Interferometric local time space estimation of motions of persistent scatterers
Abstract
Satellite imaging is shifting from the photo-interpreter era to an era of automatic monitoring and big data processing. The European Space Agency has launched two earth observation public satellites, the Sentinel1 constellation , which yield a steady flow of synthetic aperture radar images everywhere, every 3-5 days, at 310 meters resolution. Using these recurrent satellites in interferometric mode and using the precision of their return, one can monitor the Earth by interferometry, namely analyze by interferometry short times series and detect local significant changes of ground and buildings, generally caused by humanactivities.This project aims to define local procedures in time and space to assess small relative movements of persistent scatterers by interferometry in synthetic aperture radar satellite imagery (InSAR). This is theoretically possible using the "double phase difference" technique, the principle of which is to estimate only differences in phase differences between persistent and neighboring reflectors. Indeed, making these differences cancels out the circumstantialeffects due to the atmosphere, to errors in the attitude of the satellites, and tothe properties of the diffusers themselves. The application goal of the project is to monitor industrial installations and in particular their thermal deformations caused by human activity. In addition and more classically, another goal is to assess the local displacements of the soil caused by pumping processes, in particular hydraulic fracturing and the exploitation of underground water. Work will be carried out on data from the European public satellite constellation Sentinel-1 as well as data from commercial satellites such as COSMOSkyMed.The project will develop a mathematical and statistical method to select notexactly as usual persistent scatterers, but rather groups of permanent or "locally" persistent scatterers, using stochastic geometry techniques to establish a contrario models allowing to detect groups of coherent scatterers by calculating their number of false alarms. This has never been done before. The project will also take up the problem of modular inversion of linear systems where the observations are known modulo the wavelength of the sensor, to examine in a general framework the spatio-temporal methods of phase unwrapping. Thedevelopment of this project at Centre Borelli, Ecole Normale Suprieure Paris-Saclay, will benefit from its close collaboration with the Paris Tectonics and Mechanics of the Lithosphere at the Institute of Physics of the Globe and from data provided by the industrialist Kayrros.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 11, 2020
- Source ID
- N000142012684
Entities
People
- Jean-michel Morel
Organizations
- Office of Naval Research
- United States Navy
- École Normale Supérieure