" " ISSN 1684-1719, N 7, 2016

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528.71

3. PS PALSAR/ALOS

 

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20 2016 .

 

. PALSAR/ALOS . .

: , , , , ALOS, PALSAR, SARscape.

Abstract. The paper presents the results of ALOS PALSAR data processing for a dataset acquired over the territory of Moscow region. In order to obtain stable measurements in the presence of high temporal decorrelation the Persistent Scatterers technique was used. We have conducted experimental studies of the potential and restrictions of PS technique applied to long temporal series of 29 SAR images obtained during 18.06.2006 - 14.02.2011 over the Moscow city territory by ALOS PALSAR instrument (L-band SAR), 23,6 cm wavelength).

One of the important results obtained was the discovery of four-fold reduction of the PS spatial density for urban territory in L-band compared with C-band SAR like as ENVISAT ASAR. The effect may be explained by the decrease of radar cross-section of corner-like scatterers in urban territories at longer wavelengths, their respective fading and subsequent decrease of PS density.

The dependence of PS history of displacements for the targets spread across the test territory in the case of varying length K of SAR images time series was studied also. It was discovered that for K=27, 28 29 the velocities of PS displacements as well as residual heights being measured are practically the same.

To study the problem of the atmospheric phase distortions we analyzed histories of PS displacements derived using the technology of Atmospheric Phase Screen, which is calculated by SARScape software in a procedure of spatial/temporal filtering of differential interferograms from the data stack. The decrease of the PSs displacement histories correlation level was found to be typical for the PSs spaced at the distance larger than 1.5 km. At the same time high correlation level of displacement histories of densely located PSs leads to the assumption that significant amount of residual phase distortions may be associated with inaccuracy of the recovery of low-frequency spatial component of atmospheric phase screen models.

Key words: persistent scatterers technique, PS, SAR, ALOS, PALSAR, atmospheric phase screen, APS, DEM, SARscape.