Fabio Rocca - Academia.edu (original) (raw)

Papers by Fabio Rocca

2009 IEEE International Geoscience and Remote Sensing Symposium, 2009

Synthetic Aperture Radar (SAR) and Sonar (SAS) systems provide high resolution reflectivity maps ... more Synthetic Aperture Radar (SAR) and Sonar (SAS) systems provide high resolution reflectivity maps of the imaged scene by coherently combining the echoes collected along a virtual array of receivers. A peculiarity of SAS systems is that the echoes are often collected by moving a short real array of hydrophones to avoid range ambiguity. In this paper we present a modification of the standard wavenumber focusing algorithm widely used in SAR data processing to make it suitable for focusing bi-static SAS data. An autofocusing technique is then exploited to estimate and compensate for the deviation of the platform trajectory from the rectilinear one.

IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium, 2008

ABSTRACT In this paper a technique is described for the tomographic characterization of forested ... more ABSTRACT In this paper a technique is described for the tomographic characterization of forested areas through multiple SAR observations. This technique is based on a model of the second order statistics of the multi baseline, multi polarimetric, data which accounts for the presence of multiple distributed targets within the system resolution cell. The results of an experiment performed on a real P-band, multi-baseline, fully polarimetric data set relative to the forested site of Remningstorp, Sweden, are reported. Such results show the feasibility of performing a model based tomographic analysis of forests, resulting in a characterization of both the ground and the canopy in terms of elevation, spatial structure, and scattered power.

Advances in Engineering Software, 1993

2013 IEEE International Geoscience and Remote Sensing Symposium - IGARSS, 2013

ABSTRACT We propose an efficient method for the azimuth compression and Atmospheric Phase Screen ... more ABSTRACT We propose an efficient method for the azimuth compression and Atmospheric Phase Screen estimation of Geosynchronous SAR data. The method is based on the iterative processing of sub-apertures of increasing size, allowing to gradually refine the quality of the focused data and of the estimated APS. The whole processing can be easily parallelized. Results over simulated data are shown.

Proceedings of IGARSS '94 - 1994 IEEE International Geoscience and Remote Sensing Symposium, 1994

SAR Interferometric surveys are affected by several sources of decorrelation noise. An improvemen... more SAR Interferometric surveys are affected by several sources of decorrelation noise. An improvement of the phase accuracy can be achieved by minimizing that noise: this could require a careful "tuning" of some processing dependent parameters, beside a phase preserving focusing. The sensitivity of coherence with respect of processing parameters is studied, and techniques are presented t o minimize the effect of different decorrelation sources.

IEEE International IEEE International IEEE International Geoscience and Remote Sensing Symposium, 2004. IGARSS '04. Proceedings. 2004, 2004

The phase time series of a perfect point-wise Permanent Scatterer (PS) would show a phase jump pa... more The phase time series of a perfect point-wise Permanent Scatterer (PS) would show a phase jump passing from ERS to ENVISAT SAR images. A PS analysis has been carried out on a dataset including both ERS and ENVISAT images. For each PS, elevation, LOS velocity and phase jump have been jointly estimated and removed, allowing the identification of the atmospheric phase screen. The PS population so found represents the intersection of ERS and ENVISAT PS populations. The probability of natural targets to behave as PS both in ERS and ENVISAT has been analyzed as a function of their Radar Cross-Section, acquisition geometry and amplitude. Distributed targets with a narrow backscattering lobe pointed towards the first sensor (ERS) are not coherently observed by the second one (ENVISAT), whereas point-wise targets (e.g. natural corner reflectors, dihedrals and small mirrors) will remain coherent in both cases. Experimental results have been carried out on a data set of 69 ERS images and 7 ENVISAT images (ERS-like mode) on Milano over a 20 km side area.

IEEE/ISPRS Joint Workshop on Remote Sensing and Data Fusion over Urban Areas (Cat. No.01EX482), 2001

Abstract Summary form only given, as follows. The permanent scatterers (PS) technique, developed ... more Abstract Summary form only given, as follows. The permanent scatterers (PS) technique, developed by the authors during the last three years, allows the identification of radar targets particularly suitable for SAR interferometric measurements. In fact, despite its remarkable ...

IGARSS 2001. Scanning the Present and Resolving the Future. Proceedings. IEEE 2001 International Geoscience and Remote Sensing Symposium (Cat. No.01CH37217), 2001

Subject of this paper is the comparison of the results obtained exploiting the Permanent Scattere... more Subject of this paper is the comparison of the results obtained exploiting the Permanent Scatterers (PS) Technique on ERS DInSAR data with displacement measurements carried out by means of optical leveling and GPS.

IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2003

The Permanent Scatterers (PS) technique is a powerful and fully operational tool for monitoring g... more The Permanent Scatterers (PS) technique is a powerful and fully operational tool for monitoring ground deformations on a high spatial density grid of point-wise targets, exploiting long series of SAR data [1], [2], [3]. The most attractive aspect of this approach is the capability of providing measurements relative to individual radar targets with unprecedented precision. Up to now, PS analyses have been carried out on ERS, RADARSAT, and JERS data sets. The purpose of this presentation is to discuss the feasibility of updating results obtained by means of a PS analysis on ERS interferometric data using ENVISAT ASAR images. In particular, the main goal is to stitch coherently the new ENVISAT ASAR measurements to already available ERS displacement time series relative to individual PS. To this end, we will model the interferometric phase of point-wise targets taking account the different ERS and ENVISAT carrier frequencies. Then, we identify the main constraints to be met at individual Permanent Scatterers in order to guarantee the feasibility of coherent stitching.

2003 Proceedings of the International Conference on Radar (IEEE Cat. No.03EX695), 2003

IEEE International Geoscience and Remote Sensing Symposium, 2002

In this paper we start addressing the main advantages and possible applications of carrying out P... more In this paper we start addressing the main advantages and possible applications of carrying out Permanent Scatterers analyses involving more independent data sets covering the same test area (i.e. data acquired along parallel orbits relative to adjacent tracks as well as data gathered by ascending and descending passes). First interesting results are provided.

Time-Varying Image Processing and Moving Object Recognition, 1994

IEEE Transactions on Acoustics, Speech, and Signal Processing, 1979

This paper presents a technique for overcoming the problem of tissue absorption in emission tomog... more This paper presents a technique for overcoming the problem of tissue absorption in emission tomography. Given a set of equispaced projections in the interval (0, 2n), it is possible to derive an exact formula for recovering the spectrum of the image.

Signal Processing, 1979

... EMISSION TOMOGRAPHIC SYSTEM S. BELLINI and M. PIACENTINI, Centro di Studio per le Telecomunic... more ... EMISSION TOMOGRAPHIC SYSTEM S. BELLINI and M. PIACENTINI, Centro di Studio per le Telecomunicazioni Spaziali del CNRC CAFFORIO and F. ROCCA Istituto di ... Die Algorithmen der digitalen Filterung und der bidimensionellen Interpolation werden analysiert. ...

London 2013, 75th eage conference en exhibition incorporating SPE Europec, 2013

ABSTRACT Apart from the environmental impact of subsidence and uplift phenomena induced by fluid ... more ABSTRACT Apart from the environmental impact of subsidence and uplift phenomena induced by fluid injection and/or extraction, recent reservoir optimization techniques ask for timely information about many geophysical parameters, both downhole and on the surface. In particular, surface deformation measurements are lately gaining increasing attention within the reservoir engineer community, which is searching for new monitoring tools to complement seismic surveys. In the last decade, a new remote-sensing technology called PSInSAR™- based on the use of satellite radar data - is receiving an increasing attention, thanks to its capability to provide accurate, large-scale surface deformation measurements. The main advantages of PSInSAR™ data, compared to conventional geodetic networks, are essentially related to the spatial density of measurement points, the temporal frequency of the observations, the precision and the limited cost, at least for the monitoring of large areas. Since the number of radar-mounted satellite platforms is increasing, as well as the accuracy of radar measurements, this source of information will probably become more and more common in projects related to reservoir monitoring and optimization. More in detail, ground deformation measurement can provide valuable information to better understand the fluid/gas flow in the subsurface or to calibrate the geomechanical model of the reservoir/overburden, if properly interpreted and integrated with more conventional data.

2013 IEEE International Geoscience and Remote Sensing Symposium - IGARSS, 2013

ABSTRACT

2009 IEEE International Geoscience and Remote Sensing Symposium, 2009

We consider a geosynchronous Ku band system, and the defocusing effects due to the temporal and s... more We consider a geosynchronous Ku band system, and the defocusing effects due to the temporal and spatial variability of the atmospheric water vapor. Due to the very slow formation of the spatial chirp (minutes or even hours), the temporal change of the local water vapor content could be significant, thus preventing a correct image focusing and the formation of a

Science China Earth Sciences, 2010

In this paper, we carried out a combination of permanent scatterer and quasi permanent scatterer ... more In this paper, we carried out a combination of permanent scatterer and quasi permanent scatterer time-series InSAR image analyses to extract geometric information over the area of the Three Gorges Dam. For the first time, we measured and analyzed the deformation of the Three Gorges Dam and its surrounding area using 40 SAR images acquired from 2003 to 2008. Our results indicate that the temporal deformation of the left part of the dam has ceased and that the deformation of the dam was influenced by the changing level of the Yangtze River. Seasonal deformation due to varying temperature is also observed. The obtained results agree well with the published results of the Three Gorges Dam deformation obtained by employing conventional survey methods. We also found that there is an area of abnormal subsidence near Zigui County. This paper demonstrates the potential of time-series InSAR image analysis in the monitoring of dam stability and measurement of subsidence.

2009 Joint Urban Remote Sensing Event, 2009