Revealing spoofing of classical radar using quantum noise

TL;DR

This paper models electromagnetic radar spoofing considering quantum and practical noise sources, deriving optimal detection probabilities and demonstrating that Bayesian inference can reliably identify spoofing attempts.

Contribution

It introduces a comprehensive spoofing model including thermal and quantization noise, and shows near-optimal detection methods using heterodyne reception and Bayesian inference.

Findings

Quantum noise limits spoof detection accuracy.

Heterodyne reception approaches optimal detection performance.

Bayesian inference from pulse sequences enhances spoofing detection.

Abstract

Electromagnetic remote sensing technologies such as radar can be mislead by targets that generate spoof pulses. Typically, a would-be spoofer must make measurements to characterize a received pulse in order to design a convincing spoof pulse. The precision of such measurements are ultimately limited by quantum noise. Here we introduce a model of electromagnetic spoofing that includes effects of practical importance that were neglected in prior theoretical studies. In particular, the model includes thermal background noise and digital quantization noise, as well as loss in transmission, propagation, and reception. We derive the optimal probability of detecting a spoofer allowed by quantum physics. We show that heterodyne reception and thresholding closely approaches this optimal performance. Finally, we show that a high degree of certainty in spoof detection can be reached by Bayesian inference from a sequence of received pulses. Together these results suggest that a practically realizable receiver could plausibly detect a radar spoofer by observing errors in the spoof pulses due to quantum noise.