The Experts below are selected from a list of 159 Experts worldwide ranked by ideXlab platform
Alexander P. Trishchenko - One of the best experts on this subject based on the ideXlab platform.
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Reprojection of VIIRS SDR Imagery Using Concurrent Gradient Search
IEEE Transactions on Geoscience and Remote Sensing, 2018Co-Authors: Alexander P. TrishchenkoAbstract:The application of the gradient search method for reprojection of Visible Infrared Imaging Radiometer Suite (VIIRS) satellite data record (SDR) imagery is described. The method is an extension of the scheme developed earlier for reprojection of Moderate Resolution Imaging Spectroradiometer (MODIS) L1B imagery. The new scheme has three important improvements: 1) the interscan and intrascan search steps are combined into a single step to save computational time; 2) one-sided (left-right, up-down) gradients are utilized to improve convergence; and 3) the use of the map projection instead of the latitude–Longitude Coordinate system to improve performance and robustness. The scheme is computationally very fast, employing only basic arithmetic operations and precalculated matrices of spatial gradients. An average number of iteration steps for the reprojection of mid-latitude quadruple VIIRS SDR granule is less than 1.5, i.e., the scheme usually converges in less than 2 iterations. The ambiguity in the overlapping areas due to the bow-tie effect is resolved by forcing a solution located closer to the scan line center. In addition, the accuracy of VIIRS imagery geo-location was evaluated by comparison against MODIS 250 m images. Absolute geolocation biases of the VIIRS imagery over the 1-year period from June 01, 2016 to May 01, 2017 were found on average to be within 0.004 and −0.003 of the sample size ( $\Delta $ line) in the along-track direction and 0.055 and 0.035 of the sample size ( $\Delta $ pixel) in the along-scan direction for bands I2 and M7, respectively. These results demonstrate the excellent geometric performance of the VIIRS Suomi National Polar-orbiting Partnership sensor and are consistent with those reported by the VIIRS geolocation teams.
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Reprojection of VIIRS SDR Imagery Using Concurrent Gradient Search
IEEE Transactions on Geoscience and Remote Sensing, 2018Co-Authors: Alexander P. TrishchenkoAbstract:The application of the gradient search method for reprojection of Visible Infrared Imaging Radiometer Suite (VIIRS) satellite data record (SDR) imagery is described. The method is an extension of the scheme developed earlier for reprojection of Moderate Resolution Imaging Spectroradiometer (MODIS) L1B imagery. The new scheme has three important improvements: 1) the interscan and intrascan search steps are combined into a single step to save computational time; 2) one-sided (left-right, up-down) gradients are utilized to improve convergence; and 3) the use of the map projection instead of the latitude-Longitude Coordinate system to improve performance and robustness. The scheme is computationally very fast, employing only basic arithmetic operations and precalculated matrices of spatial gradients. An average number of iteration steps for the reprojection of mid-latitude quadruple VIIRS SDR granule is less than 1.5, i.e., the scheme usually converges in less than 2 iterations. The ambiguity in the overlapping areas due to the bow-tie effect is resolved by forcing a solution located closer to the scan line center. In addition, the accuracy of VIIRS imagery geo-location was evaluated by comparison against MODIS 250 m images. Absolute geolocation biases of the VIIRS imagery over the 1-year period from June 01, 2016 to May 01, 2017 were found on average to be within 0.004 and -0.003 of the sample size (Δ line) in the along-track direction and 0.055 and 0.035 of the sample size (Δ pixel) in the along-scan direction for bands I2 and M7, respectively. These results demonstrate the excellent geometric performance of the VIIRS Suomi National Polar-orbiting Partnership sensor and are consistent with those reported by the VIIRS geolocation teams.
Tatsuhiko Saito - One of the best experts on this subject based on the ideXlab platform.
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Global tsunami simulation using a grid rotation transformation in a latitude–Longitude Coordinate system
Natural Hazards, 2016Co-Authors: Daisuke Inazu, Tatsuhiko SaitoAbstract:Tsunami propagation simulation over the full-global ocean with a finite-difference method is carried out using a grid rotation transformation in a latitude–Longitude Coordinate system. Two singular points (North/South Poles) that are antipodes with each other in the latitude–Longitude Coordinate are both moved to land using the grid rotation transformation. The moved singular points are also antipodes with each other. We provide algebra to represent the grid rotation and propose two candidates of the moved singular points for practical use. One is that the computational North Pole is moved to China, and the other is the computational pole moved to Greenland. We carry out tsunami propagation simulation over the global ocean for the different candidates of the moved singular points and evaluate numerical errors due to the grid rotation transformation. The numerical errors are found to be more reduced with finer resolution of the spatial grid for the simulation. When the spatial resolution is fixed, the numerical errors are reduced over most regions for the case with the computational North Pole moved to Greenland, more than the case with the pole moved to China. We indicate that the Coriolis force effect on the tsunamis that was expected to be minor even in far fields becomes significant after long propagation (>~1 day).
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global tsunami simulation using a grid rotation transformation in a latitude Longitude Coordinate system
Natural Hazards, 2016Co-Authors: Daisuke Inazu, Tatsuhiko SaitoAbstract:Tsunami propagation simulation over the full-global ocean with a finite-difference method is carried out using a grid rotation transformation in a latitude–Longitude Coordinate system. Two singular points (North/South Poles) that are antipodes with each other in the latitude–Longitude Coordinate are both moved to land using the grid rotation transformation. The moved singular points are also antipodes with each other. We provide algebra to represent the grid rotation and propose two candidates of the moved singular points for practical use. One is that the computational North Pole is moved to China, and the other is the computational pole moved to Greenland. We carry out tsunami propagation simulation over the global ocean for the different candidates of the moved singular points and evaluate numerical errors due to the grid rotation transformation. The numerical errors are found to be more reduced with finer resolution of the spatial grid for the simulation. When the spatial resolution is fixed, the numerical errors are reduced over most regions for the case with the computational North Pole moved to Greenland, more than the case with the pole moved to China. We indicate that the Coriolis force effect on the tsunamis that was expected to be minor even in far fields becomes significant after long propagation (>~1 day).
Daisuke Inazu - One of the best experts on this subject based on the ideXlab platform.
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Global tsunami simulation using a grid rotation transformation in a latitude–Longitude Coordinate system
Natural Hazards, 2016Co-Authors: Daisuke Inazu, Tatsuhiko SaitoAbstract:Tsunami propagation simulation over the full-global ocean with a finite-difference method is carried out using a grid rotation transformation in a latitude–Longitude Coordinate system. Two singular points (North/South Poles) that are antipodes with each other in the latitude–Longitude Coordinate are both moved to land using the grid rotation transformation. The moved singular points are also antipodes with each other. We provide algebra to represent the grid rotation and propose two candidates of the moved singular points for practical use. One is that the computational North Pole is moved to China, and the other is the computational pole moved to Greenland. We carry out tsunami propagation simulation over the global ocean for the different candidates of the moved singular points and evaluate numerical errors due to the grid rotation transformation. The numerical errors are found to be more reduced with finer resolution of the spatial grid for the simulation. When the spatial resolution is fixed, the numerical errors are reduced over most regions for the case with the computational North Pole moved to Greenland, more than the case with the pole moved to China. We indicate that the Coriolis force effect on the tsunamis that was expected to be minor even in far fields becomes significant after long propagation (>~1 day).
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global tsunami simulation using a grid rotation transformation in a latitude Longitude Coordinate system
Natural Hazards, 2016Co-Authors: Daisuke Inazu, Tatsuhiko SaitoAbstract:Tsunami propagation simulation over the full-global ocean with a finite-difference method is carried out using a grid rotation transformation in a latitude–Longitude Coordinate system. Two singular points (North/South Poles) that are antipodes with each other in the latitude–Longitude Coordinate are both moved to land using the grid rotation transformation. The moved singular points are also antipodes with each other. We provide algebra to represent the grid rotation and propose two candidates of the moved singular points for practical use. One is that the computational North Pole is moved to China, and the other is the computational pole moved to Greenland. We carry out tsunami propagation simulation over the global ocean for the different candidates of the moved singular points and evaluate numerical errors due to the grid rotation transformation. The numerical errors are found to be more reduced with finer resolution of the spatial grid for the simulation. When the spatial resolution is fixed, the numerical errors are reduced over most regions for the case with the computational North Pole moved to Greenland, more than the case with the pole moved to China. We indicate that the Coriolis force effect on the tsunamis that was expected to be minor even in far fields becomes significant after long propagation (>~1 day).
Jungil Yoon - One of the best experts on this subject based on the ideXlab platform.
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The research of regeneration path data after treatment method for lateral oscillation attenuation while autonomous vehicle path data regeneration
2016 IEEE Transportation Electrification Conference and Expo Asia-Pacific (ITEC Asia-Pacific), 2016Co-Authors: Jungil YoonAbstract:In order for an autonomous vehicle to drive safely, map data with accurate path information is required. Using Latitude and Longitude Coordinate information from GPS (Global Positioning System) and GIS (Geographic Information System), an autonomous vehicle generates path data and obeys these data when driving. When the total travel(raw) path is too long, this system divides raw path into multiple sub-sections(segments) using higher degree polynomial equation curve fitting and this method enable efficiently uses path data. However, these curve fitting location data cannot be expressed as perfectly linear line even if raw path is straight, and therefore, these data always include lateral position error compared with raw path. Moreover, gather volume of lateral position error generated by GPS and IMU (Inertial Measurement Unit), oscillation on straight path is inevitable. This research uses moving average and different filter size according to segment size. Finally, via experiment with a real vehicle, system is confirmed to countering oscillation.
David Moeller - One of the best experts on this subject based on the ideXlab platform.
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Species Distribution Models and Joint Species Distribution Models of Nine Invasive Species in North America
2019Co-Authors: Thomas Lake, Ryan Briscoe Runquist, David MoellerAbstract:Model predictions are formatted as GeoTiff (TIF) files. All SDM model iterations were compiled in species TIF projection stacks. All JSDM model iterations were compiled in RData (RDA) files. Current and future climate layers, which were used to construct models, are formatted in GRID (GRD, GRI) files. Species georeferenced occurrences are formatted in Comma Separated Value (CSV) files of latitude, Longitude Coordinate pairs. These files included allow a user to replicate the inputs and examine the outputs of MaxEnt model predictions.
