-sections detailing:

    • Zero-valued coefficients and default Effective Ionisation Level;
    • Applicability and coherence of broadcast coefficients;
    • Effective Ionisation Level boundaries;
    • Integration of NeQuick G into higher level software;
    • Computation rate of ionospheric corrections.

    In a document annex titled “Performance Results,” the performance of the model is compared with that of the GPS Ionospheric Correction Algorithm (ICA) algorithm, also known as the Klobuchar model.

    “As an example of the behavior of the two models as a function of the time of day, the delay computed using Klobuchar and NeQuick G are plotted as a function of the satellite elevation and of UTC in Figure 5. For this example, in order to have a direct comparison between the two models, the delays computed using Klobuchar and NeQuick are compared with respect to the delay estimated using Global Ionospheric Map (GIM). The plots have been computed for a station in latitude [deg] 40.8234, longitude [deg] 14.2161, altitude [m] 122.6590 m, using GPS satellite PRN 11 and for day 16 of year 2010 characterized by quiet geomagnetic activity.”

    GNSS-D&T-Figure-5

    Several further figures and tables within the document annex give more details on the performance results obtained.

    The NeQuick electron density model was developed by the Abdus Salam International Center of Theoretical Physics (ICTP) and the University of Graz. The adaptation of NeQuick for Galileo single-frequency ionospheric correction algorithm (NeQuick G) has been performed by the European Space Agency (ESA) involving the original authors and other European ionospheric scientists under various ESA contracts.

    GNSS Market

    In market forecasts, Diani related some high-level results from the GSA’s 2015 GNSS Market Report.  Among other insights, the GSA predicts that the installed base of GNSS devices will triple by 2023, with per capita rates of 2.5 in North America (currently 1.4), and 2.3 in Europe and Russia (now 1.1 and 0.8, respectively). Around the rest of the world, in eight years nearly every person, on average, will possess a GNSS device. Currently rates are 0.5 in South America, 0.2 in Africa, and 0.4 in the Middle East and non-Russian Asia.

    Galileo Services: Proposal for an Industry Policy

    Axelle Pomies of Galileo Services, an association of industry players active in GNSS applications, stressed the need for a comprehensive, assertive industry policy to support the development of EGNOS/Galileo downstream sector, leading to growth, job creation, and autonomy for Europe.

    As stated in her presentation, GNSS market trends do not currently favor Europe, as the continent aggregately currently holds a market share of less than 20%, whereas the usual European market share in other high-tech sectors is around 33%. European GNSS downstream industry suffers from a competitive disadvantage vis-à-vis industry from other regions, because dedicated national programs/strategy in the United States, Russia, China, and Japan support competitiveness of their respective industries and enhance GNSS market take up, including funding from R&D to manufacturing capabilities; regulation; and massive public procurement. Europe has none of these, or at least not to the same degree.

    Among the risks this entails for European Union autonomy are that Galileo may not be used as intended; there is little predicted interest for most user applications to track four constellations. Meanwhile GPS, GLONASS and BEIDOU are already in place.

    She cited a number of key GNSS application markets where European industry must position itself strongly and securely. In her view, the most promising markets in terms of growth potential and strategic placement include:

    • Road (intelligent transport systems, connected vehicles, and advanced driver asisstance systems, or ADAS)
    • agriculture
    • autonomous/unmanned vehicles
    • rail
    • timing
    • critical infrastructures
    • multimodal logistics
    • defence
    • Internet of Things.

    In that regard, Pomies posited the necessity of a comprehensive and assertive industry policy to support the development of EGNOS/Galileo downstream sector, with the goals of  fostering the use of European GNSS infrastructures; encouraging European Industry to develop EGNSS equip/apps; fostering the manufacturing of E-GNSS based solutions in Europe; and supporting the European industry competitiveness in the GNSS global market and fostering the emergence of European champions.

    Support from European and national institutions is necessary for the full success of the EGNOS programmes, she said, and she previewed the mid-May publication of a draft position paper from Galileo Services in this regard, for wide consultation within the European downstream sector.

    Follow www.galileo-services.org for its first appearance.

    Key Issues in Intelligent Transport and Location-Based Services

    Concluding the ENC plenary, Florence Ghiron of Topos Aquitaine, a regional council of satnav and intelligent transport companies in southwest France, focused on opportunities and risks for small-to-medium enterprises. One of her key points regarding the intelligent transport systems market: the long development paths of public and regulatory policy do not help SMEs grow.

    Today, several GNSS-based road schemes are already operational, but they tend to be limited to specific applications, to regional areas and/or to specific classes of vehicles, for example, trucks above a certain weight !

    Moreover, each country tends to work with their national champion. This has led to fragmentation of the targeted markets all over Europe. Thus, the need for interoperability between schemes is an increasingly important factor.

    Among her major recommendation for supporting application and business development:

    Support GNSS stakeholders at promoting their innovative GNSS applications towards the largest possible community. This encompasses:

    • Visibility of GNSS mature solutions/applications

    • Cost-benefit analyses for already developed GNSS-applications

    • Identification of the best ways/means to help SMEs  promote their offers towards public purchasers

    • Development of a Directory of European regional and national contact points

    She further proposed additional funding mechanisms for SMEs to bridge the gap between the R&D step and the industrialization/market development phase.

    Finally, help medium/small regions and cities to purchase or procure the innovative GNSS-ITS applications they need to answer their public transportation/mobility needs.

    Further information on the Topos project SUNRISE (Strengthening User Networks for Requirement Investigation and Supporting Entrepreneurship), a European project managed by the GSA, may be found at www.topos-aquitaine.org.

    Back to Bordeaux in October

    Both Diani and Ghiron closed their presentations with invitations to return to Bordeaux in October for the Intelligent Transport Systems World Congress, themed “Towards Intelligent Mobility: Better Use of Space.” GNSS looks to take a more central role than ever in this far-reaching economic segment.

  • Obstacles in the Orbit Path of GPS III

    Source: Alan Cameron
    The Lockheed Martin GPS III Non-Flight Satellite Testbed (GNST).

    A Lockheed Martin vice president has stated that the first GPS III satellite will likely launch in 2017, not 2016 as had been projected in the most recent update.

    The company is readying the first satellite for launch availability by the end of 2015, for launch as early as the end of this year, but Space News reports that Mark Valerio, vice president and general manager of Lockheed Martin’s military space business, stated in a Feb. 18 news briefing that he expects the Air Force will schedule its launch for early 2017.

    The GPS III generation of modernized satellites — with new signals, added signal strength, and resistance to interference and jamming — was originally projected to begin orbiting in 2014. Technical difficulties have delayed the program. The principal issues, those with the payload, have now been resolved, according to Valerio.

    Valerio expects a firmer GPS III launch announcement for 2017 in March. He expected the final launch date “will depend on the health of the existing constellation, the availability of launch slots and synchronization with the ground system.”  Ultimately, the Air Force always makes the final decision on the launch date.

    Source: Alan Cameron
    Lockheed Martin is contracted to build eight GPS III satellites.

    Late last year, a spokesman for the Space and Missile Systems Center said that “The first GPS III launch is tentatively considered for the first half of FY17, based on booster availability and Air Force launch priorities.”

    The Air Force has put out feelers for other contractors to finish out the full generation of GPS III satellites. Lockheed Martin is building eight, with an option for four more, totalling 12; a complete constellation of III-generation satellites would require 24. Boeing Space and Intelligence Systems and Northrop Grumman Aerospace are reportedly interested.

    “The best thing I can do is keep marching along the plan we have,” Valerio said. “We’re certainly not afraid of the competition.” Lockheed Martin has submitted cost-cutting proposals for the current GPS III satellite design, he added.

    Ground Control

    The corresponding new ground system for GPS III, the Operational Control Segment (OCX), has also fallen behind schedule. Just this month, the Air Force announced that Lockheed Martin may develop an interim control capability, a set of changes implemented upon the current control segment, the Architecture Evolution Plan (AEP), as a backup.

    Michael Gilmore, the Defense Department’s director of operational test and evaluation, recently stated that OCX delays have pushed back GPS III operational testing “until after at least six, and as many as eight,” satellites have been launched into orbit. “This introduces significant risk that effectiveness and suitability deficiencies in GPS III satellites will not be discovered until it is too late to prevent their introduction to the operational constellation.”

    Budget Blues

    Don Jewell, GPS World’s contributing editor for defense, has written at length about the GPS III and OCX situations in his February newsletter column, “USAF FY16 Budget Plus $10B More, Please!”. We condensed some of his remarks, particular to the budget battle on Capitol Hill, for the Out in Front column of the March issue of the magazine, due out soon. Here is a further digest of those comments.

    The 2016 President’s Budget, submitted in February, contains an Air Force requested a budget of $122.2 billion. This may be too little, too late.

    On the satellite side of the house, GPS III has problems centering on development and delivery issues with a subcontractor. In this case, however, the whole satellite program is not failing, just a component, albeit an important one: the Mission Data Unit (MDU).

    For GPS III+, the Air Force plans for a two-phased competition process: a Production Readiness competition for up to three firm-fixed price contracts to mature competitors’ production designs for a competition in a full and open competition for up to 22 GPS III Production SVs [satellite vehicles] with an expected award in FY17/18.

    This sounds great if you need an entirely new GPS III system, which consists of, at a minimum, a new payload, satellite, launcher and ground C2 system. In fact, the government only needs an MDU. Failure to produce the MDU on time has delayed GPS III by 18 months to date.

    More troubling are the government proposals to entertain other bids to finish the second half of the GPS III constellation. Such a competition or re-bid will take at least three years and cost hundreds of millions of dollars — and Lockheed Martin may well win again in the end

    A significant added cost to the GPS budget concerns the need for a new ground C2 system if the total new systems approach is taken. If preliminary elements of the GPS space segment are developed without cross-checking the impact to the GPS control segment, technical, operational, budgetary and schedule impacts will be significant.

    The already perturbed OCX budget likely has not considered the integration costs of a newly developed, yet-to-be-procured GPS III+ SV. OCX today is geared for the GPS III already contracted for, and it is failing to meet that challenge.

    Budget constraints are tight and getting tighter, mandating the Air Force “do more with less” in every context. For GPS III SVs, this should — but by no means necessarily does — indicate developing an alternate MDU rather than buying a new block of GPS SVs.

     

     

     

  • GNSS System Mandates Would Violate International Trade Agreements

    A U.S. government representative stated at an international satnav forum that mandating use of specific GNSS services for applications such as air-traffic control, freight shipments, emergency calling, and road tolling could violate the terms of World Trade Organization (WTO) agreements that many nations, including all six GNSS providers, have signed. Regional mandates already exist for Glonass in Russia and Beidou in China, and have been suggested and extensively discussed in Europe, as a way of stimulating the market adoption of Galileo receiver chipsets, thus recouping some of the massive public investment in the satnav system.

    The presentation occurred during the 9th Meeting of the International Committee on Global Navigation Satellite Systems (ICG), November 10–14 in Prague, the Czech Republic.

    Jason Kim, a senior policy analyst at the U.S. Department of Commerce, stated that the United States and EU already enjoy a productive dialogue on GNSS trade issues under the 2004 U.S.-EU Agreement on GPS-Galileo Cooperation. In that agreement, both parties agreed to consult before establishing GNSS standards, certification requirements, regulations, mandates; affirmed their non-discriminatory approach with respect to GNSS trade; and established a working group to consider non-discrimination and other trade related issues. Finally, the United States and the European Union recognized and reiterated in 2004 their commitments to WTO rules including those governing technical barriers to trade (TBT), specifically, that there would be no goods discrimination based on non-tariff measures such as regulations, standards, testing, or certification.

     

    Kim made the remarks in the course of his presentation titled “GNSS Market Access.” He told GPS World that his presentation was directed less at the European Union, which has been conscientious of its WTO commitments, and more towards the rest of the ICG members, including non-provider nations that may be asked by GNSS providers to mandate specific systems..

    “To promote adoption of their systems,” Kim stated, “GNSS providers are considering/implementing equipage mandates for various applications: aviation, motor-carrier and HAZMAT vehicle tracking, car accident reporting (eCall/ERA-GLONASS), and emergency phone calls (E112).

    “The United States recommends technology-neutral, performance-based standards,” Kim continued, giving as example the U.S. E911 rules that specify a required positioning accuracy and then allow wireless carriers to choose the best technical solutions according to their lights.

    The U.S. government presentation at ICG revealed particular concern that regulations under consideration could adversely affect the sales of U.S. GPS-enabled hardware in many industry sectors. All members of the WTO, to include the six GNSS providers on the ICG, are bound to a range of trade agreements designed to promote open market access, all cited in the Prague ICG presentation: the General Agreement on Tariffs and Trade (GATT), the Agreement on Technical Barriers to Trade (TBT), and the General Agreement on Trade in Services (GATS). The United States, Europe, Japan, and 12 others are also parties to the WTO Agreement on Government Procurement (GPA).

    European Commission officials have publicly and recently stated that they are considering how to stimulate Galileo use, in particular through regulatory measures requiring that navigation equipment be installed on aircraft, automobiles, and other platforms.

    “Requiring specific systems arbitrarily prevents or penalizes imports of goods having perfectly functional GNSS capability,” said Kim. “WTO members must comply with TBT obligations in setting technical regulations.”

    He concluded his presentation by requesting that the ICG Providers’ Forum add GNSS market access to its future agenda for discussion, and consider developing a new principle on market access for future adoption.

    The ICG, an organization established in 2005 under the umbrella of the United Nations to discuss GNSS to benefit people around the world, “promotes voluntary cooperation on matters of mutual interest related to civil satellite-based positioning, navigation, timing, and value-added services. The ICG contributes to the sustainable development of the world. Among the core missions of the ICG are to encourage coordination among providers of global navigation satellite systems (GNSS), regional systems, and augmentations in order to ensure greater compatibility, interoperability, and transparency, and to promote the introduction and utilization of these services and their future enhancements, including in developing countries, through assistance, if necessary, with the integration into their infrastructures. The ICG also serves to assist GNSS users with their development plans and applications, by encouraging coordination and serving as a focal point for information exchange.”

  • Galileo: A Constellation of One?

    Matters sit not well with Galileo, the European GNSS. Only one of six currently orbiting satellites can be said to be truly and fully operational. With these troubles augmented by persistent uncertainties regarding the fitness of Soyuz rockets, despite a recent inquiry panel that identified a root cause of the August launch failure, the European Commission has nixed an upcoming December launch. The European Space Agency will have to wait until February 2015 to see if the skies clear by then for the next opportunity to place two new satellites into orbit.

    Hard-charging veteran investigative reporter Richard Langley has learned from his eastern listening post in New Brunswick that “E11 and E12 [launched three years ago] exhibit ongoing problems with the onboard clocks. E20 [launched two years ago] has experienced power-supply problems and, following a brief outage, is now broadcasting on E1 only and with a reduced power. The latest two satellites [rose August 22 of this year] are in irregular orbits and will likely not form part of the final constellation. This leaves E19 [born October 12, 2012] as the only fully operational satellite operating within specifications.

    “So, strictly speaking, only one of the currently orbiting satellites is fully operational. However, for most (E1/L1-only, single-point) users, four of the six satellites are currently quite useable. Moreover, preliminary studies suggest that, once on line, the latest two satellites will be perfectly usable, despite the irregular orbits. And, as we have heard, there will be attempts to make the orbits somewhat more circular.”

    Langley cites “knowledgeable researchers” as his sources.

    The initial quartet of in-orbit validation (IOV) satellites — E11, E12, E19, and E20 — constructed by Astrium GmbH and Thales Alenia Space have experienced a range of difficulties outlined above. The decision to cancel the next scheduled launch in December of the newest duo of full operational capability (FOC) satellites, manufactured by a consortium led by OHB AG, comes on the heels of a completed inquiry that blamed a “design ambiguity” of the Soyuz rocket’s Fregat stage for the too-low orbits of Satellites 5 and 6, but left several lingering doubts about other Soyuz issues that were uncovered and must be corrected.

    The situation is complicated by further unresolved issues aboard the two FOC satellites themselves.  They each failed to deploy one of their two solar arrays on the first try. After several days of effort and re-orientation of the satellites by ground controllers, the arrays were successfully unfolded, but the cause of the initial failure remains unknown. “There is no conclusion on a root cause,” stated one official. “Was it a consequence of the bad orbit, or is there an issue with the solar array deployment mechanism? We cannot yet say for sure.”

    As for their incorrect orbit, getting them into their originally planned paths around the Earth is impossible. They simply do not have enough fuel onboard. ESA does, however, plan to raise the perigees of the satellites to get them out of the Van Allen radiation belt, which could severely damage the satellites. The agency also envisions reducing the maximum Doppler frequency shift from 9.6 kHz to at least 6.8 kHz to allow receivers to easily acquire and track the satellites but leave enough hydrazine for future station-keeping. Spokespersons hold out hope that the satellites may yet be usable somehow, someday, after some adjustment measures are taken: a rephasing, a special almanac, perhaps other adjustments.

    Overall, a disheartening picture, with some pessimists concluding that “2013 and 2014 have been lost.” The recent slip of full operational capability declaration from 2018 to 2020 may have to be revised yet again. However, lessons learned, etcetera. Galileo has had its ups and down. Advocates may draw comfort from the wisdom imparted by 19th-century German philosopher Friedrich Wilhelm Nietzsche, “Was mich nicht umbringt, macht mich stärker.” That which does not destroy me, makes me stronger.

  • Galileo’s Two Giant Steps Back

    Galileo’s first two full-operational capability (FOC) satellites have been in a safe state since August 28, under control from the European Space Agency’s (ESA’s) center in Darmstadt, Germany, despite having been released on August 22 into lower and elliptical orbits instead of the expected circular orbits.

    ESA continues investigating the possible exploitation of the out-of-position satellites to maximum advantage, despite their unplanned injection orbits and within the limited propulsion capabilities. ESA specialists, supported by industry and France’s CNES space agency, are analyzing different scenarios that would yield maximum value for the program, and safeguard — as much as possible — the original mission objectives.

    Galileo orbits viewed from above: Orbits of the fifth and sixth satellites in red, compared to their intended position in dashed green, and the position of the four satellites launched in 2011 and 2012 in solid green. This view looks down over the South Pole to illustrate how the inclination relative to the equator is less than intended. The satellites are in an elliptical rather than circular orbit, with a maximum altitude of about 25,900 km and a minimum altitude of about 13,700 km, compared to a planned circular orbit of 23,222 km altitude.
    Galileo orbits viewed from above: Orbits of the fifth and sixth satellites in red, compared to their intended position in dashed green, and the position of the four satellites launched in 2011 and 2012 in solid green. This view looks down over the South Pole to illustrate how the inclination relative to the equator is less than intended. The satellites are in an elliptical rather than circular orbit, with a maximum altitude of about 25,900 km and a minimum altitude of about 13,700 km, compared to a planned circular orbit of 23,222 km altitude.

    Experts representing the Galileo Program provided a frank and open update at the ION GNSS+ conference in Tampa on September 10, as reported by Richard Langley:

    • An inquiry board is looking into problem to find the root cause of the anomaly. The board has already met several times.
    • An intermediate report is due shortly; a final report and recommendations will come next month.
    • ESA is considering what can be done with the two satellites; ESA hopes to be able to use them operationally as much as possible.
    • ESA is also looking at the impact on the commercial Galileo service and the search-and-rescue service.
    • ESA is narrowing down the possible causes of the anomaly.
    • ESA is waiting for the enquiry board to report before deciding on when and how the next two satellites will be launched.
    • The payloads of the errant satellites are currently off.
    • ESA wants to try to raise the perigees of the satellites to get them out of the van Allan radiation belt as soon as possible to prevent damage to the satellites. Raising the perigrees will also to reduce the maximum Doppler frequency shift from 9.6 kHz to at least 6.8 kHz to allow receivers to easily acquire and track the satellites, but leave enough hydrazine for future station keeping.
    • ESA is looking at the almanac problem and whether unused bits in the Galileo navigation message might be able to support a special almanac for the satellites.
    • ESA is also looking at possible rephasing of the satellites to optimize their use with the other satellites in the constellation.
    Galileo orbits viewed side-on: The fifth and sixth Galileo satellites in red, compared to their intended position in dashed green, and the position of the four satellites launched in 2011 and 2012, in solid green. This view looks side on to the two satellites’ orbital plane, which is off-center relative to Earth. The targeted orbit was circular, inclined at 55º to the equator at an altitude of 23,222 km.They are in a safe state, correctly pointing towards the Sun, properly powered and fully under control of an ESA–CNES team.
    Galileo orbits viewed side-on: The fifth and sixth Galileo satellites in red, compared to their intended position in dashed green, and the position of the four satellites launched in 2011 and 2012, in solid green. This view looks side on to the two satellites’ orbital plane, which is off-center relative to Earth. The targeted orbit was circular, inclined at 55º to the equator at an altitude of 23,222 km.They are in a safe state, correctly pointing towards the Sun, properly powered and fully under control of an ESA–CNES team.

    Soyuz at Fault? On August 28, the Russian newspaper Izvestia reported that “The failure of the European Union’s Galileo satellites to reach their intended orbital position was likely caused by software errors in the Fregat-MT rocket’s upper stage.”

    “The nonstandard operation of the integrated management system was likely caused by an error in the embedded software. As a result, the upper stage received an incorrect flight assignment, and, operating in full accordance with the embedded software, it has delivered the units to the wrong destination,” an unnamed source from Russian space Agency Roscosmos was quoted as saying by the newspaper.

    An independent inquiry panel has been set up by Ariane and headed by former ESA Inspector General Peter Dubock. It started work on August 28. The panel includes a couple of academics and a majority of ESA and EC figures.

    The new EC commissioner in this area, Ferdinando Nelli Feroci, invited ESA and Arianespace to his study during the first week of September to present the initial results of the inquiry.

    The commissioner commented, “The problem with the launch of the two Galileo satellites is very unfortunate. The European Commission will participate in an inquiry with ESA to understand the causes of the incident and to verify the extent to which the two satellites could be used for the Galileo programme. I remain convinced of the strategic importance of Galileo, and I am confident that the deployment of the constellation of satellites will continue as planned.”

    The commissioner expects that the Galileo constellation will be fully deployed by the end of this decade. This may qualify as optimism because system planners had envisioned for six spares ­— and three are already blown.

    Ariane and ESA did not insure the satellites.

    According to back-of-the-envelope calculations, system operators are now one short of the minimum 24 needed for full 24/7 global coverage, as they have four in orbit validation satellites up (one broken) and 22 FOCs on order (two launched and now in what could be called a junk orbit), which makes a potential maximum 23 satellites that have actually been ordered ­­— one short of the target.

    The Satellites Are Alright. Satellite manufacturer OHB Systems of Bremen, Germany, issued a release stating that “Controllers at ESA’s ESOC control centre in Darmstadt, Germany, confirm the good health and the nominal behavior of both satellites. They are in a safe configuration, are thermally stable, have stable pointing to the sun and sufficient power production. All platform subsystems have been checked and they work properly. Also, the procedures to deploy the solar arrays are successfully performed and all solar arrays are properly unfolded.”

    Further, “The orbit anomaly has no impact on the production and delivery of the in total further 20 satellites. Two FOC satellites are currently at ESTEC test facilities in Noordwijk, the remaining are in various status of integration. ”

    Blogs Alive; BBQ Mode. The chairman of the Executive Board of the German Aerospace Center, Johann-Dietrich ‘Jan’ Wörner, writes an interesting blog. A recent installment opened with a quote from Elon Musk: “Rockets are tricky.”

    Wörner went on to say, “The Soyuz launcher lifted off from the European Spaceport in French Guiana. Initially, all of the measurements suggested a perfect mission; the launcher took off at the scheduled time, followed the prescribed trajectory, and the stage separation was carried out correctly. However, the first problem became apparent when the two satellites proved unable to deploy their solar arrays as intended. A more detailed analysis then revealed that the eccentricity, the altitude and the inclination of the satellites’ orbits with respect to Earth’s equator did not meet the specifications. The upper stage had also evidently failed to induce the planned rotation around the longitudinal axis of the spacecraft (known as ‘barbeque’ mode, designed to maintain favourable thermal conditions during exposure to the Sun).”

    Further discussion of the possible causes of the anomaly can be found on a Russian site, which focuses on the Fregat stage thrusters and indicates that the Russians think the barbeque maneuver was completed, and thus not the problem.

    The other big issue is how the telemetry didn’t pick up the issue straight away.

  • A Long Look at Advanced Multisensor Navigation and Positioning

    A modern-day fable related by Steven Covey tells of a civil engineer leading a crew engaged in building a road through a dense jungle. Each day the engineer’s adept management, the crew’s motivation and energy, and the high-tech equipment at their disposal pushed the new road well beyond scheduled targets. Midway through the allotted month, the engineer decided to climb to the top of a tree to see if he could get a distant glimpse of the destination. After a few minutes, he called down to his crew, “Wrong jungle!”

    This comes to mind as we consider the well-known fact that the next generation of navigation and positioning systems must provide greater accuracy and reliability in a range of challenging environments, to meet the needs of a variety of mission-critical applications. It’s no secret that not a single navigation technology, among scores available to us, is robust enough to meet these requirements by itself. A multisensor solution is required.

    Although many new navigation and positioning methods have been developed in recent years, little has been done with all-encompassing vision to bring them together into a robust, reliable, and cost-effective integrated system. Almost all the solutions proposed — and I have conveyed many of them in the pages of GPS World, thanks to the expert engineers who designed and tested them — spring from the requirements of a particular situation, application, or industry sector. Their parameters are suitably specialized.

    What’s been lacking so far is an over-architecture for the entire field. Paul Groves of University College London has outlined such a structure in an article that will appear in the September issue of the magazine: “Four Key Challenges to Multisensor PNT.” This material was first presented at the IEEE/ION Position Location and Navigation Symposium (PLANS) in Monterey, California in May of this year.

    The magazine article will describe each challenge in turn. In each case, Groves explains the problem, proposes one or more solutions, and identifies the issues that must be resolved in order to implement those solutions. He also presents the results of some preliminary context-detection experiments and illustrates some of the problems using results from several UCL research projects. The discussion is illustrated with results from research into urban GNSS positioning, GNSS shadow matching, environmental feature matching, and context detection

    The four challenges: complexity, context, ambiguity, and environmental data handling.

    • Complexity – How to find the necessary expertise to integrate a diverse range of technologies, how to combine technologies from different organizations that wish to protect their intellectual property, how to incorporate new technologies and methods without having to redesign the whole system and how to share development effort over a range of different applications.
    • Context – How to ensure that the navigation system configuration is optimized for the operating environment and host vehicle (or pedestrian) behavior when both are subject to change.
    • Ambiguity – How to handle multiple hypotheses, including measurements of non-unique environmental features, pattern-matching fixes where the measurements match the database at multiple locations, and uncertain signal properties, such as whether reception is direct or non-line-of-sight (NLOS).
    • Environmental Data Handling – How to gather, distribute, and store the information needed to identify signals and environmental features and define their points of origin or spatial variation.

    As Groves relates in his article, many new positioning techniques have been investigated over the past fifteen years.

    • Wi-Fi positioning
    • Ultra-wideband (UWB) positioning
    • Positioning using phone signals
    • Positioning using television signals and other signals of opportunity (SOOP)
    • Bluetooth low energy positioning
    • Laser-based position fixing and dead
    • Pedestrian dead reckoning (PDR) using step detection
    • Pedestrian map matching Error! Reference source not found.
    • Magnetic anomaly matching
    • Activity-based map matching
    • GNSS shadow matching

    There have also been improvements to existing technologies.

    • Hardware required for visual navigation
    • Micro-electro-mechanical systems (MEMS) technology
    • Cold-atom technology and nuclear magnetic resonance (NMR) gyros offering aviation-grade performance with compact sensors
    • Legacy radio navigation systems, such as Distance Measuring Equipment (DME) and Loran (in Europe and South Korea) are being modernized
    • Doppler positioning is being reintroduced using Iridium communication satellites

    Finally, GNSS itself has been enhanced through multiple constellations in a continual state of upgrade and renewal, high-sensitivity receivers and network assistance, and augmentation by commercial pseudolite systems.

    Maybe it’s time for a high-level perspective on all these adjoining jungles, if we want to find our way out of them.

    Potential components of a car navigation system using commonly available equipment and other low-cost sensors.
    Potential components of a car navigation system using commonly available equipment and other low-cost sensors.

  • Occupy Media Space Now EGNOS and Galileo Mission

    By Peter de Selding

    The message to the recent European Space Solutions conference in Prague was simple enough: EGNOS is here, so let’s use it; Galileo is almost here, so let’s promote it.

    Neither task is straightforward.

    Take the European Geostationary Navigation Overlay Service (EGNOS), the European piece of a near-global network of terminals on geostationary satellites linked to networks of ground stations to verify GPS signal accuracy, primarily for aviation but with further applications as well. Other pieces of this global network are the Wide Area Augmentation System (WAAS) in the United States, the System for Differential Corrections and Monitoring (SDCM) in Russia,  GPS-aided GEO-augmented Navigation (GAGAN) in India, and Multi-functional Satellite Augmentation System (MSAS) in Japan.

    EGNOS is operational. It works. Once airports publish the required specificafions for localizer performance with vertical guidance (LPVs), aircraft with EGNOS terminals ultimately will be able to use EGNOS for flight terminations up to as low as 200 feet above the runway. Gone is the need for runway infrastructure, and welcome to the long-promised world of satellite-based augmentation systems. “It offers cheap solutions for precision approach,” said Fabio Gamba, chief executive of the European Business Aviation Association.

    In the United States, where business aviation is a bigger market than in Europe, some 3,400 LPVs have been published for 1,670 airports. In Europe, the equivalent figure is 108 LPVs at 77 airports.

    Why the sluggish response? Gamba cited a long list of issues, including some that appeared more political than technical. Part of the reason, some said, was that the EGNOS backers, including the company under contract to manage the system — European Satellite Services Provider (ESSP) of Toulouse, France — have not done enough to get the word out.

    After all, these observers said, EGNOS suffered multiple delays, and its bigger younger brother, Galileo, has had bad press for years as its business model, ownership, regulatory backing, and schedule took turns in making eyes roll in Europe.

    But that’s yesterday’s issue. Thierry Racaud, chief executive of ESSP, said EGNOS posted greater than 99 percent availability in May for its safety-of-life service, which is currently available on none of the other regional GPS augmentation systems except WAAS.

    Racaud promised that the 108 LPVs signed so far would grow to 180 by the end of this year, and that 200-foot level approaches would be certified by late 2015. He said he hoped all 28 member nations of the European Union would have concluded their EGNOS regulatory approvals by 2017 or 2018.

    “What we need now is more users,” Racaud said.

    If EGNOS is not well known on its home turf, imagine its status in Africa, where European companies are trying to sell its adoption. Abdel Nasser Saint’Anna, director of the EGNOS-Africa Joint Program Office, said Africa should be Exhibit A for an EGNOS success pitch. Of the 2,500 runways in Africa, he said, only 177 were equipped with instrument landing systems (ILS), the system EGNOS and Galileo ultimately would like to replace.

    Galileo, with Four, in Fourth

    Galileo, too, appears headed for a successful adoption in many areas around the world even if, once operational, it likely will be the fourth global GNSS system in place, after GPS, Russia’s GLONASS and China’s BeiDou — not counting the large regional Indian and Japanese systems now being developed.

    For those with scorecards, recall that four Galileo satellites, designed to validate the system’s performance, are in orbit. Carlos des Dorides, director of the European GNSS Agency (GSA) in Prague, said tests in May proved Galileo’s interoperability with GPS.

    More importantly, des Dorides said the tests demonstrated how much better it is for consumers when their terminals access GPS and Galileo together. That should be obvious. Less obvious: Results were much better than with terminals tracking both GPS and GLONASS, he said.

    The more satellites, the better? Yes, at least up to a point. Whether terminal manufacturers will see fit to incorporate all four global GNSS constellations, plus one or two of the regionals, in their hardware remains to be seen.

    But the pent-up demand for Galileo does now seem better than it was as little as a year ago, despite the fact that some Asian nations attending the conference said they need Galileo to demonstrate its vitality sooner rather than later. Some officials said signal-quality issues with Beidou, and the recent GLONASS outage, will more than make up for Galileo’s delays as long as deployment progress is visible.

    The fact remains that by 2020 there will be more than 100 GNSS satellites in medium-Earth orbit, in addition to the augmentation terminals on geostationary satellites.

    A graphic presented by SpaceTec Partners’ Rainer Horn, whose company has been charged with preparing the Asian market for Galileo, showed just how dense the Asian skies will be with GNSS assets at the end of the decade. India, China, Japan, Taiwan, and South Korea are SpaceTec’s current Asian targets.

    The message from these markets: Launch Galileo now. Drum up support. Occupy the media space.

    Did the European Commission get the message? Time will tell. The next opportunity to wave the Galileo flag comes in late August, when the first two of 22 full-operational-capability satelllites will be launched from Europe’s spaceport in South America. Two more are scheduled to follow late this year.

    Eight satellites in orbit by Christmas will not make an operational service, whatever the brochures say. But does that matter? Galileo now has secure funding, through 2020, for most — not all — of what it needs to launch a full constellation. Absent a new issue, by 2017 few will remember the delays.

    Paul Weissenberg of the European Commission, who has seen the Galileo wars up close, reminded the European Space Solutions audience in Prague that one future Galileo customer sits outside the commission’s offices, waiting for approval to use Galileo’s PRS encrypted service. The U.S. Defense Department’s desire for Galileo does not have an expiration date. Just launch it.

  • GPS Industry Breathes Sigh of Relief

    GPS Industry Breathes Sigh of Relief

    LightSquared-spectrum-W

    The U.S. Federal Communications Commission convened a June 20 workshop on “GPS Protection and Receiver Performance” whose bite turned out to be far less than its bark had led some in the GPS industry to fear. The hastily assembled workshop — three weeks notice was given — appeared at first notice to derive from the call for “GPS receiver performance standards” that was one of the outcomes of the LightSquared controversy of 2012. The FCC chief emphatically noted, however, before anyone else could say anything, that the meeting was “not about FCC-mandated receiver standards.” A nearly audible sigh came from the collected dignitaries.

    Perhaps the slotting of “GPS Protection” into first position within the workshop’s title might have given some clue. The meeting did turn out to be a less-than-alarming gathering of stakeholders, and in fact a reiteration of the need to emphasize and safeguard critical infrastructure and public safety — two key uses of GPS.

    Two weeks prior to the workshop, Brad Parkinson declared to the National Space-Based Positioning, Navigation, and Timing (PNT) Advisory Board that “A number of manufacturers are quite panicked over this because of the possibility of some superposition of, in essence, how you design a receiver for GPS. This could vastly affect the whole substance of what we are if carried to the point that someone dictates how you design a receiver. I think that’s kind of dangerous.”

    But the meeting, in the end, took a positive, protective, and conciliatory tone, even as the FCC continues beating the drum for more frequencies for mobile broadband, citing the need “get more out of the radio spectrum.”

    “Today is about federal and non-federal leaders coming together to discuss successful industry-driven collaborations and GPS receiver performance,” said FCC Chairman Tom Wheeler in his opening remarks. “These are not abstract issues. But let me also be specific about what today is not. It is not about FCC-mandated receiver standards. Rather it is about the best way to protect GPS operations in the context of evolving technology and adjacent spectrum activities.”

    The specter of adjacent spectrum use hovered intermittently throughout the day, appearing  fully in the presentation by LightSquared and one from the President’s representative. Otherwise, scant mention was made of the oft-expressed 2012 sentiment that GPS receivers needed to be modified in the way they work, to stop their alleged “peeking” into adjacent spectrum.

    Peekin’? We don’t need no steenkin’ peekin’!

    After further introductory remarks from the FCC’s head of Public Safety and Homeland Security Bureau, the audience heard a technology market update from the U.S. Consumer Electronics Association (CEA). The report relied almost entirely upon the European GNSS Agency’s (GSA’s) 2013 GNSS Market Report for its global statistics, while displaying some domestic charts of its own. Among the conclusions: GPS/GNSS is an enabling technology for innovation and disruption; and the consumer market, defined as road and location-based services (LBS), represents the biggest opportunity. The CEA presentation is available here.

    The morning’s first panel discussion focused on the importance of GPS for critical infrastructure and public safety users, with presentations by Qualcomm, Motorola, and AT&T in addition to various government agencies. Cormac Conroy, vice president at Qualcomm, emphasized the critical role of GPS in emergency calls from mobile phones (E-911) and what he called “enhanced location services”: vehicle and pedestrian navigation, location-based alerts and reminders, and location as context in mobile apps.

    Other speakers, including representatives from Ericsson, T-Mobile, Spirent, Garmin, NovAtel, and John Deere, covered GPS’s role in timing and thus controlling the nation’s power grid, the financial markets, the telecommunication network including cable TV, and the national breadbasket, precision agriculture. Paul Galyean of Deere said that “Certainty on the spectrum environment is needed. It’s difficult to design for the future without it.” And further, if GPS receivers had to filter out cellular activity, this “might impact sensitivity, involve excessive size or cost, and might cause distortion of GPS measurements.” The Deere presentation is available here.

    Chris Hegarty from the MITRE Corporation gave one of the day’s most compelling arguments for not overhauling GPS receiver methodology: the extremely long lead times for commercial passenger aircraft. “Until 2022 every new Boeing and Airbus is going to fly off with $250,000 worth of navigation equipment that has three $50,000 GPS receivers and antennas and everything else, and they are going to want to use that for 20 to 25 years. So, you have a timing issue. Even if we all decided today that we wanted to do that, some communities simply aren’t going to be able to get it into place until we’re all dead.”

    White House Espouses Adjacent Spectrum

    Tom Power, deputy chief technology officer for telecommunications, held up the banner for “efficient use of spectrum” and pronounced the Administration opposed to “listening in.” Ironic, given its other proclivities. He advocated against some technologies exerting undue elbow room on “nearby users who want to make a change.”

    Representing the latter contingent, LightSquared restricted its performance to showing, with reputed science, how other users such as cellular, Bluetooth, WiFi, and even laptop computers pour more power into the GPS band than does LightSquared.  The presentation of Geoffrey Stearn, vice president of spectrum development, is viewable here.