PTTI Sessions

PTTI Pre-Conference Tutorials
The following pre-conference tutorials will be offered on January 28:

• Introduction to Time and Frequency Statistics
• Atomic Clocks Overview
• Basics of GPS/GNSS
• Timescales and Timekeeping
• Time and Frequency Transfer Techniques

A PTTI 50TH ANNIVERSARY SPECIAL PRESENTATION
The Development of Coordinated Universal Time
Dr. Dennis D. McCarthy, U.S. Naval Observatory, Contractor

PTTI Poster Session
Open to all topics within the timing community. Attendees who have research to present who would rather not deliver an oral presentation are encouraged to submit a poster to this session.
Co-chairs:
Dr. Demetrios Matsakis, U.S. Naval Observatory
Dr. James Hanssen, U.S. Naval Observatory

Alternative Techniques in Time Dissemination
In recent years, recognition of the ubiquity and vulnerabilities of GNSS has given rise to alternative and novel methods for positioning, navigation, time dissemination and time transfer (PNT). As a result, alternative technologies to augment, or even replace GNSS, have received attention. This session focuses on alternative PNT with an emphasis on alternate technologies for time dissemination and time transfer.
Chair:
Dr. Kenneth Senior, U.S. Naval Research Laboratory

Fiber Link Time Transfer
Precise time, time interval and frequency transfer over optical fibers can produce superior uncertainties compared to alternative satellite-based methods. Fiber links used for comparing optical clocks and for disseminating accurate time. This session is devoted to fiber optic time and frequency transfer techniques based on dedicated fiber or shared telecommunication data channels and infrastructure.
Co-chairs:
Dr. Marina Gertsvolf, National Research Council of Canada, Canada
Dr. Paul-Eric Pottie, Observatoire de Paris, France

GNSS Time and Frequency Transfer
Continued development and deployment of GNSS constellations and satellites has expanded the opportunities and complexities of time transfer using GNSS. This session will focus on the advances in GNSS time transfer, using GPS, Galileo, GLONASS, and BeiDou, as well as augmentation systems. Topics may include: multi-GNSS approaches in both analysis techniques (P3, PPP, IPPP) and calibration, GNSS system timescales and system interoperability.
Co-chairs:
Dr. Pascale Defraigne, Observatoire Royal de Belgique, Belgium
Dr. Giancarlo Cerretto, Istituto Nazionale di Ricerca Metrologica, Italy

Ground Based Time and Frequency Transfer
This session focuses on time transfer that is not GNSS oriented. Potential topics include computer time transfer such as NTP, PTP, white rabbit, Sync-E, and related systems; geostationary satellite time and frequency transfer such as TWSTFT and passive TW time and frequency transfer; time transfer over dedicated links and/or free-space typically produces lower uncertainties than time transfer via satellites, and as such has become a desirable method for comparison.
Co-chairs:
Shinn-Yan (Calvin) Lin, Chunghwa Telecom, Taiwan
Dr. Daniele Rovera, Observatoire de Paris, France

Laboratory Reports and Activities
An opportunity for timing laboratories (including those operated by national metrology institutes, military, and/or 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:
Victor Zhang, National Institute of Standards and Technology
Stephen Mitchell, U.S. Naval Observatory

Next Generation Clocks
New advances and plans for clocks and clock measurement techniques with PTTI applications. The primary focus is atomic clock design and current and expected future performance for microwave and optical clocks in the areas of stability, operability, and robustness to environmental disturbances.
Co-chairs:
Dr. Scott Crane, U.S. Naval Research Laboratory
Dr. Daphna Enzer, Jet Propulsion Laboratory

PTTI Applications in Space
This session is devoted to all aspects of precise timekeeping in space. Suggested topics include: precise timekeeping for satellite communications, performance of clocks and frequency standards in the space environment, precise time in GNSS, and precision timekeeping for space physics and astrophysics. Other PTTI applications are certainly welcome, though the connection to PTTI in space must be clear.
Co-chairs:
Dr. James Camparo, The Aerospace Corporation
James Hagerman, Lockheed Martin Space

Space and Terrestrial Clocks
Precision clocks are critical in many applications such as navigation, precision timing, scientific measurements, geological mapping, and communication. Recently newer generations of atomic clocks are making such applications more effective that will enable future capabilities. This session is devoted to clocks being produced or deployed by industries and laboratories for various uses in both earth and space applications. Submissions regarding development of clocks or other time and frequency hardware are welcome. Topics may include (but are not entirely limited to) new product development, product design upgrades or enhancements, and/or hardware or system performance.
Co-chairs:
Peter Cash, Microsemi
Dr. Thomas McClelland, Frequency Electronics, Inc.

Time Scales and Algorithms
Analysis, description and implementation of current and new time scale algorithms. Potential topics for this session include: time scales based on primary/secondary frequency standards, optical frequency standards, optical cavities; the generation and steering of UTC, UTC(k), and reference GNSS time scales with increasing performance; algorithms and methods that advance the state of the art in clock data analysis and their applications; use of Kalman filters and other robust statistical techniques; and novel processing of measurement data to reduce the measurement noise in time scales.
Co-chairs:
Dr. Patrizia Tavella, Bureau International des Poids et Mesures
Dr. Jian Yao, National Institute of Standards and Technology

Timing Applications in Financial Markets
Timing applications in 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. Judah Levine, National Institute of Standards and Technology
Dr. Elizabeth Laier-English, National Physical Laboratory, UK

ITM Peer Reviewed Sessions

Advanced Integrity for Critical Applications
New concepts in GNSS and multi-sensor systems integrity monitoring for air, automotive, rail, maritime and space applications. Navigation and/or integrity requirement definition for new safety-critical, liability-critical or mission-critical applications. Development of fault detection and exclusion algorithms. Protection level derivation. Performance analysis considering GNSS satellite and constellation faults, interference and spoofing. Potential implications of future GNSS performance.
Co-chairs:
Dr. Carl Milner, ENAC, France
Dr. Ilaria Martini, European Commission (Advisor), Belgium

Innovative Navigation Algorithms
Use of multi-constellation, multi frequency GNSS signals. Robust positioning in challenging environments. Collaborative/cooperative positioning algorithms and theories. Algorithms and techniques that exploit network connectivity to assist and improve navigation. Innovative estimation techniques including distributed state estimation, advanced filtering and those which integrate 3D models, landmarks and other information sets. Cloud and crowd-sourced navigation. Algorithms developed for innovative applications as well as a new take on modelling and numerical problems in navigation and positioning.
Co-chairs:
Nicola Linty, Politecnico di Torino, Italy
Dr. Allison Kealy, RMIT University, Australia

UAV Navigation Technology and Algorithms
New navigation or positioning techniques for UAV applications. Requirements for position, velocity and attitude information feeding both control systems and payload systems. Absolute and relative positioning/navigation requirements and performance achieved by GNSS, GNSS/INS, GPS-denied/degraded solutions, combinations of other aiding sources. Specific UAV applications, requirements, and particular challenges or constraints. Map building for UAV operations. Detect and avoid systems.
Co-chairs:
Dr. Boris Pervan, Illinois Institute of Technology
Dr. Zhen Zhu, East Carolina University

Advanced GNSS Signal Processing for Challenging Environments
GNSS receiver signal processing techniques for operations in challenging environments like indoor, urban canyons, foliage, scintillation or high-dynamics. Improved acquisition and tracking sensitivity, robustness and accuracy. Mitigation of multipath and NLOS signals. Weak signal processing techniques and algorithms. Use of multiple GNSS signals including new GNSS signals. Receiver processing techniques that take advantage of GNSS integration with other sensors.
Co-chairs:
Dr. Sai Kalyanaraman, Rockwell Collins
Elias Gkougkas, Universität der Bundeswehr München, Germany

Advanced Multi-Sensor Hybridization Algorithms
Fusion algorithms of data from multiple sensors. Algorithms, test methods, and results of implementations integrating diverse sensors such as GNSS, inertial sensors, odometers, magnetometers, radar, LiDAR, cameras, barometers, maps, signals of opportunity, infrared, ultrasound sensors, etc.
Co-chairs:
Dr. Sun Rui, Nanjing University of Aeronautics & Astronautics, China
Dr. Andrey Soloviev, QuNav

GNSS Augmentation Systems and their Evolution
Augmentation of GNSS positioning to support aviation, maritime, rail, automotive and other applications. Developments in both ABAS, GBAS and SBAS. Multi Frequency Multi Constellation systems. Dissemination of integrity support information. Private global and regional augmentation systems. Augmentation system design, reference station equipment, user equipment and performance.
Co-chairs:
Dr. Denis Bouvet, Thales Avionics, France
Dr. Sam Pullen, Stanford University

GNSS Interference and Jamming Detection, Characterization and Mitigation
Techniques for improving the robustness of GNSS receivers in the presence of jamming and/or interference. Techniques for geo-locating jammers. Characterization of the jamming threat. Effects of GNSS interference on receiver performance. Compatibility of GNSS with other RF systems/services. Characterization and mitigation of intra and inter system multiple access interference as well as interference of non-GNSS systems. Receiver design trade-offs and approaches for interference environments. Spectrum management, policy, and frequency protection issues and approaches.
Co-chairs:
Dr. Felix Antreich, Instituto Tecnológico de Aeronáutica, Brazil
Dr. Laura Ruotsalainen, National Land Survey of Finland, Finland

GNSS Remote Sensing and Atmospheric Science
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. 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. Modeling of propagation channel. 3-D tomographic reconstruction, Storm-Enhanced Densities (SEDs), Traveling Ionospheric Disturbances (TIDs), plasma bubbles, and scintillation. Case studies and multiyear statistical overviews, now-casting and forecasting space weather for aviation, marine, geodetic, and timing applications. Impacts of the atmosphere and of space weather on the operation of GNSS.
Co-chairs:
Adria Rovira, Universitat Politècnica de Catalunya, Spain
Dr. Anthea Coster, MIT Haystack Observatory

GNSS Spoofing Detection, Characterization and Mitigation
Techniques for improving the robustness of GNSS receivers in the presence of spoofing or meaconing. Techniques for geo-locating spoofers. Anti-spoofing techniques based on receiver-only methods, additional sensors or external infrastructures. Spoofing threat characterization for different user communities. Signal authentication techniques at signal and system level.
Co-chairs:
Dr. Dennis Akos, Colorado University at Boulder
Dr. Beatrice Motella, Institute Superiore Mario Boella, Italy

High Precision GNSS Positioning Techniques
New algorithms and methods for improving RTK and PPP techniques, including in challenging environments. Multi-frequency, multi-constellation algorithms. PPP with integer ambiguity resolution. Reliable cycle-slip detection. Improved ambiguity resolution success rate and convergence time. High precision in urban/challenging environments, including integration of GNSS with other sensors. Low-cost RTK implementation. Carrier phase multipath mitigation. Heading and attitude determination using multiple antennas.
Co-chairs:
Dr. Sébastien Carcanague, Swift Navigation
Dr. Sandra Verhagen, Delft University of Technology, The Netherlands

Modernized, Emerging and Future Core GNSS Constellations
Modernized constellations characteristics, performance and programmatic aspects. New civil, military and governmental user capabilities and performance. Open and authorized GNSS services, search and rescue, commercial and authentication services. Optimization of GNSS signal structure, codes and data message. New payload performance. Concepts for interoperability, compatibility and interchangeability of GNSS constellations. Integration with regional augmentation systems and use of those new systems to support future applications.
Co-chairs:
Stefan Wallner, European Space Agency, The Netherlands
Dr. Changdon Kee, Seoul National University, South Korea

Navigation Methods for Autonomous Systems
Use of GNSS and/or alternative/complementary navigation technologies (signals of opportunity, vision, lidar, etc.) for autonomous air, land, marine, or space vehicles or systems. Innovative applications for autonomous systems and resulting navigation accuracy requirements. Collaborative positioning of vehicles. Algorithms for path planning, guidance, and control of autonomous vehicles. Design of navigation algorithms and fusion architectures. Technologies to address safety aspects.
Co-chairs:
Dr. Stephan Weiss, Alpen-Adria University, Austria
Dr. Mathieu Joerger, University of Arizona

Next Generation Receiver and Antenna Technology
Advances 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. Zheng Yao, Tsinghua University, China
Dr. Cécile Mongrédien, u-blox, Switzerland

Non-GNSS Navigation Methods, Technologies and Performance
Technologies for providing navigation and/or timing capability when GNSS is not available/used. Navigation method, performance and foreseen evolution of these systems. Use of current or future signals of opportunity (5G, LTE, Wi-Fi, cellular tower ranging, RFID, Bluetooth, NFC, Digital radio, Digital TV, etc.). Use of mega LEO constellations. Use of inertial sensors, cameras, LiDAR, mm-wave radars, etc. Techniques based on SLAM and its variants. Image-based and terrain referenced navigation systems. Use of DME, e-LORAN, LDACS and other forms of Alternate PNT. Use of environmental features.
Co-chairs:
Dr. Maarten Uijt de Haag, Ohio University
Liang Chen, Wuhan University, China

Plenary Session

Chair:

Space Applications
GNSS applications in the space domain to include orbit and attitude determination, orbital maneuvering, rendezvous and docking, and formation flight. Use of GNSS by space launchers. GNSS and sensor integrations for current and novel applications including remote sensing, radio occultation and aerial photogrammetry.
Co-chairs:
Dr. Penina Axelrad, University of Colorado at Boulder
Joon Wayn Cheong, University of New South Wales, Australia