The problem of spatial signature estimation using a uniform linear array with unknown receiver gain and phase responses is studied. Sufficient conditions for simultaneously iden- tifying the spatial signatures and the calibration parameters are derived, and a closed form ESPRIT-like estimator is proposed. The performance of the method is investigated by means of simulations, and on experimental data collected with an antenna array in a suburban en- vironment. The results show that the absence of receiver calibration is not critical for uplink signal waveform estimation using a plane wave model
