Proceedings Article | 21 December 2000
Proc. SPIE. 4173, SAR Image Analysis, Modeling, and Techniques III
KEYWORDS: Information fusion, Roentgenium, Sensors, Synthetic aperture radar, Interferometry, Phase interferometry, Buildings, Data processing, Phase measurement, Binary data
In this paper we evaluate a combined phase unwrapping method that improves the results in difficult areas (containing noise and discontinuities) taking advantage of the Region Growing (RG) and Weighted Least Mean Square (WLMS) algorithms. The performance of the combined method is based on the following steps. Starting from the wrapped phase, a binary mask is calculated using a first RG solution, in order to generate a mask which is able to consider low-quality pixels. Afterwards, the WLMS solution is calculated using the wrapped phase and the RG mask. To obtain this WLMS solution it is not necessary to compute many iterations, since the objective of this step is just to ease the subsequent RG process. Therefore, the calculation time is smaller than with a WLMS solution separately, because it needs a larger number of iterations to converge. As commented, at this stage the RG algorithm is applied in order to unwrap the error of the WLMS solution, which is expected to have less noise than the input interferogram. Therefore, the RG is able to handle its values in a relatively easy manner. Finally, the first WLMS solution and the unwrapped error are added to obtain the desired unwrapped phase.
