PTTI Sessions

PTTI Pre-Conference Tutorials
The following pre-conference tutorials will be offered on January 29:

• GNSS Clocks: History, Present and Future
• Clock Measurements and Statistics
• Timescale and GNSS Reference Time
• GNSS Time Transfer/Code and Carrier Phase
• Clocks in Geodesy/Navigation Solutions and Applications
• Time Dissemination and Applications with NTP/PTP

Advances in Computer Time Transfer: NTP, PTP, and Related Systems
The two primary protocols used to deliver accurate time stamps to computer systems, the Network Time Protocol (NTP) and the Precision Time Protocol (PTP), also known as IEEE- 1588. Topics include NTP and PTP time transfer over both wide and local area networks, and the measurement and evaluation of servers, clients, and networks. Other computer time transfer systems including Synchronous Ethernet (SyncE), White Rabbit, and proprietary and proposed systems will also be explored.
Co-chairs:
Jeff Prillaman, U.S. Naval Observatory,
Jian Yao, NIST,

Advances in Geostationary Satellite Time and Frequency Transfer
Time transfer via geostationary satellites, including the Two-Way Satellite Time and Frequency Transfer (TWSTFT) method utilized for contributions to TAI and UTC. Also included are one-way transmissions and time code services from communications satellites used for television, radio, and meteorological applications.
Co-chairs:
Dr. Stefania Romisch, NIST
Russell Bumgarner, U.S. Naval Observatory

Advances in GNSS Time Transfer
Advances in GNSS time transfer, in particular time transfer with GPS, Galileo, GLONASS, and BeiDou, as well as the various augmentation systems. Measurements techniques (P3, PPP, IPPP, etc.), advances in receivers and antennas, system interoperability and multi-GNSS time transfer, and the results of time transfer campaigns and intercomparisons.
Co-chairs:
Ed Powers, U.S. Naval Observatory
Lisa Perdue, Spectracom

Advances in Optical Time Transfer (free-space and fiber based)
Time transfer over dedicated optical fibers typically produces lower uncertainties than time transfer via satellites, and as such has become a preferred method for comparing optical clocks and the best microwave clocks. This session is devoted to optical time transfer techniques, and results obtained over short, medium, and long distances. Additional topics include free space optical links for time transfer.
Co-chairs:
Dr. Sven-Christian Ebenhag , SP Technical Research Institute of Sweden
Dr. Michael Dennis, Johns Hopkins University/APL

Advances in PTTI Measurement Techniques
Advances in measurement techniques and metrics used in PTTI applications. Methods for calibrating cables, fibers, receivers, antennas, and other hardware utilized in time transfer systems; systems and techniques for the measurement of PM/AM noise; and measurement methods for clock characterization (including statistics for stability analysis and forecasting clock drift/aging), and new advances in measurement instrumentation.
Co-chairs:
Craig Nelson, NIST
Nathan Martina, U.S. Naval Observatory

Advances in Time Transfer via Radio Signals
Time transfer methods based on signals that originate from ground based radio transmitters. Time transfer via LF radio signals including eLORAN, MF/HF comm channels, existing system-radio signals, and line of sight signals (FM radio, VHF, UHF, microwave).
Co-chairs:
Lin Haas, BAE Systems
Dr. Eric Adles, Johns Hopkins University/APL

Advances in Ultrastable Microwave and Optical Clocks
New advances in clocks for PTTI applications. The primary focus is on atomic clock design and current and expected future performance for high-end laboratory based clocks. High-end microwave clocks as well as optical clocks.
Co-chairs:
Dr. Jeff Sherman, NIST
Dr. James Camparo, The Aerospace Corporation

Environmental Effects on Portable Clocks
Environmental effects in small, portable clocks. Emphasis will be on environmental characterization of clocks as well as techniques to mitigate degradation of clock performance due to the environment. Additionally, there is interest in advances on portable clocks designed for extreme environments.
Co-chairs:
Dr. Daphna Enzer, Jet Propulsion Laboratory
Bryan Owings, Microsemi

Next Generation PTTI Applications
New and developing PTTI applications. New applications that rely on precise time as well as new techniques for precise time generation or dissemination.
Co-chairs:
Greg Weaver, John Hopkins University/APL
Edoardo Detoma, (Retired), Italy

The Role of PTTI in Electric Power Distribution
The implementation of the “smart grid,” or an electric power distribution system that can automatically detect and react to local changes in electricity usage, is one of the largest critical infrastructure PTTI applications. This session focuses on the role of PTTI in the smart-grid, including the design, use, and calibration of phasor measurement units (PMUs).
Co-chairs:
Blair Fonville, U.S. Naval Observatory
Peter Cash, Microsemi

The Role of PTTI in Improving GNSS Invulnerability, Reliability, and Performance
Techniques and methodologies for improving GNSS invulnerability, reliability, and performance for PTTI applications, in particular ways to “protect, toughen, and augment” GNSS time. Methods to prevent or mitigate intentional and unintentional RF interference (jamming), the transmission of false information (spoofing), multipath signal reflections, and GNSS broadcast errors, such as those that occurred with GPS in January 2016. Also included, methods for satellite clocks to autonomously assess the quality of their timekeeping.
Co-chairs:
Dr. Christine Hackman, U.S. Naval Observatory
Dr. Erin Griggs, Space Sciences and Engineering

The Role of PTTI in Telecommunications
The role of PTTI in the design and implementation of mobile telephone networks (CDMA, GSM, etc.), messaging systems, Wi-Fi and WiMAX, and other types of wired and wireless networks used for communications.
Co-chairs:
Lee Cosart, Microsemi
Jay Hanssen, U.S. Naval Observatory

The Role of PTTI in the Financial Sector
Banks and financial markets rely on accurate time information to guard against fraud and protect consumers. This has become more important in recent years due to the increased use of electronic trading platforms and high frequency trading (HFT). This session is devoted to the role of PTTI in the financial sector, including methods for insuring that high accuracy, traceable, and verifiable time stamps are available at wide spread locations.
Co-chairs:
Dr. Marina Gertsvolf, NRC, Canada
Michael Lombardi, NIST

Time Scales and Algorithms
The description and implementation of current and new time scales, including: time scales that include continuously running primary frequency standards, algorithms and methods that advance the state of the art in clock data analysis and their applications; the generation of UTC(k) and reference GNSS time scales with increasing performance; and the use of Kalman filters and other robust statistical techniques.
Co-chairs:
Dr. Elizabeth Laier English, National Physical Laboratory, UK
Ken Senior, Naval Research Laboratory

Timing Laboratory Activities and Updates
The opportunity for timing laboratories (including those operated by national metrology institutes, military, and academic organizations) to provide updates describing their current and future PTTI activities; including UTC(k) generation and performance, time dissemination, time services, calibrations, and related research activities.
Co-chairs:
Ronald Beard, Naval Research Laboratory
Dr. John Burke, Air Force Research Laboratory

ITM Peer Reviewed Sessions

Advanced Integrity for Autonomous Systems
New concepts in multi-constellation GNSS integrity and continuity monitoring at the user receiver and at the ground segment. Development of fault detection and exclusion algorithms, protection level derivation, and navigation requirement definition for RAIM and ARAIM. Integrity, continuity, and availability analysis considering satellite and constellation faults, interference and spoofing. Potential implications of future GNSS performance for automated navigation applications in aviation (manned or unmanned), automotive, rail, maritime and space transportation. Requirement definition for new Safety-of-Life applications. Integrity of multi-sensor systems and sensor fusion algorithms.
Co-chairs:
Dr. Okuary Osechas, German Aerospace Center (DLR), Germany
Dr. Mathieu Joerger, The University of Arizona

Algorithms for GNSS Processing and Sensor Integration
New signal processing techniques for GNSS receivers and other navigation devices to provide improved acquisition, robustness, accuracy, sensitivity, timeliness, or other benefits. Processing techniques that take advantage of multiple GNSS signals and new signal designs. Direct position estimation, vector tracking, batch processing or Bayesian techniques (particle filter) and processing techniques that take advantage of GNSS integration with other sensors at the signal processing level. Utilization of navigation data from out-of-band sources and use of high-rate, near-real-time data from scientific GNSS arrays, including the impact of new arrays. Compressing, prioritizing and scheduling network reference data through limited communication channels.
Co-chairs:
Dr. Andrey Soloviev, QuNav
Dr. Sherman Lo, Stanford University

Atmospheric Science and Space Applications
Effects of the troposphere and ionosphere on GNSS signals. Impacts of the atmosphere and of space weather on the operation of GNSS. New techniques and use of GNSS for atmosphere, ionosphere or space weather monitoring for operational systems. New ground-based GNSS experiments and networks. Monitoring of space and local weather for GNSS. Data assimilation methods and modeling of propagation and effects. Occultation of GNSS signals. 3-D tomographic reconstruction, Storm-Enhanced Densities (SEDs), Traveling Ionospheric Disturbances (TIDs), plasma bubbles, and scintillation. High, mid, and low-latitude phenomena. Events from and studies of the solar minimum. Case studies and multiyear statistical overviews, now-casting and forecasting space weather for aviation, marine, geodetic, and timing applications. Novel technologies to model and mitigate atmospheric errors.
Co-chairs:
Dr. Susumu Saito, ENRI, Japan
Dr. Rezy Pradipta, Boston College

Autonomous Navigation
Use of GNSS and alternative/complementary navigation technologies (sensors, signals of opportunity, vision, etc.) for autonomous air, land, marine, or space vehicles or systems. Innovative applications for unmanned autonomous systems and resulting navigation accuracy requirements. Algorithms for path planning, guidance, and control of autonomous vehicles. Techniques based on simultaneous location and mapping (SLAM) and its variants. Design of navigation algorithms and fusion architectures. Safety related aspects of autonomous vehicle operation.
Co-chairs:
Dr. Gert Trommer, Karlsruhe Institute of Technology, Germany
Dr. Zak Kassas, University of California, Riverside

GNSS Augmentation Systems
Augmentation of GNSS positioning to support users in aviation, maritime, rail, automotive and other applications. Developments in both GBAS and SBAS. Governmental SBAS augmentation systems such as WAAS, EGNOS, GAGAN, QZSS, and MSAS. Interoperability of SBAS systems with GBAS and/or on-board RAIM. Private global and regional augmentation systems. Augmentation system design, reference station equipment, user equipment and performance. Dissemination of integrity support information via high and low capacity data channels from SBAS and GBAS.
Co-chairs:
Jolana Dvorska, Honeywell International, Czech Republic
Santiago Perea Diaz, German Aerospace Center (DLR), Germany

GNSS in Challenging Environments
Operation of GNSS receivers in challenging environments like urban canyons, indoor and high-dynamics applications, etc. Effect and mitigation of signal degradation due to scintillation or foliage. Weak signal processing techniques and algorithms. Indoor positioning applications. Mitigation of multipath in indoor and urban environments. First-responder personal navigation and urban ground-vehicle navigation. Algorithms for providing robustness, test methods for characterizing performance and results of receiver testing.
Co-chairs:
Dr. Olivier Julien, ENAC, Franc
Dr. Mohamed Youssef, Sony North America

GNSS Remote Sensing
Techniques for remote sensing. GNSS Earth observation techniques. Radio occultation measurements of the troposphere and ionosphere. Reflectometry for environmental remote sensing of land, ocean and ice. Detection of natural hazards such as earthquakes, tsunamis, and volcano eruptions.
Co-chairs:
Dr. Seebany Datta-Barua, Illinois Institute of Technology
Dr. Attila Komjathy, NASA JPL

GNSS Resilience Technologies
Systems for providing navigation and/or timing capability when GNSS is not available. Redundant systems to GNSS where backups may be required, such as safety of life applications. Alternative and hybrid location methods suitable for consumer products. Positioning using Wi-Fi, cellular tower ranging, RFID, Bluetooth, Near Field Communication (NFC), HD Radio/Digital Audio Broadcasting (DAB), Digital TV and other signal of opportunity. Orientation and motion estimation from image/LiDAR/LaDAR sequences. Map/terrain/landmark matching techniques. Combinations of all the above methods with inertial sensor measurements. Other topics may include DME, LORAN, LDACS and other forms of APNT.
Co-chairs:
Dr. Chun Yang, Sigtem Technology, Inc.
Mitch Narins, Strategic Synergies

High Precision GNSS – PPP
New algorithms and methods for improving Precise Point Positioning (PPP) techniques. PPP with integer ambiguity resolution. Ambiguity resolution for GLONASS, Galileo and BeiDou. Methods and algorithms for reliable cycle-slip detection. Estimation of signal biases relevant for PPP, such as fractional phase biases or differential code biases. Novel numerical approaches and algorithms for PPP with multiple constellations. Preserving precision accuracy in challenged urban environments. Improving re-convergence after signal outages. Interoperability of correction services with different user equipment. Methods for precise prediction of satellite orbits and clocks.
Co-chairs:
Dr. Terry Moore, University of Nottingham, UK
Dr. Byungwoon Park, Sejong University, South Korea

High Precision GNSS – RTK
New algorithms and methods for improving Real Time Kinematic (RTK) techniques: multi-frequency, multi-constellation RTK; improved algorithms for ambiguity resolution; reliable ambiguity resolution over long baselines; network RTK; PPP-RTK in wide areas; heading and attitude determination using multiple antennas; low-cost single frequency RTK implementation; and carrier phase multipath mitigation.
Co-chairs:
Dr. Sunil Bisnath, York University, Canada
Dr. Xiaohong Zhang, Wuhan University, China

Interference Mitigation and Spectrum Management
Techniques for improving the robustness of GNSS receivers in the presence of jamming and/or spoofing. Techniques for geo-locating jammers and/or spoofers. Receiver-based anti-spoofing techniques and use of external infrastructure. Signal authentication techniques and related challenges. Effects of interference on GNSS RF bands. Theoretical and test results describing effects of GNSS interference on receiver performance. Compatibility of GNSS with terrestrial and satellite based services. Interoperability interference assessments among various GNSS systems and with non-GNSS systems. Receiver design trade-offs and approaches for interference environments. Spectrum management, policy and frequency protection issues and approaches.
Co-chairs:
Dr. Alex Stratton, Rockwell Collins
Dr. Jiwon Seo, Yonsei University, South Korea

Modernized and Emerging GNSS
New civil, military and governmental user capabilities and performance, including availability and accuracy improvement concepts of GPS, GLONASS, Galileo, BeiDou, QZSS and IRNSS. Open and authorized GNSS services, search and rescue services and commercial services. Optimization of GNSS signal structure, codes and data message. Concepts for interchangeability of GNSS constellations. Analysis of system performance, mutual interference, impact on noise floor. Tools for assessment of RF compatibility and GNSS signal simulators. Modernized constellations characteristics and programmatic aspects, ground control and monitoring segments. Performance analysis of new satellites. User equipment architecture and design. Integration with regional augmentation systems and use of those new systems to support future applications.
Co-chairs:
Dr. José Ángel Ávila-Rodríguez, ESA, The Netherlands
Ken Alexander, Federal Aviation Administration

Multi-Sensor Navigation
Fusion of data from multiple sensors. Algorithms, test methods, and results of implementations integrating diverse sensors. Coupling of GNSS with inertial sensors, odometers, radar, LiDAR, optical cameras, barometers, infrared or ultrasound sensors. Use of network connected devices for navigation; including smartphones, navigation apps, GNSS-based personal navigation systems with online maps, etc.
Co-chairs:
Dr. Allison Kealy, RMIT University, Australia
Dr. Juan Ignacio Giribet, University of Buenos Aires, Argentina

Next Generation Receiver and Antenna Technology
Advancements in GNSS receivers providing advantages in terms of performance, cost, and power consumption. Implementation and demonstration of advanced receiver hardware and flexible architectures as well as advances in software-defined GNSS receivers and processing methods. Multi-mode, multi-frequency receivers tracking new and/or modernized GNSS broadcasts. Advances in RF front-end electronics including multi-GNSS front-ends. Improved designs for GNSS antennas, arrays and antenna electronics with emphasis on size reductions, multi-frequency coverage, precision, multipath mitigation and interference suppression.
Co-chairs:
Dr. Jean-Marie Sleewaegen, Septentrio Satellite Navigation, Belgium
Dr. Pau Closas, Northeastern University

UAV Operation and Navigation Technology
UAS integration into non-segregated airspace. Detect and avoid systems. Algorithms and tools for path planning. Ground vehicle GN&C systems. New navigation and positioning techniques for UAV applications. Requirements for position, velocity and attitude information; map building for UAV operations.
Co-chairs:
Dr. Demoz Gebre-Egziabher, University of Minnesota
Dr. Robert Leishman, Air Force Institute of Technology