Search results for "radar"
showing 10 items of 248 documents
Remote Sensing Observations of Thunderstorm Features in Latvia
2017
AbstractThunderstorms are the most hazardous meteorological phenomena in Latvia in the summer season, and the assessment of their characteristics is essential for the development of an effective national climate and weather prediction service. However, the complex nature of convective processes sets specific limitations to their observation, analysis and forecasting. Therefore, the aim of this study is to analyse thunderstorm features associated with severe thunderstorms observed in weather radar and satellite data in Latvia over the period 2006–2015. The obtained results confirm the applicability of the selected thunderstorm features for thunderstorm nowcasting and analysis in Latvia. The …
A Simultaneous Observation of Lightning by ASIM, Colombia-Lightning Mapping Array, GLM, and ISS-LIS
2021
The Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station (ISS) provides optical radiances and images of lightning flashes in several spectral bands. This work presents a lightning flash simultaneously observed from space by ASIM, the Geostationary Lightning Mapper (GLM) and the Lightning Imaging Sensor on the International Space Station (ISS-LIS); and from ground by the Colombia-Lightning Mapping Array (Colombia-LMA). Volumetric weather radar provides reflectivity data to help to interpret the effects of the cloud particles on the observed optical features. We found that surges in radiance in the band at 777.4 nm appear to be related mostly with lightning processe…
Influence of competition on performance factors in under-19 soccer players at national league level.
2020
The aim of this study was to analyse and quantify the acute effects of competition on several performance factors in under-19 male soccer players. To this end, 198 national league players (17.56 ± 0.78 years) performed various tests to measure jump capacity, kicking velocity and sprint times immediately pre-match (T1), at half-time (T2) and post-match (T3). Tests included kicking the ball to measure ball velocity (KICK), sprinting for 40 meters, timing the first 30 meters (30mACCEL), the last 10 meters (10mACCEL) and the total distance (40mACCEL), and performing countermovement jumps (CMJ). For subsequent analysis, the sample was divided into 5 playing positions: goalkeepers (n = 24), defen…
Development of the International Severe Asthma Registry (ISAR): A Modified Delphi Study
2019
BACKGROUND: The lack of centralised data on severe asthma has resulted in a scarcity of information about the disease and its management. The development of a common data collection tool for the International Severe Asthma Registry (ISAR) will enable standardised data collection, subsequently enabling data interoperability.OBJECTIVES: To create a standardised list of variables for the first international registry for severe asthma via expert consensus.METHODS: A modified Delphi process was used to reach consensus on a minimum set of variables to capture in ISAR: the core variables. The Delphi panel brought together 27 international experts in the field of severe asthma research. The process…
Non-contact ultrasonic inspection of skin/core bond in honeycomb with lamb waves
2003
The assessment of skin/core bond in honeycomb samples was carried out by a bistatic ultrasonic non-contact system. Lamb waves were generated by a Nd:YAG pulsed laser and detected by an air-coupled capacitance transducer located in pitch-catch configuration. Periodically spaced line sources, generated on the sample surface using a four element lenticular array, allowed generation of narrow-band directional Lamb waves. Changes in amplitude of the transmitted signal permitted detection of skin/core disbonds.
Acoustic Environmental Monitoring System for Acoustic Maps
2008
In this work, it is developed a data acquisition and analysis system for the monitoring of acoustic environmental noises and the elaboration of dynamic acoustic maps. This project is based on the obtaining of acoustic data in different measure points, and it is formed by a mesh of connections based on GPRS NODES and a Software Server for the administration and control of the data.
New Trend to Evaluate the Management of Companies: An Application of the Methodologies of Radar Chart
2014
The methodology of radar chart arises as an alternative answer to traditional measures on management of companies' activities. How to answer to market disruptions? It is a question solved by this methodology, which allows us to measure the management of each area represented on a radar chart by applying principles of plane geometry. In this methodology, a decision on a management area affects to the result of other areas because it has a multidirectional effect. Its application is carried out on a Spanish company.
Sensitivity analysis on the relationship between vegetation growth and multi-polarized radar data
2009
Spatially distributed soil moisture is required for watershed applications such as drought and flood prediction, crop irrigation scheduling, etc. In particular, an accurate assessment of the spatial and temporal variation of soil moisture is necessary to improve the predictive capability of runoff models, and for improving and validating hydrological processes forecasting. In recent years, several models have been developed in order to retrieve soil moisture using RADAR data. However, these models need precise prior knowledge about surface roughness. Within this framework, the present research aims to investigate the capabilities of multi polarimetric RADAR images to overcome the use of in …
Modelling of ERS-2 radar backscattering over rocky arid regions
2003
This paper discusses the potential of radar signals to characterize stone cover over bare soil surfaces in arid rocky regions. Ground truth and radar measurements were made over two arid sites: Avdat (Israel) and Foumtillich (Morocco). An empirical approach is proposed to derive stone cover percentage from pin profiler measurements. A numerical Moment method based on integral equations of backscattering has been used to study the influence of stone cover on simulated radar signal. The results of the simulations are compared with European Remote Sensing Satellite (ERS-2) radar measurements over test areas with different stone covers. Excellent agreement is observed between numerical simulati…