  A multiple input, multiple output (MIMO) radar emits probings signals with
multiple transmit antennas and records the reflections from targets with
multiple receive antennas. Estimating the relative angles, delays, and Doppler
shifts from the received signals allows to determine the locations and
velocities of the targets. Standard approaches to MIMO radar based on digital
matched filtering or compressed sensing only resolve the angle-delay-Doppler
triplets on a $(1/(N_T N_R), 1/B,1/T)$ grid, where $N_T$ and $N_R$ are the
number of transmit and receive antennas, $B$ is the bandwidth of the probing
signals, and $T$ is the length of the time interval over which the reflections
are observed. In this work, we show that the \emph{continuous}
angle-delay-Doppler triplets and the corresponding attenuation factors can be
recovered perfectly by solving a convex optimization problem. This result holds
provided that the angle-delay-Doppler triplets are separated either by $10/(N_T
N_R-1)$ in angle, $10.01/B$ in delay, or $10.01/T$ in Doppler direction.
Furthermore, this result is optimal (up to log factors) in the number of
angle-delay-Doppler triplets that can be recovered.
