Multi-baseline phase unwrapping via maximum likelihood phase gradient estimation

In this paper, a novel multi-baseline phase unwrapping approach is proposed based on maximum likelihood estimation (MLE) method. Topography phase gradient is acquired by fusing multi-baseline InSAR data. It is convenient to obtain unwrapped phase by using gradient integral. Since search interval is critical for the uniqueness and accuracy of solution, low-precision digital elevation model (DEM) is imported to improve the estimation interval. Simulations corroborate the validity of maximum likelihood unwrapped phase estimation method proposed in our work.