The Importance of Simulation During the Pre-Operational Years of a New GNSS System

John Fischer

The Korean Positioning System (KPS) is being developed to address the unique challenges for Korea in providing accurate Position, Navigation, and Timing (PNT) to its citizens: accurate satellite signal reception in canyons, both urban and rural; resilience to jamming and spoofing from the North; and creating a sovereign system, independent of other countries, to ensure its future prosperity. There are already four major Global Navigation Satellite Systems (GNSS) and two regional ones in operation, so Korea can learn from these deployments and improve, using the latest technology available. One lesson from the past is the importance of simulation at every step in the development process. Deploying a new GNSS system is a major undertaking taking decades to go from conception to full operation. Simulation is important at every stage: at the initial design stage to verify performance before the huge expense of building and launching satellites happen. Then, after first launch, it takes years to fully deploy a constellation, so there will be a transitional operational phase where only one or two Space Vehicles (SVs) are transmitting signals. At this stage, the first transmissions are being verified. Users have limited capability and need hardware simulation to completely characterize the full constellation behavior. Finally, once the constellation is at the Full Operational Capability (FOC) stage, simulation is used to test production equipment efficiently, verify interoperability with other GNSS systems, and most importantly, test resilience against jamming and spoofing. The threats from the North and other sources are constantly evolving, so the simulation must evolve with them. Additionally, there are many other uses of the GNSS signals beside just PNT, such as environmental remote sensing, so the simulations must be highly adaptable for decades.

Keywords: GPS, GNSS simulation, KPS, anti-spoofing, anti-jamming