This work tackles the problem of interferometric phase estimation in the presence of layover by using nonuniform multibaseline interferometric synthetic aperture radar systems. The effects of nonuniform sampling on Fourier-based and superresolution spectral estimation methods are investigated. The impact on both the spectral properties and on the interferometric phase estimation performance is considered. The analysis of interferometric phase estimation performance is based on Monte Carlo simulations, comparing with the corresponding Cramer Rao lower bound. The focus is on realistic single-pass acquisition systems with a low number of phase centers and a nonuniform linear array structure