GPS World

Tag: GNSS receiver

  • Airborne GNSS receivers: Who’s doing what?

    Airborne GNSS receivers: Who’s doing what?

    Rockwell Collins new generation GPS-4000-100 receiver

    It’s still exceptionally difficult to qualify GNSS receivers for airborne use so there are only a few existing suppliers.

    They include CMC Electronics with its line of OEM and enclosure products, Rockwell Collins with a new generation of airborne receivers just entering the market, Thales in Europe continuing to offer ARINC standard and multi-mode packaged receivers, Garmin still leading the panel-mount market for business aviation, Trimble/Ashtech continuing to promote its GPS/GLONASS airborne receiver, and newer entrants including Aspen/Accord with the NexNav GNSS line, and Avidyne with a home-grown embedded receiver in its flight management systems.

    It’s been a while since we reviewed the status of certified airborne receivers, and I was prompted to do so by news that Rockwell Collins has a new generation of receiver which has just received Technical Standard Order (TSO) approval from FAA.

    Rockwell Collins has fielded GPS products for 20+ years, and the GPS-4000S — with SBAS capability — has been fielded for more than 8 years, so parts obsolescence may become an issue. With new constellations, and with more countries implementing Space Based Augmentation Systems (SBAS), the 10 channel + 2 SBAS design needed an update. So Rockwell Collins undertook a bold step to develop and certify a radically new architecture for airborne applications — a software defined receiver.

    Some Members of the Rockwell Collins Navigation Center of Excellence, in Melbourne FL (L-R); Jeremy Kazmierczak – Senior Systems Engineer; Eyal Wilamowski – GNSS Project Engineer; De Yao – Senior Electrical Engineer; Angelo Joseph – GNSS Architect, Technical Project Manager; and Principal Systems Engineer Vikram Malhotra – Senior Systems Engineer

    A multi-frequency prototype first came together during two years of intense work by a couple of individuals, led by Angelo Joseph, an ex-NovAtel Aviation Group engineer with 15 years of GNSS design experience. When this proof-of-concept receiver demonstrated the required capability, a new GNSS receiver team was put together in Melbourne, Florida, to develop a fully qualified receiver, designed and built to stringent airborne standards.

    Over the next six years, hardware was proven to meet performance, environmental, electrical, safety, high-integrity and reliability standards, and software was carefully developed and tested to meet the highest aviation qualification requirements — referred to as “Level A.”

    In the process, a number of patents were generated — two have so far been approved in the United States:

    • Low-cost high integrity integrated multi-sensor precision navigation system, US 9513376 B1
    • Universal channel for location tracking system, US 9702979 B1

    The universal-channel technique enables the new receiver  to be configured to track any satellite navigation signal on all 14 + 4 SBAS channels (ultimately, this GNSS engine is anticipated to be able to track 100+ GNSS satellite signals), so the receiver is ready for when other constellations are approved for airborne navigation — for instance, European approval for Galileo use may be high on the list of new capabilities.

    CMA-6024 GPS/SBAS/GBAS sensor

    The new receiver is capable of LPV (localizer performance with vertical guidance) precision approaches to CAT I (down to ~200ft height in ~1/2 mile visibility). It features combined Required Navigation Performance (RNP) and approach capability, 10-Hz deviation output computations (20-Hz outputs), plug-and-play replacement for existing Rockwell Collins GPS receivers. It is Automatic Dependent Surveillance (ADS-B) compliant and has fast cold-start (<2 mins @ low SNR).

    With production spooling up in Melbourne, Florida, it is available now for installation on business and regional aircraft.

    An additional TSO application is underway to enable anticipated installations on Airbus and Boeing commercial transport aircraft. Work on the Rockwell Collins Next Generation Multi-Mode Receiver, the GLU-2100, is well advanced with an estimated availability at the end of this year.

    In Europe, Thales markets the TopStar-C certified GNSS receiver solution for aircraft and helicopter navigation and approach, providing LPV, RNP and ADS-B, with Ground Based Augmentation System (GBAS) capability promised in the near future. Compliant with all these latest navigation functions, TopStar-C is available as both standard fit (installed as basic fit on a new aircraft) and for retrofit on aircraft and helicopters alike.

    CMA-4124 GNSSA Precision Approach Receiver

    The Thales Multi-Mode Receiver (MMR) is part of the TopFlight Line, which includes comprehensive solutions for communication, navigation and surveillance. The MMR is configured with GNSS landing system (GLS) and navigation capability, Instrument Landing System (ILS) and Microwave Landing System (MLS) receivers in one package.

    ILS still provides Cat III precision landing system (effectively 700 ft visibility of the runway down to 50 ft) capability at a few key airports where severe weather can really disrupt scheduled airline operations. Nevertheless, ILS may encounters integrity problems due to FM interference and multipath reflection, which may degrade landing capabilities under low-visibility conditions — just when its most needed. MLS can provide Cat. III B (effectively 600 ft visibility of the runway down to 35 ft) landing alternative to ILS, but is fielded at very few airports.

    Meanwhile, GLS is part of the international strategic plan to provide precision approach capability worldwide to an increasing number of runways. So airlines may soon have a number of precision-landing options at airports around the world — ILS, MLS or GLS — and the Thales MMR provides all three capabilities.

    Garmin GTN-650 panel-mount Nav/Comm System

    CMC Electronics introduced the CMA-6024 GPS Satellite Based Augmentation System and Ground Based Augmentation System (SBAS/GBAS) CAT-l/ll/lll Precision Approach Solution at the National Business Aircraft Association show in November 2016. CMC has been in the business of supplying certified GPS receivers for commercial air transport, business aviation and helicopter markets, either directly or through Honeywell and other partners for over 35 years — almost as long as GPS has been around! The CMC family of airborne receivers also has another connection with NovAtel — they were developed as a collaborative effort with NovAtel and incorporate patented Narrow Correlator signal tracking technology.

    The CMA-6024 aviation GPS/SBAS/GBAS sensor has an embedded VHF Data Broadcast (VDB) receiver and an integrated GPS navigation sensor, is self-contained, and fully certified Precision Approach and navigation GBAS/GLS solution, certified to Design Assurance Level A.

    Garmin GPS/Nav/Comm/Multi-Function Display.

    The CMA-6024 provides a navigation solution that is fully compliant with Automatic Dependent Surveillance-Broadcast (ADS-B) and Required Navigation Performance (RNP). It comes with SBAS Localizer Performance/Localizer Performance with Vertical Guidance (LP/LPV) and GBAS Global Navigation Satellite System Landing System (GLS) GAST-C/D Precision Approach guidance for all aircraft. And it meets or exceeds the most stringent environmental requirements set out in RTCA/DO-160G, meeting additional requirements for specific aircraft, such as higher vibration levels for helicopters.

    CMC’s family of GPS products includes the CMA-5024 GPS Landing System Sensor that meets the requirements for Instrument Flight Rules (IFR), civil certified GNSS, and also the CMA-4124 OEM GNSSA receiver card for embedded applications.

    An SBAS/WAAS-certified, 15-channel GPS with 5-Hz outputs is embedded in the Garmin GTN-650 Nav/Comm unit, enabling GPS-guided LPV glide-path instrument approaches down to 200 ft. The system also includes VHF navigation capabilities, with a 200-channel VOR (VHF Omnidirectional Range) and ILS receiver for approaches with ILS localizer and glideslope. VOR navigation using the extensive ground VOR beacon system uses radial direction and distance to each VOR beacon within receiver range.

    FreeFlight FMS/GPS

    In addition, course deviation and roll steering outputs may be coupled to compatible autopilots so that IFR flight procedures may be flown automatically. And, when coupled with a flight display and compatible autopilot, the aircraft can fly fully coupled missed approaches, including heading legs as well as holds and search and rescue patterns.

    In 2015, Aspen Avionics acquired Accord Technology, an Indian company which claims to have developed the first GPS WAAS airborne sensor to be authorized under US FAA TSO-C145c. These receivers are now marketed as the ‘NexNav’ product line. This receiver was apparently the first to comply with FAA AC20-165A for ADS-B GPS position source and is also sold as an OEM GPS SBAS card-level receiver authorized to TSO-204.

    There are currently three NexNav receiver versions:

    • Mini (TSO-C145c SBAS Class Beta-1 only)
    • Max (TSO-C145c SBAS Class Beta -1, -2, -3) and
    • Micro-i GPS SBAS for TSO-C199 TABS for aircraft and experimental aircraft.
    SBAS/GNSS (WAAS/GPS) 1201 Sensor

    All NexNav GPS WAAS receivers are compatible with other SBAS systems around the world, including the European EGNOS, Japanese MSAS and Indian GAGAN.

    FreeFlight also markets two GNSS sensors and a suite of aircraft avionics.

    The 1203C sensor houses a high-performance 15-channel GPS engine with advanced interference protection and quick update rates, and is designed for business, regional, airline transport and heavy rotary-wing aircraft. The 1203C is certified to TSO-C145c and meets position source requirements for ADS-B and Required Navigation Performance (RNP) and other L-NAV operations. Another 1201 Sensor GNSS is specifically for General Aviation aircraft.

    Bendix/King KSN 770 Flight Information Management System

    Bendix/King GNSS navigation capability, like other General Aviation avionics suppliers, is often buried within a cockpit display system that serves to tune radios, and display information from weather radar, Enhanced Ground Proximity Warning System (EGPWS), XM Datalink Weather, Terrain awareness and warning System (TAWS) and Traffic Collision Avoidance System (TCAS).

    Nevertheless, the KSN 770 features Wide Area Augmentation System (WAAS) and Localizer Performance with Vertical Guidance (LPV), and is specified as a “WAAS GPS enroute and approach navigation system.”

    Ashtech, now a Trimble subsidiary, still lists the venerable GG12 OEM GPS/GLONASS receiver on its website, now somewhat updated to include SBAS as the GG12W.

    Ashtech is careful to describe its OEM receiver as “capable of being qualified” within a TSO-ed FMS systems — presumably the approach has been to provide all the required qualification data to integrator companies, who include this receiver within the FMS as the GNSS navigation and approach receiver. The integrator then submits the Ashtech data to FAA to support their system TSO application.

    Avidyne now integrates its own in-house-developed GNSS receiver into its line of cockpit mount FMS and related GNSS navigation and approach systems. And here there is another connection with Angelo Joseph — his work at Avidyne before he went to Rockwell Collins was to develop this Avidyne receiver to replace a bought-out embedded OEM GNSS receiver. The FMS has been certified using this new receiver to TSO-C146d — Stand-Alone Airborne Navigation Equipment using GPS augmented by WAAS, including Airborne Supplemental Navigation Equipment using the Global Positioning System (GPS) — Gamma 3.

    Avidyne IFD540 display

    There are clearly other companies who supply avionics for GA and Commercial Air Transport aircraft, but this article has attempted to capture a cross-section of GNSS offerings. Other notables include Sagem/Safran in France, Universal Avionics in Tucson, and quite possibly several others that we will no doubt hear about shortly!

    As aviation agencies move towards adding the use of other constellations beyond GPS into approved, international navigation standards, there surely has to be significant change across the board for aviation as a whole as improved integrity and availability provide more options and capability. The existing avionics suppliers should be able to maintain market by offering more capability, and there might even be more opportunity for new entrants to come into the market with disruptive products, but for sure the future looks good for the industry.

  • Sokkia GNSS receivers now integrated with TerraGo Magic

    Sokkia GNSS receivers now integrated with TerraGo Magic

    GCX3

    TerraGo Magic now offers advanced integration and support for the Sokkia line of GNSS receivers, including the new GCX3.

    TerraGo Magic is a zero-code platform-as-a-service that enables customers to build their own custom mobile apps without writing any code by choosing from a menu of available, field-tested features.

    Featuring advanced constellation tracking and longer range base to rover communication, the GCX3 offers lightweight, compact and ergonomic benefits — along with centimeter-accurate positioning — now with expanded satellite tracking capabilities.

    “The GCX3 features the new second generation POST2 integrated antenna – adding BeiDou, Galileo, SBAS, QZSS, and GAGAN satellite tracking in addition to GPS and GLONASS to provide users with the best positioning availability,” said Jason Tuck, branch manager at Topcon Solutions. “With TerraGo Magic, users can build their fully customized apps, tailored for their specific industry requirements and capture high-precision data in real-time from the receiver.”

    “TerraGo Magic custom apps combined with the Sokkia GCX3 receiver is a superior solution for our partners and customers in utility, energy and other industries that require high-accuracy data collection,” said John Timar, vice president of worldwide sales at TerraGo. “Our integration makes it possible to capture the full fidelity and GPS data record with a user experience and modern mobile features unmatched by legacy GPS data collectors.”

  • GeoCue’s GNSS kit for drones provides survey-level accuracy

    GeoCue’s GNSS kit for drones provides survey-level accuracy

    GeoCue Group has released a GNSS positioning system that will allow users of DJI Phantom 4 Pros and Inspire 2 drones, as well as most drones using higher end cameras, to achieve survey-level accuracy with minimum ground control.

    Loki, GeoCue’s new direct geopositioning system for small unmanned aerial systems, solves the two fundamental problems associated with this technology:

    • Positioning Accuracy. Loki uses the new AsteRx-m2 multi-frequency, multi-constellation GNSS engine from Septentrio, which has 448 hardware channels.
    • Camera Events. GeoCue has invented a patent-pending method of detecting camera events from Phantoms/Inspires and synchronizing those events to GNSS positioning. No modifications to the drone are necessary; the adapter cable is “plug and play.”
    GeoCue’s Loki positioning kit uses the Septentrio AsteRx-m2 GNSS engine.

    Loki is a self-contained kit that provides all of the hardware and software needed to equip a drone with a post-processed kinematic (PPK) multifrequency, multi-constellation, differential, carrier-phase GNSS.

    Using a local base station (not included), Loki provides centimeter-level positioning with minimal, and in some cases, no ground-control points (though GCPs are always recommended for quality assurance).

    “GeoCue has been a long-time Septentrio OEM development partner,” said Neil Vancans, vice president of Septentrio Americas. “They have offered our previous generation sUAS board on their high-end AV-900, achieving remarkable results in both accuracy and reliability. By solving the problem of connecting the virtual camera trigger on DJI drones to our AsteRx-m2 GNSS engine, they can achieve professional mapping accuracies with consumer-grade UAVs.”

    DroneDeploy of San Francisco has become a leader in cloud-based processing for DJI, as well as other drones. DroneDeploy has enabled users of Phantom and Inspire drones to easily upload drone images, work online with analytics, and download point clouds and orthophotos to desktops for advanced processing.

    Without Loki, achieving acceptable network accuracy requires the time-consuming placement of ground-control targets throughout the mapping site.

    GeoCue and DroneDeploy have been working together to ensure a smooth Loki-DroneDeploy workflow from field to finish.

    “The GeoCue Loki system is an exciting product for anyone using drones to make maps with high accuracy,” said Mike Winn, CEO and co-founder of DroneDeploy. “The Loki’s combination of high-end GNSS positioning and DJI camera synchronization enables survey-grade accuracy with the simplest workflow that we’ve seen — making the Loki a great fit for the DroneDeploy platform.”

    “I am very excited to be working with industry leaders such as DroneDeploy on our Loki project,” said Lewis Graham, president and CTO of GeoCue Group. “Loki provides high accuracy positional data to downstream processing solutions. More significantly, it does this for DJI Phantom 4 Pro and Inspire 2 drones. Combining DJI, Loki and cloud processing solutions such as DroneDeploy provides a very streamlined and cost effective solution for high accuracy site surveys.”

    The Loki kit includes:

    • Loki PPK Controller using the Septentrio AsteRx-m2 GNSS engine (GPS L1, L2, L5 and GLONASS L1, L2, L3, 448 hardware channels).
    • Maxtena M1227HCT-A2-SMA high performance, active, multiband GNSS antenna
    • Antenna ground plane with mounting kit
    • Antenna to controller cable
    • USB cable for data transfer and Loki controller charging
    • Personality cable (user selects either DJI or DSLR)
    • AirGon ASP software suite
    • Mounting kits for DJI Inspire 2 and Phantom 4 Pro
    • 1 year of maintenance and technical support

    Loki requires a local multifrequency base station (not included but available from GeoCue). Loki is shipping to early adopter customers in August 2017. It will be available for the general market in September 2017.

    It will release with direct support for DroneDeploy and AirGon’s Bring Your Own Drone (BYOD) Mapping Kit. Loki’s introductory price will be USD $4,995. GeoCue is currently accepting preorders.

    Loki will be on display September 6-8 at the InterDrone 2017 conference in Las Vegas and at Commercial UAV Expo, also in Las Vegas, October 24-26. A workshop dedicated to high accuracy mapping with DJI drones using Loki is being held in conjunction with the Commercial UAV Expo. Register at www.expouav.com.

  • System of Systems: First GPS/Galileo receiver flown in space

    System of Systems: First GPS/Galileo receiver flown in space

    By Werner Enderle and James J. Miller

    The European Space Agency (ESA) and the U.S. National Aeronautics and Space Administration (NASA) are conducting a joint GPS/Galileo space receiver experiment onboard the International Space Station (ISS). This will be the first time that a combined GPS/Galileo receiver will operate in space.

    The project aims to demonstrate the robustness of a combined GPS/Galileo waveform uploaded to NfASA hardware already operating in the challenging space environment: the Space Communications and Navigation (SCaN) software-defined radio testbed.

    Testing activities include analysis of the GPS/Galileo signal and onboard position/velocity/time (PVT) performance; processing of code- and carrier-phase GPS/Galileo raw data for precise orbit determination (POD); and validating the added value of a space-borne dual-GNSS receiver compared to a single-system receiver under the same conditions.

    This collaboration was initiated in 2014 and a Technical Understanding was signed in 2016.

    Many new space applications may not be possible if constrained to using the limited signal availability associated with any single constellation of GNSS satellites.

    This research therefore seeks to demonstrate the enhanced capabilities brought by the use of satellites from two or more GNSS constellations in the space domain. The net result will be more resilient space operations, greater mission flexibility, and enhanced PVT performance.

    The project is currently in the testing and verification phase, and it is expected that the final implementation of the combined GPS/Galileo waveform on NASA’s SCaN Testbed on-board the ISS will be completed in September/October 2017, so that the initial operations of the first combined GPS/Galileo receiver in space can start in the October/November 2017 timeframe.

    The researchers plan to present preliminary results at the UN International Committee on GNSS (ICG)-12 in Kyoto, Japan in December.

    From ESA’s side, ESOC’s Navigation Support Office (NavSO) and ESTEC Experts for Radio Navigation Systems and Techniques (TEC-ESN) are involved in this project.

    The overall project management from ESA’s side and POD aspects are covered by NavSO, and ESTEC’s Technical Directorate is in charge of the Galileo waveform development and implementation of the SW on the FPGA in cooperation with NASA. This activity is done with technical support from industry participants such as Qascom. Industry participation is a vital component as new markets for multi-GNSS receivers and complex space applications continue to emerge.

    From NASA’s side, the project is sponsored by the Space Communications and Navigation (SCaN) Program within the Human Exploration and Operations Mission Directorate (HEOMD) at NASA Headquarters in Washington D.C. Integration and experimentation activities are being performed by the NASA Glenn Research Center.

    NASA has initiated an international effort within the ICG to develop a fully interoperable multi-GNSS Space Service Volume (SSV), where a combination of constellation services will be available well above low-Earth orbit (LEO) to support newly emerging geostationary Earth orbit (GEO) and high-Earth orbit (HEO) missions — ranging from more precise station keeping to extend GEO belt capacity and maneuver recovery to enabling formation flyers and satellite servicing operations.

    WERNER ENDERLE is head of Navigation Office, Ground Systems Engineering Department at the European Space Operations Centre of the European Space Agency.

    JAMES J. MILLER is deputy director, Policy & Strategic Communications – Space Communications and Navigation in the Human Exploration and Operations Mission Directorate at NASA headquarters.

    Anomalous GPS Signals from SVN49

    By Fabio Dovis, Nicola Linty, Mattia Berardo, Calogero Cristodaro, Alex Minetto, Lam Nguyen Hong, Marco Pini, Gianluca Falco, Emanuela Falletti, Davide Margaria, Gianluca Marucco, Beatrice Motella, Mario Nicola and Micaela Troglia Gamba

    Researchers at the Navigation Signal Analysis and Simulation (NavSAS) Group of the Politecnico di Torino detected in mid-May the presence of anomalous spikes in the L1 signal spectrum. The origin of the spikes was identified to be transmission of a non-standard code from a non-operational GPS satellite (GPS IIF-9, SVN49). Here we report on signal observations and address possible impacts on GNSS signal processing.

    On May 17, 2017, during outdoor data collection, NavSAS researchers detected two spikes in the L1 spectrum, with sufficient power to be clearly visible on a display processing raw digital samples at the receiver’s intermediate frequency.

    An initial check looked for a possible interfering source in the experimental set-up, since it was quite complex with multiple pieces of electronic equipment. The likelihood of this source was soon dispelled as the same kind of spectrum was visible on a spectrum analyzer (SA) connected to an active survey-grade GNSS antenna on the lab roof; results shown in FIGURE 1.

    The spectrum is centered at 1575.42 MHz, with the SA set to a frequency span of 5 MHz. Connecting the SA to different survey-grade antennas on the roof, we found no remarkable differences. The spikes continued to appear on subsequent days, becoming clearly visible around 13:00 UTC and disappearing around 19:00 UTC.

    Figure 1. L1 Spectrum of the received signal at 16:51 (Central European Summer Time; 14:51 UTC) on May 19, 2017, at the NavSAS Lab, Torino (located at 45°03’54.98767″ N, 7°39’32.28920″ E, 311.9667 meters).

    Exclusion of Terrestrial Sources. The 24-hour repetition period of the phenomenon, along with the shape of the spectrum, could indicate the presence of a signal anomaly from a GNSS satellite. In a battery of tests, we probed the L1 spectrum in a wider area using assorted equipment.

    (For more details and figures, see the full version of this article.)

    For various reasons, we ended up focusing on a non-operational satellite: SVN49, launched March 24, 2009. We concluded that transmission of a non-standard code (NSC) from this satellite was the origin of the problem in the L1 spectrum.

    Transmission of NSCs for testing purposes is foreseen in the GPS Interface Specification, IS-GPS-200. GPS satellites can switch off regular broadcasts of C/A code and P/Y code and transmit a non-standard C/A code and non-standard Y code.

    Such operation is intended to protect users from receiving and utilizing erroneous satellite signals in case of unhealthy conditions on the spacecraft. Strictly speaking, this case cannot be formally considered as an “anomaly,” because the transmission of non-standard codes is documented in the IS-GPS-200.

    Therefore, the transmission of an NSC can be considered a normal operation in itself, though it may reflect a problem with the transmitting satellite.

    In this case the choice of the spreading sequence, which is likely a square wave, allowed the total power of the signal to be concentrated in just a few spectral components, thus originating continuous-wave-like in-band signals.

    The distribution of the harmonics, the main components of which are at ±500 kHz, and the presence of the odd harmonics only, matches an earlier case in 2006 of a transmission of an NSC modulated as a binary-phase-shift-keying (BPSK) sequence with alternating logical 0s and 1s, transmitted at the C/A code chipping rate (Rc=1.023 megachips per second). The hypothesis of the BPSK with Rc=1.023 megachips per second spreading signal has been verified by simulation.

    However, the NSC is designed to have negligible effect on tracking other healthy GPS satellite signals. Nonetheless, an NSC transmission can have a non-negligible impact in performance of user equipment.

    When a GPS satellite is switched to NSC mode, a receiver immediately loses its capability to track that satellite signal. This is not the case with SVN49, as it is currently declared non-operational. However, due to the modified code sequence, a further effect is possible: the NSC introduces irregular components at a sustained level in the GPS signal spectrum.

    According to Notice Advisory to Navstar Users (NANU) 2017001, SVN49 was broadcasting standard signals as PRN04 (though set unhealthy) since the beginning of the year; NANU 2017042 announced that PRN04 was to be re-allocated to SVN38 on May 18.

    This switch matches the dates when we started to see the spikes, since, probably, SVN49 started that day to use the “square wave” for the spreading.

    Implementing the square wave local code, it has been possible to successfully acquire and track the NSC.
    The real-time software receiver N-Gene has been forced to acquire and track in real time the signal coming from SVN49. The receiver decoded the navigation message transmitted by SVN49, which exhibits a regular format, even if marked with an unhealthy flag.

    Impact on Receiver Processing. Interference with harmonic components such as those generated by the use of a square wave could strongly impact a GNSS receiver in the acquisition and tracking blocks, because the interference power is dispersed over the whole search space by the correlation with the local code, compromising the acquisition accuracy and impacting other functional blocks.

    The impact of interference spectral lines depends on their location within the frequency band. This is due to the almost periodic nature of the GNSS signals. The spectrum of a GNSS signal has components spaced at multiples of the inverse of the code period (for example, 1 kHz for GPS C/A code) with different power allocated to each component depending on the shape of the code spectrum.

    The effect is larger in the case of matching of the interference spectral components with the ones of the GNSS signal. Furthermore, in this case, the strongest harmonics are close to the L1 carrier frequency and are not mitigated by the front-end filter since they fall within its narrow bandwidth.

    The overall GNSS scenario has changed a lot recently. Galileo and BeiDou are also present, and Galileo signals, due to the different structure and code periods, have spectral lines spaced at 0.25 kHz. The frequency modulation of the interfering signal due to the variable Doppler shift is thus even more likely to hit some of the spectral components of these signals.

    We are investigating further to assess the impact of the interfering signal from SVN49 on Galileo-based high accuracy applications.

    U.S. Air Force Response

    The 2nd Space Operations Squadron is performing maintenance on a presently non-operational satellite. SVN49 is broadcasting non-standard C/A and non-standard Y codes as described in IS-GPS-200. Space professionals continue to conduct safe and responsible command and control of the constellation to continue to provide accuracy that exceeds established system requirements.

    As always, GPS users who experience issues should address them through the appropriate channels: military users should contact DSN 560-2541, commercial 719-567-2541 while civilian users should contact the U.S. Coast Guard Navigation Center at 703-313-5900.

    Very Respectfully,

    Nicholas J. Mercurio, Capt., USAF
    Director, 14th Air Force/JFCC SPACE Public Affairs

  • NovAtel’s OEM7 7.03.00 firmware offers new and enhanced features

    NovAtel’s OEM7 7.03.00 firmware offers new and enhanced features

    NovAtel’s OEM7 v7.03.00 firmware is now available on all OEM7 receivers. The OEM7700, OEM719 and OEM729 can be updated to the 7.03.00 firmware, which supports new features like the SPAN Land Vehicle technology, direct inertial measurement unit (IMU) connections and tracking of the NavIC Indian regional satellite system on the L5 frequency.

    The SPAN Land Vehicle feature provides performance benefits specifically for extended loss of GPS signals, robust alignment routines and improved attitude performance for fixed-wheel land vehicle applications. During extended periods of GNSS outage, typically in low-dynamic operating environments or in dense urban canyons, the SPAN Land Vehicle feature optimizes integrated GNSS+INS performance to maintain accurate position, velocity and attitude.

    To achieve this, NovAtel uses intelligent vehicle dynamics modeling and its patented Antenna Phase Windup Technology. Intelligent vehicle modeling identifies IMU errors in the integrated GNSS+INS system that accumulate after extended GNSS outages and reduces the impact of those errors within the SPAN solution.

    NovAtel’s Antenna Phase Windup technology is used to sense changes in direction and, when combined with intelligent vehicle modeling, corrects for IMU errors in attitude (roll, pitch, yaw).
    Users can now connect SPAN enabled OEM7 receivers directly to the ADIS-16488 and Epson G320N IMUs using an SPI interface, and to the STIM300 IMU using RS422, without the need for an interface card.

    OEM7 receivers with NavIC L5 frequency tracking enabled will be able to access the test signals of the Indian Regional Navigation Satellite System (IRNSS) before it becomes operational (targeted for early 2018).

  • SXblue introduces Platinum survey-grade GNSS receiver

    SXblue introduces Platinum survey-grade GNSS receiver

    Geneq has introduced the SXblue Platinum, the latest model in the SXblue series. This high-accuracy GNSS receiver is compatible with iOS, Windows and Android Bluetooth, and provides real-time professional-grade positioning information.

    Powered by 394 channels, the SXblue Platinum uses all constellations (GPS, GLONASS, Galileo, BeiDou and QZSS) with triple frequency, and provides the ability to use global or local coverage for corrections (SBAS, L-band and RTK).

    With the scalable SXblue Platinum Basic, users can activate any frequency or constellation at anytime following initial purchase. The receiver is also field-upgradable, which means that these options can be remotely activated when convenient.

    The Platinum was developed on the success of the proven SXblue receivers that were designed to optimize SBAS performances under tree canopy and in rugged terrain. In addition to location performances when working in a restricted environment, the SXblue Platinum is introducing an L-band signal correction via the Atlas service. This worldwide satellite-based correction system can deliver up to sub-decimeter accuracy. Thanks to its new Tracer technology, the receiver can sustain its level of accuracy when the Atlas signal is interrupted. The Atlas service can also stream data over the internet (NTRIP) while ensuring the best available vertical and horizontal accuracy.

    Another innovative feature integrated on the Platinum model is the aRTK technology. This feature will allow RTK corrections to be received via the Atlas service, when RTK corrections have not been received for a period of time. For an Atlas-subscribed user device, a high accuracy will still be available at the subscribed service level until RTK is restored.

    The new receiver is the same compact, lightweight, palm-sized unit as the SXblue series, which is completely dustproof and ruggedized. The internal, rechargeable, field-replaceable Li-Ion battery has on-board LEDs for easy access to battery life information.

    The SXblue Platinum is targeted at GPS/GIS mapping and survey professionals in industries such as forestry, utilities, agriculture, environmental and other natural resource industries in addition to local, state and federal government users.

    With a wide variety of compatible software and mobile devices, the support team can help users choose the perfect solution for their applications. A free iOS application for NTRIP/DIP configuration, named iSXblue RTN, is available from the App Store.

  • Trimble unveils Catalyst receiver at Esri UC

    The Trimble Catalyst software-defined GNSS receiver for Android devices is now available through Trimble’s global distribution network. Trimble’s Gareth Gibson gives an overview of its features at the 2017 Esri User Conference, which took place July 10-14 in San Diego, California.

  • New Spectra Precision GNSS receiver gives surveyors flexibility

    New Spectra Precision GNSS receiver gives surveyors flexibility

    Spectra Precision has introduced its new SP90m multi-frequency and multi-application GNSS receiver.

    Spectra Precision’s SP90m GNSS receiver.

    The Spectra Precision SP90m is a powerful, highly versatile, ultra-rugged and reliable GNSS positioning solution for a wide variety of real-time and post-processing applications. It features integrated communications options such as Bluetooth, Wi-Fi, UHF radio and cellular modem as well as two MSS L-band channels to receive Trimble RTX correction services.

    With a modular form factor, the SP90m is flexible and can be used as a base station, campaign receiver, continuously operating reference station (CORS), real-time kinematic (RTK) or Trimble RTX rover, or integrated on-board a machine.

    The patented Z-Blade GNSS-centric technology uses all available GNSS signals to deliver fast and reliable positions in real-time. The SP90m GNSS receiver also allows the connection of two GNSS antennas for precise heading or relative positioning determination without a secondary GNSS receiver.

    The SP90m’s unique design enables a broad range of mounting capabilities. In addition to the wide range of built-in communication options, the SP90m features an internal removable battery, internal memory, optional accessory kits for specific applications.

    The receiver is also compatible with a variety of software solutions such as Spectra Precision Survey Pro. The weatherproof, high-impact-resistant molded aluminum housing ensures the user’s investment is safe in extreme field conditions, which is important for campaign or base-station applications.

    “With the addition of the SP90m receiver to its portfolio, Spectra Precision has introduced a new generation of ultra-rugged, compact and feature rich GNSS solution to the surveying market,” said Olivier Casabianca, general manager of Trimble’s Spectra Precision Division. “This highly flexible receiver can be used where a typical integrated receiver on a range pole is not optimal and other configurations may be required. It is an ideal solution for geospatial professionals looking for a single receiver that can be used for multiple applications.”

    The Spectra Precision SP90m receiver is available now through the Spectra Precision global dealer network. For more information, visit www.spectraprecision.com or email: [email protected].

  • Oscilloquartz unveils dual-antenna GNSS SyncReach for small cells

    Oscilloquartz has launched the OSA 5405 SyncReach, an integrated PTP grandmaster and GNSS receiver with a patent-pending dual antenna and receiver to enable the mass roll out of small cells.

    The new technology has been specifically engineered to provide accurate and affordable phase synchronization for the rapidly growing small-cell market and meet the stringent timing requirements of 4.5G and 5G connectivity.

    With the OSA 5405, operators can migrate from legacy GNSS RF antennas and cables to standard, cost-effective copper and fiber Ethernet cabling, reducing capital expenditure and operating expenses, Oscilloquartz said.

    Available in both indoor and outdoor variants, the OSA 5405 can be deployed in challenging environments, including urban canyons where GPS signals fail. The OSA 5405’s miniscule form factor also enables it to be positioned on indoor windows to avoid multipath signal interference from objects within the building.

    The OSA 5405 uses a unique dual GNSS antenna and receiver algorithm to mitigate interference from multipath signals that can affect accuracy, particularly in urban canyons, according to the company.

    “We’re at the start of a new era. With the internet of things (IoT) connecting more wireless devices and 5G just around the corner, small cells will have a big role to play,” said Gil Biran, general manager at Oscilloquartz. “This market is set to grow exponentially in the next few years. Small cells will soon be everywhere and that makes precise synchronization essential. Operators urgently need a way to reliably and affordably deliver new levels of phase accuracy.

    “We’ve created our OSA 5405 to effectively deliver small cell synchronization in any environment and eliminate all restrictions,” Biran said. “Our new technology radically simplifies GNSS antenna installation. The use of PTP removes the need to compensate for cable delay and extends the reach of GNSS. It enables operators to forget about archaic and expensive RF cables and use simple copper cabling or optical fiber for longer distances. And, with variants that can be positioned in almost any location, it provides strictly accurate timing precisely where it’s needed.”

    The compact design and power-over-Ethernet capabilities of the indoor- or outdoor-mounted OSA 5405 enable synchronization at the edge of the mobile network. This creates dramatic reductions in complexity and power requirements as well as lower costs for installation and operation.

    Another feature of the new technology is IP connectivity, so that synchronization becomes another element of the internet of things.

    The OSA 5405’s highly precise GNSS-sourced synchronization is supported by network-based Sync-E and PTP backups. In high-rise buildings it can also deliver synchronization recovered from the GNSS smart receiver over optical fiber.

    The ADVA FSP Network Manager with comprehensive Syncjack assurance guarantees efficient operation.

    “Make no mistake; the launch of our OSA 5405 is a major milestone in the progress towards mass-scale small cell deployment,” said Nir Laufer, product line director at Oscilloquartz. “With its plug-and-play simplicity, miniscule form factor and multiple timing functions in a single device, this is a key technology for 5G networks and the IoT.

    “Currently deployed in trials with major carriers, it will shortly be available to all operators looking to harness next-generation synchronization precisely where it’s needed,” Laufer said.

  • Rockwell Collins and QinetiQ join on next-generation GNSS receivers

    Rockwell Collins and QinetiQ have signed a global alliance agreement to collaborate on the development of next-generation, multi-constellation open-service and secure GNSS receivers.

    The effort will support the mission needs of military, government and critical national infrastructure.

    The family of receivers being developed will provide military, government and professional users the flexibility of selecting relevant GNSS capability to meet operational, geographical or budgetary needs and provide GNSS accuracy and timing.

    This will improve safety, increase mission effectiveness and reduce operational costs for ground troops, vehicles and high-dynamics GNSS-guided weapons, Rockwell Collins said.

    Rockwell Collins is major contractor for secure military GPS receivers and QinetiQ is an expert in the field of open-service solutions with access to critical satellite navigation system technologies that enable the development of multi-constellation solutions.

    “This alliance agreement with QinetiQ is a great opportunity to bring together our strengths,” said Colin Mahoney, senior vice president of international and service solutions for Rockwell Collins. “Working together, our customers will experience unprecedented levels of availability, accuracy and assurance of positioning, navigation and timing for conducting their missions.”

    “As we move into the era of multi-constellation satellite receivers, this market-leading agreement and the investments of both companies sends a clear message to our customers and shareholders that QinetiQ and Rockwell Collins are taking every step necessary to stay at the forefront of GNSS technical development and product delivery,” said Steve Wadey, CEO of QinetiQ. “The development will be centered in Europe, led from the U.K., supporting the global market.”

  • Satlab announces SLX-1 multi-application receiver mobile upgrade

    Satlab announces SLX-1 multi-application receiver mobile upgrade

    Swedish-based survey and GIS equipment maker Satlab Geosolutions has upgraded its multi-purpose multi-frequency GNSS receiver.

    SLX-1 receiver by Satlab.

    The SLX-1 was initially released as a CORS receiver but is now able to function as a mobile sensor suitable for any application where a rugged multi-application GNSS receiver is required.

    Based on embedded Linux operating system, the SLX-1 is a true multi-user and multi-tasking solution. The CORS design is ideal for long unattended and continuous operation and its mil-spec construction makes it ideal for mobile operations in the most rugged environments.

    The receiver tracks GPS, GLONASS, BDS, GALILEO, QZSS and SBAS constellations and can maximize the tracking to observe all visible GNSS satellite signals, thereby providing maximum performance for accuracy.

    With in-built Ethernet, 3.5G wireless, WiFi, Bluetooth and multiple serial communications for data transmission and/or reception, as well as a 64GB (expandable) internal memory, the receiver can simultaneously transmit/receive corrections while recording raw data in multiple sessions.

    The SLX-1 supports real-time TCP/IP, Satlab internet RTK and NTRIP in both server and client modes, as well as external radio Tx/Rx, making it compatible with most modern GNSS receivers on the market.

    With high performance precision GNSS measurement techniques, direct-millimeter accuracy with the highest levels of quality assurance is obtained. CMR, CMR+, sCMRx, RTCM2.x, RTCM3.x, RTCM32 and Binex differential formats, as well as Rinex and Raw data logging/output, are all supported so the receiver can be easily integrated into existing CORS networks, SatLab’s VRS NRTIP Caster Software or SatLab’s proprietary intRTK Cloud service. Equally, in Rover mode, it can easily connect any existing correction network or single-base source using any of its inbuilt communication modes.

    Control of the receiver is easily achieved by logging into the internal Web server either remotely or direct connection using Ethernet port or the inbuilt Wi-Fi hotspot. In Rover mode, real-time NMEA messages can be sent via any of two RS232 or single RS485 ports or via Bluetooth. It also has an external clock interface, event marker and PPS output.

    With a rugged anodized aluminum alloy metal case, internal lithium battery for up to 24 hours independent operation, two lane external voltage inputs with range 7-36VDC and PoE, the SLX-1 is designed to stay on regardless of environmental factors. If power is lost, once restored the receiver will reboot using the last settings and continue working normally.

    “This is an exciting upgrade to our popular SLX-1 CORS receiver, and now adds true multi-functional performance for both base and mobile operations to our increasing range of GNSS mobile products,” said Bjorn Agardh, CEO of Satlab. “The simplicity yet sophisticated capabilities of the SLX-1 combined with our free internet RTK global server services makes provision of correction data seamless and simple.”

    The mobile upgrade for the SLX-1 receiver is available now with a simple firmware upgrade that is available for free download and continues the promise that, there are no hidden costs of ownership with any Satlab product.

  • Telit introduces ultra-slim, smart antenna GNSS location module

    Telit introduces ultra-slim, smart antenna GNSS location module

    Telit has introduced an ultra-slim family of smart antenna GNSS receiver modules. The fully integrated modules include a comprehensive feature set that eliminates the need for additional components. They are designed for Internet of Things (IoT) projects with size, cost and time constraints.

    Easing the burden for developers with little or no RF design experience, the SL876Q5-A is compliant with regulatory and industry standards specifications. The module combines an omni-directional low profile embedded antenna and an internal RF switch. This combination is suitable for applications needing two antennas, such as personal trackers and alarms, which must be equipped with a main and a backup antenna when the signal becomes compromised.

    SL876Q5-A_TelitA turnkey solution, the SL876Q5-A includes features such as an additional low noise amplifier (LNA), surface acoustic wave filter and efficient power management technology in an ultra-slim leadless chip carrier (LCC) package.

    The inclusion of several low-power modes reduces total power consumption while maintaining position accuracy, which extends battery life — a critical requirement for wearables, personal trackers, and other battery-dependent applications.

    “The SL876Q5-A delivers on everything our customers and partners have come to expect from the industry’s leading IoT solutions provider,” said Ronen Ben-Hamou, Telit’s EVP of products and solutions. “IoT developers continuously search for solutions that simplify the design process. We’ve developed a compact solution with features that deliver industry-leading performance without compromising performance. Not only does the SL876Q5-A eliminate the need for additional components in most use cases, but also cuts development time and costs considerably.”

    SL876Q5-A Features

    • Full GNSS for exceptional coverage:

    Quad-GNSS: GPS/ QZSS and GLONASS or BeiDou and it is Galileo ready

    A-GNSS: Onboard generation and server-generated file injection that can be stored into the embedded flash memory

    • Omni-directional antenna design delivers high performance in sensitivity, tracking performance and accuracy
    • MEMS wakeup feature offers lowest power consumption
    • Built-in LNA for improved sensitivity
    • Primary port: UART, I2C, or SPI. Secondary port: UART or I2C, I2C supports MEMS wakeup only
    • Embedded RF switch allows easy integration with external antennas
    • Ultra-slim design, 11 x 11.9 x 2.3 mm LCC package for space constrained devices
    • Flash memory enables firmware upgrades, customization, and AGPS file storage, which is ideal for battery-dependent devices

    Availability begins in the second quarter of 2017. Learn more about the new SL876Q5-A slim antenna module.