The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, we present the results of D-InSAR technique and conventional leveling at selected area in Tianjin city, using 8 ENVISAT SAR images between 17 October 2003 and 17 February 2005.The D-InSAR results show that the subsidence rate reached over 5 cm/year (7 cm within 16 months) in highly sinking area, and it is consistent with leveling results. D-InSAR is able to provide more details of urban...
A new interferometric SAR mode has been recently introduced termed differential interferometry (Diff-Tomo). In this paper, two new potentials coming from the joint elevation- velocity resolution capability of Diff-Tomo are introduced. The first concerns differential measurements and elevation profiling of volumetric scatterers with non rigid motion and possible temporal decorrelation. The second concerns...
Radar Polarimetry, Radar Interferometry and Polarimetric SAR Interferometry represent the current culmination in active 'Microwave Remote Sensing' technology, but we still need to progress very considerably in order to reach the limits of physical realizability. Whereas with radar polarimetry the textural fine-structure, target orientation, symmetries and material constituents can be recovered with...
Recently, many researches have demonstrated that polarimetric SAR interferometry is the most promising technique for forest parameter extraction. In this paper, we present a robust forest height extraction technique based on reliable phase estimation. The more accurate interferometric phase estimation can be attained with the reliable ground phase and canopy phase using three-stage inversion process...
A necessary step for every DInSAR technique is to properly select the data from which deformation information will be calculated. Two main processes must be done in this sense, the interferogram set creation and the quality pixel selection. In this paper we will present advances concerning both issues: a new method for selecting a high quality and reduced interferogram set solving an equivalent minimum...
The DInSAR technique enables to determine with precision the surface displacements, using a combination of multiple interferograms. The DInSAR processing steps generate different kinds of errors, which propagate in the entire chain. This work is focused on a particular type of error generated during the DInSAR processing: the unwrapping related errors. The errors generated during the unwrapping process...
In this work we present a methodology for developing a Permanent Scatterers (PS) analysis jointly exploiting data acquired from parallel orbits to estimate height and deformation trend of multi-angle urban targets. The methodology allows applying the PS technique also in areas where the number of ASAR acquisitions per single track would prevent to get reliable estimates. Preliminary experimental results...
Multiple SAR signals acquired along different orbits can be exploited for reconstructing a three dimensional (3-D) reflectivity profile of the scene along azimuth, range and elevation co-ordinates. For the 3-D image formation, the problem of the non-uniform spacing of the orbits has to be considered. In this paper we propose a technique based on two steps: 1) a preprocessing step, in which the samples...
Polarimetric SAR interferometric data can provide estimates of forest biomass density. There are different approaches to deal with the inversion problem, such as neural networks and the traditional optimal estimation approach. This paper presents a study to evaluate their performance by means of quantitative indexes addressing both the computation time and the retrieval accuracy. Better forest parameters...
InSAR data acquired from independent overlapping tracks can be exploited for a reliability assessment of the Persistent Scatterer InSAR (PS-InSAR) technique. This is obtained by means of the datum connection of multiple tracks, simultaneously evaluating the misclosures between multi-track PS-InSAR estimates. Due to a different viewing geometry, many of the detected PS will physically not be the same...
Bistatic SAR systems are an emerging research field. In which context, the Universitat Politecnica de Catalunya is developing a ground based bistatic system using ESAs ENVISAT and ERS-2 as transmitters. In this paper we characterize the bistatic interferometric phase and the different sources of decorrelation. We will also present a bistatic interferometric simulator which is able to generate realistic...
This paper presents the concept and initial breadboarding results of geostationary atmospheric sounder (GAS), which is being developed by Saab Space AB and Omnisys AB, Sweden, and funded by European Space Agency (ESA). GAS utilizes interferometric synthetic aperture radiometry to obtain desired spatial (30 km) and temporal (nowcasting) resolution for measurement of atmospheric temperature and humidity...
This paper presents the concept of Dynamic Persistent Scatterers Interferometry (PSI) processing, which enables the sequential estimation of parameters. The method is based on the Integer Least Squares (ILSQ) PSI concept and makes use of the estimation vector and corresponding variance-covariance matrix of the initial estimation epoch. In addition, the concept of multi-modal adaptive estimation and...
In this paper we show the results of an airborne differential SAR interferometry (DInSAR) experiment carried out over the Perugia area, center of Italy, by using the X-Band OrbiSAR system. Measurements on corner reflectors allowed us evaluating the system detection capability.
There is under consideration a combined influence of the transients in the filters of the radar system selective circuits, non-equidistance of the taken readings and divergence of the beams at the distance up to the earth surface reflecting elements that is comparable with a synthetic antenna aperture value. There is taken into account influence of the above-mentioned factors on the resolution capability...
Permanent monitoring of potential rock-slide area can be done using interferometric radar measurements where the accuracy is limited by the variation of the velocity of light, i.e. variation of the refractive index. Using differential interferometric measurements, the measurement accuracy can be very good if the distance between the reference and the potential rock-slide area is small. However, if...
In this paper, two techniques for estimating accurate height profiles of the ground, using multi-baselines interferometric synthetic aperture radar (In-SAR) data and an a-priori inaccurate digital elevation model (DEM) of the observed scene, are analyzed. The methods are both based on maximum likelihood (ML) estimation: the first estimates directly the quota of each pixel of the image, independently...
An alternative interpolation technique for SAR image coregistration in interferometric processing is formulated and described. The proposed algorithm is based on the 1- D Farrow interpolator and, when combined with an adequate implementation, it involves a smaller computational burden than the conventional method and yields high accuracy. Basically, this technique enables to carry out the coregistration...
This work presents a phase unwrapping (PU) algorithm for SAR interferometry based on an approximate grid-based filter (GbF). This PU algorithm, which makes use of state space techniques, performs simultaneously noise filtering and phase unwrapping. The formulation of this technique provides independence from noise statistics and is not constrained by the non-linearity of the problem. Results obtained...
A grown importance in long-term operational glacier monitoring has emerged, mainly due to the connection of glacier recession to climate changes. Up to now, mainly two types of methods have been used for the estimation of glacier flow velocities: Image matching and differential interferometry (DInSAR). Although the principal potential of DInSAR for glacier velocity estimation has been shown in several...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.