So much of the focus in SATCOM technology largely depends on what goes on in the outer space, but the things that happen down here on earth is just as significant. The fact is that every satellite, no matter how technologically equipped or advanced, is still considered as only a part of a larger system. So today, let us understand the importance of satellite earth stations, and some of the potential obstacles or challenges for organizations working with the satellites on the ground.
What are Satellite Earth Stations?
Source: https://www.esoa.net/technology/operating-in-space.asp
Satellite earth stations are the ground-based facilities designed to provide real-time communication with the satellites. The personnel at these stations send the radio signals to the satellite (uplink) receive data transmissions from the satellite, and in some cases, act as command and control centers for the complete satellite network. Isn’t it amazing? Therefore, from the satellite earth station, data can be easily analyzed, the altitude and movement of the satellite and information about its critical systems can be monitored, and satellites can be hence controlled by the decision makers.
If at all something goes off the track with a satellite, the crew deployed at these stations will be the first to know about the same. They will try and identify the source of the problem and then devise a solution for it. Simply put, a satellite earth station is like the brain of the complete satellite network.
Source:https://www.nasa.gov/directorates/heo/scan/communications/outreach/funfacts/txt_relay_satellite.html
What are the Potential Challenges and the Design Considerations for Satellite Earth Stations?
The equipment that you can find at a satellite earth station will vary depending on the type of satellite and the nature of the space mission, however, similarities can be found in all stations. Important aspects of a typical satellite earth station include:
- The system clock
- Antenna system
- Transmitting and receiving RF equipment
- Data-user interface
- Telemetry, tracking and command (TT&C) equipment
- Mission data recovery
- Station control center
But how do government owned space agencies or private companies decide where to build the satellite earth station? Well, it is determined by the type of satellite used, its orbital path and the coverage required. Oftentimes, the apt locations for earth stations are not the places where command and control or data analysis can be performed, so that the mission data will have to be relayed to the other ground stations or directly to the end users at their specific location. And, even if everything is working well at a particular ground station, contact might be lost due to some atmospheric conditions. Connecting to multiple stations at one point is an effective way to get around rain fade interfering with communications at a specific satellite earth station.
How Satellites Work?
Communication satellites are nothing but the space mirrors that can help us bounce radio, TV, internet data, and other kinds of information from one side of Earth to the other.
Like, if you want to send something like a TV broadcast from one side of Earth to the other, there are three stages involved. Firstly, there’s the uplink, where the data is sent to the satellite from a satellite earth station. Next, the satellite processes the data using a number of onboard transponders like, radio receivers, transmitters and the amplifiers. These transponders boost the incoming signals and alter their frequency, so that the incoming signals don’t interfere with the outgoing signals. And finally, there’s the downlink, where the data is sent back down to another satellite earth station anywhere on Earth. Usually, there is just a single uplink, but there may be billions of downlinks. While a communications satellite might relay a signal between one sender and receiver, usually the satellite broadcasts comprise of one or more uplinks and multiple downlinks.
