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en:hf_tx_subsys [2017/12/03 15:42]
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en:hf_tx_subsys [2018/01/23 16:54] (current)
ashley
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 {{ ru:​hf-transmitter.jpg?​direct&​200|}} {{ ru:​hf-transmitter.jpg?​direct&​200|}}
-The radio communication system is one of the key service ​of on-board systems. However, like many engineering systems it does not have an ideal solution. ​Designing ​each device you need to search for a balance between the data transfer rate and the [[power_subsys|power consumption]] of the on-board radio equipment as well as between the width of the antenna directional pattern and its efficiency. Each new satellite project requires special approaches to solve the problem of data exchange between the board and the Earth.+The radio communication system is one of the key services ​of the on-board systems. However, like many engineering systems it does not have an ideal solution. ​When designing ​each deviceyou need to search for a balance between the data transfer rate and the [[power_subsys|power consumption]] of the on-board radio equipmentas well as between the width of the antenna directional pattern and its efficiency. Each new satellite project requires special approaches to solve the problem of data exchange between the board and the Earth.
  
-The standard solution is to install low-speed communications equipment on the satellite to [[uhf_tx_subsys| transmit telemetry]] via the "​board-to-Earth"​ line and control commands to the satellite via the "​Earth-to-board"​ line. As a rule, in this case the satellite is equipped with either an omnidirectional antenna or a system of spot beam antennas. Such a system allows communication with the spacecraft irrespective of its orientation and rotation speed; it consumes low power but also provides ​small data transfer speed (about 9600 bps).+The standard solution is to install low-speed communications equipment on the satellite to [[uhf_tx_subsys| transmit telemetry]] via the "​board-to-Earth"​ line, as well as control commands to the satellite via the "​Earth-to-board"​ line. As a rule, in this case the satellite is equipped with either an omnidirectional antenna or a system of spot beam antennas. Such a system allows ​for communication with the spacecraft irrespective of its orientation and rotation speed; it consumes low powerbut also provides ​a low data transfer speed (about 9600 bps).
  
-Another option is to use a high-frequency high-speed transmitter with a spot beam antenna to transmit payload information to the  [[sim_earth|Earth]] ​on the "​board-to-Earth"​ line. The data transfer speeds ​in this way are tens and hundreds of megabits per second. However, such equipment consumes more power and requires precise orientation of the on-board antenna (and hence of the entire satellite) relative to the Earth in order to get the directivity diagram ​of the on-board antenna to the ground receiving station.+Another option is to use a high-frequencyhigh-speed transmitter with a spot beam antenna to transmit payload information to the  [[sim_earth|Earth]] ​via the "​board-to-Earth"​ line. The data transfer speeds ​using this option ​are tens and hundreds of megabits per second. However, such equipment consumes more power and requires precise orientation of the on-board antenna (and hencethe entire satellite) relative to the Earth in order to get the directional pattern ​of the on-board antenna to the ground receiving station.
  
-High-frequency (HF) high-speed transmitter is implemented as a separate module in the construction set including ​a simple LED that flashes with a specified frequency and a certain sequence. At the moment when the light from this "​transmitter" ​gets on the high-frequency receiver ​to [[sim_earth|the Earth]], it is considered that the communication channel is opened ​and it is possible to transmit the data of photos from the satellite to the ground (in reality - via WiFi network). ​+The high-frequency (HF)high-speed transmitter is implemented as a separate module in the construction set, and includes ​a simple LED that flashes with a specified frequency and a certain sequence. At the moment when the light from this "​transmitter" ​is received by the high-frequency receiver ​on [[sim_earth|the Earth]], it is considered that the communication channel is open and it is then possible to transmit the data (photosfrom the satellite to the ground (in reality - via WiFi network). ​
  
-The high-frequency ​transmitter is one of the main consumers of electricity on board the satellite. It is highly discouraged to keep it permanently ​on if there is no special need for it: too much load on the power supply system will lead to a quick accumulator slump and emergency deactivation of the "board".+The HF transmitter is one of the main consumers of electricity on board the satellite. It is highly discouraged to keep it on permanently ​if there is no special need for it. Too much load on the power supply system will lead to a quick battery drainage ​and an emergency deactivation of the "​board."
en/hf_tx_subsys.txt · Last modified: 2018/01/23 16:54 by ashley