Shooting for the Stars – Maintaining a Satellite Uplink

By Devon Pike | October 2008


I work as a satellite earth station engineering technician for one of the major satellite television companies in the United States. Basically, my team is responsible for the equipment that sends the signals to the satellites that, in turn, broadcast the signals down to your home satellite dish in order to provide you with quality television programming.

First of all, let me list some of the things that attracted me to the industry in the first place. Satellite communications remains one of the backbones of the telecommunications industry. It can be rapidly deployed to parts of the world that remain unconnected to our modern infrastructure via terrestrial links. This makes it far more flexible and efficient in responding to the changing needs of media, business and government.

Whether it’s the need for a live news feed from a conflict zone or the necessity of sending large amounts of scientific data from rural research sites, the absence of fiber optic or cellular communications networks will require the use of spacecraft which are accessible from nearly every part of the globe. This has led to the expansion of the satellite industry in the last decade, despite the concurrent expansion of “landline” networks from within urban centers.

Indeed, despite having the option of cable television available to them, many ordinary people have chosen instead to seek services from the satellite providers due to reasons that range from lower prices to simple dissatisfaction with the competitor’s product. Satellite networks provide more than just television: they traffic in multiple forms of electronic communications, including providing Internet connectivity, operating on-spacecraft cameras and RADAR (called remote sensing), and relaying data between other satellites.

My final reason for pursuing a career in satellite broadcasting is a romantic one. I come from a generation that idolized astronauts. My family watched as the space race was proudly fought and families sat on their roofs to see the return of the shuttle on a moonless night. Knowing that the buttons I push are affecting something flying 26,000 miles out in space adds significantly to the “cool factor” of what I do.

Satellite ground station technicians (at least those involved in “unlinking” signals to the spacecraft) are usually RF guys. They specialize in radio frequency and/or microwave signals used in transmit and downlink paths. Technicians also provide for the tracking of the spacecraft by the parabolic antennas (uplink dishes) and in some cases the encoding and modulation of the data into the transmit signal. I work in an industry that is broadcasting around the clock, all 24 hours of each day are staffed by teams working rotating shifts of various durations sometimes three, eight-hour shifts and sometimes two 12-hour shifts. Each team is responsible for the continuous broadcast of all the services with minimal interruption.

The system is set up with multiple-redundancy points so that if one piece of equipment fails, the system automatically detects the fault and the broadcast traffic is instantly swapped to the backup equipment. The technicians then respond and troubleshoot the failed equipment, which now is offline and out of the signal path. Major maintenance that is performed on equipment is scheduled for a “maintenance window” in which any time interruption that might occur statistically will impact fewer customers (for example: at 3 a.m.).

The equipment in which we are responsible for can be broken down into the major elements of the signal path: compression, modulation, and transmission. With digital broadcasts, video signals are compressed using methods such as MPEG-2 or MPEG-4. They are modulated into the RF waveform using a scheme such as phase-shift keying (two examples include QPSK and 8-PSK) and amplified using a High Powered Amplifier (HPA) such as a Klystron or Traveling Wave Tube.

The tracking of the spacecraft, whether they are in a geosynchronous orbit or moving more dramatically, requires some proprietary knowledge about tracking systems. Computer track systems cause an antenna to follow a preprogrammed course. Step track systems cause an actively tracking antenna to step around a spacecraft looking for the strongest beacon signal to follow. A mono-pulse type tracking follows a beacon signal as well, but uses a sum-and-error value to determine the spacecraft’s location.

Working with satellite uplink equipment requires some specialized skill sets that are sometimes difficult to come by in the civilian world. Many in the industry are ex-military people who have received specialized training during their service. I’m aware of only one civilian school in the U.S. that specializes in this field, and that is the Mitchell Technical Institute in South Dakota. However, working in the broadcast engineering field for a local news station or cable company can lead to opportunities within satellite uplink and network operations centers. From there, it is often possible to learn from those working with the earth station and to transfer to the department when they are looking for someone entry-level but enthusiastic to learn.

 

Comments

One Response to “Shooting for the Stars – Maintaining a Satellite Uplink”

September 09, 2009 at 3:55 am, Wayne Pearson said:

It is indeed a very interesting field to work in.Nothing makes me more happy than to have tons of challenges being thrown at me and expected to solve them in the shortest possible time.

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