Mapping ground motions by open-source persistent and distributed scatterers Sentinel-1 radar interferometry: Ho Chi Minh city case study.

Recent, an advanced Persistent Scatterers and Distributed Scatterers (PSDS) InSAR algorithm has been implemented as an open-source TomoSAR package (https://github.com/DinhHoTongMinh/TomoSAR). This effort aims to contribute the spatial distribution of subsidence in Ho Chi Minh City (HCMC), the most crowded city and economic hub of Viet Nam, in its horizontal and vertical components by using TomoSAR. With Sentinel-1 data, taking into account the presence of east-west horizontal motion, our findings indicate that the accuracy of the decomposed vertical velocity can be improved by up to 3 mm/year for Sentinel-1 data. The obtained results revealed that subsidence is most pronounced in the areas along the Sai Gon River, in the northwest-southeast axis, and in the southwest of the city, with a maximum value of 80 mm/yr, which is in accordance with the findings of the literature. The amplitude of east-west horizontal velocities is relatively small and large-scale eastward movement can be observed in the west of the city at a rate of 3-5 mm/year. This confirmed that the displacement in Ho Chi Minh City area is mainly vertical downward.