Abstract: A novel method based on the weighted joint covariance matrix fitting for synthetic aperture radar interferometry is presented. The method takes advantage of the coherence information of the neighboring pixel pairs and makes use of the interferometric information embedded in a joint covariance matrix, which makes it possible to estimate the interferometric phase in the presence of large coregistration errors, even up to one pixel. Benefiting from weighting on the joint covariance matrix and employing matrix fitting to estimate the interferometric phase instead of eigendecomposition, the method does not need to calculate the signal subspace dimension, thus avoiding the effect of the rank variation of the signal subspace. A fast algorithm for the interferometric phase estimation is proposed in which the closed-form solution to the interferometric phase is directly obtained, for the angle scanning search based method is time-consuming. The results of numerical simulations and real data demonstrate the validation of the proposed method.