COLORADO SPRINGS, Colo. — Satellite signals beamed down to military warplanes, unmanned aircraft, ground stations or vehicles are affected by a range of disruptive phenomena — enemy jammers, atmospheric white noise or weather. These disturbances make it difficult to predict if a signal will be clearly received.
To compensate for these unpredictable scenarios, engineers are relying on simulations to predict how satellite links will perform, says Steve Williams, business manager for RT Logic, of Colorado Springs, Colo.
“Signal simulations can help identify communications problems, and take corrective actions without having to use, and possibly compromise the performance of real, on-line satellite systems,” Williams says in an interview.
His company recently partnered with Analytical Graphics (AGI) to develop a layered simulation system that is designed to replicate scenarios that military satellite communications signals might encounter. The system also can be used to create worst-case scenarios that would be impossible, dangerous or expensive to create in the real world, such as a nuclear disturbance, extreme weather conditions, or a downed aircraft.
AGI’s STK software provides visual and mathematical models that are used by RT Logic’s channel simulator to create real electrical signals, Williams says.
An operator can see on a computer screen actual communication links between satellites, airplanes and ground stations.
For example, if an airplane flying over a humvee was transmitting signals to the ground, the link would be affected by high Doppler shift rates and varying range delays that the humvee’s receiver would need to track. The simulation lets the operator verify performance and make necessary changes.
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