  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.
