Publications associées à Radar speed gun

Snowfall microphysics: a dual-frequency and Doppler spectral radar perspective

Snowfall is an essential component of the hydrological cycle, as it is involved in most precipitation on Earth, either directly as snow falling to the ground or indirectly as rain melted from snow. At the same time, the ice phase of clouds and precipitatio ...

EPFL2023

Dual-frequency spectral radar retrieval of snowfall microphysics: a physics-driven deep-learning approach

Alexis Berne, Anne-Claire Marie Billault--Roux, Gionata Ghiggi

The use of meteorological radars to study snowfall microphysical properties and processes is well established, in particular via a few distinct techniques: the use of radar polarimetry, of multi-frequency radar measurements, and of the radar Doppler spectr ...

COPERNICUS GESELLSCHAFT MBH2023

Radar and ground-level measurements of clouds and precipitation collected during the POPE 2020 campaign at Princess Elisabeth Antarctica

Alexis Berne, Alfonso Ferrone

The datasets presented in this article were collected during a four-months measurement campaign at the Belgian research base Princess Elisabeth Antarctica (PEA). The campaign, named PEA Orographic Precipitation Experiment (POPE), was conducted by the Envir ...

2023

Learning about the vertical structure of radar reflectivity using hydrometeor classes and neural networks in the Swiss Alps

Alexis Berne, Floortje Elisabeth Maria Van den Heuvel, Marco Gabella, Urs Martin Germann

The use of radar for precipitation measurement in mountainous regions is complicated by many factors, especially beam shielding by terrain features, which, for example, reduces the visibility of the shallow precipitation systems during the cold season. Whe ...

2020

Microphysics and dynamics of snowfall associated with a warm conveyor belt over Korea

Alexis Berne, Josué Etienne Gehring, Nikola Besic, Etienne Gabriel Henri Vignon, Nicolas Jean François Jullien

On 28 February 2018, 57mm of precipitation associated with a warm conveyor belt (WCB) fell within 21 h over South Korea. To investigate how the large-scale circulation influenced the microphysics of this intense precipitation event, we used radar measureme ...

Copernicus Publications2020

Radar measurements of blowing snow off a mountain ridge

Michael Lehning, Wolf Hendrik Huwald, Josué Etienne Gehring, Benjamin Andreas Walter

Modelling and forecasting wind-driven redistribution of snow in mountainous regions with its implications on avalanche danger, mountain hydrology or flood hazard is still a challenging task often lacking in essential details. Measurements of drifting and b ...

2020

A Sensor Fusion Approach to the Estimation of Instantaneous Velocity Using Single Wearable Sensor During Sprint

Kamiar Aminian, Frédéric Meyer, Salil Apte, Farzin Dadashi, Vincent Gremeaux

Power-Force-Velocity profile obtained during a sprint test is crucial for designing personalized training and evaluating injury risks. Estimation of instantaneous velocity is requisite for developing these profiles and the predominant method for this estim ...

2020

The Microphysics of Stratiform Precipitation During OLYMPEX: Compatibility Between Triple-Frequency Radar and Airborne In Situ Observations

Jussi Sakari Leinonen

The link between stratiform precipitation microphysics and multifrequency radar observables is thoroughly investigated by exploiting simultaneous airborne radar and in situ observations collected from two aircraft during the OLYMPEX/RADEX (Olympic Mountain ...

2019

Unraveling hydrometeor mixtures in polarimetric radar measurements

Alexis Berne, Jacopo Grazioli, Josué Etienne Gehring, Nikola Besic, Marco Gabella, Christophe Praz, Urs Martin Germann

Radar-based hydrometeor classification typically comes down to determining the dominant type of hydrometeor populating a given radar sampling volume. In this paper we address the subsequent problem of inferring the secondary hydrometeor types present in a ...

Copernicus GmbH2018

From model to radar variables: a new forward polarimetric radar operator for COSMO

Alexis Berne, Daniel Wolfensberger

In this work, a new forward polarimetric radar operator for the COSMO numerical weather prediction (NWP) model is proposed. This operator is able to simulate measurements of radar reflectivity at horizontal polarization, differential reflectivity as well a ...

Copernicus GmbH2018

Spatial variability in snow precipitation and accumulation in COSMO–WRF simulations and radar estimations over complex terrain

Varun Sharma, Michael Lehning, Alexis Berne, Franziska Gerber, Nikola Besic, Marco Gabella, Urs Martin Germann

Snow distribution in complex alpine terrain and its evolution in the future climate is important in a variety of applications including hydropower, avalanche forecasting and freshwater resources. However, it is still challenging to quantitatively forecast ...

2018

Retrieval of the raindrop size distribution from polarimetric radar data using double-moment normalisation

Alexis Berne, Timothy Hugh Raupach

A new technique for estimating the raindrop size distribution (DSD) from polarimetric radar data is proposed. Two statistical moments of the DSD are estimated from polarimetric variables, and the DSD is reconstructed using a double-moment normalisation. Th ...

Copernicus GmbH2017

Small-Scale Variability of the Raindrop Size Distribution and Its Effect on Areal Rainfall Retrieval

Alexis Berne, Timothy Hugh Raupach

The drop size distribution (DSD) describes the microstructure of liquid precipitation. The high variability of the DSD reflects the variety of microphysical processes controlling raindrop properties and affects the retrieval of rainfall. An analysis of the ...

American Meteorological Society2016

Variability of the raindrop size distribution across scales in Mediterranean rainfall : characterisation and stochastic simulation

Timothy Hugh Raupach

Measurement of rain is made difficult by the high variability of the precipitation process, down to raindrop scale. Point measurements are generally accurate, but their lack of spatial representativeness is a significant limitation. Weather radars indirect ...

EPFL2016

Polarimetric radar and in situ observations of riming and snowfall microphysics during CLACE 2014

Alexis Berne, Jacopo Grazioli, Luca Panziera

This study investigates the microphysics of winter alpine snowfall occurring in mixed-phase clouds in an inner-Alpine valley during January and February 2014. The available observations include high-resolution polarimetric radar and in situ measurements of ...

Copernicus Publications2015

Synergy of hyperspectral and microwave remote sensing data to derive bio- and geo-physical parameters for land applications

Jelena Stamenkovic

Retrieval of bio/geophysical variables from remote sensing imagery is an important research field. Due to the development and availability of different EO satellites, especially the ones with hyperspectral sensors, the combined use of radar and optical ima ...

EPFL2015

Orographic effects on snow deposition patterns in mountainous terrain

Michael Lehning, Alexis Berne, Marc Schneebeli Zeugin, Danny Eddy Scipion Castillo

Orographic lifting of air masses and other topographically modified flows induce cloud and precipitation formation at larger scales and preferential deposition of precipitation at smaller scales. In this study, we examine orographic effects on small-scale ...

Wiley-Blackwell2014

New diagnostics for density measurement on Frascati Tokamak upgrade

Fabio Avino, Anton Petrov

In FTU, density profile is measured with two new diagnostics: a CO2/CO scanning interferometer and a time-of-flight radar (denominated refractometer). The first, using two scanning beams, can provide a plasma density profile every 62.5 mu s. Two lasers (CO ...

Elsevier Science Bv2013

Scaling analysis of the variability of the rain drop size distribution at small scale

Alexis Berne, Marc Schleiss, Joël Jaffrain

Like precipitation, the raindrop size distribution (DSD) is strongly variable in space and time. Understanding this variability is important for quantifying and minimizing some of the uncertainties in radar measurements and their interpretation in terms of ...

Elsevier2012

High-resolution vertical profiles of polarimetric X-band weather radar observables during snowfall in the Swiss Alps

Michael Lehning, Alexis Berne, Marc Schneebeli Zeugin

An X-band polarimetric radar was deployed in the eastern Swiss Alps at an altitude of 2133 m. Radar measurements were complemented with several weather stations deployed in an altitude range from 1500 to 3100 m as well as with a fixed GPS ground station th ...

Amer Meteorological Soc2012