On Friday, specialist American satellite telecommunications company Orbcomm declared operational a new ground station at the Satellite Applications Centre (SAC) of the Council for Scientific and Industrial Research, at Hartebeeshoek, west of Pretoria.
“We are hosting Orbcomm’s ground station in South Africa. The ground station belongs to them, but it’s on SAC property. But we had conditions that had to be fulfilled. SAC doesn’t simply host telecommunications ground stations. We accepted this only because we could add value to it,” explained SAC International Telemetry, Tracking and Control contract manager Tiaan Strydom. “We provide operations support and maintenance support. It makes use of our existing expertise.”
Orbcomm describes itself as “a leading provider of global satellite and cellular data communications solutions for asset tracking, management, and remote control”. It has its own fleet of microsatellites in low Earth orbit.
Miniaturised tracking and communications systems can be fitted to vehicles or containers or other assets, which can transmit an receive alphanumeric message packages – rather akin to SMSs on cell phones.
Thanks to the satellite fleet, coverage is pretty much global and is independent of any cell phone networks (although, where such networks are available, they can be used). This means that client companies can monitor data from, send instructions to, and track the location of, their assets almost anywhere.
The ground station is composed of two identical Very High Frequency/Ultra High Frequency planar arrays, each housed in its own radome – these are the first large radomes erected at the SAC.
The planar arrays are made from composites and the actual antennas, in the form of metal cross couples, are mounted on the arrays. Each array can rotate 360 ˚ in azimuth and elevate from 0 ˚ to 90 ˚, with a maximum movement rate of 5 ˚/sec, in both azimuth and elevation.
Two antennas means that one is always tracking a satellite while the other is ready to track the next satellite to appear over the horizon, guaranteeing uninterrupted coverage. This ground station has its own stand alone back-up power system.
“This is something new for us,” stated Strydom. “We normally do telemetry, tracking and control, or receive imagery or space or Earth observation data, and not telecommunications data.”