Session P3: PTTI Morning Tutorials


Date: Wednesday, January 26, 2022
Time: 8:30 a.m. - 11:35 a.m.

Sign in to:

  • Add papers to your schedule
  • Download full papers and presentations

Tutorials Introduction: New Visions For Clocks and Time Distribution From Space

8:30 a.m. - 8:35 a.m.

Dr. David R. Scherer, Lead Scientist, The MITRE Corporation

This year’s tutorials sessions are open to all PTTI and ITM attendees. This session brings together talks in the area of novel systems for time distribution from space. After an overall introduction to the topic, sessions cover atomic clocks, Kalman filtering for clock estimation, and specific implementations for time distribution from space.

Time, Satellite Navigation and the Kepler Systems

8:35 a.m. – 10:05 a.m.

User positioning in satellite navigation relies on pseudoranges, accurate orbits and the synchronization of satellite clocks. The latter requires extremely stable atomic clocks as well as the accurate characterization of their offsets with respect to a common basis called system time. The topics (ultra-) stable clocks and system time are addressed in separate tutorials. Together with accurate orbits, they are the basis for the current performance of GPS, GLONASS, Galileo and Beidou. Additionally, pseudoranges from the corresponding satellites are a central element for comparing time over continents in order to create Time Atomic International. The current approach to satellite navigation, which relies solely on the measurement of pseudoranges, needs a substantial amount of modelling. The newly proposed Kepler System follows a different approach and does not require long-term stable clocks for navigation anymore. It directly synchronizes the satellites using optical intersatellite links and uses these links to provide ultra-accurate ranges for orbit determination as well. An additional constellation of 6 or more LEO satellites furthermore enables the direct observability of L-band signal biases and phase center variations. As a consequence, the Kepler System has the potential of achieving centimeter-accurate positioning globally without further augmentation. Additionally, an ultra-stable clock (discussed in a separate tutorial) introduced in the “perfectly” synchronized Kepler system provides a global time reference which might be used in multiple ways.

Dr. Christoph Guenther, Director, German Aerospace Center (DLR), Germany
Christoph Günther studied theoretical physics at the Swiss Federal Institute of Technology in Zurich. He received his diploma in 1979 and completed his PhD in 1984. He worked on communication and information theory at Brown Boveri and Ascom Tech. From 1995, he led the development of mobile phones for GSM and later dual mode GSM/Satellite phones at Ascom. In 1999, he became head of the research department of Ericsson in Nuremberg. Since 2003, he is the director of the Institute of Communication and Navigation at the German Aerospace Center (DLR) and since December 2004, he additionally holds a Chair at the Technische Universität München (TUM). His research interests are in satellite navigation, communication, and signal processing.

Break: 10:05 a.m. – 10:35 a.m.

Atomic Clocks: The Forerunner of our Quantum Infrastructure

10:35 a.m. – 11:35 a.m. 

The technology that underpins atomic clocks is critical to many of the proposed commercial quantum solutions. All rely on probing atomic/ionic transitions that can be extremely sensitive to environmental effects and present challenges in providing low cost, robust fieldable solutions. Approaches must satisfy not only highest performance applications, but also have a broad enough market appeal to ensure ready supply. In this tutorial, we will discuss the challenges that atomic clock and future quantum technology face, with respect to not only the technical approach, but also the supply chain issues that must be addressed.

Dr. Richard Overstreet, Associate Technical Fellow, Frequency and Timing, Microchip Technology
Richard Overstreet is Chief Scientist at the Microchip Frequency and Time Systems location in Beverly, MA and focuses on development of volume manufacturable atomic clocks at all levels of SWaP-C.



12:15 p.m. – 1:15 p.m.: Attendee Lunch Buffet Served