• Network-centric warfare, and

  • Secure military communications.

Realizing reductions in the size, weight, and power requirements and increases in the ruggedness of PTTI devices without sacrificing performance would put more accurate and precise timekeeping in the hands of the warrior, improving capabilities in all of the above operations. Chapter 5 discusses applications of PTTI techniques and devices to real military scenarios.

Research areas related to PTTI that, if pursued, should lead to improved military capabilities include the following:

  • Atomic, molecular, and optical physics. Recent advances such as the realization of Bose-Einstein condensates hold promise for pushing the limits of our fundamental laboratory time standards.

  • Materials science. Advanced materials can help isolate the high-performance elements of atomic clocks from environmental effects and reduce the size and weight of these devices. Materials advances will be necessary, for example, to successfully produce a chip-scale atomic clock.

  • Chemistry. Advances that improve the availability of high-perfection quartz would have immediate impact on devices that currently rely on quartz crystal oscillators as clocks or as local oscillators. This includes most PTTI devices used by the DOD.

Chapter 4 discusses these and other research areas that can be pursued to advance DOD capabilities in PTTI.

The health of the U.S. PTTI infrastructure, discussed in Chapter 3, is mixed. The United States has been a leader in PTTI science and technology since at least the time after World War II, but in the last two decades its dominant position in PTTI has been eroded by increased foreign investment in PTTI sciences. University programs in atomic, molecular, and optical (AMO) physics and precision measurement produce sufficient numbers of scientists to enter PTTI work, but these researchers require 5 or more years apprenticeship after their formal studies before they become independently productive PTTI researchers. This is unlike the situation in several other countries, where there are special programs of study in key aspects of PTTI science and technology. Certain aspects of the U.S. PTTI infrastructure are in jeopardy, especially U.S. expertise in high-performance crystal oscillators. Industrial support for DOD needs in high-performance clocks and frequency standards is narrow and shallow. Most industrial firms focus their efforts on the much larger and less demanding low-performance commercial markets and could not readily shift their product development and production into high-performance devices, which are highly complex. The handful of firms that is capable of producing high-performance devices for defense purposes finds the demand for these devices to be too small and intermittent to support a business. Private industry currently has no incentive to conduct R&D related to high-performance devices suitable for military use.

Based on its analysis of the above factors and the current status of U.S. PTTI research and development, the committee has formulated a dozen findings and five associated recommendations.


Finding: Accurate time and frequency have been, are, and will be critical to the Navy’s (and indeed all of DOD’s) warfighting capability.

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