Mutual coupling and phase control on large HF arrays

When using a large phase array in order to carry out active sensing or direction finding in the HF band, various effects act on the processing of the array signals. Some are related to the design of the array and can be corrected (insufficient knowledge of the sensor positions, lack of antennas reproducibility). Others affect the shape of the wavefront onto the array due either to propagation internal to the antenna (VSWR) or to external propagation (multipaths, ionospheric channel fluctuations, mutual coupling between elements).<>