Telecomunicazioni > Telerilevamento


http://www.elet.polimi.it/dsp

Focus

Development of remote sensing methodologies and signal processing techniques for oil prospecting, pipeline monitoring, seabed topography and deformation detection (using acoustic waves), Digital Elevation Model, ground deformation measurement and 3D scene reconstruction (using microwaves). In essence, the targets are either insonified from the ground in one case or illuminated with microwaves from air or space, in the other. The reflected wave field is focused, using multidimensional frequency or space- time domain techniques. The physical characteristics of the propagation medium and of the scatterers are determined solving the inverse problem.

Risultati principali della ricerca


Repeated-pass INSAS for sea-bed motion measurement
In the framework of a two-year project promoted and financed by Eni, experimental activities were conducted on testing innovative approaches for estimating sea-bed altimetry and motion.
The selected methodology is based on repeated surveys carried out by a 300KHz Synthetic Aperture Sonar (SAS) mounted on an underwater autonomous vehicle operated by (NURC- Nato) in several sea campaigns in the Tyrrhenian Sea near La Spezia.
A phase preserving, full-bandwidth SAS focusing technique has been developed and repeat-pass SAS interferograms have been generated for the first time.

L and P band SAR Tomography
Development of operational techniques for carrying out tomographic analyses of distributed media from airborne and ground based data, involving accurate phase calibration of the data-set and advanced beamforming. Development of a new matrix decomposition technique for the separation of ground and volume scattering from multi-baseline, multi-polarimetric SAR data (Algebraic Synthesis). New insights about the physics of radar scattering from forested areas, mostly involving the role of double bounce scattering from trunk-ground and canopy-ground interactions.

SAR
Evaluation of performances, coding of the processor and support to calibration of the forecoming Argentinean constellation SAOCOM (two L-band SAR satellites). The group is also supporting its spin-off, Aresys, to carry out similar ativities for the next generation of ESA SAR (Sentinel1-A an Sentinel1-B): desgn of high-quality phase preserving processor and development of an innovative calibration scheme based on natural stable reflector, that is quite accurate and innovative. The group is currently active in the design of the future generation of SARs, like a Ka-band single pass interferometer, sub-contracted from Thales Alenia Space, and the proposal of a geostationary SAR as VIII ESA Explorer mission (2010).

Geophysical data processing
This geophysical research is carried out in collaboration with ENI. It is addressed to the development and validation of innovative tools for depth imaging. It includes imaging of converted waves, identification and removal of multiple reflections and efficient modeling of the effects of anisotropy on wave propagation. The activities are aimed to innovate the methodologies and to develop efficient computer codes.

Vibroacoustic monitoring of pipelines
In the framework of an ongoing project promoted and financed by Eni, DEIB the group is testing innovative approaches for monitoring fluid transportation pipelines. The basic principle is the remote detection of acoustic/elastic waves generated by third party interferences and guided within the pipeline. The group has run several field test campaigns in order to validate the mathematical models and to derive the technical specifications of a new monitoring proprietary system, which is now in the pre-industrialization phase.