Expert Opinions: Considerations for simulating GNSS signals for UAVs

Q: What are the key factors to consider when simulating GNSS signals for UAVs?

Mitsuo Shiono, CEO, IP-Solutions, Zero C Seven Inc.

A: For UAV simulation, a record-and-playback system is obviously less applicable, as the user is more interested in defining system operability within a range of parameters rather than in any generalized case. A high-dynamic user performance is required, but users should look at a simulator’s static performance first to ensure high accuracy. Interference, both intentional and unintentional, is the main challenge. At least two RF outputs are required to facilitate development of differential and RTK algorithms and to simulate multiple antennas.

Iurie Ilie, Chief Technical Officer, Skydel

A: Safety and compliance to existing regulations are the key factors for UAVs. To evaluate them in harsh environments, the GNSS simulator should push the UAV’s navigation system to the limits. The simulator should allow for creation of complex scenarios with drastic changes in satellite constellations, signal/frequency diversity and signal quality. The simulation of multipath signals and interference should account for relative dynamics between the UAV and the environment. Importing six-degrees-of-freedom (DOF) complex trajectories is another important factor to consider.

Tim Erbes, Chief Technology Officer, Talen-X

A: The UAS simulator must support realistic flight profiles with the ability to integrate autopilot controllers. Affordable simulators need to support closed-loop simulation so the guidance logic will have an impact on the simulated signals. Another critical aspect to consider is the ability to integrate the threat signals enabling counter-UAS testing. We must have a simulation capable of supporting all signals present in the environment — PNT, threats and communications.