Monitoring the actual surface deformation caused by subsurface fluid activities is crucial for comprehending the subsurface fluid mutation process. Incorporation of InSAR observations in a prior volume strain model can facilitate the estimation of subsurface fluid volumetric changes and three-dimensional (3-D) surface deformation. However, the model parameters, i.e., the thickness and depth of the subsurface fluid reservoir, are assumed to be known a priori. Therefore, it is impossible to acquire the precise model parameters in practice. Therefore, we proposed a novel approach for adaptive est...