Research objectives and content
Interferometric Synthetic Aperture Radar (InSAR) is a powerful technique for rapid and accurate high-resolution topographic mapping. If two SAR images derived from two spatially separated antennas are considered, their phase difference can be usefully exploited to generate Digital Elevation Maps (DEMs) of the scene under investigation. Among the current problems of this not yet mature technique, the interferometric phase equivocation (phase is measured modulo 2pi) and the data noise have a great impact on the achievable performance.
Recently Multi-baseline SAR Interferometry techniques have
been proposed in the literature, extending the standard single-baseline (two-antenna) InSAR. The aims are solving one of the key problems in InSAR, the reduction of the errors in the unwrapping of the interferometric phase, and enhancing height estimation accuracy. In fact, the baseline length affects height estimation accuracy and phase unwrapping complexity. The availability of a set of different baselines and a proper processing may achieve the following goals: absolute phase retrieval, improved estimation accuracy and reduced phase aliasing, moreover adaptivity to varying look angle and local terrain slope, and reduction of the blind angles. The current Multi-baseline techniques are still based on sub-optimal signal processing algorithms, and are tailored just to repeat-pass satellite systems. The great potential of the Multi-baseline methodology has not yet been fully exploited. The objective of this project is twofold. First, to synthesize statistically optimal signal processors for exploting entirely the additional information available at the multiple baselines. Second, to study the possible extension of the Multi-baseline data acquisition to single-pass platforms, both airborne and spaceborne, or rather to develop new Multi-channel interferometric sensors.
Training content (objective, benefit and expected impact)
It is expected that there should be some very valuable cross-fertilization with the, Antennas and Radar Group at UCL. The applicant will acquire a wider competence and make deeper the knowledge in the area of Interferometric SAR. Moreover, conditions for future cooperation between the Department of Electronic and Electrical Engineering of UCL and the Department of Information Engineering of the University of Pisa should be established.
Links with industry / industrial relevance (22)