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Time Synchronization Over Radio
Time synchronization over radio is the procedure used for time transfer performed by humans over two-way radio circuits, including voice, telegraph, and teletype. Radiotelegraph procedure ACP 124(A) is the earliest Allied military document of the Cold War to define a time transfer method. It consists of: Note that ZUA is a military-only operating signal. Civilians would need to use the appropriate Q code The Q-code is a standardised collection of three-letter codes that each start with the letter "Q". It is an Operating signals, operating signal initially developed for commercial radiotelegraphy, radiotelegraph communication and later adopted b ... operating signal, which also uses following the signal, instead of preceding the signal: Telephone and radiotelephone procedure ACP 125(A) describes the format: ACP 125(G) updates the above procedure as follows: Stations without the ability to acquire a time signal accurate to at least one second should request a time check ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Transfer
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. Multiple techniques have been developed, often transferring reference clock synchronization from one point to another, often over long distances. Accuracy approaching one nanosecond worldwide is economically practical for many applications. Radio-based navigation systems are frequently used as time transfer systems. In some cases, multiple measurements are made over a period of time, and exact time synchronization is determined retrospectively. In particular, time synchronization has been accomplished by using pairs of radio tel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-way Radio
A two-way radio is a radio transceiver (a radio that can both transmit and receive radio waves), which is used for bidirectional person-to-person voice communication with other users with similar radios, in contrast to a broadcast receiver, which only receives transmissions. Two-way radios usually use a half-duplex communication channel, which permits two-way communication, albeit with the limitation that only one user can transmit at a time. (This is in contrast to simplex communication, in which transmission can only be sent in one direction, and full-duplex, which allows transmission in both directions simultaneously.) This requires users in a group to take turns talking. The radio is normally in receive mode so the user can hear all other transmissions on the channel. When the user wants to talk, they press a " push-to-talk" button, which turns off the receiver and turns on the transmitter; when the button is released, the receiver is activated again. Multiple channels are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold War
The Cold War was a period of global Geopolitics, geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which lasted from 1947 until the dissolution of the Soviet Union in 1991. The term ''Cold war (term), cold war'' is used because there was no direct fighting between the two superpowers, though each supported opposing sides in regional conflicts known as proxy wars. In addition to the struggle for ideological and economic influence and an arms race in both conventional and Nuclear arms race, nuclear weapons, the Cold War was expressed through technological rivalries such as the Space Race, espionage, propaganda campaigns, Economic sanctions, embargoes, and sports diplomacy. After the end of World War II in 1945, during which the US and USSR had been allies, the USSR installed satellite state, satellite governments in its occupied territories in Eastern Europe and N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating Signals
Operating signals are a type of brevity code used in operational communication among radio and telegraph operators. For example: * Prosigns for Morse code * Wire signal#92 Code, 92 Code: telegraph brevity codes * Q code: initially developed for commercial radiotelegraph communication and adopted by other radio services * QN Signals: published by the ARRL and used in Amateur radio * R and S brevity codes: published by the British Post Office in 1908 for coastal wireless stations and ships, superseded in 1912 by Q codes * X code: used by European military services in wireless telegraphy * Z code: used in early radiotelegraph communication See also * Brevity code * SINPO code - code used to describe the quality of radio transmissions, especially in reception reports written by shortwave listeners * R-S-T system- information about the quality of a radio signal being received. Used by amateur radio operators, shortwave listeners. * Morse code abbreviations * Telegraphese External l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Q Code
The Q-code is a standardised collection of three-letter codes that each start with the letter "Q". It is an Operating signals, operating signal initially developed for commercial radiotelegraphy, radiotelegraph communication and later adopted by other radio services, especially amateur radio. To distinguish the use of a Q-code transmitted as a question from the same Q-code transmitted as a statement, operators either prefixed it with the military network question marker "" () or suffixed it with the standard Morse question mark (). Although Q-codes were created when radio used Morse code exclusively, they continued to be employed after the introduction of voice transmissions. To avoid confusion, transmitter call signs are restricted; countries can be issued unused Q-Codes as their ITU prefix e.g. List of ITU letter codes, Qatar is QAT. Codes in the range QAA–QNZ are reserved for aeronautical use; QOA–QQZ for maritime use and QRA–QUZ for all services. "Q" has no official ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Synchronization In North America
Time synchronization in North America can be achieved with many different methods, some of which require only a telephone, while others require expensive, sensitive, and rare electronic equipment. In the United States, the United States Naval Observatory provides the standard of time, called UTC(USNO), for the United States military and the Global Positioning System, while the National Institute of Standards and Technology provides the standard of time for civil purposes in the United States, called UTC(NIST). ITU-R Standard Frequency and Time Signals A standard frequency and time signal service is a station that operates on or immediately adjacent to 2.5 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz, and 25 MHz, as specified by ''Article 5'' of the ITU Radio Regulations (edition 2012). The US service is provided by radio stations WWV (Colorado) and WWVH (Hawaii). The methods below provide either Coordinated Universal Time (UTC), which is defined by ''Recommen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
