A distributed radar system, apparatus, architecture, and method is provided for coherently combining physically distributed radars to jointly produce target scene information in a coherent fashion without sharing a common local oscillator (LO) reference by configuring a first (slave) radar to apply fast and slow time processing steps to target returns generated from a second (master) radar, to compute an estimated frequency offset and an estimated phase offset between the first and second radars based on information derived from the fast and slow time processing steps, and to apply the estimated frequency offset and estimated phase offset to generate a bi-static virtual array aperture at the first radar that is coherent in frequency and phase with a mono-static virtual array aperture generated at the second radar, thereby achieving better sensitivity, finer angular resolution, and low false detection rate.