The Experts below are selected from a list of 33687 Experts worldwide ranked by ideXlab platform
Augustine A Adeolu - One of the best experts on this subject based on the ideXlab platform.
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extensive vertebral Scalloping in a thoracolumbar junction spinal schwannoma
Surgical Neurology International, 2020Co-Authors: Toyin Ayofe Oyemolade, Augustine A AdeoluAbstract:Severe vertebral Scalloping in spinal schwannoma is very rare. When present, extensive Scalloping of the vertebral bodies possesses significant treatment challenges in patients with spinal tumors. We present the computed tomography scan and magnetic resonance images of spinal schwannoma with marked vertebral Scalloping in a 40-year-old Nigerian.
Rolf Scheiber - One of the best experts on this subject based on the ideXlab platform.
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Scalloping correction in tops imaging mode sar data
IEEE Geoscience and Remote Sensing Letters, 2012Co-Authors: Steffen Wollstadt, Pau Prats, M Bachmann, Josef Mittermayer, Rolf ScheiberAbstract:This letter presents an investigation on Scalloping correction in the Terrain Observation by Progressive Scan (TOPS) imaging mode for synthetic aperture radar systems with electronically steered phased array antennas. A theoretical simulation of the Scalloping is performed, and two correction methods are introduced. The simulation is based on a general cardinal sine (sinc) antenna model as well as on the TerraSAR-X (TSX) antenna model. Real TSX data acquired over rainforest are used for demonstration and verification of the Scalloping simulation and correction. Furthermore, a calibration approach, taking into account the special TOPS imaging mode properties, is introduced.
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tops imaging with terrasar x mode design and performance analysis
IEEE Transactions on Geoscience and Remote Sensing, 2010Co-Authors: Adriano Meta, Pau Prats, Josef Mittermayer, Rolf Scheiber, Ulrich SteinbrecherAbstract:This paper reports about the performed investigations for the implementation of the wide-swath TOPS (Terrain Observation by Progressive Scan) imaging mode with TerraSAR-X (TSX). The TOPS mode overcomes the limitations imposed by the ScanSAR mode by steering the antenna along track during the acquisition of a burst. In this way, all targets are illuminated with the complete azimuth antenna pattern, and, thus, Scalloping is circumvented, and an azimuth dependence of signal-to-noise ratio and distributed target ambiguity ratio (DTAR) is avoided. However, the use of electronically steered antennas leads to a quantization of the steering law and a nonideal pattern for squinted angles (grating lobes and main lobe reduction). The former provokes spurious peaks, while the latter introduces slight Scalloping and DTAR deterioration. These effects are analyzed and quantified for TSX, and a TOPS system design approach is presented. Next, the requirements concerning interferometry are investigated. Finally, several results are shown with the TSX data, including a comparison between the TOPS and the ScanSAR modes and the reporting of the first TOPS interferometric results.
Pau Prats - One of the best experts on this subject based on the ideXlab platform.
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Scalloping correction in tops imaging mode sar data
IEEE Geoscience and Remote Sensing Letters, 2012Co-Authors: Steffen Wollstadt, Pau Prats, M Bachmann, Josef Mittermayer, Rolf ScheiberAbstract:This letter presents an investigation on Scalloping correction in the Terrain Observation by Progressive Scan (TOPS) imaging mode for synthetic aperture radar systems with electronically steered phased array antennas. A theoretical simulation of the Scalloping is performed, and two correction methods are introduced. The simulation is based on a general cardinal sine (sinc) antenna model as well as on the TerraSAR-X (TSX) antenna model. Real TSX data acquired over rainforest are used for demonstration and verification of the Scalloping simulation and correction. Furthermore, a calibration approach, taking into account the special TOPS imaging mode properties, is introduced.
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tops image quality and processor verification study Scalloping reduction
2010Co-Authors: Steffen Wollstadt, Pau PratsAbstract:The report presents the results from the investigation and simulation of residual Scalloping and residual Scalloping reduction in the TOPS imaging mode w.r.t. TerraSAR-X and Sentinel-1. First, the simulation of the residual Scalloping is done by means of an azimuth antenna pattern intensity evaluation w.r.t. single TOPS bursts. Second, two Scalloping reduction/correction methods are evaluated and applied to the simulated data. Finally both approaches are applied to real TerraSAR-X raw data or image data, respectively. The results are discussed in the conclusion and a recommendation for Sentinel-1 is presented. This report is the Technical Note 2 on “WP 220 Scalloping Reduction” and on “WP 221 Scalloping Reduction Demonstration with TOPS Processor” in the frame of the ESA/ESTEC Contract: “TOPS Image Quality and Processor Verification Study”. Both belong to the superordinate workpackage “WP 200 Sentinel-1 Image Quality”.
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tops imaging with terrasar x mode design and performance analysis
IEEE Transactions on Geoscience and Remote Sensing, 2010Co-Authors: Adriano Meta, Pau Prats, Josef Mittermayer, Rolf Scheiber, Ulrich SteinbrecherAbstract:This paper reports about the performed investigations for the implementation of the wide-swath TOPS (Terrain Observation by Progressive Scan) imaging mode with TerraSAR-X (TSX). The TOPS mode overcomes the limitations imposed by the ScanSAR mode by steering the antenna along track during the acquisition of a burst. In this way, all targets are illuminated with the complete azimuth antenna pattern, and, thus, Scalloping is circumvented, and an azimuth dependence of signal-to-noise ratio and distributed target ambiguity ratio (DTAR) is avoided. However, the use of electronically steered antennas leads to a quantization of the steering law and a nonideal pattern for squinted angles (grating lobes and main lobe reduction). The former provokes spurious peaks, while the latter introduces slight Scalloping and DTAR deterioration. These effects are analyzed and quantified for TSX, and a TOPS system design approach is presented. Next, the requirements concerning interferometry are investigated. Finally, several results are shown with the TSX data, including a comparison between the TOPS and the ScanSAR modes and the reporting of the first TOPS interferometric results.
Toyin Ayofe Oyemolade - One of the best experts on this subject based on the ideXlab platform.
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extensive vertebral Scalloping in a thoracolumbar junction spinal schwannoma
Surgical Neurology International, 2020Co-Authors: Toyin Ayofe Oyemolade, Augustine A AdeoluAbstract:Severe vertebral Scalloping in spinal schwannoma is very rare. When present, extensive Scalloping of the vertebral bodies possesses significant treatment challenges in patients with spinal tumors. We present the computed tomography scan and magnetic resonance images of spinal schwannoma with marked vertebral Scalloping in a 40-year-old Nigerian.
M Shimada - One of the best experts on this subject based on the ideXlab platform.
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a new method for correcting scansar Scalloping using forests and inter scan banding employing dynamic filtering
IEEE Transactions on Geoscience and Remote Sensing, 2009Co-Authors: M ShimadaAbstract:The Scanning Synthetic Aperture Radar (ScanSAR) is very useful for Earth observation because of its wider imaging swath and shorter revisit time. However, ScanSAR is sometimes affected by the following three artifacts: (1) Scalloping, which often appears as repeating weak azimuth stripes at both edges of the focused burst image; (2) azimuth ambiguity (i.e., a form of ghosting that appears over the adjacent uniform area when the pulse repetition frequency is below the Doppler bandwidth); and (3) radiometric discontinuity (i.e., banding) between two adjacent scans. This paper proposes three methods to correct these artifacts, which are, specifically, the proposal for Scalloping correction using Amazon Rainforest data, band limitation, and the correction for the inter SCAN banding using the dynamic gain correction algorithm. Several corrected sample data sets of the Phased-Array L-band SAR onboard the Advanced Land-Observing Satellite are presented to demonstrate the validity of the proposed methods.
