Basic terminology

◎Amateur radio stations (amateur stations, radio stations)
A general term for radio equipment and those who operate radio equipment.
・ Space Station: Radio station to be established in space
・ Artificial satellite station: Radio station established on an artificial satellite
・ Earth station: A radio station established on the ground that communicates with the space station

 The ground station consists of an antenna, a communication device, a tracking device, and a computer for operating the equipment of the ground station and storing data.
Ground stations are used to send commands to CubeSat and receive telemetry (housekeeping) and mission data from satellites.
Telemetry data is used to monitor the status of satellites and plan satellite operations.

A CubeSat is a type of small satellite consisting of standard unit cubes.
One CubeSat unit (U) is 100 x 100 x 100 [mm].
A 1U CubeSat, the smallest possible, is very small with a mass of less than 1.33kg.

◎ Amateur satellite communication
 A communication method that uses an amateur station established on an artificial satellite.
Communication with the amateur radio station on the International Space Station (ISS) is also amateur satellite communication.
In most cases, as UHF and VHF bands are used the antenna can be small. If the satellite is within the visible range, communication is possible even from a balcony of a condominium.


◎ Modulation method

・ FM
The transmitted sound is clear. However, the disadvantage is that it uses a wide frequency range.
FM is used in the amateur radio frequency above 28MHz, in particular the 144MHz and 430MHz bands.

・ AM
Although it is not widely used at present, it is typically operated in the 50MHz band using the same method as AM radio.

Communication is possible without using a wide frequency range compared to FM and AM. SSB is widely used in amateur radio as it is possible to communicate over longer distances than FM and AM.

・ CW
Although it takes time to send the code character by character using Morse code, CW is popular because it can communicate with distant stations with a small transmission output. A third-class amateur radio license or higher is required to use CW.

◎HF band (High Frequency)
This is a short wave band. It uses the reflection of the ionosphere to enable communication over long distances. The density of the ionosphere changes depending on the season and time of day in conjunction with the activity of the sun, and so the frequency suitable for communication also changes.

◎VHF band (Very High Frequency), UHF band (Ultra High Frequency)
Frequency bands higher than the HF band. It is able to pass through the ionosphere and reach into space.

◎UART(Universal Asynchronous Receiver/Transmitter)
Devices or standards for serial communication


◎TNC(Terminal Node Controller)
It is a device used for digital communication (packet communication) by amateur radio, and is equivalent to a modem for personal computer communication.

Artificial satellites pass over the ground station in different orbits every day. A device that rotates an antenna to point it at the satellite.


◎QSL Card
 Exchange a communication certificate called a QSL card when communicating with amateur radio (not a must).
Enjoy collecting cards.
QSL cards can be exchanged directly, but the general method is to use the QRL (Japan Amateur Radio League) QSL card transfer service.
Forwarding service is available when both are members of JARL.