Design and implementation of a calibration source system for MIMO high-frequency radar

MIMO technology is effective to expand the aperture of radar arrays, which can improve the angular resolution. To ensure the consistency of the array amplitude and phase in the MIMO high-frequency-surface-wave-radar and guarantee the accuracy of orientation estimation in radar detection, we design and implement a MIMO HFSWR calibration source system based on asynchronous FIFO delayed retransmission, which overcomes traditional calibration limitations, such as the inability to calibrate transmitting and receiving arrays simultaneously and suboptimal calibration accuracy. Additionally, to resolve the problem that far-field HFSWR calibration must be conducted using drones or ships over the sea, we propose a near-field calibration method based on the designed calibration source system. This scheme enables the simultaneous calibration of the MIMO radar transmitting and receiving arrays in on-land near-field region. The results from the near-field calibration experiments indicate that when using multiple signal classification DOA estimation, RMSE of the angle estimation error is reduced to 0.7° after near-field calibration.