Towards automated lake ice classification using dual polarization RADARSAT SAR imagery

Lake ice, as one of the most important component of the cryosphere, is a valuable indicator of climate change and variability. The Laurentian Great Lakes are the world’s largest supply of freshwater and their ice cover has a major impact on regional weather and climate, ship navigation, and public safety. Monitoring detailed ice conditions on large lakes requires the use of satellite-borne synthetic aperture radar (SAR) data that provide all-weather sensing capabilities, high resolution, and large spatial coverage. Ice experts at the Canadian Ice Service (CIS) have been manually producing operational Great Lakes image analysis charts based on visual interpretation of the SAR images. Ice services such as the CIS would greatly benefit from the availability of an automated or semi-automated SAR ice classification algorithm. We investigated the performance of the unsupervised segmentation algorithm “glocal” iterative region growing with semantics (IRGS) for lake ice classification using dual polarized RADARSAT-2 imagery. Here, the segmented classes with arbitrary labels are manually labelled based on visual interpretation. IRGS was tested on 26 RADARSAT-2 scenes acquired over Lake Erie during winter 2014, and the results were validated against the manually produced CIS image analysis charts. Analysis of various case studies indicated that the “glocal” IRGS algorithm can provide a reliable ice-water classification using dual polarized images with a high overall accuracy of 90.2%. The improvement of using dual-pol as opposed to single-pol images for ice-water discrimination was also demonstrated. For lake ice type classification, most thin ice types were effectively identified but thick and very thick lake ice were often confused due to the ambiguous relation between backscatter and ice types. Texture features could be included for further improvement. Overall, our “glocal” IRGS classification results are close to visual interpretation by ice analysts and would have expected to be closer if they could draw ice charts at a more detailed level

Ice measurement on the wind turbines' blades by close-range photogrammetry methods

Photogrammetric scanning for measuring the thickness of ice is quite new in the wind energy field. When the rotor blades were mounted on the wind turbine tower, ice thickness inspections became nearly impossible to be performed in the past but by image base modeling methods, geometry extraction of ice of frosted blades are possible in the form of mesh models. In this research thesis, 3D model of wind turbine blades without ice is designed as reference Master CAD data. A prototype of this CAD model is made by a 3D printer machine which after painting, a pattern of retro targets is added to blades surfaces. Digital Single-Lens Reflex (SLR) camera is used to capture several images of objects with different modes of lighting and illumination. A series of point clouds is produced by using the Structure from Motion (SfM) method and VisualSfM software. Each point cloud has an arbitrary coordinate system that is scaled and transferred to Global Coordinate System by 3D transform on CATIA software based on similar features between 3D point cloud and master CAD data. When the ice has sufficient texture, such as rime ice and the texture is captured in the images, a point cloud corresponding to the captured region will also be detected. The position of ice on the blades is detected by coded retro targets on blade’s surface and the order of image acquisition. The generated point cloud and its mesh are compared with the Master CAD or reference geometric model and finally shows in 3D format, the shape, thickness and approximate mass of ice on the blades. This study focused on the feasibility of reconstruction of 3D polygonal mesh models by images captured from a wind turbine blade with a configuration of digital SLR cameras. The main objective of this reconstruction is to identify the volume and shape of ice-accumulated areas on the wind turbine blades in arctic regions. Geometrical comparison of these triangular mesh models with the non-iced blade CAD data could reveal the geometry of accumulated ice

CONCEPTUAL DESIGN REPORT

Brookhaven National Laboratory has prepared a conceptual design for a world class user facility for scientific research using synchrotron radiation. This facility, called the ''National Synchrotron Light Source II'' (NSLS-II), will provide ultra high brightness and flux and exceptional beam stability. It will also provide advanced insertion devices, optics, detectors, and robotics, and a suite of scientific instruments designed to maximize the scientific output of the facility. Together these will enable the study of material properties and functions with a spatial resolution of {approx}1 nm, an energy resolution of {approx}0.1 meV, and the ultra high sensitivity required to perform spectroscopy on a single atom. The overall objective of the NSLS-II project is to deliver a research facility to advance fundamental science and have the capability to characterize and understand physical properties at the nanoscale, the processes by which nanomaterials can be manipulated and assembled into more complex hierarchical structures, and the new phenomena resulting from such assemblages. It will also be a user facility made available to researchers engaged in a broad spectrum of disciplines from universities, industries, and other laboratories

European Union Timber Regulation Impact on International Timber Markets

The trade of illegal timber, often from illegal logging, has severe environmental, social and economic consequences. The EU’s response to this problem came with the Forest Law Enforcement, Governance and Trade (FLEGT) Action Plan, with its specific goal to end illegal logging, thereby improving sustainability of forest resources. In March 2013, an additional step was taken by implementing the EU Timber Regulation (EUTR). The EUTR requires proof of timber’s origin and legality to ensure that no illegal timber is imported into the EU. To this end the EU intends to block imports of any wood or wood product which comes from unknown sources. Certification of sustainable forest management will help EU importers minimize risk, which is an essential part of their required due diligence system. Monitoring organizations are established to assist trade associations and businesses to construct comprehensive due diligence systems. National competent authorities are designated to follow the trade of the new FLEGT-licensed timber and timber products. In the first year of the EUTR there are positive impacts, of which the most important is awareness of the disastrous situation with illegal logging, driven by exports of illegal timber. Another positive development is tropical timber exporters documenting the legality of their wood exports. Yet another positive feature is establishment of due diligence systems by EU importers. However, there are considerable problems for ensuring legal trade; for example the lack of comprehensive documentation of origin and legality. Analysis of recent trends establishes changes in the European timber trade in terms of sourcing, substitution, diversion to less-demanding countries. Short-term forecasts of market trends and changes will enable further policy assessment to achieve the objectives of improved legality in international timber markets.JRC.H.3-Forest Resources and Climat

Low-velocity matter wave source for atom interferometry produced by Zeeman-tuned laser cooling and magneto-optic trapping

A continuous, low-velocity, nearly monochromatic atomic beam is created using laser cooling and two-dimensional magneto-optic trapping. Rubidium atoms from an effusive oven are slowed and cooled using Zeeman-tuned slowing. The scattering force from a counter-propagating, frequency-stabilized diode laser beam is used to decelerate the thermal beam of atoms to a velocity of ~ 20 m/s. A spatially varying magnetic field is used to Zeeman shift the resonance frequency of the atom to compensate for the changing Doppler shift, thereby keeping the slowing atoms resonant with the fixed frequency laser. This slowing process also cools the beam of atoms to a temperature of a few Kelvin. The slow beam of atoms is loaded into a two-dimensional magneto-optic trap or atomic funnel. The atoms are trapped along the axis of the funnel and experience a molassestype damping force in all three spatial dimensions. By frequency shifting the laser beams used to make the trap, the atoms are ejected at a controllable velocity. The continuous matter-wave source has a controllable beam velocity in the range of 2 to 15 m/s, longitudinal and transverse temperatures of approximately 500 μK, and a flux of 3.4 x10⁹ atoms/s. At 10 m/s, the de Broglie wavelength of the beam is 0.5 nm. The spatial profile of the atomic beam was characterized 30 cm from the exit of the atomic funnel using a surface ionization detector. The low-velocity atomic beam is an ideal source for atom interferometry and a variety of applications in the field of atom optics