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  • Galileo E1, E5a Performance for Multi-Frequency, Multi-Constellation GBAS

    Galileo E1, E5a Performance for Multi-Frequency, Multi-Constellation GBAS

    Pullen-Galileo-O
    Photo: Galileo

    Analysis of new Galileo signals at an experimental ground-based augmentation system (GBAS) compares noise and multipath in their performance to GPS L1 and L5. Raw noise and multipath level of the Galileo signals is shown to be smaller than those of GPS. Even after smoothing, Galileo signals perform somewhat better than GPS and are less sensitive to the smoothing time constant. 

    By Mihaela-Simona Circiu, Michael Felux, German Aerospace Center (DLR), and Sam Pullen, Stanford University

    Several ground-based augmentation system (GBAS) stations have become operational in recent years and are used on a regular basis for approach guidance. These include airports at Sydney, Malaga, Frankfurt and Zurich. These stations are so-called GBAS Approach Service Type C (GAST C) stations and support approaches only under CAT-I weather conditions; that is, with a certain minimum visibility. Standards for stations supporting CAT-II/III operations (low visibility or automatic landing, called GAST D), are expected to be agreed upon by the International Civil Aviation Organization (ICAO) later this year. Stations could be commercially available as soon as 2018.

    However, for both GAST C and D, the availability of the GBAS approach service can be significantly reduced under active ionospheric conditions. One potential solution is the use of two frequencies and multiple constellations in order to be able to correct for ionospheric impacts, detect and remove any compromised satellites, and improve the overall satellite geometry (and thus the availability) of the system.

    A new multi-frequency and multi-constellation (MFMC) GBAS will have different potential error sources and failure modes that have to be considered and bounded. Thus, all performance and integrity assumptions of the existing single-frequency GBAS must be carefully reviewed before they can be applied to an MFMC system. A central element for ensuring the integrity of the estimated position solution is the calculation of protection levels. This is done by modeling all disturbances to the navigation signals in a conservative way and then estimating a bound on the resulting positioning errors that is valid at an allocated integrity risk probability.

    One of the parameters that is different for the new signals and must be recharacterized is the residual uncertainty attributed to the corrections from the ground system (σpr_gnd). A method to assess the contribution of residual noise and multipath is by evaluating the B-values in GBAS, which give an estimate of the error contribution from a single reference receiver to a broadcast correction. Independent data samples over at least one day (for GPS) are collected and sorted by elevation angle. Then the mean and standard deviations for each elevation bin are determined.

    Here, we evaluate the E1 and E5a signals broadcast by the operational Galileo satellites now in orbit. In the same manner as we did for GPS L5 in earlier research, we determine the σpr_gnd values for these Galileo signals. As for GPS L5, results show a lower level of noise and multipath in unsmoothed pseudorange measurements compared to GPS L1 C/A code.

    DLR GBAS Facility

    DLR has set up a GBAS prototype at the research airport in Braunschweig (ICAO identifier EDVE) near the DLR research facility there. This ground station has recently been updated and now consists of four GNSS receivers connected to choke ring antennas, which are mounted at heights between 2.5 meters and 7.5 meters above equipment shelters. All four receivers are capable of tracking GPS L5 (in addition to GPS L1 and L2 semi-codeless) and Galileo E1 and E5a signals. Figure 1 gives an overview of the current ground station layout, and Table 1 gives the coordinates of the antennas.

    Figure 1 DLR ground facility near Braunschweig Airport, also shown in opening photo at left.
    Figure 1. DLR ground facility near Braunschweig Airport, also shown in opening photo at left.
    TABLE 1. Ground receiver antenna coordinates.
    Table 1. Ground receiver antenna coordinates.

    Smoothing Techniques

    The GBAS system corrects for the combined effects of multiple sources of measurement errors that are highly correlated between reference receivers and users, such as satellite clock, ephemeris error, ionospheric delay error, and tropospheric delay error, through the differential corrections broadcast by the GBAS ground subsystem. However, uncorrelated errors such as multipath and receiver noise can make a significant contribution to the remaining differential error. Multipath errors are introduced by the satellite signal reaching the antenna via both the direct path from the satellites and from other paths due to reflection. These errors affect both the ground and the airborne receivers, but are different at each and do not cancel out when differential corrections are applied.

    To reduce these errors, GBAS performs carrier smoothing. Smoothing makes use of the less noisy but ambiguous carrier-phase measurements to suppress the noise and multipath from the noisy but unambiguous code measurements.

    The current GBAS architecture is based on single-frequency GPS L1 C/A code measurements only. Single-frequency carrier smoothing reduces noise and multipath, but ionospheric disturbances can cause significant differential errors when the ground station and the airborne user are affected by different conditions. With the new available satellites (GPS Block IIF and Galileo) broadcasting in an additional aeronautical band (L5 / E5), this second frequency could be used in GBAS to overcome many current limitations of the single-frequency system.

    Dual-frequency techniques have been investigated in previous work. Two dual-frequency smoothing algorithms, Divergence Free (Dfree) and Ionosphere Free (Ifree), have been proposed to mitigate the effect of ionosphere gradients.

    The Dfree output removes the temporal ionospheric gradient that affects the single-frequency filter but is still affected by the absolute difference in delay created by spatial gradients. The main advantage of Dfree is that the output noise is similar to that of single-frequency smoothing, since only one single-frequency code measurement is used as the code input (recall that carrier phase noise on both frequencies is small and can be neglected).

    Ifree smoothing completely removes the (first-order) effects of ionospheric delay by using ionosphere-free combinations of code and phase measurements from two frequencies as inputs to the smoothing filter. Unlike the Dfree, the Ifree outputs contain the combination of errors from two code measurements. This increases the standard deviation of the differential pseudorange error and thus also of the position solution.

    Noise and Multipath in New GNSS Signals

    GBAS users compute nominal protection levels (H0) under a fault-free assumption. These protection levels are conservative overbounds of the maximum position error after application of the differential corrections broadcast by the ground system, assuming that no faults or anomalies affect the position solution. In order to compute these error bounds, the total standard deviation of each differentially corrected pseudorange measurements has to be modeled. The standard deviation of the residual uncertainty (σn, for the nth satellite) consists of the root-sum-square of uncertainties introduced by atmospheric effects (ionosphere, troposphere) as well as of the contribution of the ground multipath and noise. In other words, these error components are combined to estimate σn2 as described in the following equation:

    Pullen-Eq1   (1)

    The ground broadcasts a value for σpr_gnd (described later in the section) associated with the pseudorange correction for each satellite. These broadcast values are based on combinations of theoretical models and actual measurements collected from the ground receivers that represent actual system characteristics. Unlike the ground, σpr_air is computed based entirely on a standardized error model. This is mainly to avoid the evaluation of multipath for each receiver and each aircraft during equipment approval.

    In addition to the characteristics of nearby signal reflectors, multipath errors are mainly dependent on signal modulation and other signal characteristics (for example, power, chip rate). In earlier research, we showed that the newly available L5 signals broadcast by the GPS Block IIF satellites show better performance in terms of lower noise and multipath. This mainly results from an increased transmitted power and a 10 times higher chip rate on L5 compared to the L1 C/A code signal.

    In this work, we extend this evaluation to the new Galileo signals and investigate their impact on a future multi-frequency, multi-constellation GBAS. Characterization of these new signals is based on ground subsystem measurements, since no flight data with GPS L5 or Galileo measurements are available at the moment. We assume that the improvements observed by ground receivers are also applicable to airborne measurements. This assumption will be validated as soon as flight data are available.

    The measurements used were collected from the DLR GBAS test bed over 10 days (note that Galileo satellite ground track repeatability is 10 sidereal days) between the December 14 and 23, 2013. In that period, four Galileo and four Block IIF GPS satellites were operational and broadcast signals on both aeronautical bands E1 / L1 and E5a / L5.

    In Figure 2, the suppression of multipath and noise on the Galileo signals can be observed, where the code multipath and noise versus elevation for GPS L1 C/A BSPK(1), Galileo E1 (BOC (1,1)) and Galileo E5a (BPSK(10)) signals are shown. The code multipath and noise was estimated using the linear dual-frequency combination described in equation (2), where MPi represents the code multipath and noise on frequency i, ρi the code measurement, and ϕi,and ϕj represent the carrier-phase measurements on frequencies i and j, respectively. Carrier phase noises are small and can be neglected.

    Pullen-Eq2   (2)

    Figure 2. Raw multipath function of elevation for GPS L1, Galileo E1 (BOC (1,1)) and Galileo E5a (BPSK(10)) signals.
    Figure 2. Raw multipath function of elevation for GPS L1, Galileo E1 (BOC (1,1)) and Galileo E5a (BPSK(10)) signals.

    The multipath on the Galileo E1 (BOC(1,1)) signal (the magenta curve) is lower than the GPS L1 C/A (BPSK(1))  (black curve), especially for low elevation, where the advantage of the E1 BOC(1,1) is more pronounced. The lower values can be explained by the wider transmission bandwidth on E1 and the structure of the BOC signal. Galileo E5a (green data in Figure 2) again shows a better performance than Galileo E1. This was expected due to the higher chip rate and higher signal power. A comparison of the raw multipath and noise standard deviations for GPS L1, L5 and Galileo E1, E5a signals is presented in Figure 3.

    Figure 3. Ratios of the multipath and noise standard deviation function of elevation.
    Figure 3. Ratios of the multipath and noise standard deviation function of elevation.

    The curves there show the ratios of the standard deviations for each elevation bin. The values for GPS L1 are almost 1.5 times larger than those for Galileo E1 BOC(1,1) (green curve) for elevations below 20°. For high elevations, the ratio approaches 1.0. This corresponds to the observations in the raw multipath plot ( Figure 2). With the same signal modulation and the same chip rate, E5a and L5 have very similar results (red curve), and the ratio stays close to 1.0 for all elevations.

    The blue and the purple curves in Figure 3 show the ratio of GPS L1 C/A (BPSK(1)) and GPS L5 (BPSK(10)), and Galileo E1 (BOC(1,1)) and Galileo E5a (BPSK(10)), respectively. The ratio of GPS L1 to GPS L5 (blue curve) increases with elevation from values around 2.5 for low elevations, reaching values above 3.5 for elevations higher than 60°. As Galileo E1 performs better, the ratio between Galileo E1 and Galileo E5a (purple curve) is smaller, from a value of 1.5 for elevations below 10 degrees to a value of 3.0 for high elevations.

    Until now, we have presented the evaluation of raw code noise and multipath. However, in GBAS, carrier smoothing is performed to minimize the effect of code noise and multipath. The value that describes the noise introduced by the ground station is represented by a standard deviation called σpr_gnd and is computed based on the smoothed pseudoranges from the reference receivers. In the following section, we focus on the evaluation of σpr_gnd using different signals and different smoothing time constants. Note that, in this study, σpr_gnd contains only smoothed multipath and noise; no other contributions (for example, inflation due to signal deformation or geometry screening) are considered.

    B-values and σpr_gnd

    B-values represent estimates of the associated noise and multipath with the pseudorange corrections provided from each receiver for each satellite, as described in Eurocae ED-114A and RTCA DO-253C. They are used to detect faulty measurements in the ground system. For each satellite-receiver pair B(i,j), they are computed as:

    Pullen-Eq3   (3)

    where PRCTX represents the candidate transmitted pseudorange correction for satellite i (computed as an average over all M(i) receivers), and PRCSCA(i,k) represents the correction for satellite i from receiver k after smoothed clock adjustment, which is the process of removing the individual receiver clock bias from each reference receiver and all other common errors from the corrections. The summation computes the average correction over all M(k) receivers except receiver j. This allows detection and exclusion of receiver j if it is faulty. If all B-values are below their thresholds, the candidate pseudorange correction PRCTX is approved and transmitted. If not, a series of measurement exclusions and PRC and B-value recalculations takes place until all revised B-values are below threshold. Note that, under nominal conditions using only single-frequency measurements, the B-values are mainly affected by code multipath and noise.

    Under the assumption that multipath errors are uncorrelated across reference receivers, nominal B-values can be used to assess the accuracy of the ground system. The standard deviation of the uncertainty associated with the contribution of the corrections (σpr_gnd) for each receiver m is related to the standard deviation of the B-values by:

    Pullen-Eq4   (4)

    where M represents the number of the receivers and N represents the number of satellites used. The final sigma takes into account the contribution from all receivers and is computed as the root mean square of the standard deviation of the uncertainties associated with each receiver (Equation 4).

    Figure 4 shows the evaluation of (σpr_gnd) for the Galileo E1, BOC(1,1) signal and the GPS L1 C/A signal for increasing smoothing time constants (10, 30, 60, and 100 seconds). Starting with a 10-second smoothing constant, Galileo E1 shows much better performance than GPS L1. The difference shrinks as the smoothing constant increases due to the effectiveness of smoothing in reducing noise and short-delay multipath. However, even with 100-second smoothing (the purple curves), Galileo E1 BOC(1,1) shows lower values of (σpr_gnd).

    Figure 4. σ(pr_gnd) versus elevation for Galileo E1 (dotted lines) and GPS L1 (solid lines for different smoothing constants: red (10s), green (30s), cyan (60s), purple (100s).
    Figure 4. σ(pr_gnd) versus elevation for Galileo E1 (dotted lines) and GPS L1 (solid lines for different smoothing constants: red (10s), green (30s), cyan (60s), purple (100s).

    A similar comparison is presented in Figure 5, of the performance of GPS L1 and Galileo E5a. The Galileo E5a signal is significantly less affected by multipath, and the difference stays more pronounced than in the Galileo E1 – GPS L1, even with 100-second smoothing. It can be also observed that the Galileo signals have a lower sensitivity to the smoothing constant. The Galileo E1 signal shows an increase of sensitivity for low elevations (below 40°), while on E5a, a smoothing constant larger than 10 seconds has almost no impact on the residual error. Thus, a shorter smoothing constant on Galileo E5a generates approximately the same residual noise and multipath a 100-second smoothing constant on GPS L1.

    Figure 5. σ(pr_gnd) versus elevation for Galileo E5a (dotted lines) and GPS L1 (solid lines) for different smoothing constants: red (10s), green (30s), cyan (60s), purple (100s).
    Figure 5. σ(pr_gnd) versus elevation for Galileo E5a (dotted lines) and GPS L1 (solid lines) for different smoothing constants: red (10s), green (30s), cyan (60s), purple (100s).

    The values for (σpr_gnd) are, however, impacted by the number of satellites which are used to determine a correction. Since only a very limited number of satellites broadcasting L5 and Galileo signals are currently available, these results should be considered preliminary. The first evaluations strongly indicate that with the new signals, we get better ranging performance. Based on the performance advantage of the new signals, a decrease of the smoothing constant is one option for future application. This would reduce the time required (for smoothing to converge) before including a new satellite or re-including a satellite after it was lost.

    In the current GAST-D implementation, based on GPS L1 only, guidance is developed based on a 30-second smoothing time constant. A second solution, one with 100 seconds of smoothing, is used for deriving the Dv and Dl parameters from the DSIGMA monitor and thus for protection level bounding (it is also used for guidance in GAST-C). During the flight, different flight maneuvers or the blockage by the airframe can lead to the loss of the satellite signal.

    Figure 6 shows the ground track of a recent flight trial conducted by DLR in November 2014. The colors represent the difference between the number of satellites used by the ground subsystem (with available corrections) and the number of satellites used by the airborne subsystem in the GAST-D position solution. One of the purposes of the flight was to characterize the loss of satellite signals in turns. In turns with a steeper bank angle, up to 3 satellites are lost (Turns 1, 3, and 4), while on a wide turn with a small bank angle (Turn 2), no loss of satellite lock occurred. It is also possible for airframe to block satellite signals, leading to a different number of satellites between ground and airborne even without turns.

    Figure 6. Ground track of a flight trial conducted by DLR. The colors represent difference between number of SVs used by the ground system and number of SVs used by the airborne.
    Figure 6. Ground track of a flight trial conducted by DLR. The colors represent difference between number of SVs used by the ground system and number of SVs used by the airborne.

    With this in mind, a shorter smoothing constant would allow the satellites lost to turns or to airframe blockage to be re-included more rapidly in the position solution. However, a new smoothing constant would have to be validated with a larger amount of data. Data from flights trials has to be evaluated as well to confirm that similar levels of performance are reresentative of the air multipath and noise.

    In a future dual-frequency GBAS implementation, an important advantage of lower multipath and noise is to improve the Ifree position solution. In earlier research, we demonstrated that the error level of the Dfree solution is almost the same as for single-frequency, but an increase in error by a factor of 2.33 was computed for the Ifree standard deviation based on L1 C/A code and L2 semi-codeless measurements.

    If the errors on L1 (E1) and L5 (E5a) code and carrier phase measurements are statistically independent the standard deviation of the σIfree can be written as,

    Pullen-Eq5   (5)

    where α=1−f 21 ∕ f 25, and σL1,σL5 represent the standard deviations of the smoothed noise and multipath for L1 (E1) and L5 (E5a), respectively. Considering σpr_gnd,L1(E1)) = σpr_gnd,L5(E5a)) in equation (5), the noise and multipath error on Ifree (σIfree) increases by a factor of 2.59.

    Figure 7 shows the ratio σIfree/σL1 using measured data. We observe that the measured ratio (the black curve) is below the theoretical ratio computed based on the assumption of statistically independent samples (the constant value of 2.59). This is explained by the fact that the multipath errors in the measurements are not independent but have some degree of statistical correlation. The standard deviations are computed based on the same data set used in the raw multipath and noise assessment using 100-second smoothed measurements sorted into elevation bins of 10° spacing.

    Figure 7. Measured ratio σIfree/σL1 function of elevation.
    Figure 7. Measured ratio σIfree/σL1 function of elevation.

    Conclusion

    We have shown how GBAS can benefit from the new signals provided by the latest generation of GPS and Galileo satellites. We have demonstrated improved performance in terms of lower noise and multipath in data collected in our GBAS test bed. When GBAS is extended to a multi-frequency and multi-constellation system, these improvements can be leveraged for improved availability and better robustness of GBAS against ionospheric and other disturbances.

    Acknowledgment

    Large portions of this work were conducted in the framework of the DLR internal project, GRETA.

    Manufacturers

    The ground facility consists of four JAVAD GNSS Delta receivers, all connected to Leica AR 25 choke ring antennas.

    Mihaela-Simona Circiu is is a research associate at the German Aerospace Center (DLR). Her research focuses on multi-frequency multi-constellation Ground Based Augmentation System. She obtained a 2nd level Specialized Master in Navigation and Related Applications from Politecnico di Torino.

    MIchael Felux is is a research associate at the German Aerospace Center (DLR). He is coordinating research in the field of ground-based augmentation systems and pursuing a Ph.D. in Aerospace Engineering at the Technische Universität München.

    Sam Pullen is a senior research engineer at Stanford University, where he is the director of the Local Area Augmentation System (LAAS) research effort. He has supported the FAA and others in developing GNSS system concepts, requirements, integrity algorithms, and performance models since obtaining his Ph.D. from Stanford in Aeronautics and Astronautics.

  • UK Space Agency Awards SBAS Africa Contract to Avanti

    Avanti Communications has been appointed by the UK Space Agency to deliver a crucial air navigation project in Africa, SBAS-AFRICA. The satellite operator has been awarded the contract under the agency’s International Partnership Space Programme (IPSP), which exists to open up opportunities for the UK space sector to share expertise in real-world satellite technology and services overseas.

    Africa has just 3 percent of global air traffic, and yet air accidents in Africa account for roughly 20 percent of the worldwide total. By demonstrating potential improvements in flight safety via SBAS technologies, the project can provide socio-economic benefits to the continent, according to a news release from Avanti.

    Based on prior cost-benefit modeling which identified a €1.7 billion potential economic benefit to the African aviation sector from the deployment of SBAS services, SBAS-AFRICA will help accelerate the adoption of GNSS-based flight operations, positively influence the evolution of aviation safety in Africa and encourage development in the wider African economy.

    SBAS-AFRICA will deliver a satellite-based augmentation system for GNSS-based operations in the aviation sector, serving significant parts of Africa in partnership with a number of local stakeholders. The project will use a unique asset, Avanti’s ARTEMIS L1 Navigation transponder, to provide a navigation data broadcast service.

    “SBAS-AFRICA brings an innovative and pragmatic approach to deploying SBAS services in Africa,” said Matthew O’Connor, Chief Operating Officer at Avanti Communications. “It establishes crucial collaboration between the UK and a number of African countries, including South Africa and Ghana. Participating countries will benefit hugely from expertise gained, placing them at the forefront of navigation services across the continent and, crucially, helping to improve aviation safety for a major generator of economic benefit in Africa.”

    He continued, “The Artemis satellite will play an integral role in this project. We expect that such a showcase for its performance, accuracy and quality will provide further evidence of what can be achieved with this technology and lead to significant commercial opportunities.”

    “The UK Space Agency is delighted to play a role in fostering new international partnerships that not only enable innovative UK space companies like Avanti to provide more high-tech exports that can boost our space sector but also allow the UK to widely share the considerable social and economic benefits that space technology and infrastructure can provide,” said David Parker, chief executive of the UK Space Agency.

  • GSA’s 2015 Report Dives Deep into Global GNSS Market

    GSA’s 2015 Report Dives Deep into Global GNSS Market

    FIGURE 1. Cumulative core revenue, 2013–2023.
    FIGURE 1. Cumulative core revenue, 2013–2023.

    2015 GNSS Market Report: European GNSS Agency Provides a Fresh Look at Worldwide Growth

    The fourth edition of the European GNSS Agency’s (GSA’s) GNSS Market Report provides a comprehensive source of knowledge on this dynamic global market. The report has become a key reference for organizations building their GNSS market strategies. The new edition provides:

    • Comprehensive updates on previous analyses;
    • New statistics of the GNSS receiver capabilities of the 31 top global manufacturers, offering in total more than 300 models;
    • Insights on the GNSS industry and regional shares of the GNSS market
    • A more granular segmentation of the global GNSS market, namely: European Union (EU28); North America (including the United States, Canada, Mexico); Asia-Pacific (including China, Japan, Australia, India, Republic of Korea); Non-EU28 Europe (Norway, Switzerland, Russia, Ukraine);  Middle East and Africa (Turkey, Israel, South Africa, UAE, Saudi Arabia); South America and Caribbean (including Brazil, Argentina, Colombia, Guatemala)
    • Information on a new market segment: Timing and Synchronization
    • Plus additional applications within existing segments, such as recreational navigation, fishing vessels, personal locator beacons, emergency locator transmitters and digital tachograph.
    TABLE 1. Top 10 companies in each group based on 2012 revenue.
    TABLE 1. Top 10 companies in each group based on 2012 revenue.

    Key Findings

    Top-line insights from the fourth GSA GNSS Market Report:

    • The global GNSS downstream market is forecast to increase by 8.3 percent annually from 2013– 2019, then slow down to 4.6 annually around 2023, growing on average faster (7 percent) than the forecast global GDP in this period (6.6 percent).
    • The installed base in the mature regions of EU28 and North America will grow steadily (8 percent per year) to 2023. The primary region of growth will be Asia-Pacific, which is forecast to grow 11 percent per year from 1.7 billion in 2014 to 4.2 billion devices in 2023 — more than the EU and North America together. The Middle East and Africa will grow at the fastest rate (19 percent per year), but starting from a lower base.
    • Location-Based Services (LBS) and Road dominate cumulative GNSS revenues, driven by booming sales of smartphones and in-vehicle devices, location-aware applications and data services.
    • With emerging economies catching up in terms of GNSS devices per capita, the Digital Divide will narrow, driven by the take-up of smartphones. The growing dominance of smartphones (3.08 billion in 2014) is foreseen as the most popular platform to access LBS.
    • In the analysis of the capabilities of GNSS receivers and chipsets, it is reported that more than 60 percent of currently available receivers and chipsets support a minimum of two constellations with more than 20 percent supporting all four of them.
    FIGURE 2. SUPPORTED CONSTELLATION BY RECEIVERS Chart shows the percentage of available receivers capable of tracking signals from one GNSS (such as GPS only), two GNSS (GPS + Galileo, GPS + GLONASS, GPS + BeiDou), three GNSS (GPS + Galileo + GLONASS, GPS + Galileo + BeiDou, GPS + GLONASS + BeiDou) or tracking signals from all constellations at the same time. The percentages add up to 100 percent. We can conclude that almost 60 percent of all available receivers, chipsets and modules are supporting a minimum of two constellations, showing that multi-constellation is becoming a standard feature across all market segments.
    FIGURE 2. SUPPORTED CONSTELLATION BY RECEIVERS Chart shows the percentage of available
    receivers capable of tracking signals from one GNSS (such as GPS only), two GNSS (GPS
    + Galileo, GPS + GLONASS, GPS + BeiDou), three GNSS (GPS + Galileo + GLONASS, GPS +
    Galileo + BeiDou, GPS + GLONASS + BeiDou) or tracking signals from all constellations at
    the same time. The percentages add up to 100 percent. We can conclude that almost 60
    percent of all available receivers, chipsets and modules are supporting a minimum of two
    constellations, showing that multi-constellation is becoming a standard feature across all
    market segments.

    New Charts

    The report includes new infographics presenting:

    • Global GNSS downstream market size, core and enabled (2013 to 2023)
    • GNSS industry share by region (2012)
    • The global shares of companies among components manufacturers, systems integrators and value-added service providers (2012)
    • Capability of GNSS receivers and chipsets, all segments (2015)
    • Supported constellation by receivers and chipsets , all segments (2015)
    • Detailed analysis of key GNSS segments: LBS, Road, Aviation, Rail, Maritime, Agriculture, Surveying, Timing and Synchronization, quantified in terms of:
      • Shipments of GNSS devices by application and region (2013 to 2023)
      • Installed base of GNSS devices by application and region (2013 to 2023)
      • Core revenues from GNSS device sales by application and region (2013 to 2023)
      • Capability of GNSS receivers and chipsets (2015)
      • Supported constellation by receivers and chipsets (2015).
    FIGURE 3. LOCATION-BASED SERVICES SECTOR GNSS shipments by type; GNSS penetration in mobile phones is defined as the proportion of mobile telephones in use in the world that is GNSS enabled.
    FIGURE 3. LOCATION-BASED SERVICES SECTOR GNSS shipments by type; GNSS penetration in
    mobile phones is defined as the proportion of mobile telephones in use in the world that is
    GNSS enabled.
    FIGURE 4. ROAD SECTOR Core revenue from GNSS device sales and services by application.
    FIGURE 4. ROAD SECTOR Core revenue from GNSS device sales and services by application.

    Methodology

    The “GSA GNSS Market Report” is compiled by the GSA and the European Commission and was produced using the GSA’s systematic Marketing Monitoring and Forecasting Process.

    The underlying market model uses advanced forecasting techniques applied to a wide range of input data, assumptions, and scenarios to forecast the size of the GNSS market in terms of shipments, revenue and installed base of receivers.

    Historical values are anchored to actual data in order to ensure a high level of accuracy. Assumptions are provided by expert opinions and model results are cross-checked against the most recent market research reports from independent sources, before being validated through an iterative consultation process with sector experts and stakeholders.

    Download

    Readers can download the entire 29-MB report free.

  • EGNOS-Africa Joint Programme Office Launched

    The SAFIR (Satellite navigation services for AFrIcan Region) project has officially launched the EGNOS-Africa Joint Programme Office, laying the first stone of its future office building in a ceremony in Dakar, Senegal.

    SAFIR is part of the Africa-EU long-term strategic partnership to enhance safety in air transport. Its global objective is to build capacity within African ACP countries for the future deployment of GNSS/EGNOS in the region. The three-year project is funded by the European Union and financed from the 10th EDF Intra ACP envelope with 3.7 million euros, under an international consortium led by ASECNA (Agence pour la Sécurité de la Navigation Aérienne en Afrique et à Madagascar) with Egis, Pildo Labs and ESSP.

    The ceremony took place in Dakar on March 3. Those attending included Matthias Petschke, EU Satellite Navigation Programmes director; Karolina Stasiak from the UE Delegation in Sénégal; and Amadou Ousmane Guittèye, director general of ASECNA.

    “Satellite navigation can bring huge societal benefits, be it in transport, in agriculture or land management,” Petschke said in remarks at the launch ceremony. “Satellite-based augmentation systems in particular, like EGNOS, can bring enormous social and economic benefits. I attach, therefore, great importance to the setting up of the EGNOS Africa Joint Programme Office and am particularly pleased to see this team of African experts who have extensive experience and knowledge to support the development of an African satellite based augmentation system.”

    In his speech, Guittèye said, “The first mission of the JPO is to ensure Africa has developed adequate competencies and then to coordinate the implementation of the development and of the deployment of GNSS/EGNOS services and applications in the continent. The EGNOS-Africa Joint Programme Office (JPO) is a pan-African entity that acts for the benefit of Africa and supports stakeholders in their GNSS/EGNOS strategy, developments and implementation.”

    The ceremony also was attended by officials from the International Civil Aviation Organisation (ICAO), the African Civil Aviation Commission (AFCAC), the Agence Nationale de l’Aviation Civile et de la Météorologie (ANACIM) , the Aéroports du Sénégal (ADS) and local authorities.

    The SAFIR project began on January 15, 2013. It covers the set-up, staffing and operations of an EGNOS-Africa Joint Programme Office, and sets up and supports a number of technical working sessions composed of regional stakeholders concerned with GNSS/EGNOS in sub-Saharan Africa.

    ASECNA has 18 member states. With air navigation safety as its main mission, it cooperatively manages African airspace for the countries of Benin, Burkina Faso, Cameroun, Central African Republic, Comoros, Congo, Côte d’Ivoire, France, Gabon, Guinea Bissau, Equatorial Guinea , Madagascar, Mali, Mauritania, Niger, Senegal, Chad and Togo.

  • GPS in McMurdo Transmitter Makes Finding Planes Easier

    The The Kannad Integra Smart Pack by McMurdo Group could make it twice as easy to find missing aircraft. Photo: McMurdo Group
    The The Kannad Integra Smart Pack by McMurdo Group could make it twice as easy to find missing aircraft. Photo: McMurdo Group

    McMurdo Group, maker of end-to-end search and rescue solutions, has launched the Kannad Integra Smart Pack, an aviation emergency locator transmitter (ELT) bundle with both GPS and antenna redundancy. The product can result in Integra Smart Pack-equipped aircraft being twice as likely to be found in the event of an emergency compared to standard ELTs.

    The Kannad Integra Smart Pack includes:

    • The Kannad Integra ELT – a small, light ELT with a built-in antenna and embedded GPS receiver.

    • The new Kannad Integra e-NAV NMEA – an NMEA-standard interface cable that connects the Integra ELT to the aircraft GPS. The latest known aircraft GPS position is continually updated and stored on the interface cable itself to provide an additional level of redundancy over the embedded Integra ELT GPS data.

    Traditional ELTs rely on an aircraft’s external antenna and GPS equipment, which is subject to failure in the event of an emergency. The Integra ELT, however, can operate independently of the aircraft to provide key positioning data through its internal antenna and GPS receiver.

    With the Integra Smart Pack bundle, in the event that the Integra ELT’s internal GPS antenna is unsuccessful for any reason, the positioning coordinates from the Integra e-NAV NMEA will be used. This additional GPS redundancy will result in better location positioning and higher chance of rescue.

    “McMurdo is delighted to continue its long history of aviation search and rescue innovation with the introduction of the Kannad Integra Smart Pack,” said Christian Belleux, head of McMurdo’s Kannad Aviation Business Unit. “The Integra Smart Pack is a must-have SAR [search-and-rescue] solution to help ensure accelerated rescue response in the event of an emergency and to ultimately save more lives.”

    The Integra ELT Smart Pack is suitable for all types of aircraft with specific versions to support helicopters, general aviation planes and large commercial jets. Once activated, the Integra ELT transmits a distress signal to alert international rescue services to the emergency location via the global Cospas-Sarsat Search and Rescue satellite system, which has helped to save more than 37,000 lives since 1982.

    The McMurdo Group is exhibiting this week at Heli Expo 2015, Booth 5465, in Orlando, Fla.

  • GPS Source Offers Antenna for Harsh Environments

    GPS Source Offers Antenna for Harsh Environments

    GPS-Source-MIL-STD-antenna

    GPS Source has released a new GNSS antenna that is robust, lightweight, and suitable for harsh environments. It is designed for long-term, high-precision applications worldwide, the company said.

    The antenna was engineered for the demanding aviation environment, in both commercial and military applications. Built to military standards (MIL-STD), it is impact resistant, tolerant of exposure to dust, chemicals and jet fuels, and has the ability to withstand shock and vibration.

    Signal reception is unaffected by antenna placement. Designed to operate in the most extreme and demanding applications, it gives outstanding results, enabling maximum satellite reception, with ultra-low Dilution of Precision (DOP), GPS Source said.

    “We are very excited about the new GNSS antenna,” said Robert Horton, CEO of GPS Source. “Our advanced technology provides superior performance in both GPS L1/L2 and GLONASS L1/L2. This is the best solution for technically demanding users.”

    The antenna is available in multiple colors and with multiple connector options.

     

  • EGNOS Operations Introduced in Mediterranean Region: MEDUSA

    EGNOS Operations Introduced in Mediterranean Region: MEDUSA

    By Ugo Celestino, European Commission, Antonella Di Fazio, Telespazio SpA, Vicente José Giner Herrera, Ineco, Patrizio Vanni, ENAV SpA, and Francisco Javier Deblas, ESSP.

    This article describes a live demonstration of an aviation application in Tunisia, to help the local aviation community in validating the use of the European Geostationary Navigation Overlay Service (EGNOS) to guide airplanes during landing operations. This activity constitutes the first complete experience of EGNOS Safety of Life (SoL) service for aviation approaches outside Europe. We present here the obtained results that are useful not only for Tunisia, but as a valuable case study for other countries outside Europe interested in using EGNOS in aviation.

    EGNOS, operational since 2009, has a European regional coverage that could be quite easily extended to areas adjacent to European Union through the deployment of limited additional ground infrastructure elements, but sharing the same existing space segment and leveraging the other core ground infrastructure.

    The European Commission has put in place a series of actions since 2006 to support the EGNOS service extension in neighbouring areas. The MEDiterranean follow-Up for EGNOS Adoption (MEDUSA) is an on-going European initiative related to EGNOS extension in the Euromed region, including North African and Middle East countries around the Mediterranean basin: Algeria, Egypt, Israel, Jordan, Lebanon, Libya, Morocco, Palestine, Syria, and Tunisia. MEDUSA runs a program of technical assistance action in these Euromed countries, in order to prepare them for an optimal adoption and exploitation of European GNSS services in their priority market segments.

    The Mediterranean Extension of EGNOS

    EGNOS is Europe’s first venture into satellite navigation and paves the way for Galileo, Europe’s independent global satellite navigation system currently under deployment.

    EGNOS is a satellite-based augmentation system (SBAS), whose signal is compliant to the international SBAS interoperability standards: standards – MOPS (Minimum Operational Performance Standards) and ICAO SARPs (International Civil Aviation Organization Standard and Recommended Practices).  In its current version (V2) it augments the open public service offered by the American Global Positioning System (GPS), by providing correction data that enables to improve GPS position accuracy, and provides integrity information about the GPS system (integrity information is fundamental for aeronautical applications like approaches). EGNOS is interoperable with the other equivalent regional systems. Today other SBASs are the U.S Wide Area Augmentation System (WAAS), the Japanese Multi-functional Satellite Augmentation System (MSAS), the Indian GPS Aided Geo Augmented Navigation (GAGAN) and the Russian System for Differential Correction and Monitoring (SDCM). The future version (V3) of EGNOS will augment Galileo signal as well.

    Today EGNOS is operational, and available for use in aviation since 2011, giving opportunities for users to have more accurate and reliable positioning for enhancing existing applications, developing new applications and particularly the safety critical ones. Already more than 150 landing procedures are operational across Europe (some of them also in countries out of the European Union, such as Switzerland, Norway, Guernsey), with many others under development to reach 100 percent Approaches with Vertical Guidance (APV) coverage in the European instrumental runways as per ICAO recommendation.

    EGNOS provides three services:

    • EGNOS Open Service (OS), launched in 2009, is delivered free of charge. It is open for use to anyone with an EGNOS-enabled receiver. This can be any receiver compatible with satellite-based augmentation systems. Being based on GPS, the EGNOS signal does not require major changes for receivers. Today, many mass market receivers available on the market are also EGNOS enabled. EGNOS OS is particularly suitable for mass market and some applications like surveying.
    • EGNOS Safety-of-life Service (SoL) is authorized for European civil aviation and operational since March 2011. EGNOS SoL delivers the integrity message providing the verification of the GPS system and timely warnings (within six seconds), when the system or its data should not be used for navigation. Since integrity relates to the trust that can be placed in the correctness of the location information supplied by GPS, thanks to this feature EGNOS is able to meet the demands of safety-critical applications in sectors such as aviation.
    • EGNOS Data Access Service (EDAS) launched in 2012, delivers a terrestrial commercial data service. It consists of a server that gets the data directly from EGNOS system and disseminates it via terrestrial networks in real time, within guaranteed maximum delay, security and performance. EDAS is particularly suitable for professional applications. It provides EGNOS raw data and corrections enabling software solutions that implement products and value added services built on them.

    EGNOS infrastructure consists of three geostationary satellites over Europe and a network of ground stations (Ranging and Integrity Monitoring Station – RIMS) located to provide services whose coverage includes southern Europe, North Africa and some Middle East countries.

    The EGNOS RIMS network supports a flexible network geometry that gradually adapts to service coverage requirements evolution. From the originally envisaged coverage over European Union’s countries, the EGNOS RIMS network is being expanded over Europe’s neighbouring areas, thus increasing the number of beneficiary countries. EGNOS SoL service is highly sought by several non-EU countries for the benefits it can bring to their civil aviation, in providing a solution to comply with ICAO requirements for Performance Based Navigation (PBN).

    The present layout of the EGNOS RIMS network is presented in Figure 1.

    Medusa_image001
    Figure 1. EGNOS ground segment.

    Figures 2 and 3 show respectively  today’s coverage of EGNOS OS availability (source: European Satellite Services Provider, the service provider of EGNOS) and the APV-I availability performance commitment provided by EGNOS SoL (source: EGNOS Safety of Life Service Definition Document, EGN-SDD SoL, V2.0, European Commission, 2013), obtained relying on the above presented ground segment.

    Medusa_image002
    Figure 2. EGNOS OS Availability.

    EGNOS OS Availability. The Figure 2 map is obtained by projecting the error at pseudorange level into the position domain. The computed error assumes that the GPS satellites used are those with an elevation angle above the local horizon (with a mask angle of 5º) and does not consider any possible factor depending on local characteristics that could produce different results (optimistic or pessimistic) with respect to the results computed using real receivers located in the considered areas. Moreover, it represents an estimation of EGNOS OS availability during a very limited period of time being an estimation, thus it does not imply any commitment or reference for the performances which can be obtained during different periods.

    Medusa_figure3
    Figure 3. EGNOS APV-I Availability.

    Other initiatives for a further extension in North Africa and Middle East are already being developed, under the umbrella of the Euromed GNSS programme. In parallel with the infrastructure deployment, the Euromed GNSS programme also includes actions to support the introduction and exploitation of EGNOS services. The first stage was completed in the frame of the Euromed GNSS I/MEdiTerranean Introduction of GNSS Services (METIS) project in the period 2006-2009, the second stage is presently running in the frame of the Euromed GNSS II/MEDUSA project. Further initiatives are being planned for 2015 and beyond.

    EGNOS Use in Aviation

    EGNOS was initially designed and developed to be used in aviation, similarly to the U.S. Federal Aviation Administration  WAAS, to support different types of aviation applications and, in particular, to meet the performance requirements set by the International Civil Aviation Organization (Annex 10) for the implementation of APV-I, which enable the implementation of LPV final approaches, as reported in Table 1.

    Medusa_image004
    Table 1. ICAO Operational Requirements.

    EGNOS is one of the GNSS elements recognised by ICAO (Annex 10) as a radionavigation aid. It is an important element of a global SBAS systems mosaic, that started with the American system WAAS in 2003, and that is gradually completed by other more recent SBAS: EGNOS itself, MSAS (Japan), GAGAN (India), SDCM (Russia), and some countries like Australia and South Korea that have launched feasibility studies to develop their own SBAS.

    It is expected that, in a not too far future, most parts of the world will profit from SBAS services, following the current coverage extension plans and SBAS system evolutions. The final objective, as also shared at ICAO level, is that as many airdromes worldwide, as possible, can offer instrument approaches with vertical guidance, with an outstanding increase in global safety rates.

    Additionally, the use of EGNOS allows taking full advantage of GNSS for all phases of flight, including final approach. Therefore, EGNOS means for aviation a fundamental and strategic tool to help meet ICAO’s recommendations, aimed at the adoption of a PBN oriented airspace use policy, for all countries. The 37th Assembly of ICAO (28 September – 8 October 2010) resolved that APV procedures should be implemented as either a primary or backup strategy for precision approaches at all instrument runway ends by 2016.

    APV is a major safety initiative. ICAO recognises SBAS and Barometric Vertical Navigation (Baro-VNAV) as the two acceptable (and often complementary) means of implementing APV procedures, which are safer than NPA (Non Precision Approach).

    GNSS based navigation enables RNAV (aRea NAVigation) with a higher cost effectiveness in comparison with the old conventional, sensor ground-based, navigation procedures. This is especially true for wide, even desert unequipped areas (or difficult to maintain) like those in North Africa and Middle East.

    EGNOS benefits are maximized in final approach manoeuvres, providing GNSS lateral and vertical guidance, and enabling APV-I approaches.

    Final approach procedures based on GNSS are classified as RNP approaches (RNP APCH, as shown in the next figure), namely: Lateral Navigation (LNAV) with GPS lateral guidance and no vertical guidance; LP with GPS + SBAS (EGNOS) for lateral guidance (CAT-I localizer performance) and no vertical guidance; Lateral Navigation/Vertical Navigation (LNAV/VNAV) with GPS lateral guidance and Baro-Vertical Navigation (VNAV) vertical guidance (Baro-VNAV approach procedures can be flown with SBAS vertical guidance upon the approval of the Air Navigation Service Provider (ANSP)) and the LPV (Localizer Performance with Vertical Guidance) with GPS + EGNOS for both lateral and vertical guidance.

    Medusa_image005
    Figure 4. RNP approaches.

    Those procedures not including vertical guidance are intended to be flown with the Constant Descent Final Approach (CDFA) technique (to avoid dangerous dive and drive practices), supported by most Flight Management Systems (FMS).

    Regarding the operational LPV main figures, the European regulation (EU OPS -REGULATION (EC) No 859/2008 usually known as EU OPS) allows LPV operational minima (Decision Height – DH) down to 250 ft, expected to be possibly lowered down to 200 ft by 2015 (LPV-200), similarly to what is already permitted by the FAA, in the United Sates for WAAS based LPV approaches (a DH of 200 ft would make LPV approaches very competitive, when benchmarked against ILS CAT-I, precision approach, or even Ground Based Augmentation System (GBAS) CAT-I precision approach).

    In the last few years, about 150 LPV procedures (status as of July 2014) have been published in European airports, and the number of procedures and countries introducing EGNOS is continuously increasing.

    Euromed GNSS I/METIS and Euromed GNSS II/MEDUSA

    In parallel with the development of the infrastructures necessary for extending EGNOS availability across the Euromed region, the European Commission has put in place initiatives to prepare and assist the Euromed countries for the optimal use and adoption of the relevant services.

    These consist in two sequential projects, the first being Euromed GNSS I/METIS project and the second being Euromed GNSS II /MEDUSA.

    Running from mid 2006 up to the end of 2009, METIS acted as a pioneer in the Euromed countries and built national/regional liaisons with decision-makers and key stakeholders, interested in sharing experience and absorbing know-how. The project assisted the 10 Euromed countries to identify their priorities in relation to the use of EGNOS services, to validate the relevant opportunities from the strategic/social and economic perspectives, and to elaborate a suitable strategy and a plan of actions for facilitating EGNOS adoption and exploitation.

    MEDUSA Case Study in Tunisia: LPV Approaches in the Airport of Monastir Using EGNOS

    As part of the technical assistance actions programme in the priority domains, MEDUSA implements demonstrations and validations of EGNOS services in concrete applications.

    For EGNOS SoL, the technical assistance action consisted in the validation of GNSS approaches, including LPV approaches, designed and constructed in MEDUSA along with the relevant safety assessment and business case for the airport of Monastir in Tunisia (35°45’29’’ N 10°45’17’’ E). The selection of the airport was driven by a trade off between the EGNOS service availability with required APV-I performances and the specific needs of the Tunisian Air Navigation Service Provider – ANSP (OACA, Office de l’Aviation Civile et des Aéroports). According to OACA, Monastir is among the airports in Tunisia presenting favourable conditions, in terms of operational constraints and traffic, for concretely proving the added value of EGNOS for final approaches.

    The airport has two runways, RWY 07 and RWY 25, the former is equipped with an ILS CAT-I, the latter only supports NPA approaches. The installation of an ILS in RWY 25 was discarded due to technical constraints. This infrastructure has proven to be insufficient to fully cover the airport needs, that suffers some Delays-Diversions-Cancellations (DDCs) as a result of local specific meteorological conditions, frequent fog banks entering from the sea in the early morning, combined with desert haze. These conditions make LPV ideal procedures, as backups to RWY 07, and enabling APV approaches to RWY 25. Finally, Monastir’s TWR ATC (Tower Air Traffic Control ) staff has been involved in OACA’s PBN development, for which they were ideal candidates to evaluate the benefits possibly achievable from the use of EGNOS.

    This MEDUSA’s technical assistance action is the first complete experience for the use of EGNOS SoL service outside Europe. It was conceived as a realistic exercise of RNP APCH procedures implementation, following the guidelines provided by ICAO in the “EUR RNP APCH Guidance Material (EUR Doc 025)” and including all the activities required, from the scenario adequacy study to flight validation and the requirements analysis for the final publication in the AIP (Aeronautical Information Publication).  OACA was directly involved in all activities, providing inputs/feedbacks and for training purposes.

    A set of three GNSS based approach procedures was produced for each RWY, following ICAO 8168 PANS OPS design principles. The next figures show the combined charts type elaborated, that include minima boxes for three RNP approaches (LNAV, LNAV/VNAV and LPV). The procedures construction preserves the current Monastir arrivals structure, following airspace management principles and facilitating the operational approval. As illustrated in the charts, in both cases for the three minima the calculated OCH (Obstacle Clearance Height) values improve with respect to the already existing conventional approaches, providing significant operational and safety benefits.

    Figure 5. GNSS approaches for RWY 07.
    Figure 5. GNSS approaches for RWY 07.
    Figure 6. GNSS approaches for RWY 25.
    Figure 6. GNSS approaches for RWY 25.

    An on-site GNSS performance monitoring campaign was performed by OACA, with the support of GEMCO’s staff, 3 months before the flight trials schedule, covering both EGNOS and GPS signal performances. Besides, an APV-I availability study for the area and specifically for Monastir airport during 1 month before the flight validation was purposely elaborated by the European EGNOS service provider (ESSP). Both analyses, confirmed suitable APV-I performance in terms of availability and continuity, making feasible the implementation of LPV approach procedures in line with ICAO prescriptions.

    The next figures show the EGNOS APV-I availability and continuity measured on one day during the period of the flight validation (conducted from 30 January to 1 February 2014), in particular at Monastir airport for the considered time-lag:

    • APV-I availability was over 99%;
    • APV-I continuity presented a total value lower than 5×10-4/15s;
    • 95th percentile of Horizontal APV-I accuracy was between 1.1 and 1.2 meters and the 95th percentile of Vertical APV-I Accuracy is around 1.4 meters, thus showing a very good accuracy level;
    • Horizontal and Vertical safety indexes were lower than 0.25, representing a very good integrity margin.

    Additionally, the results of the on-site GNSS performance monitoring campaign showed quite stable performances with small fluctuations during the whole period of observation, and no problems or outages were observed.

    (EGNOS APV-I Availability is defined as the percentage of epochs in a month in which the Protection Level are below Alert Limits for this APV-I service (HPL<40m and VPL<50m) over the total period (source: ESSP).

    EGNOS APV-I Continuity Risk is defined as the result of dividing the total number of single continuity breaks using a time-sliding window of 15 seconds by the number of samples with valid and available PA navigation solution. A single continuity break occurs if the system is available at one epoch and becomes not available for the following 15 seconds (source: ESSP).)

    Figure 7
    Figure 7. APV-I availability on 31.01.2014.
    Figure 8
    Figure 8. APV-I continuity on 31.01.2014.

    The flight validation campaign was carried out according to ICAO doc 9906 with a Piaggio P180 Avanti II (from ENAV flight inspection department) suitably equipped with UNIFIS 3000 system and a Rockwell Collins FMS 3000 with SBAS LPV approach capabilities.

    Figure 9
    Figure 9. Piaggio P180 Avanti II aircraft and the FMS messages during the flight validation.

    The outcomes of this concrete experience have allowed the Tunisian authorities to identify the main elements for the publication of the validated procedures in their national AIP. They have also contributed to the analysis of the necessary process for the operational adoption of GNSS, including EGNOS, in aviation in countries beyond the EU boundaries.

    The activities performed on performance assessment have been preparatory for discussions on GNSS monitoring and data recording on going at ICAO Navigation System Panel level, that would produce ICAO guidelines for States.

    Therefore, this Tunisia’s “case study” represents a practical and realistic example that could be beneficial for the other non-EU countries in terms of best practice and lesson learnt. Moreover, methodology and guidelines have been derived to be possibly injected to other non-European countries interested to introduce EGNOS operations in aviation.

    Lessons Learned and Outlook

    Through its achievements, MEDUSA is opening the way for the introduction of EGNOS SoL service in North Africa and Middle-East region, and it is also defining a suitable path to be followed by other interested non-European countries. Overall, MEDUSA is continuing to confirm the ability to foster cooperation and involvement in EGNOS programme of the great majority of the Euromed countries. Further to Tunisia, other Euromed countries have already expressed their interest in relation to the EGNOS use in aviation, considering each country’s strategy and also in the light of a common shared regional perspective. Besides, the results obtained by MEDUSA are useful also for other regions interested to use EGNOS in aviation.

    Additionally, MEDUSA is clearly showing that Euromed region, presently lacking the full support of SBAS technologies, represents an opportunity for EGNOS service extension, with many benefits for the countries of the region and for Europe.

    On one hand, being SBAS an effective and efficient technology to enable the aviation community of the Euromed countries to comply with ICAO recommendations on PBN implementation by year 2016 across the region, the services coverage extension of existing SBAS systems (EGNOS in the case of the Euromed countries) can be one of the most efficient ways to move forward. In fact, the Euromed national ANSPs consider the readiness of EGNOS SoL service as one of the main drivers and factors when designing their PBN strategy. EGNOS, which is already operational since 2009 and available for use in aviation since 2011, can deliver added-value services to the Euromed region, just by leveraging the existing European infrastructure with only incremental, marginal and natural extension. The EGNOS coverage extension across the Euromed region can provide significant benefits and particularly to those Euromed countries with few ILS or reduced navaids coverage, and enhance safety and efficiency to the whole aviation community.

    On the other hand, the European Union has to gain from an EGNOS-based long term links with its neighbouring regions, by increasing bilateral/multilateral cooperation and interaction (e.g. assistance, mutual cooperation) among public and semi-public bodies (e.g. ANSPs, Civil Aviation Authorities), by strengthening EGNOS SoL coverage in the southern/peripheries of EU (e.g. Malta, Cyprus, Greece, Southernest Italian islands, Canary islands), by pursuing and supporting other EU policies in several sectors (like transports, e.g. harmonizing aviation safety standards across the Mediterranean, Transport Policy of the Mediterranean Partners), and last but not least by achieving a first step towards EGNOS extension to the whole African continent which will bring in similar, additional benefits just described above.

    A win-win opportunity to be seized.

  • SkyTraq GNSS Receiver Module Provides Indoor/Outdoor Positioning

    SkyTraq S2525DR8 Photo: SkyTraq Technology
    Photo: SkyTraq Technology

    SkyTraq Technology, Inc., a fabless GNSS positioning technology company, has introduced an all-in-one S2525DR8 GNSS dead-reckoning module, with integrating MEMS sensor and interface logic on-board. The module is designed for road vehicles requiring high accuracy 100 percent positioning availability.

    The S2525DR8 offers accuracy for both indoor and outdoor positioning. It is based on SkyTraq’s Venus 8 multi-GNSS platform and uses a high-performance automotive-grade XV-8100CB analog output gyroscope and 16-bit differential ADC. A 3D option adds a barometric pressure sensor on-board, offering improved accuracy for altitude reading and altitude change detection over an accelerometer-based scheme in 3D dead reckoning.

    Another monitoring option adds an accelerometer on-board, offering high-accuracy vehicle acceleration monitoring for driver behavior characterization, accident reconstruction analysis, or trigger event recording. The S2525DR8 is compact at 25 x 25 millimeters. It contains a level shifter on board, capable of direct interface to a vehicle odometer and forward/reverse signals ranging from 3V to 30V.

    The SPI interface pins on the module allow autonomous data logging to an external SPI Flash memory device. For high-performance vehicle navigation systems, S2525DR8 provides continuous navigation inside tunnels and underground parking lots without signals; highly accurate barometric altitude enables identification of which level the vehicle is on in a stacked multi-level high-way or a multi-story car park. For automatic vehicle locating or fleet management systems, location can be identified immediately after power on, whether the vehicle is outdoors or indoors under a signal-denied environment.

    The S2525DR8 provides reliable, uninterrupted position, speed and heading information in challenging environments; it is suitable for demanding vehicle navigation and tracking applications requiring the highest accuracy and availability, SkyTraq said. The S2525DR8 is now being manufactured in ISO/TS 16949 automotive-certified factories; an evaluation kit, sample, datasheet, and reference design are available now. A 3D option with barometric sensor and a vehicle-dynamics monitoring option with accelerometer will be available in the first quarter of 2015.

  • Euromed Conference on Satnav Services Set for Dec. 17 in Tunis

    As part of European project MEDUSA coordinated by Telespazio (Finmeccanica/Thales), a workshop will be held in Tunis on Dec. 17 with stakeholders in civil aviation to promote the use of European satellite navigation systems in Libya, specifically EGNOS.

    MEDUSA (Mediterranean follow-up for EGNOS Adoption) is a project funded by the European Commission as part of Euromed program GNSS with the objective of promoting the use of European satellite navigation services (E-GNSS), starting from EGNOS (European Geostationary Navigation Overlay Service) ahead of Galileo, in the Euromed area.

    MEDUSA assists and prepares countries in the area (Algeria, Egypt, Jordan, Israel, Lebanon, Libya, Morocco, Palestine, Syria and Tunisia) in the adoption process of E-GNSS services, mainly in aviation as well as in other transportation sectors. To this end, MEDUSA implements a ”program of assistance actions” in countries from the area to transfer abilities, create technological capacities and share good practices.

    Moreover, MEDUSA has created an operational and cooperation structure, called GEMCO (Galileo EuroMEd Cooperation Office), with a long-term working plan providing for the participation at a regional level of all beneficiary countries.

    Located in Tunis, GEMCO acts as a reference point and catalyzer for all Euromed countries and towards Europe. Through GEMCO, MEDUSA favors initiatives connected to E-GNSS in the Euromed region, and contributes to the implementation of assistance actions of the project like national and regional workshops, training sessions, and days dedicated to studying.

    GEMCO will host the MEDUSA meeting with stakeholders of Libya’s civil aviation to analyze the country’s needs, identify priorities and help define a strategic vision in the short, medium and long-term in relation to the possible operative introduction of the use of EGNOS. Libya, which has repeatedly shown interest in the project and EGNOS (whose perspective of availability of coverage of respective service is provided for in the short and medium-term), represents an opportunity for EGNOS mainly in the aviation and helicopter sectors.

  • DARPA Program Addresses Degraded Visibility for Helicopters

    DARPA Program Addresses Degraded Visibility for Helicopters

    Degraded visibility — which encompasses diverse environmental conditions including severe weather, dust kicked up during takeoff and landing, and poor visual contrast among different parts of terrain — often puts both the safety and effectiveness of tactical helicopter operations at risk. Current sensor systems that can provide the necessary visualization through obscurants struggle with latency and are too large, heavy and power-intensive to comply with military rotary-wing operations.

    The Defense Advanced Research Projects Agency‘s (DARPA’s) Multifunction RF (MFRF) program seeks to overcome these challenges and enhance the survivability and combat effectiveness of helicopters facing degraded visibility. The program aims to develop multifunction sensor technology that would enable sensor packages small, light and efficient enough for installation on existing and future helicopter designs. MFRF would enable pilots to:

    • Take off, fly and land safely in degraded and zero-visibility conditions
    • Avoid collisions with other aircraft, terrain and man-made obstacles (e.g. power lines)
    • Improve target detection, identification and engagement

    MFRF completed successful flight demonstrations on a UH-60L Black Hawk combat helicopter (see video above) to demonstrate the Synthetic Vision Avionics Backbone (SVAB) technology portion of the program. The SVAB technology demonstration fused millimeter-wave radar with multiple terrain databases and onboard platform navigation to create high-resolution 2D and 3D visualizations of local environmental conditions.

    Pilots referred to the visualizations in real time to distinguish terrain features (slope, roughness, landing suitability), detect objects in a landing zone, detect and avoid obstacles, and navigate in GPS-denied conditions. The software architecture of the SVAB also demonstrated plug-and-play sensor control and display.

    “These successful tests take us closer to future cost-effective, ‘plug-and-play’ systems that would improve situational awareness and mission effectiveness for manned and unmanned platforms alike,” said Bruce Wallace, DARPA program manager.

    DARPA-helicopter_RF-W
    Photo: DARPA

     

  • China to Join Effort on Aircraft Satnav Standards

    China to Join Effort on Aircraft Satnav Standards

    EGNOS is Europe’s first venture into satellite navigation. EGNOS broadcasts augmented information through a trio of geostationary satellites linked to a network of monitoring ground stations, to sharpen the accuracy and reliability of GPS signals across the continent.
    EGNOS is Europe’s first venture into satellite navigation. EGNOS broadcasts augmented information through a trio of geostationary satellites linked to a network of monitoring ground stations, to sharpen the accuracy and reliability of GPS signals across the continent. Photo: EGNOS

    Europe’s EGNOS augmentation system sharpens the accuracy and reliability of GPS signals so they can safely be used for landing approaches across a growing number of European airports. But aviation is a global enterprise — so the aim is to develop a seamless network of augmentation systems in future.

    That is the task of an international group of experts, the Satellite Based Augmentation Systems (SBAS) Interoperability Working Group (IWG), whose 27th  meeting took place in Tampa, Florida, September 8-10, hosted by the Institute of Navigation.

    Satellite augmentation systems combine dedicated ground stations and satellite transponders to sharpen satnav accuracy and provide integrity data — providing continuously updated reliability levels — across given geographical regions. These systems are based on GPS for now, but plans are to move to a multi-constellation design in the post-2020 era, making use of Europe’s Galileo, China’s Beidou and Russia’s GLONASS systems as well.

    SBAS providers from around the globe gathered at Tampa, Florida, for the latest meeting of the SBAS Interoperability Working Group September 8-10. IWG 27 was hosted by the Institute of Navigation.
    SBAS providers from around the globe gathered at Tampa, Florida, for the latest meeting of the SBAS Interoperability Working Group September 8-10. IWG 27 was hosted by the Institute of Navigation. Photo: SBAS
    SBAS systems enhance any type of location-based satnav use, but in practice, aviation is the main driver. The ESA-developed European Geostationary Navigation Overlay Service, EGNOS, commenced its general-public Open Service in 2009, with the Safety-of-Life Service for aircraft vertical landing approaches following in 2011.

    For next-generation SBAS systems, the IWG is designing a multi-constellation and dual-frequency standard for heightened accuracy and reliability, building up to offering SBAS coverage on a worldwide basis.

    Didier Flament, representing ESA — which co-chaired this IWG meeting with the U.S. Federal Aviation Authority — commented: “Among the achievements of the Tampa IWG has been the presentation of an ongoing review of a standard message definition for the new and second SBAS channel — known as L5 — of the second-generation SBAS system, to be used along with the current L1 signal.

    ASECNA Member States.
    ASECNA Member States.
    “A single definition coordinated between ESA and the European Commission on one side and the U.S. Federal Aviation Administration on the other is progressing. The formal IWG review loop has  started, with the aim of finalizing the convergence for early 2015. The aim is to have it ready to submit to the international SBAS standardization bodies — the International Civil Aviation Organization (ICAO), the U.S. Radio Technical Commission for Aeronautics and the European Organization for Civil Aviation Equipment — in the first quarter of next year.”

    The meeting also introduced two new SBAS development projects, adding to the five existing projects presented at IWG 26. The first was presented by the Agency for Air Navigation Safety in western Africa and Madagascar (ASECNA), a public international organization with 18 member states.

    China's BeiDou SBAS development plan, presented at IWG 27 in September 2014.
    China’s BeiDou SBAS development plan, presented at IWG 27 in September 2014.

    ASECNA’s project aims to take a two-step approach, commencing with EGNOS-style vertical landing guidance for selected airports, based on EGNOS constituents, with a tentative schedule of 2018, moving to upgrade to the dual-frequency multi-constellation service across the whole of ASECNA airspace after 2020.

    The second new project is China’s own BeiDou SBAS. After discussions at ICAO level, China has committed to delivering SBAS services over China that are fully compliant with ICAO standards.

    “This new plan has been highly welcomed by the aviation community and other SBAS providers,” Didier said. “Chinese representatives have also confirmed their intention to become part of the SBAS IWG and contribute to the work done to finalise the future standard.”

    The follow-up IWG meeting will take place in February 2015 and will be hosted by ASECNA in Dakar, Senegal.

    About EGNOS

    EGNOS, the European Geostationary Navigation Overlay Service, is Europe’s first venture into satellite navigation. Its development was managed by the European Space Agency (ESA) under a tripartite agreement with the European Commission (EC) and the European Organization for the Safety of Air Navigation (Eurocontrol).

    The ownership of the EGNOS assets was transferred from ESA to the EC in April 2009 and EGNOS officially entered service on October 1, 2009. The service is delivered, through a contract with the European GNSS Service Agency (GSA), by the European Satellite Services Provider, ESSP SaS, founded by seven air navigation service providers. ESA is the design and procurement agent for EGNOS on behalf of the EC.