An eigenstructure-based method for direction finding in the presence of sensor mutual coupling, gain, and phase uncertainties is presented. The method provides estimates of the directions-of-arrival (DOA) of all the radiating sources as well as calibration of the gain and phase of each sensor and the mutua1. coupling in the receiving array. Calibration sources at known locations are not required. Conditions are provided for the existence of a solution. The proposed algorithm is described in detail, and its behavior is illustrated by numerical examples.