In this paper, a new method of the interferometric phase estimation based on the model of the optimal weighted joint data (OWJD) vector is introduced. The method performs the optimization on the received radar echo vector by using the construction of the OWJD vector and all coherence information available, i.e., the processing based on the model of the OWJD vector can not only adaptively coregister the SAR images, but also accurately determine the dimensions of the noise subspace, which is independent of the magnitude and direction of the coregistration error. Theoretical analysis and experimental results show that the method can provide the accurate estimation of the interferometric phase even if the coregistration error is close to one pixel.