Radar Range Deception with Time-Modulated Scatterers

TL;DR

This paper introduces a method to deceive radar systems by using time-modulated scatterers to manipulate Doppler signatures, enabling cloaking and false target positioning, with experimental validation on linear frequency modulated radars.

Contribution

It presents a novel theoretical and experimental approach for radar deception using time-modulated scatterers, applicable to common radar waveforms and capable of creating illusionary target positions.

Findings

Effective radar cloaking demonstrated experimentally.

Ability to make objects appear closer than actual distance.

Method compatible with semi-passive, time-dependent metasurfaces.

Abstract

Modern radar systems are designed to have high Doppler tolerance to detect fast-moving targets. This means range and Doppler estimations are inevitably coupled, opening pathways to concealing objects by imprinting artificial Doppler signatures on the reflected echoes. Proper temporal control of the backscattered phase can cause the investigating radar to estimate wrong range and velocity, thus cloaking the real position and trajectory of the scatterer. This deception method is exploited here theoretically for arbitrary Doppler tolerant waveforms and then tested experimentally on an example of the linear frequency modulated radar, which is the most common waveform of that class used in practice. The method allows retaining radio silence with a semi passive (battery assisted) approach that can work well with time-dependent metasurfaces. Furthermore, as an insight into new capabilities, we demonstrate that temporally concealed objects could even be made to appear closer than they truly are without violating the laws of relativity.