1,831 research outputs found
On the influence of regional features on the precision of near surface wind speed retrieval over the ocean
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A rotating knife-beam altimeter for wind-swath remote sensing of ocean: wind and waves
No full textThe use of a nadir altimeter radar with a rotating knife-beam antenna pattern isconsidered for improved measurements of the sea surface wind and wave parameters over a wide swath. Theoretical calculations suggest the antenna beam rotating about the vertical axis is able to provide wide swath of order 250-350 km. Processing of the signals using time or Doppler sampling techniques results in the division of the antenna footprint into elementary scattering cells of the order of 14x14 km. The theoretical algorithms developed here indicate that the system may be used to retrieve the variance of large-scale slopes, the direction of wave propagation and the wind speed in each cell. The possibility of measuring significant wave height is also analyzed. The combination of linear motion of the radar and the rotation of the knife-beam antenna can be exploited to build up a two-dimensional map of the surface, which enables better understanding of wave processes and to study their structure and temporal dynamics using repeated observations
On the problem of the near ocean surface wind speed retrieval by radar altimeter: a two-parameter algorithm
No full textThe concept of a microwave radar with an asymmetric knifelike beam for the remote sensing of ocean waves
No full textThe features of near-nadir probing of the ocean surface from a satellite are investigated, and a new configuration of a microwave radar for the surface slopes measurement is proposed. Numerical modeling is used to examine the feasibility of a spaceborne implementation, to devise a measuring technique, and to develop a data processing algorithm.It is shown that the radar with a knifelike beam (1° × 25°–30°) can be used to measure the variance of surface wave slopes. Using range selection and a new processing procedure to synthesize data, it is possible to achieve the spatial resolution required to study wave processes on the ocean surface from satellites. A new approach to wind speed retrieval at and near nadir is also discussed
PIDR(s): IDR(s) as a Projection Method
No full textThe Induced Dimension Reduction(s) method (or the IDR(s) method) is an example of an iterative method used for solving systems of linear equations. Projection methods are a special type of iterative method. They find an approximate solution in a subspace (the right subspace) by requiring that the residual is orthogonal to another subspace (the left subspace). In this thesis we investigate how we can implement IDR(s) as a projection method. We call this method IDR(s), which stands for Projected IDR(s).We present an implementation of PIDR(s) for solving systems of linear equations and for solving eigenvalue problems. These implementations are not meant to be optimal, but they are used to show that IDR(s) can indeed be seen as a projection method.Track: educationScience Education and CommunicationApplied Science
Actie podium van de stad - De plek voor overlapping van publieke en private actie; onderzoeksrapport. Het grote huis en de kleine stad - de stad van ankers in plaats van wortels; essay, onderdeel van onderzoeksrapport.
No full textHet onderzoeksrapport is in samenwerking van bovengenoemde auteurs tot stand gekomen. Het essay is enkel geschreven door M.B. Dekker.At home in the city - BerlinDwellingArchitectur
Author Correction:A 41,500 year-old decorated ivory pendant from Stajnia Cave (Poland)
No full textCorrection to: Scientific Reports https://doi.org/10.1038/s41598-021-01221-6, published online 25 November 2021The original version of this Article contained errors in the author list where Marjolein D. Bosch was omitted from the author list, and Mikołaj Urbanowski was incorrectly listed as an author of the original Article, and has subsequently been removed.The Author contributions section now reads:“S.T. W.N. and A.N. conceived the project; S.T., W.N., A.P., M.B., S.C., M.D., H.F., A.M., M.D. B., D.P., M.P.R., C.M.R., V.S-M., G.M.S., P.S., M.S., K.S., A.V., F.W., H.W., A.W., M.Z., S.B., A.N., J-J. H., performed research; S.T., A.P., W.N., M.B., M.D.B., S.C., M.D., H.F., A.M., D.P., M.P.R., C.M.R., V.S-M., G.M.S., P.S., M.S., K.S., A.V., F.W., H.W., A.W., M.Z., S.B., A.N., J-J. H. analysed all archaeological data; S.T. and A.P. wrote the paper with the collaboration of all the co-authors.”The original Article and its accompanying Supplementary Information file have been corrected
Internet and e-health Care: an Interdigital Field of Study
No full textThe foreword focuses on a historical definition of the e-health field. The author contributed to shaping the e-health field in the international community being one of the pioneers' scholars since the 1990s. The chapter discusses current and challenging future scenarios based on the international evolution that brings about new challenges
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