124,392 research outputs found
Long-wavelength Pol-InSAR for glacier ice extinction estimation
No full textIn recent years there has been increased interest in using synthetic aperture radar (SAR) to study and monitor glaciers for climate change research. This paper describes the estimation of ice extinctions through modelling of Pol-InSAR (polarimetric interferometric SAR) coherences as a combination of a surface contribution (from the snow-firn interface and wind-induced features) and a volume response. Ground-to-volume scattering ratios derived from a novel polarimetric decomposition are used in conjunction with Pol-InSAR interferometric coherence magnitudes to invert the extinction of the ice layer. The inversion is performed with experimental airborne Pol-InSAR data at L- and P-band collected using DLR's E-SAR system over the Austfonna ice cap in Svalbard, Norway as part of the 2007 ICESAR campaign. Extinction-dependencies on frequency and glacier zone are investigated, and validation is performed comparing P-band sounder data to inverted extinction values
sj-docx-1-pol-10.1177_02633957221148951 – Supplemental material for Economic development, corruption, and income inequality: The role of the informal sector
No full textSupplemental material, sj-docx-1-pol-10.1177_02633957221148951 for Economic development, corruption, and income inequality: The role of the informal sector by Mathew Y H Wong in Politics</p
Extinction estimation over land ice using long-wavelength Pol-InSAR
No full textIn recent years there has been increased interest in using SAR to study and monitor glaciers and ice sheets for glaciological and climate change research. This paper describes for the first time the estimation of ice extinction through the modelling of Pol-InSAR coherences as a combination of a surface contribution from the snow-ice interface and a volume response. Separation of the ground and volume contributions is obtained through decomposition of the polarimetric coherency matrix. Both model-based Freeman 2- and 3-component and eigenvector decompositions are examined. Ground-to-volume scattering ratios derived from polarimetry are used in conjunction with Pol-InSAR interferometric coherences to invert the extinction of the ice layer. Validation is performed with airborne Pol-InSAR data at L- and P-band collected using DLR's E-SAR system over the Austfonna ice cap in Svalbard, Norway as part of the ICESAR campaign
Daniel H. GARRISON, The Student's Catullus.
No full textTordeur Pol. Daniel H. GARRISON, The Student's Catullus.. In: L'antiquité classique, Tome 69, 2000. p. 350
Matrix-POL architecture for integrated power supply
No full textIn this study, integrated H-bridge converter with the Matrix-POL power supply system is proposed. From the simulation results, the validity of the Matrix-POL is revealed. The results revealed that the fast response to the load current and the voltage change can be done with duty and parallel number control by the proposed system.7th International Power Electronics Conference, IPEC-Hiroshima - ECCE Asia 2014; Hiroshima; Japan; 18 May 2014 through 21 May 201
Characterisation of oriented volumes in glacier ice and extinction inversion with Pol-InSAR
No full textIn recent years there has been increased interest in using SAR to study and monitor glaciers and ice sheets for glaciological and climate change research. This paper describes the estimation of ice extinctions through the modelling of Pol-InSAR coherences as a combination of a surface contribution from the snow-ice interface and a volume response from an oriented particle cloud. Separation of the ground and volume contributions is obtained using a novel decomposition of the polarimetric covariance matrix which allows for preferential particle orientations and accounts for the influence of the dielectric constants of ice and snow. Ground-to-volume scattering ratios derived from polarimetry are used in conjunction with Pol-InSAR interferometric coherences to invert the extinction of the ice layer. Validation is performed with airborne Pol-InSAR data at L- and P-band collected using DLR's E-SAR system over the Austfonna ice cap in Svalbard, Norway as part of the ICESAR campaign
Patterns of Su(H) and Pol II recruitment.
No full text<p>A: Table showing, for each cluster, the proportion of genes with Su(H) binding within 10 kb [ # Su(H)] and with each Pol II state (Pol II: AU, AP, P and UB as described in main text). In cases where individual transcripts of a gene had different Pol II states, the gene was assigned a state as follows: AU>AP>P>UB. Conditions where >30% of genes are ascribed to a particular class are indicated in bold. B–D: Enrichment for Su(H) (blue) and Pol II (red) across the <i>W/hid</i> (B), <i>CG4398</i> (C) and <i>hairy</i> (D) genes at different time points (min) after Notch activation (Su(H) 0.5–4.5, Pol II 0–4.7 fold enrichment on a log<sub>2</sub> scale).</p
Estimation of glacier ice extinction using long-wavelength airborne Pol-InSAR
No full textIn recent years there has been increased interest in using synthetic aperture radar (SAR) to study and monitor glaciers and ice sheets for glaciological and climate change research. This paper describes the estimation of ice extinctions through modeling of Pol-InSAR (polarimetric interferometric SAR) coherences as a combination of a surface contribution (from the snow-firn interface and wind-induced sastrugi features) and a volume response. Ground-to-volume scattering ratios derived from a novel polarimetric decomposition are used in conjunction with Pol-InSAR coherence magnitudes to invert the extinction of the ice layer. The inversion is performed for experimental airborne Pol-InSAR data at L- and P-band acquired by DLR's E-SAR system over the Austfonna ice cap in Svalbard, Norway as part of the 2007 ICESAR campaign. Extinction-dependencies on frequency and glacier facie
are investigated, and validation is performed comparing ground penetrating radar data to SAR backscatter and extinction values
Dual Pol-InSAR Forest Height Estimation By Means Of TANDEM-X Data
No full textThe TanDEM-X mission [1] provides for the first time single pass (single- and dual-) polarimetric interferometric data from
space. This allows the acquisition and analysis of Pol-InSAR data without the disturbing effect of temporal decorrelation on
a global scale. Polarimetric interferometric X-band data are now available for different forest ecosystems (from boreal to
tropics) in different seasons. The penetration capability of X-band in vegetation is limited and depends strongly on the
corresponding forest conditions. However, first data analysis showed sufficient penetration to apply Pol-InSAR height
estimation at least for a boreal forest scenario [2]. The limitations of X-band for forest parameter estimation can be identified
by analyzing data sets from different forest types. Additionally seasonal effects like leaf fall or freezing conditions may
change the backscattering behavior or penetration capability of X-band for forests. It was already shown that the ability to
penetration depends on the seasonal stage of a forest. Figure 1 on the left shows the penetration depth of X-band by means of
boreal forest (Krycklan forest northern Sweden) for a summer (Figure 1 left side) and a winter (Figure 1 middle) acquisition.
Penetration depth of the winter acquisition is with a mean of 11.8m significantly larger than for the summer acquisition with
a mean of 9.45m. This is probably due the lower dielectricity of the tree compartments in frozen conditions
MULTIBASELINE POLARIMETRIC SAR INTERFEROMETRY FOREST HEIGHT INVERSION APPROACHES
No full textPolarimetric SAR interferometry (Pol-InSAR) is a radar remote sensing technique that is sensitive to the vertical distribution of scattering processes in volumes. The Random Volume over Ground (RVoG) model is a powerful tool used to invert forest height from Pol-InSAR data. But Pol-InSAR inversion performance depends critically on uncompensated decorrelation contributions (i.e. temporal decorrelation in repeat pass system) and the height sensitivity of the effective baseline, represented by the vertical wavenumber . To overcome these constraints a multibaseline Pol-InSAR inversion approach could be an effective solution. In this paper, different approaches for combining multibaseline Pol-InSAR inversion results are proposed and discussed. Multibaseline Pol-InSAR data acquired by DLR’s E-SAR system over the Traunstein forest during the TempoSAR 2008 campaign are used
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