Results 41 to 50 of about 83,591 (207)

BarnebyLives: An R package to create herbarium specimen labels and clean spreadsheets

Applications in Plant Sciences, EarlyView.
Abstract Premise Accessioning herbarium specimens is labor intensive, yet remains vital for research in ecology, evolution, and conservation. As institutional support for herbaria declines, efficient tools are needed to streamline this process. The R package BarnebyLives was developed to assist collectors by supplementing collection notes, verifying ...
Reed Clark Benkendorf, Jeremie B. Fant
wiley   +1 more source

Ambiguities and Image Quality in Staggered SAR [PDF]

, 2015
Staggered SAR is an innovative synthetic aperture radar (SAR) concept, where the pulse repetition interval (PRI) is continuously varied. This, together with digital beamforming (DBF) in elevation, allows high-resolution imaging of a wide continuous swath
Villano, Michelangelo, Alberto Moreira, Moreira, Alberto, Krieger, Gerhard, Michelangelo Villano, Gerhard Krieger   +5 more
core   +1 more source

Range Ambiguity Suppression Approach for Quad-pol SAR Systems Based on Modified Azimuth Phase Coding

Leida xuebao, 2017
For conventional quadrature-polarimetric (quad-pol) Synthetic Aperture Radar (SAR) systems, as cross-polarized (cross-pol) channels are influenced by the strong co-polarized (co-pol) range ambiguous returns, the range ambiguity levels of cross ...
Zhu Xiaojing, Li Fei, Wang Robert, Wang Wei, Sun Xiang   +4 more
doaj   +1 more source

A new occurrence of tetrapod footprints from the Late Triassic of the Candelária Sequence, Brazil

The Anatomical Record, EarlyView.
Abstract The Hyperodapedon Assemblage Zone of the Candelária Sequence (Santa Maria Supersequence, Paraná Basin) preserves one of the most significant Late Triassic continental vertebrate assemblages in southern Brazil. Despite the relatively well‐documented body fossil record from this interval, ichnological records remain comparatively scarce.
Murilo Andrade‐Silva, Heitor Francischini   +1 more
wiley   +1 more source

Immersed Boundary Projection Method for Boundaries With Slip Velocities

International Journal for Numerical Methods in Fluids, EarlyView.
A formulation of the immersed boundary method for incompressible flow over arbitrarily‐shaped bodies with surface slip described by the Navier boundary condition is presented. The wall slip velocity and the boundary force are determined implicitly through a projection to satisfy both the boundary condition and the divergence‐free condition of the ...
Takehiro Fujii, Takeshi Omori
wiley   +1 more source

Ship Discrimination Using Polarimetric SAR Data and Coherent Time-Frequency Analysis

Remote Sensing, 2013
This paper presents a new approach for the discrimination of ship responses using polarimetric SAR (PolSAR) data. The PolSAR multidimensional information is analyzed using a linear Time-Frequency (TF) decomposition approach, which permits to describe the
Canbin Hu, Laurent Ferro-Famil, Gangyao Kuang   +2 more
doaj   +1 more source

Pancharatnam–Berry Phase Driven by Electrical Restructuring of Liquid Crystal Polarization Grating Period

Laser &Photonics Reviews, EarlyView.
Electrically controlled liquid‐crystal twist diffraction element based on the Pancharatnam–Berry phase enables switchable structural periodicity and simultaneous generation of orthogonal circularly polarized coherent waves for multifunctional planar photonic devices.
Elena Melnikova, Katsiaryna Pantsialeyeva, Alexei Tolstik, Veranika Stanevich, Daminika Dashkevich, Anatoli Murauski, Alexander Muravsky, Alina Karabchevsky   +7 more
wiley   +1 more source

Grating‐Lens Empowered Metafiber for Large‐Angle Light Collection With 3D Nanoprinted Structures

Laser &Photonics Reviews, EarlyView.
A grating‐lens‐based Metafiber enables efficient light coupling into single‐mode fibers at large incidence angles. By combining diffraction and focusing on the fiber facet using a 3D nanoprinted holographic structure, light is selectively coupled only at specific angles while suppressing unwanted signals. This approach achieves high coupling efficiency
Jun Sun, Markus A. Schmidt
wiley   +1 more source

Image-Domain Discrimination of Real Ship Targets and Azimuth-Ambiguity Ghosts in Maritime SAR Images

IEEE Access
Azimuth ambiguities in maritime synthetic aperture radar (SAR) images can generate ghost-like responses near strong ship scatterers, thereby increasing false alarms and degrading ship-target interpretation and automatic target recognition.
Min-Seok Kang, Seung-Jae Lee, Sanghyuck Han   +2 more
doaj   +1 more source

Investigations on the Coregistration of Sentinel-1 TOPS with the Conventional Cross-Correlation Technique

Remote Sensing, 2018
In Sentinel-1 TOPS mode, the antenna sweeps in the azimuth direction for the purpose of illuminating the targets with the entire azimuth antenna pattern (AAP).
Yuxiao Qin, Daniele Perissin, Jing Bai
doaj   +1 more source