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We consider waveform design for colocated multiple-input, multiple-output (MIMO) radar systems where the signal phase is subject to random phase perturbations during propagation. We formulate an iterative algorithm to obtain both waveform parameters and the space-time adaptive weights to maximize the signal-to-interference-plus-noise ratio (SINR). We ensure that the impact of the chosen waveforms...
An Over-The-Horizon Radar (OTHR) has been deployed near Ottawa, Canada. The radar is aimed northward and collects auroral echoes through line-of-sight propagation and ground echoes from beyond the horizon through ionospheric reflection. These echoes have been resolved in the three spatial dimensions of range, azimuth, and elevation, as well as in the temporal dimension of Doppler. It is shown that...
The spatial autocorrelation of an electric field associated with an electromagnetic wave packet is modified by propagation through the ionosphere. An analytic formula for the autocorrelation is derived based on a linear plasma density profile for the ionosphere and a power-law turbulence spectrum for ionospheric irregularities. This work provides guidance for interpreting the results of radio experiments...
Under certain conditions, it is shown that adaptive arrays with up to six spatial dimensions (three on transmit and three on receive) can provide vast improvements in auroral-zone clutter suppression capability compared to one-dimensional adaptive receive arrays. The required conditions are that the array manifold vector and its associated clutter covariance matrix are factorable into the n-fold Kronecker...
New data is presented from an over-the-horizon radar experiment featuring simultaneous multiple transmit channels and multiple receive channels. A joint transmit-receive adaptive beamformer is demonstrated, whereby nulls are placed in the direction of auroral clutter echoes on both transmit and receive. It is shown that the level of the clutter suppression produced by the joint transmit-receive beamformer...
High frequency Over-the-Horizon Radar (OTHR) provides an economical means to track noncooperative air targets over large expanses of land and ocean. However, OTHR in Canada is confounded by the presence of radar clutter from the region of the aurora borealis. Given the time-varying nature of auroral clutter, this paper proposes joint adaptive transmit and receive beamforming as a key tool to deal...
High frequency Over-the-Horizon Radar (OTHR) provides an economical means to track noncooperative air targets over large expanses of land and ocean. However, early attempts to run OTHR in Canada in the 1970s were confounded by the presence of intense radar clutter originating in the auroral zone. Recent advances in Multiple-Input Multiple-Output (MIMO) OTHR technology, namely orthogonal waveform transmit...
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