Radio plays a big part in our daily life. It updates us with breaking news, entertains us with the best music, and informs us of recurring sports events. But have you ever wondered about its working mechanism? What is terrestrial radio? How does it broadcast to you anytime and anywhere?
Terrestrial radio is the technical term for radio signals that are transmitted by a terrestrial station. You can think of it as any radio signals that travel on the surface of the Earth.
A type of non terrestrial radio is satellite radio, which transmits signals from satellites.
Terrestrial Radio: What’s It?
1. Definition, purpose, and stations
The terrestrial radio definition is implied in its name. The term stands for any radio waves that are sent by a station located on Earth. To convert and listen to the signals, listeners need a land-based receiver.
Terrestrial radio networks include one-to-many stations that broadcast to a large audience and two-way radio systems that are used to communicate within a team, usually used by police officers, the military, or firefighters.
Television programs are also an application of terrestrial radio, in which radio signals are used to transmit videos.
Terrestrial radio is prominently for radio station broadcasting and communicating among members of a community, which, nowadays, wireless phones and the Internet can do. So, what makes it remain a vital form of communication?
Under special circumstances, such as when a natural disaster strikes, all means of communication will be affected but terrestrial radio wave. With radio, communication continues without cellular phone service, Wifi, and even power.
During their early days, terrestrial radio stations only broadcasted in two forms: AM (amplitude modulation) and FM (frequency modulation). Now, you may have heard of digital radio broadcasting, which uses bits (0s and 1s) to deliver signals instead, allowing for more channels and lower interference than.
2. The development of terrestrial radio
The history of terrestrial radio dates back to the 1900s. Initially, radio stations could only transmit telegraphy signals, not audio. In 1904, John Ambrose Fleming – an English physicist, invented a valve system that could detect radio signals. This set the first stone for the upcoming terrestrial radio era.
About the year 1920, valve technology became more complete, which soon made radio transmissions available all over the world. During this time, many broadcasters were established; the earliest one was the KDKA station in Pennsylvania.
Back then, the only available modulation was AM. Though AM radio signals didn’t require complex setups, they were vulnerable to interference from the elements and electronic devices.
In 1933, FM radio was introduced. The inventor Edwin H. Armstrong used VHF (very high frequency) to transmit the signals. This helped reduce interference and provide better sound quality. However, FM consumed too much bandwidth of the spectrum space.
The disadvantage of FM led to the invention of digital radio in 1995, which used digital technology to broadcast radio signals. During this time, terrestrial trunked radio (TETRA) was also introduced. It was a standard two-way radio system in Europe.
3. Examples of terrestrial radio technology
Examples of terrestrial radio include the AM and FM stations that you play in your car every day. According to the FCC (Federal Communications Commission), there are 15,330 AM and FM channels in the US, with approximately 4,000 of them being non-profit FM stations.
A recent product of terrestrial radio is DAB (Digital Radio Broadcasting) and DAB+. Both provide outstanding audio quality compared with AM and FM. With DAB, listeners will find minimal interruption and static noise.
Plus, DAB can transmit to fast-moving objects at up to 200 km/h. So, you can still enjoy your radio when traveling on a train or subway.
Terrestrial Radio Vs Internet Radio
While terrestrial radio transmits radio signals via land-based stations, Internet radio transmits signals via the Internet. This erases geographic difficulties and interferences and allows users to access the content from places all over the world, provided that they have a stable Internet connection.
The first Internet radio station was established in 1993. Since then, the technology has rapidly developed, and more stations have been introduced. Some popular platforms are TuneIn Radio, iHeartRadio, AccuRadio, and Sirius XM.
With more advanced technology, Internet Radio allows users to pick their favorite programs, rate the content they listen to, and even curate their own channel.
In terms of quality, Internet radio surpasses DAB and HD radio. This is because Internet bandwidth is cheaper than that of terrestrial radio signals; thus, stations can broadcast higher quality at a lower cost.
Is terrestrial radio AM and FM?
Yes. Terrestrial radio includes two main categories: AM and FM radio. While AM radio uses short or medium wave bands to transmit, you can only find FM stations in the VHF (very high frequency) wave bands (88 MHz to 108 MHz.)
Unlike Internet radio, terrestrial radio is often free of charge, though you might find pop-up commercial ads to compensate for the cost of running a station.
What is the difference between terrestrial radio and satellite radio?
Terrestrial radio vs satellite radio: what is the difference? While terrestrial radio transmits via land-based stations, satellite radio transmits via satellites orbiting around the Earth.
Unlike terrestrial radio, satellite radio is not limited by geography. It can broadcast a program through an entire continent. As of 2022, the only satellite radio available in North America is Sirius XM. To listen to the service, you must have a compatible device and pay a monthly or yearly subscription fee.
Meanwhile, AM and FM radios are usually free. Digital terrestrial platforms, such as HD Radio, require users to have a compatible head unit or purchase a tuner, but they don’t charge any further fee.
Is terrestrial radio still relevant?
Yes. Despite the surge of Internet and Satellite radio, terrestrial radio remains irreplaceable in many situations.
Firstly, it provides unique local content and allows two-way radios. You will find information about nearby traffic jams, road accidents, and local weather on AM and FM stations. In addition, truckers, boaters, and police officers all rely on it as a means of communication.
Secondly, terrestrial radio stays reliable in the unfortunate event that disaster strikes. When infrastructures (e.g., cellular towers, phone landlines, power supply stations) are down, AM radio signals can still be detected.
What is terrestrial radiation?
The earth naturally bears radioactive materials within it. These materials can cause terrestrial radiation and affect humans through digestion, inhalation, or skin exposure.
What is UMTS terrestrial radio access network?
UMTS terrestrial radio access network (or UTRAN) implies 3G – the cellular network that allows us to connect our cell phones to public Internet services.
To wrap up, terrestrial radio stands for the radio signals that travel along the surface of the Earth, transmitted by a land-based station and received by a land-based device.
We hope our article on “What is terrestrial radio?” helped you gain insights into the vast world of radio and learn the origin of this broadcasting system. If you are interested in the topic, don’t forget to browse our website for more information. Thank you for reading!
Robert is our content writer. He has in-depth knowledge about two-way radio communication, including mobile, handheld, and base, as well as ham radio satellite and emergency communication. He is in charge of researching and reviewing the best and latest products as well as gathering information about your queries and issues in using ham radios.