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Time and frequency transfer is a scheme where multiple sites share a precise reference time or frequency. The technique is commonly used for creating and distributing standard time scales such as International Atomic Time (TAI). Time transfer solves problems such as astronomical observatories correlating observed flashes or other phenomena with each other, as well as cell phone towers coordinating handoffs as a phone moves from one cell to another.
PPS commonly refers to:
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The Timation satellites were conceived, developed, and launched by the United States Naval Research Laboratory in Washington, D.C. beginning in 1964. The concept of Timation was to broadcast an accurate time reference for use as a ranging signal to receivers on the ground. On 31 May 1967, the Timation-1 satellite was launched. This was followed by the Timation-2 satellite launch in 1969. The results of this program and Air Force Project 621B formed the basis for the Global Positioning System (GPS). The Navy's contribution to the GPS program continued to be focused on ever more accurate clocks.
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The terms "DOD-STD-2167" and "DOD-STD-2168" are the official specification numbers for superseded U.S. DoD military standards describing documents and procedures required for developing military computer systems. Specifically:
Trusted Computer System Evaluation Criteria (TCSEC) is a United States Government Department of Defense (DoD) standard that sets basic requirements for assessing the effectiveness of computer security controls built into a computer system. The TCSEC was used to evaluate, classify, and select computer systems being considered for the processing, storage, and retrieval of sensitive or classified information.
References
- ↑ DOD-STD-1399-441; United States Department of Defense.
- ↑ ICD-GPS-060B: GPS User Equipment (Phase III) Interface Control Document for the Pecise Time and Time Interval (PTTI) Interface, Global Positioning System Joint Program Office, 2002
