Accession Number:



Navy PTTI Report

Descriptive Note:

Conference paper

Corporate Author:


Personal Author(s):

Report Date:


Pagination or Media Count:



The U.S. Naval Observatory is charged under Department of Defense DoD instruction 5000.2 with the responsibility for maintaining the timing standard in support of all DoD operations. Accomplishment of this task involves generating a time reference and then disseminating the Precise Time and Time Interval PTTI information to users within, as well as outside, DoD. A major effort has been undertaken by Navy scientists in recent years to upgrade and improve these services. Understanding the characteristics of atomic clocks, such as hydrogen masers, cesium beam frequency standards, and stored ion devices, is a prerequisite for modelling their performance and developing the most stable time reference possible. Algorithms for optimum clock ensembling and precision clock steering must be developed to ensure the stability of the time reference. Implementing new methods for time transfer, such as two-way satellite time transfer and laser ranging, will lead to improved accuracies to lass then ons nanosecond. In addition, the determination of astronomical time based on the Earths rotation and definition of parameters for the position of the poles, enable the correction of the dynamical reference frame of Earth-orbiting satellites to an inertial reference frame, which is needed to improve the precision of satellite orbits. Current and planned initiatives in PTTI within the Navy, such as those listed above, are described.

Subject Categories:

  • Test Facilities, Equipment and Methods
  • Computer Hardware
  • Navigation and Guidance

Distribution Statement: