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Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called dots and dashes or dits and dahs. Morse code is named after Samuel Morse, an inventor of the telegraph.
Signals intelligence (SIGINT) is intelligence-gathering by interception of signals, whether communications between people or from electronic signals not directly used in communication. Signals intelligence is a subset of intelligence collection management. As sensitive information is often encrypted, signals intelligence in turn involves the use of cryptanalysis to decipher the messages. Traffic analysis—the study of who is signaling whom and in what quantity—is also used to integrate information again.
Wireless telegraphy or radiotelegraphy is transmission of telegraph signals by radio waves. Before about 1910, the term wireless telegraphy was also used for other experimental technologies for transmitting telegraph signals without wires, such as electromagnetic induction, and ground conduction telegraph systems.
The International Radiotelephony Spelling Alphabet, commonly known as the NATO phonetic alphabet or the ICAO phonetic alphabet, is the most widely used radiotelephone spelling alphabet. The ITU phonetic alphabet and figure code is a variant.
The Q-code is a standardized collection of three-letter codes all of which start with the letter "Q". It is an operating signal initially developed for commercial 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 "INT" or suffixed it with the standard Morse question mark UD.
The Allied military phonetic spelling alphabets prescribed the words that are used to represent each letter of the alphabet, when spelling other words out loud, letter-by-letter, and how the spelling words should be pronounced for use by the Allies of World War II. They are not a "phonetic alphabet" in the sense in which that term is used in phonetics, i.e. they are not a system for transcribing speech sounds.
Ten-codes, officially known as ten signals, are brevity codes used to represent common phrases in voice communication, particularly by law enforcement and in Citizens Band (CB) radio transmissions. The police version of ten-codes is officially known as the APCO Project 14 Aural Brevity Code.
Tropospheric scatter is a method of communicating with microwave radio signals over considerable distances – often up to 300 kilometres (190 mi), and further depending on terrain and climate factors. This method of propagation uses the tropospheric scatter phenomenon, where radio waves at UHF and SHF frequencies are randomly scattered as they pass through the upper layers of the troposphere. Radio signals are transmitted in a narrow beam aimed just above the horizon in the direction of the receiver station. As the signals pass through the troposphere, some of the energy is scattered back toward the Earth, allowing the receiver station to pick up the signal.
The APCO phonetic alphabet, a.k.a. LAPD radio alphabet, is the term for an old competing spelling alphabet to the ICAO radiotelephony alphabet, defined by the Association of Public-Safety Communications Officials-International from 1941 to 1974, that is used by the Los Angeles Police Department (LAPD) and other local and state law enforcement agencies across the state of California and elsewhere in the United States. It is the "over the air" communication used for properly understanding a broadcast of letters in the form of easily understood words. Despite often being called a "phonetic alphabet", it is not a phonetic alphabet for transcribing phonetics.
A signal strength and readability report is a standardized format for reporting the strength of the radio signal and the readability (quality) of the radiotelephone (voice) or radiotelegraph signal transmitted by another station as received at the reporting station's location and by their radio station equipment. These report formats are usually designed for only one communications mode or the other, although a few are used for both telegraph and voice communications. All but one of these signal report formats involve the transmission of numbers.
Radiotelephony procedure includes various techniques used to clarify, simplify and standardize spoken communications over two-way radios, in use by the armed forces, in civil aviation, police and fire dispatching systems, citizens' band radio (CB), and amateur radio.
Communication with submarines is a field within military communications that presents technical challenges and requires specialized technology. Because radio waves do not travel well through good electrical conductors like salt water, submerged submarines are cut off from radio communication with their command authorities at ordinary radio frequencies. Submarines can surface and raise an antenna above the sea level, then use ordinary radio transmissions, however this makes them vulnerable to detection by anti-submarine warfare forces. Early submarines during World War II mostly traveled on the surface because of their limited underwater speed and endurance; they dived mainly to evade immediate threats. During the Cold War, however, nuclear-powered submarines were developed that could stay submerged for months. In the event of a nuclear war, submerged ballistic missile submarines have to be ordered quickly to launch their missiles. Transmitting messages to these submarines is an active area of research. Very low frequency (VLF) radio waves can penetrate seawater a few hundred feet, and many navies use powerful shore VLF transmitters for submarine communications. A few nations have built transmitters which use extremely low frequency (ELF) radio waves, which can penetrate seawater to reach submarines at operating depths, but these require huge antennas. Other techniques that have been used include sonar and blue lasers.
Project 25 is a suite of standards for digital mobile radio communications designed for use by public safety organizations in North America. P25 radios are a direct replacement for analog UHF radios, but add the ability to transfer data as well as voice, allowing for more natural implementations of encryption and text messaging. P25 radios are commonly implemented by dispatch organizations, such as police, fire, ambulance and emergency rescue service, using vehicle-mounted radios combined with handheld walkie-talkie use.
ACP-131 is the controlling publication for the listing of Q codes and Z codes. It is published by the Combined Communications Electronics Board (CCEB) countries, and revised from time to time. When the meanings of the codes contained in ACP-131 are translated into various languages, the codes provide a means of communicating between ships of various nations, such as during a NATO exercise, when a common language is not in effect.
Radio code is any code that is commonly used over a telecommunication system such as Morse code, brevity codes and procedure words.
A spelling alphabet, word-spelling alphabet, voice procedure alphabet, radio alphabet, or telephone alphabet is a set of words used to stand for the letters of an alphabet in oral communication. A spelling alphabet is also often called a phonetic alphabet, especially by amateur radio enthusiasts, recreational sailors in the US and Australia, and NATO military organizations. However, this conflicts with the usage of the same phrase in phonetics to mean a notation used for phonetic transcription or phonetic spelling, such as the International Phonetic Alphabet, which is used to indicate the sounds of human speech.
A radiogram is a formal written message transmitted by radio. Also known as a radio telegram or radio telegraphic message, radiograms use a standardized message format, form and radiotelephone and/or radiotelegraph transmission procedures. These procedures typically provide a means of transmitting the content of the messages without including the names of the various headers and message sections, so as to minimize the time needed to transmit messages over limited and/or congested radio channels. Various formats have been used historically by maritime radio services, military organizations, and Amateur Radio organizations.
16-line message format, or Basic Message Format, is the standard military radiogram format for the manner in which a paper message form is transcribed through voice, Morse code, or TTY transmission formats. The overall structure of the message has three parts: HEADING, TEXT, and ENDING. This heading is further divided into procedure, preamble, address, and prefix. Each format line contains pre-defined content. An actual message may have fewer than 16 actual lines, or far more than 16, because some lines are skipped in some delivery methods, and a long message may have a TEXT portion that is longer than 16 lines by itself.
The QSA code and QRK code are interrelated and complementary signal reporting codes for use in wireless telegraphy. An enhanced format, SINPO code, was published in the ITU Radio Regulations, Geneva, 1959, but is longer and unwieldy for use in the fast pace of Morse code communications.
Allied Communications Publications are documents developed by the Combined Communications-Electronics Board and NATO, which define the procedures for communicating in computer messaging, radiotelephony, radiotelegraph, radioteletype (RATT), air-to-ground signalling, and other forms of communications used by the armed forces of the five CCEB member countries and/or NATO.
References
- ↑ "Standard Z Signals". APCO International Historical Collection.