Time and frequency transfer describes mechanisms for comparing measurements of time and frequency from one location to another. The technique is commonly used for creating and distributing standard time scales such as International Atomic Time (TAI).

Examples include:

Simultaneous observation methods:

• Simultaneous carrier phase observation of GPS signals
• Time transfer by simultaneous observation of TV transmissions
• Time transfer by simultaneous observation of radio astronomy signals

Two-way transfer methods:

• Two-Way Satellite Time and Frequency Transfer

See also:

• Synchronization

External links:

• http://tycho.usno.navy.mil/gpscp.html
• http://www.metas.ch/en/labors/4/tvgps.html
• http://www.boulder.nist.gov/timefreq/time/carrierphase.htm
• http://www.colorado.edu/engineering/GPS/TimeTransfer.html
• http://www.npl.co.uk/time/eftf2000.pdf