Publications de Valentin Simeonov

Translational screening platform to evaluate chemotherapy in combination with focal therapy for retinoblastoma

Paul Joseph Dyson, Valentin Simeonov, Fabien Kuttler, Irina Sinenko, Patrik Aouad

Retinoblastoma is the most common pediatric eye cancer. It is currently treated with a limited number of drugs, adapted from other pediatric cancer treatments. Drug toxicity and relapse of the disease warrant new therapeutic strategies for these young pati ...

WILEY2023

Raman lidar in operational meteorology

Valentin Simeonov, Bertrand Calpini, Todor Dinoev, Ilya Serikov

Water vapor and temperature spatial distribution and their temporal evolution are among the most important parameters in numerical weather forecasting and climate models. The operational relative humidity/temperature profiling in meteorology is carried out ...

SPIE-INT SOC OPTICAL ENGINEERING2018

First principle calibration of water vapor Raman lidars

Valentin Simeonov

A new method for calibration of water vapor Raman lidars based on first principles is proposed. The calibration constant of a Raman lidar is derived from a set of water vapor and nitrogen Raman backscatter signals measured with the lidar receiver in a cell ...

Spie-Int Soc Optical Engineering2017

Absolutely calibrated Raman lidar as a reference tool in atmospheric humidity profiling

Valentin Simeonov

Raman lidars exploit the proportionality between the intensity of scattered by a Raman process laser radiation and the number density of the scattering molecules to derive water vapor mixing ratio profile. Water vapor/air mixing ratio is directly proportio ...

2014

Instrumental correction of the uneven PMT aging effect on the calibration constant of a water vapor Raman lidar

Valentin Simeonov, Bertrand Calpini, Salomon Fastig

The water vapor profile derived from Raman lidar measurements is obtained by taking the ratio of water vapor and nitrogen Raman-shifted signals. The proportionality factor that converts the signal ratio to water vapor/air mixing ratio is referred to as lid ...

Spie-Int Soc Optical Engineering2014

Are atmospheric surface layer f lows ergodic?

Valentin Simeonov, Marc Parlange, Gabriel George Katul, Chad Higgins, Martin Froidevaux

The transposition of atmospheric turbulence statistics from the time domain, as conventionally sampled in field experiments, is explained by the so-called ergodic hypothesis. In micrometeorology, this hypothesis assumes that the time average of a measured ...

American Geophysical Union2013

Raman Lidar for Meteorological Observations, RALMO - Part 2: Validation of water vapor measurements

Valentin Simeonov, Bertrand Calpini

The Raman Lidar for Meteorological Observations (RALMO) was installed at the MeteoSwiss Regional Center of Payerne, Switzerland, in summer 2008. One of its aims is to provide continuous vertical profiles of tropospheric water vapor during day and night at ...

European Geosciences Union2013

Measured and Estimated Water Vapor Advection in the Atmospheric Surface Layer

Valentin Simeonov, Marc Parlange, Chad Higgins, Martin Froidevaux, Eric Richard Pardyjak

The flux of water vapor due to advection is measured using high-resolution Raman lidar that was orientated horizontally across a land-lake transition. At the same time, a full surface energy balance is performed to assess the impact of scalar advection on ...

American Meteorological Society2013

Coherent structures and the k(-1) spectral behaviour

Valentin Simeonov, Marc Parlange, Marc Calaf Bracons, Holly Jayne Oldroyd

l Here we present unique evidence of a k(-1) scaling behaviour in the atmospheric boundary layer and its connection to large scale coherent structures within the boundary layer. Wind lidar measurements were conducted above a lake under cold atmospheric con ...

Amer Inst Physics2013

Raman Lidar for Meteorological Observations, RALMO - Part 1: Instrument description

Hubert van den Bergh, Valentin Simeonov, Marc Parlange, Bertrand Calpini, Pablo Roberto Ristori, Todor Dinoev

A new Raman lidar for unattended, round-the-clock measurement of vertical water vapor profiles for operational use by the MeteoSwiss has been developed during the past years by the Swiss Federal Institute of Technology, Lausanne. The lidar uses narrow fiel ...

European Geosciences Union2013