Method for measuring the movement of urban areas and landslide areas.

摘要

Process for radar measurements of movements in urban areas and areas landslide, taking N 20 images available via a radar synthetic or SAR opener over a period of several years, identifies for each resolution cell, the scatterers whose electromagnetic characteristics remain unaltered over time, and which are called Dispersing permanent or PS, characterized in that said PS are identified through the following steps: (a) forming N-1 differential interferograms with respect to the main image, called master using a digital elevation model or DEM, having a vertical accuracy better than 50 meters; (B) generating a time series of the interferometric phases (127, 116-118), for each pixel (112- 115) of the image of step (a) chosen according to statistical properties of the modulus of the reflectivity, then obtain differences between time series that belong to neighboring pixels; (C) calculating the linear phase components for each differential time series of step (b) with respect to the baseline, and the phase components associated with the model constant speed subsidence, already known, with respect to time; (D) associating the relative error between the precise elevation of the pixel supplied from DEM of step (a) with the linear phase component of step (c) with respect to the baseline; (E) associating the relative movement of the pixel in the direction of the SAR to the polynomial phase variation with time of step (c); (F) obtaining the phase residuals by subtracting the contributions calculated in steps (d) and (e) after a phase unwrapping procedure on the sparse mesh formed by the previously selected pixels; and (g) analyzing the power spectral density of the phase residuals.