Dr. Philippe L. Keckhut Profile

Dr. Philippe L. Keckhut

Reseacher IPSL/Vice Director at LATMOS

SPIE Involvement:

Conference Program Committee | Author

Proceedings Article | 12 July 2019 Open Access

Introducing the atmospheric thermodynamics lidar in Space: ATLAS

Paolo Di Girolamo, Andreas Behrendt, Volker Wulfmeyer, Adolfo Comerón, Philippe Keckhut, Alain Hauchecorne, Evelyne Richard, Franco Marenco, Geraint Vaughan, Mathias Rotach, Roland Potthast, Alan Geer, Belay Demoz, Joseph Santanello, David Whiteman, David Turner

Proceedings Volume 11180, 111806P (2019) https://doi.org/10.1117/12.2536160

KEYWORDS: LIDAR, Raman spectroscopy, Temperature metrology, Troposphere, Climatology, Atmospheric modeling, Thermodynamics, Backscatter, Space operations, Telescopes

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SPIE Journal Paper | 21 December 2018 Open Access

Special Section Guest Editorial: Advances in Remote Sensing for Air Quality Management

Barry Gross, Klaus Schäfer, Philippe Keckhut

JARS, Vol. 12, Issue 04, 042601, (December 2018) https://doi.org/10.1117/12.10.1117/1.JRS.12.042601

KEYWORDS: Aerosols, Remote sensing, Atmospheric particles, Ozone, Satellites, Pollution, Spatial resolution, Sensors, Carbon monoxide, Image fusion

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Proceedings Article | 2 May 2018 Presentation + Paper

Think the way to measure the Earth Radiation Budget and the Total Solar Irradiance with a small satellites constellation

M. Meftah, P. Keckhut, L. Damé, S. Bekki, A. Sarkissian, A. Hauchecorne

Proceedings Volume 10641, 106410S (2018) https://doi.org/10.1117/12.2303616

KEYWORDS: Sensors, Radiometry, Solar cells, Solar radiation, Satellites, Sun, Camera shutters, S band, Control systems, Global Positioning System

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Within the past decade, satellites constellations have become possible and practical. One of the interest to use a satellites constellation is to measure the true Earth Radiation Imbalance, which is a crucial quantity for testing climate models and for predicting the future course of global warming. This measurement presents a high interest because the 2001-2010 decade has not shown the accelerating pace of global warming that most models predict, despite the fact that the greenhouse-gas radiative forcing continues to rise. All estimates (ocean heat content and top of atmosphere) show that over the past decade the Earth radiation imbalance ranges between 0.5 to 1W^-2. Up to now, the Earth radiation imbalance has not been measured directly. The only way to measure the imbalance with sufficient accuracy is to measure both the incoming solar radiations (total solar irradiance) and the outgoing terrestrial radiations (top of atmosphere outgoing longwave radiations and shortwave radiations) onboard the same satellite, and ideally, with the same instrument. The incoming solar radiations and the outgoing terrestrial radiations are of nearly equal magnitude of the order of 340.5W^-2. The objective is to measure these quantities over time by using differential Sun-Earth measurements (to counter calibration errors) with an accuracy better than 0.05Wm^-2 at 1σ. It is also necessary to have redundant instruments to track aging in space in order to measure during a decade and to measure the global diurnal cycle with a dozen satellites. Solar irradiance and Earth Radiation Budget (SERB) is a potential first in orbit demonstration satellite. The SERB nano-satellite aims to measure on the same platform the different components of the Earth radiation budget and the total solar irradiance. Instrumental payloads (solar radiometer and Earth radiometers) can acquire the technical maturity for the future large missions (constellation that insure global measurement cover) by flying in a CubeSat. This paper is intended to demonstrate the ability to build a low-cost satellite with a high accuracy measurement in order to have constant flow of data from space.

Proceedings Article | 13 May 2016 Paper

SERB, a nano-satellite dedicated to the Earth-Sun relationship

Mustapha Meftah, Étienne Bamas, Pierre Cambournac, Philippe Cherabier, Romain Demarets, Gaspard Denis, Axel Dion, Raphaël Duroselle, Florence Duveiller, Laetitia Eichner, Dimitri Lozeve, Guillaume Mestdagh, Antoine Ogier, Romane Oliverio, Thibault Receveur, Camille Souchet, Pierre Gilbert, Germain Poiet, Alain Hauchecorne, Philippe Keckhut, Alain Sarkissian

Proceedings Volume 9838, 98380T (2016) https://doi.org/10.1117/12.2222660

KEYWORDS: Ultraviolet radiation, Solar radiation, Climatology, S band, Antennas, Earth's atmosphere, Satellites, Solar cells, Sun, Radiometry

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SPIE Journal Paper | 23 April 2015

Introduction to the Maïdo Lidar Calibration Campaign dedicated to the validation of upper air meteorological parameters

Philippe Keckhut, Yann Courcoux, Jean-Luc Baray, Jacques Porteneuve, Hélène Vérèmes, Alain Hauchecorne, Davide Dionisi, Françoise Posny, Jean-Pierre Cammas, Guillaume Payen, Franck Gabarrot, Stephanie Evan, Sergey Khaykin, Rolf Rüfenacht, Brigitte Tschanz, Niklaus Kämpfer, Philippe Ricaud, Abdel Abchiche, Jimmy Leclair-de-Bellevue, Valentin Duflot

JARS, Vol. 9, Issue 01, 094099, (April 2015) https://doi.org/10.1117/12.10.1117/1.JRS.9.094099

KEYWORDS: LIDAR, Calibration, Clouds, Temperature metrology, Observatories, Microwave radiation, Satellites, Ozone, Wind measurement, Global Positioning System

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The first operations at the new High-altitude Maïdo Observatory at La Réunion began in 2013. The Maïdo Lidar Calibration Campaign (MALICCA) was organized there in April 2013 and has focused on the validation of the thermodynamic parameters (temperature, water vapor, and wind) measured with many instruments including the new very large lidar for water vapor and temperature profiles. The aim of this publication consists of providing an overview of the different instruments deployed during this campaign and their status, some of the targeted scientific questions and associated instrumental issues. Some specific detailed studies for some individual techniques were addressed elsewhere. This study shows that temperature profiles were obtained from the ground to the mesopause (80 km) thanks to the lidar and regular meteorological balloon-borne sondes with an overlap range showing good agreement. Water vapor is also monitored from the ground to the mesopause by using the Raman lidar and microwave techniques. Both techniques need to be pushed to their limit to reduce the missing range in the lower stratosphere. Total columns obtained from global positioning system or spectrometers are valuable for checking the calibration and ensuring vertical continuity. The lidar can also provide the vertical cloud structure that is a valuable complementary piece of information when investigating the water vapor cycle. Finally, wind vertical profiles, which were obtained from sondes, are now also retrieved at Maïdo from the newly implemented microwave technique and the lidar. Stable calibrations as well as a small-scale dynamical structure are required to monitor the thermodynamic state of the middle atmosphere, ensure validation of satellite sensors, study the transport of water vapor in the vicinity of the tropical tropopause and study their link with cirrus clouds and cyclones and the impact of small-scale dynamics (gravity waves) and their link with the mean state of the mesosphere.

Proceedings Article | 24 July 2014 Paper

SUAVE: a UV telescope for space weather and solar variability studies

L. Damé, M. Meftah, A. Irbah, A. Hauchecorne, P. Keckhut, E. Quémerais

Proceedings Volume 9144, 914431 (2014) https://doi.org/10.1117/12.2057705

KEYWORDS: Mirrors, Space telescopes, Telescopes, Silicon carbide, Ultraviolet radiation, Ultraviolet telescopes, Sun, Sensors, Charge-coupled devices, Visible radiation

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Proceedings Article | 3 June 2014 Paper

A nano-satellite to study the Sun and the Earth

M. Meftah, A. Irbah, A. Hauchecorne, L. Damé, A. Sarkissian, P. Keckhut, P.-O. Lagage, S. Dewitte, A. Chevalier

Proceedings Volume 9085, 90850Y (2014) https://doi.org/10.1117/12.2050134

KEYWORDS: Sun, Ultraviolet radiation, Solar radiation, Earth's atmosphere, Ozone, Climatology, Sensors, Satellites, Solar energy, Temperature metrology

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SPIE Journal Paper | 30 July 2013 Open Access

Subgrid-scale cirrus observed by lidar at mid-latitude: variability effects of the cloud optical depth

Philippe Keckhut, Jean-Marie Perrin, Gérard Thuillier, Christophe Hoareau, Jacques Porteneuve, Nadege Montoux

JARS, Vol. 7, Issue 01, 073530, (July 2013) https://doi.org/10.1117/12.10.1117/1.JRS.7.073530

KEYWORDS: Clouds, LIDAR, Light scattering, Scattering, Particles, Lawrencium, Climatology, Aerosols, Observatories, Geometrical optics

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SPIE Journal Paper | 25 June 2013

Local enhanced solar irradiance on the ground generated by cirrus: measurements and interpretation

Gérard Thuillier, Jean-Marie Perrin, Philippe Keckhut, Francois Huppert

JARS, Vol. 7, Issue 01, 073543, (June 2013) https://doi.org/10.1117/12.10.1117/1.JRS.7.073543

KEYWORDS: Clouds, LIDAR, Particles, Atmospheric modeling, Atmospheric particles, Scattering, Cameras, Ozone, Solids, Diamond

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Proceedings Article | 23 December 2003 Paper

Raman water-vapor lidar implemented on an existing lidar system in the southern tropics

Laurent Robert, Philippe Keckhut, Jean Leveau, Fabrice Chane-Ming, Jacques Porteneuve

Proceedings Volume 5154, (2003) https://doi.org/10.1117/12.504721

KEYWORDS: LIDAR, Raman spectroscopy, Calibration, Telescopes, Sensors, Photodiodes, Mirrors, Ultraviolet radiation, Visible radiation, Signal detection

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Proceedings Article | 21 March 2003 Paper

Climatology of the upper troposphere with lidar

Philippe Keckhut, Gerard Ancellet, Leah Goldfarb, Alain Hauchecorne, Emmanuel Riedinger, Jean-Luc Baray, Bertrand Cadet, Jean Leveau, Tantely Randriambelo, Anne Rechou, Laurent Robert

Proceedings Volume 4893, (2003) https://doi.org/10.1117/12.466505

KEYWORDS: LIDAR, Climatology, Troposphere, Clouds, Ozone, Raman spectroscopy, Aerosols, Optical fibers, Lanthanum, Stratosphere

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Proceedings Article | 19 August 1998 Paper

Lidar monitoring of the stratosphere

Philippe Keckhut

Proceedings Volume 3504, (1998) https://doi.org/10.1117/12.319592

KEYWORDS: Ozone, Stratosphere, LIDAR, Aerosols, Atmospheric modeling, Atmospheric particles, Climatology, Sensors, Gases, 3D modeling

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Proceedings Article | 19 August 1998 Paper

Mesospheric temperature inversions observed from long-term lidar measurements at mid and low latitudes

Thierry Leblanc, I. McDermid, Philippe Keckhut, Alain Hauchecorne

Proceedings Volume 3504, (1998) https://doi.org/10.1117/12.319572

KEYWORDS: LIDAR, Temperature metrology, Climatology, Mesosphere, Satellites, Atmospheric propagation, Earth observing sensors, Molecules, Knowledge management, Modulation

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Proceedings Article | 19 August 1998 Paper

Climatology of the middle-atmosphere temperature from long-term lidar measurements at mid and low latitudes

I. McDermid, Thierry Leblanc, Philippe Keckhut, Alain Hauchecorne, Chiao She, David Krueger

Proceedings Volume 3504, (1998) https://doi.org/10.1117/12.319557

KEYWORDS: LIDAR, Climatology, Temperature metrology, Mesosphere, Stratosphere, Sodium, Error analysis, Composites, Knowledge management, Atmospheric modeling

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Showing 5 of 14 publications

Conference Committee Involvement (26)

Lidar and Optical Remote Sensing for Environmental Monitoring XVII

2 December 2024 | Kaohsiung, Taiwan

Lidar Remote Sensing for Environmental Monitoring XVI

24 September 2018 | Honolulu, Hawaii, United States

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing

11 September 2018 | Berlin, Germany

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing

11 September 2017 | Warsaw, Poland

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing

26 September 2016 | Edinburgh, United Kingdom

Lidar Remote Sensing for Environmental Monitoring XV

4 April 2016 | New Delhi, India

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing

21 September 2015 | Toulouse, France

Lidar Remote Sensing for Environmental Monitoring XIV

14 October 2014 | Beijing, China

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing

22 September 2014 | Amsterdam, Netherlands

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing IX

23 September 2013 | Dresden, Germany

Lidar Remote Sensing for Environmental Monitoring XIII

29 October 2012 | Kyoto, Japan

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing

27 September 2012 | Edinburgh, United Kingdom

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing

19 September 2011 | Prague, Czech Republic

Lidar Remote Sensing for Environmental Monitoring XI

12 October 2010 | Incheon, Korea, Republic of

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing

20 September 2010 | Toulouse, France

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing V

31 August 2009 | Berlin, Germany

Lidar Remote Sensing for Environmental Monitoring IX

18 November 2008 | Noumea, New Caledonia

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing IV

17 September 2008 | Cardiff, Wales, United Kingdom

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing

17 September 2007 | Florence, Italy

Lidar Remote Sensing for Environmental Monitoring VIII

29 August 2007 | San Diego, California, United States

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing II

13 September 2006 | Stockholm, Sweden

Lidar Technologies, Techniques, and Measurements for Atmospheric Remote Sensing

19 September 2005 | Bruges, Belgium

Lidar Remote Sensing for Environmental Monitoring VI

2 August 2005 | San Diego, California, United States

Lidar Remote Sensing for Industry and Environmental Monitoring V

9 November 2004 | Honolulu, Hawai'i, United States

Lidar Remote Sensing for Environmental Monitoring IV

3 August 2003 | San Diego, California, United States

Lidar Remote Sensing for Industry and Environment Monitoring III

24 October 2002 | Hangzhou, China

Showing 5 of 26 Conference Committees

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