Practical beamspace MIMO approach for auroral clutter control in over-the-horizon radar

High-latitude over-the-horizon radar operations require a strategy to control clutter from plasma irregularities in the aurora borealis. The radar target and clutter signals arrive at different elevation angles and can be separated using two-dimensional transmit and/or receive arrays. Non-causal adaptive transmit beamforming requires a multiple-input multiple-output approach, with the number of transmitted waveforms minimized to preserve unambiguous Doppler. One can obtain performance approaching that of a fully adaptive array using only two waveforms transmitted on conventional beams separated in elevation.