Superresolution of coherent sources by adaptive array techniques

The resolution of two coherent sources, which are spacially separated by less than one beamwidth, is attempted via three different nonlinear-processing adaptive array superresolution techniques which are known to have impressive performance against incoherent sources. When the coherent sources maintain a fixed phase difference, none of the three techniques is able to resolve the sources satisfactorily. However, when there is sufficient relative motion or equivalent 'Doppler cycles' between the sources, then all three techniques are capable of accurately locating the sources at fractions of a beamwidth under favorable conditions. The fixed phase case can also be resolved by generating synthetic 'doppler cycles' via either real or electronic motion of the sampling subaperture.