Phase continuous radar test set

A method of generating phase-continuous, coherent radar target returns is described which leverages existing Commercial Off-The-Shelf (COTS) Radio Frequency (RF) channel simulator technology. This hardware-in-the-loop system avoids the generation of unintentional spurious signals due to the discrete range steps typically utilized in traditional radar test sets. The time delay, Doppler, and amplitude variations are entirely phase continuous, replicating the true analog behavior of a real target return. Digital signal processing techniques are employed to interpolate the RF propagation and scattering effects. The interpolation smoothes the motion dynamics to ensure a pure analog signal return to the radar. The radar test set also provides physics-compliant Doppler characteristics by time domain expansion/compression of the modulation as well as the RF carrier. Often, Doppler is simply emulated with a shift in the carrier frequency only. Doppler shifts on the modulation result in degradations in radar signal processing such as pulse compression fidelity. Without properly imparting time domain expansion/compression, these degrading effects are not tested. Further, the radar test set provides correlated range/Doppler dynamic motion without discrete phase discontinuity artifacts enabling superior test performance.