PSInSAR Study of Lyngenfjord Norway, using TerraSAR-X Data

In this research paper, focus is given on exploring the potential of Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) technique for the measurement of landslide, which is the extension of existing DInSAR technique. In PSInSAR technique, the movement is measured by finding the phase shift in the scatterers present in the study area through the course of time. The backscattering of such a scatterer does not change during the study. By using this technique, 32 datasets acquired over a period of time i.e. from 2009 to 2011 over the area of Troms County of Lyngen Fjord, Norway are analysed. The dataset utilised are acquired with TerraSAR-X and TanDEM-X pair, in Stripmap mode of acquisition. Coregistration of dataset with subpixel accuracy is done with master images is done to align all the dataset correctly. APS estimation is done in order to remove the phase decorrelation caused by the atmosphere, movement, etc. using algorithms for phase unwrapping which allowed the processing of sparse data and the effect of atmosphere is reduced by doing analysis on temporal basis of the phase shift in interferograms of successive datasets. By this study it has been tried to show the estimation of shift can be done by the temporal analysis of the data acquired by TerraSAR-X. The velocity output is displayed in a map reflecting the velocity of movement. Apart from this, the data properties such as baseline distribution both temporal and spatial are displayed in a chart. Other outputs obtained are the atmospheric Phase Screen, sparse point distribution, reflectivity map of the study area etc. are displayed using a map of terrain. The output velocity obtained of the terrain movement is found to be in the range of −40 mm/yr to −70 mm/yr

Exploring the role of FDG-PET in the assessment of bone marrow involvement in lymphoma patients as interpreted by qualitative and semiquantitative disease metabolic activity parameter

Bone marrow biopsy (BMB) is currently the standard method to evaluate marrow involvement in malignant lymphomas. However, there exist a number of pitfalls in this technique that can have important implications for initial staging, prognostification, and treatment of the disease. The present study was undertaken to investigate the utility of FDG-PET imaging in the detection of bone marrow involvement in untreated lymphoma patients. Forty untreated patients (36 males and 12 females) with either Hodgkin′s disease (HD) (n = 17) or non-Hodgkin′s lymphoma (NHL) (n = 31) underwent whole body FDG-PET study for disease evaluation. Bone marrow uptake of FDG was graded as absence or presence of disease activity at marrow sites by qualitative assessment. Semiquantitative analysis involved deriving disease metabolic index (DMI) using the following formula: DMI = SUV max of suitable circular ROI over PSIS or trochanteric region/ SUVmax of similar ROI over adjoining background. Findings of BMB and FDG-PET were compared for final analysis. Eleven out of 17 HD patients (12 males and 5 females) demonstrated concordance between FDG PET findings and BMB reports. Remaining 6 cases showed discordance of FDG-PET demonstrating presence of marrow involvement at marrow sites and uninvolved marrow on BMB. Twenty six of the 31 NHL cases (24 males and 7 females) demonstrated concordance between FDG PET findings and BMB reports. Remaining 5 cases showed discordance of FDG-PET demonstrating presence of marrow involvement at marrow sites and uninvolved marrow on BMB. All the BMB positive patients (2 of HD and 5 of NHL) demonstrated disease activity in bone marrow on FDG-PET study. All patients with absence of disease activity at marrow sites on FDG-PET scan (9 of HD and 21 of NHL) had histology proven uninvolved marrow. The quantitative assessment by DMI showed a mean of >2.5 in HD and NHL patients at the PSIS region and the trochanteric region bilaterally in cases of bone marrow involvement by the disease. FDG-PET is a useful adjuvant to BMB for the evaluation of bone marrow involvement in lymphoma patients. The disease metabolic index of >2.5 at the marrow sites can serve as a semiquantitative parameter for such diagnosis on FDG-PET in untreated patients of lymphoma

Exploring the role of FDG-PET in the assessment of bone marrow involvement in lymphoma patients as interpreted by qualitative and semiquantitative disease metabolic activity parameter

Bone marrow biopsy (BMB) is currently the standard method to evaluate marrow involvement in malignant lymphomas. However, there exist a number of pitfalls in this technique that can have important implications for initial staging, prognostification, and treatment of the disease. The present study was undertaken to investigate the utility of FDG-PET imaging in the detection of bone marrow involvement in untreated lymphoma patients. Forty untreated patients (36 males and 12 females) with either Hodgkin\u2032s disease (HD) (n = 17) or non-Hodgkin\u2032s lymphoma (NHL) (n = 31) underwent whole body FDG-PET study for disease evaluation. Bone marrow uptake of FDG was graded as absence or presence of disease activity at marrow sites by qualitative assessment. Semiquantitative analysis involved deriving disease metabolic index (DMI) using the following formula: DMI = SUV max of suitable circular ROI over PSIS or trochanteric region/ SUVmax of similar ROI over adjoining background. Findings of BMB and FDG-PET were compared for final analysis. Eleven out of 17 HD patients (12 males and 5 females) demonstrated concordance between FDG PET findings and BMB reports. Remaining 6 cases showed discordance of FDG-PET demonstrating presence of marrow involvement at marrow sites and uninvolved marrow on BMB. Twenty six of the 31 NHL cases (24 males and 7 females) demonstrated concordance between FDG PET findings and BMB reports. Remaining 5 cases showed discordance of FDG-PET demonstrating presence of marrow involvement at marrow sites and uninvolved marrow on BMB. All the BMB positive patients (2 of HD and 5 of NHL) demonstrated disease activity in bone marrow on FDG-PET study. All patients with absence of disease activity at marrow sites on FDG-PET scan (9 of HD and 21 of NHL) had histology proven uninvolved marrow. The quantitative assessment by DMI showed a mean of >2.5 in HD and NHL patients at the PSIS region and the trochanteric region bilaterally in cases of bone marrow involvement by the disease. FDG-PET is a useful adjuvant to BMB for the evaluation of bone marrow involvement in lymphoma patients. The disease metabolic index of >2.5 at the marrow sites can serve as a semiquantitative parameter for such diagnosis on FDG-PET in untreated patients of lymphoma

Polarimetric calibration of spaceborne and airborne multifrequency SAR data for scattering-based characterization of manmade and natural features

The Polarimetric Synthetic Aperture Radar (PolSAR) systems use electromagnetic radiations of different polarizations in the microwave frequency to collect the scattering information from targets on the Earth. Nevertheless, as with any other electronic device, the PolSAR systems are also not ideal and subjected to distortions. The most important of these distortions are the polarimetric distortions caused due to the channel imbalance, phase bias, and crosstalk between the different polarization channels. For the spaceborne PolSAR systems, the Earth's ionosphere also contributes to an additional polarimetric distortion known as the Faraday rotation. An effort was made in this study to perform the polarimetric calibration of the Quad-pol and Compact-pol PolSAR datasets acquired using different airborne and spaceborne PolSAR systems to estimate and minimize these polarimetric distortions. The investigation was also done to analyze the impact of these polarimetric distortions on the scattering mechanisms from ground targets and on its dependency on the radar wavelength. The study was done using the UAVSAR L-band Quad-pol dataset, RADARSAT-2 Quad-pol dataset, ALOS-2 PALSAR-2, ISRO's L&S- Band Airborne SAR (LS-ASAR) Quad-pol and Compact-pol datasets, and the RISAT-1 Compact-pol dataset. Calibration of the airborne PolSAR data was carried to understand the level of polarimetric distortions in the LS-ASAR product that is a precursor mission to the spaceborne Dual-Frequency L&S Band NASA-ISRO Synthetic Aperture Radar (NISAR) mission. It is understood that the crosstalk is the dominant polarimetric distortion, which severely affects the PolSAR datasets compared to the other polarimetric distortions, and it is more for the higher wavelength PolSAR systems. The Quegan, Improved Quegan, and Ainsworth algorithms for crosstalk estimation and minimization was performed for the different Quad-pol datasets and it was found that the Improved Quegan algorithm is suitable for removing crosstalk from datasets having high crosstalk and the Ainsworth algorithm is suitable for removing crosstalk from datasets having low crosstalk. The Freeman method of the polarimetric calibration was implemented for the compact-pol datasets and it was able to considerably minimize the polarimetric distortions. The coherency matrix, scattering matrix, model-based decomposition, polarimetric signatures, and roll invariant parameter-based analysis revealed that all the datasets after polarimetric calibration were showing the correct scattering responses expected from the ground targets.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Mathematical Geodesy and PositioningPhysical and Space Geodes