Interferometric Synthetic Aperture Radar (IFSAR) is a technique for ra and accurate topographic mapping.
The Digital Elevation Model (DEM) of the scene under investigation is built up by using the phase difference of the signals received by two spatially separated antennas. However, the measured phase difference is restricted to the range [-Pi, Pi], whereas the useful one covers a larger range.
The DEM generation is, therefore, carried out by: conventional SAR dat processing of the two received signals, accurate registration of the two complex images, and phase unwrapping of the measured phase difference.
Concerning the phase unwrapping techniques, the difficulties involved this particular application are given by the typical SAR system geometry. As matter of facts, when the terrain slope grows the measured phase difference may result undersampled (layover regions). Furthermore, due to either decorrelation or shadow effects, the measured signals may have low Signal-to-Noise ratios.
The above mentioned aberrations render the inversion from measured pha to DEM profile very difficult, and the uses of local inversion techniques generate global errors.
The objective of this project is to examine the possibility to use SAR focusing algorithms that directly generate registered images and the use of global phase unwrapping techniques that confine the DEM errors around the aberration sources.