نتایج جستجو برای: ماهواره envisat
تعداد نتایج: 6744 فیلتر نتایج به سال:
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...
Current operation mode of SAR can be roughly divided into two types: strip-map mode and burst mode. The most conventional mode is strip-map mode, in which the swath width is quite limited. The other type is burst mode, which is an active option to overcome this limitation by cyclically scanning several subswaths, known as ScanSAR. In addition, Envisat ASAR has another type of burst mode, that i...
In radar images, point scatterers provide reflections that can often be attributed to a single physical object, usually smaller than the resolution cell size. Stable point scatterers with high backscatter coefficients through time (mainly ’man-made features’) are potential targets for InSAR deformation analysis. A-priori knowledge about the observation statistics of InSAR point scatterer measur...
RESUME A model is developed for the quantitative prediction of the azimuth radiometric modulation, commonly known as scalloping, that is occasionally present in burst mode SAR products from RADARSAT-1 and ENVISAT. The model is based on the combined effects of poor Doppler estimation, placement of the burst sequence in the azimuth beam pattern for the target area, and the details involved in per...
The very short temporal separation (about 28 minutes) of the ERS-2 and ENVISAT satellites is very attractive to obtain almost-simultaneous acquisitions, appealing for SAR Interferometric applications both for the very high temporal correlation, for the strong reduction of atmospheric artefacts, and for monitoring fast displacements. The problem of the interferometric combination of such data ar...
Tracking and monitoring ocean features which have short coherent time periods from sequential satellite images requires that the images have both very high spatial resolutions and short temporal sampling intervals (i.e., repeated cycles). Satellite images from a single sensor in a polar-orbiting satellite usually cannot meet these requirements since high spatial resolution of the sensor may res...
Several radiative techniques have been developed for inverse estimation of the leaf area indes (LAI) using optical data measured below the canopy (e.g. hemispherical photography) or above the canopy (remote sensing). In the inversion, a model of the three-dimensional distribution of leaves in the canopy is used to define the required relation between LAI and canopy transmittance and reflectance...
در این پژوهش هدف شناسایی و اندازه گیری زمین لغزش در منطقه سمیرم واقع در 150 کیلومتری جنوب اصفهان با استفاده از تکنیک تداخل سنجی راداری می باشد. داده های مورد استفاده شامل 28 تصویر راداری است که توسط ماهواره envisat بین سال های 2003 تا 2010 میلادی تهیه شده است. این تکنیک منجر به شناسایی دو زمین لغزش مهم در جاده سمیرم-یاسوج شده و بعضی از مناطق لغزش سنگی نیز شناسایی شده است. به منظور بررسی زمانی ز...
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