UCL Department of Geography
Professor Philip Lewis
  
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Professor Philip Lewis

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Professor of Remote Sensing




Wordle: Lewis-publications

email: p.lewis@ucl.ac.uk ph:  +44-020-7679-0585

web:    http://www.geog.ucl.ac.uk fax: +44-020-7679-4293
http://ucl.academia.edu/Lewis

 

 

 

Scopus ID 7402869589

Jobs

NERC NCEO PhD available NOW: Land surface GPP and land-atmosphere interactions from GOSAT fluorescence

MSc Remote Sensing and Environmental Mapping

Seminar and related information
Application and course information: MSc Remote Sensing
Application and course information: MSc Environmental Mapping

Software

librat MC ray tracing software and instructions for lidar simulation from here.

Instructions for running ADEL-wheat simulations (on the UCL Geography system only at this point) from here.

librat MC ray tracing wiki from here

 

 

Some projects

NERC Centre for Terrestrial Carbon Dynamics

http://ctcd.group.shef.ac.uk/ctcd.html

NERC National Centre for Earth Observation

http://www.nceo.ac.uk

ESA Fire RT modelling

http://www2.geog.ucl.ac.uk/~plewis/ESA-fire

ESA GlobAlbedo

http://www.globalbedo.org

ESA EOLDAS

http://www.assimila.eu/eoldas
http://www.geog.ucl.ac.uk/~plewis/eoldas
Spatial Data assimilation in EO-LDAS

 

 

Kernels.009.005.h18v04.backGround.jpg
MODIS bihemispherical reflectance (DOY 009, 041, 105 on RGB) scaled [0.016:0.128]

Address:

Department of Geography
University College London
Gower St.
London WC1H 6BT
United Kingdom

Locations of visitors to this page



Animated Ask Lewis (experimental automatic answers)

Ask Lewis (experimental automatic answers)

 

 

Biography

Career History


2008-present:   Professor of Physical Geography, Department of Geography UCL.
2002-2008:      Reader in Remote Sensing, Department of Geography UCL.
1992 - 2002:    Lecturer in Remote Sensing, Department of Geography UCL.
1991 - 1992:    PGRA, Dept. Photogrammetry and Surveying, UCL;
NERC grant to TIGER 3.1 Project - Improved determination of 
albedo and surface roughness at multiple spatial scales using
remote sensing data and physical models surface roughness
for HAPEX-SAHEL.
1988 - 1991:    PGRA, Dept. Photogrammetry and Surveying, UCL;
NERC grant Angular variations of reflectance in multiple
look-angle satellite and aircraft data.

University Education


1996:   University College London, University of London
Ph.D. Remote Sensing, 
Dept. Geomatic Engineering (formerly Photogrammetry and Surveying)
Botanical Plant Modelling for Remote Sensing Simulation Studies
1988:   University of London.
M.Sc. Remote Sensing. (Distinction).
1987:   Queen Mary College, University of London
B.Eng. Avionics, Dept. Aeronautical Engineering (First Class Hons.).

Committees / Tutorships / Professional body membership

  • Chair of Exam Board (MSc in Remote Sensing; Undegraduate
    Geography; Geography & Economics) (2002-2003)
  • Deptartmental Exams Tutor (2001-2004) (deputy: 1997-2000)
  • Member, Remote Sensing and Photogrammetry Society (RSPS)
    (1987+)
  • Remote Sensing and Photogrammetry Society Modelling and
    Advanced Techniques SIG (MATSIG) committee member (1998+)
  • Permanent member Functional Structural Plant Modelling (FSPM) Board (2002+)
  • Scientific Committee ISPRS International Conference on Spectral Signatures in
    Remote Sensing (2004+)
  • Associate Team member NASA EOS MODIS Land Group (1992+)
  • Member of NERC Peer Review College (2003+)
  • NERC Steering Committee: Data Assimilation Research Centre
    (2001+)

 

Publications

Journals:



      [2012]

    1. Hancock, S., Lewis, P., Foster, M., Disney, M. I., and Muller, J. -P. (2012) Measuring forests with dual wavelength lidar: a simulation study over topography, Agricultural and Forest Meteorology, 161, 123-133.
    2. Calders, K., Lewis, P., Disney, M. I., Verbesselt, J. and Herold, M. (2012, submitted) Modelling LiDAR waveforms to solve for canopy properties, Rem. Sens. Environ.
    3. Guanter, L., Frankenberg, C., Dudhia, A., Lewis, P.E., Gomez--Dans, J., Kuze, A. , Suto , H., Grainger, R.G. (2012) Retrieval and global assessment of terrestrial chlorophyll fluorescence from GOSAT space measurements, Remote Sensing of Environment, 121, 236-251
    4. Lewis, P., Gomez--Dans, J., Kaminski, T., Settle, J., Quaife, T., Gobron, N., Styles, J., Berger, M. (2012) An Earth Observation Land Data Assimilation System (EO-LDAS). Remote Sensing of Environment, 120, 219-235.


    5. [2011]

    6. Hancock, S., Disney, M., Muller, J-P., Lewis, P., Foster, M., (2011) A threshold insensitive method for locating the forest canopy top with waveform lidar, Remote Sensing of Environment, Available online 11 August 2011, ISSN 0034-4257, 10.1016/j.rse.2011.07.012.
    7. Disney, M. I., Lewis, P., Gomez-Dans, J., Roy, D., Wooster, M. and Lajas, D. (2011) 3D radiative transfer modelling of fire impacts on a two-layer savanna system, Remote Sensing of Environment, 115, 1866-1881, DOI: 10.1016/j.rse.2011.03.010
    8. Wang, Z., C. B. Schaaf, P. Lewis,Y. Knyazikhin, M. A. Schull, A. H. Strahler, T. Yao, R. B. Myneni, M. J. Chopping and J. B. Blair, Retrieval of canopy height using moderate-resolution imaging spectroradiometer (MODIS) data, Remote Sensing of Environment, 115, 1595-1601, 2011.
    9. M. G. De Kauwe, M. I. Disney, T. Quaife, P. Lewis and M. Williams (2011) An assessment of the MODIS collection 5 Leaf Area Index product for a region of mixed coniferous forest, Remote Sensing of Environment, 115(2), 767-780. doI:10.1016/j.rse.2010.11.004
    10. M. Disney, V. Kalogirou, P. Lewis, A. Prieto-Blanco, S. Hancock and M. Pfeifer (2010) Simulating the impact of discrete-return lidar system and survey characteristics over young conifer and broadleaf forests Remote Sensing of Environment, 114(7), 1546-1560 doi:10.1016/j.rse.2010.02.009


    11. [2010]

    12. Miguel O. Roman, Crystal B. Schaaf, Philip Lewis, Gail P. Anderson, Feng Gao, Jeffrey L. Privette, Alan H. Strahler, Curtis E. Woodcock, and Mike Barnsley, (2010) Assessing the Coupling between Surface Albedo derived from MODIS and the Fraction of Diffuse Skylight over Spatially-Characterized Landscapes Remote Sensing of Environment 114(4),738-760
    13. T. Quaife and P. Lewis (2010) Temporal constraints on linear BRF model parameters IEEE Transactions on Geoscience and Remote Sensing, doi:10.1109/TGRS.2009.2038901


    14. [2009]

    15. Stoy P.C., Williams M., Disney M., Prieto-Blanco A., Huntley, B., Baxter, R.Lewis P. (2009) Upscaling as ecological information transfer: A simple framework with application to arctic ecosystem carbon exchange Landscape Ecology, 24: 971-986.
    16. M. Disney, P. Lewis M. Bouvet, A. Prieto-Blanco and S. Hancock (2009) Quantifying surface reflectivity for spaceborne lidar via two independent methods, IEEE Transactions on Geoscience and Remote Sensing (TGARS) 47(9) 3262-3271


    17. [2008]

    18. Quaife, T., S. Quegan, M. Disney, P. Lewis, M. Lomas, and F. I. Woodward (2008), Impact of land cover uncertainties on estimates of biospheric carbon fluxes, Global Biogeochem. Cycles, 22, GB4016, doi:10.1029/2007GB003097. (ISI cited 1)
    19. David P. Roy, Junchang Ju, Philip Lewis, Mike J. Choate, Crystal Schaaf, Feng Gao (2008) Multi-temporal MODIS-Landsat data fusion for relative radiometric normalization, gap filling, and prediction of Landsat data Remote Sensing of Environment, 112(6), 3112-3130 (ISI cited by: 10)
    20. J.-L. Widlowski, M. Robustelli, M. Disney, J.-P. Gastellu-Etchegorry, T. Lavergne, P. Lewis, P. R. J. North, B. Pinty, R. Thompson, M. M. Verstraete, (2008) The RAMI On-line model checker (ROMC): A web-based benchmarking facility for canopy reflectance models, Remote Sensing of Environment, 112(3), 1144-1150. (ISI cited by: 5)
    21. T. Quaife, P. Lewis, M. DE Kauwe, M. Williams, B. Law, M. Disney, P. Bowyer (2008), Assimilating Canopy Reflectance data into an Ecosystem Model with an Ensemble Kalman Filter, Remote Sensing of Environment, 112(4),1347-1364. (ISI cited by: 7)


    22. [2007]

    23. J. Grace, C. Nichol, M. Disney, P. Lewis, T. Quaife, P. Bowyer (2007), Can we measure terrestrial photosynthesis from space directly, using spectral reflectance and fluorescence?, Global Change Biology, 13 (7), 1484-1497., doi:10.1111/j.1365-2486.2007.01352.x. (ISI cited by: 19)
    24. P. Lewis and M. Disney (2007) Spectral invariants and scattering across multiple scales from within-leaf to canopy, Remote Sensing of Environment 109, 196-206. (ISI cited by: 9)
    25. J-L. Widlowski, M. Taberner, B. Pinty, V. Bruniquel-Pinel, M. Disney, R. Fernandes, J-P. Gastellu-Etchegorry, N. Gobron, A. Kuusk, T. Lavergne, S. Leblanc, P. E. Lewis, E. Martin, M. Mottus, P. R. J. North, W. Qin, M. Robustelli, N. Rochdi, R. Ruiloba, C. Soler, R. Thompson, W. Verhoef, M. M. Verstraete, D. Xie, (2007), The third RAdiation transfer Model Intercomparison (RAMI) exercise: Documenting progress in canopy reflectance models, Journal of Geophysical Research, 112, D09111, doi:10.1029/2006JD007821. (ISI cited by: 19)
    26. D. Huang, Y. Knyazikhin, R.E. Dickinson, M. Rautiainen, P. Stenberg, M. Disney, P. Lewis, A. Cescatti, Y. Tian, W. Verhoef, and R.B. Myneni (2007), Canopy spectral invariants for remote sensing and model applications, Remote Sensing of Environment, 106, 106-122. (ISI cited by: 23)


    27. [2006]

    28. Roy, D.P., Lewis, P., Schaaf, C., Devadiga, S., Boschetti, L. (2006) The Global impact of cloud on the production of MODIS n-day and daily rolling n-day bi-directional reflectance model based composites for terrestrial monitoring IEEE Geosci. and Rem. Sens., 3(4), Oct 2004, 452-456. (iISI cited by: 13)
    29. M. Disney, P. Lewis, P. Saich (2006) 3D modelling of forest canopy structure for remote sensing simulations in the optical and microwave domains, Remote Sensing of Environment. Rem. Sens. Environ., 100(1), 114-132. (doi:10.1016/j.rse.2005.10.003, PDF) (iISI cited by: 20)


    30. [2005]

    31. D.P. Roy, Y. Jin, P.E. Lewis and C.O. Justice (2005) Prototyping a global algorithm for systematic fire-affected area mapping using MODIS time series data, Remote Sensing of Environment Volume 97, Issue 2 , 30 July 2005, Pages 137-162 (PDF) (ISI cited by: 67)


    32. [pre-2005]

    33. Disney, M. I., Lewis, P., Thackrah, G., Quaife, T., Barnsley, M. J. (2004) Comparison of MODIS broadband albedo with values derived from other EO data at a range of scales and ground measurements, over an agricultural site, Int. Journ. Rem. Sens., 25(23), 5297-5317 (PDF). (iISI cited by: 5)
    34. Pinty, B.; Widlowski, J.-L.; Taberner, M.; Gobron, N.; Verstraete, M. M.; Disney, M.; Gascon, F.; Gastellu, J.-P.; Jiang, L.; Kuusk, A.; Lewis, P.; Li, X.; Ni-Meister, W.; Nilson, T.; North, P.; Qin, W.; Su, L.; Tang, S.; Thompson, R.; Verhoef, W.; Wang, H.; Wang, J.; Yan, G.; Zang, H. (2004) Radiation Transfer Model Intercomparison (RAMI) exercise: Results from the second phase J. Geophys. Res., Vol. 109, No. D6, D06210 10.1029/2003JD004252 25 March 2004(PDF) (iISI cited by: 30)
    35. D. Roy, P. Lewis, C. Justice, (2001) Burned Area Mapping Using Multi-Temporal Moderate Spatial Resolution Data - a Bi-Directional Reflectance Model-Based Expectation Approach Remote Sensing of Environment, 83, 263-286. (iISI cited by: 79)
    36. Schaaf, C. B., A. H. Strahler, F. Gao, W. Lucht, X. Li, X. Zhang, Y. Jin, E. Tsvetsinskaya, J.-P. Muller, P. Lewis, M. Barnsley, G. Roberts, C. Doll, S. Liang, and J. L. Privette, (2002) First operational BRDF, albedo nadir reflectance products from MODIS, Remote Sensing of Environment, 83, 135-148.(PDF). (ISI cited by: 306)
    37. M.Barnsley, P. Lewis, S. O'Dwyer, M. Cutter, M.I. Disney, P. Hobson, and D. Lobb (2000) On the Potential of CHRIS-PROBA for mapping vegetation characteristics from space. Remote Sensing Reviews, 19:171-189. (PS version 26.1MB) , Tex version (43K) .(ISI cited by: 0 (RSR missing from ISI))
    38. Lucht, W. and P. Lewis (2000) Theoretical noise sensitivity of BRDF and albedo retrieval from the EOS-MODIS and MISR sensors with respect to angular sampling. International Journal of Remote Sensing 21(1) 81-89. (ISI cited by: 42)
    39. C. Justice, A. Belward, J. Morisette, P. Lewis, J. Privette, F. Baret Developments in the validation of satellite products for the study of the land surface. International Journal of Remote Sensing 21(17) 3383-3390 (ISI cited by: 59)
    40. Atkinson, P.M. and P. Lewis. (2000) Geostatistical classification for remote sensing: an introduction. Computers and Geosciences, 26, 361-371. (ISI cited by: 58)
    41. M.I. Disney, P. Lewis, and P. North (2000) Monte Carlo ray tracing in optical canopy reflectance modelling. Remote Sensing Reviews, 18:163-196. (ISI cited by: 0 (RSR missing from ISI))
    42. P. Lewis , (1999) Three-dimensional plant modelling for remote sensing simulation studies using the Botanical Plant Modelling System .Agronomie: Agriculture and Environment Vol.19, No.3-4, pp.185-210 (ISI cited by: 32)
    43. P. Lewis , M.I. Disney, M.J.Barnsley and J-P Muller (1999) Deriving albedo maps for HAPEX-Sahel from ASAS data using kernel-driven BRDF models. Hydrology and Earth System Sciences, 3(1), 1-13. (ISI cited by: 32)
    44. A.J. McDonald, F. Gemmel, and P. Lewis , (1998) Investigation of the utility of spectral vegetation indices for determining information on coniferous forests. Remote Sensing of Environment 66(3), 250-272. (ISI cited by: 42) <
    45. C. Justice, E. Vermote, J. Townshend, R. Defries, D. Roy, D. Hall, V. Salomonson, J. Privette, G. Riggs, A. Strahler , W. Lucht, R. Myneni, Y. knyazi, S. Running, R. Nemani, Z. Wan, A. Huete, W. van Leeuwen, R. Wolfe, L. Giglio, JJ-P. Muller , P. Lewis and M. Barnsley (1998) The Moderate Resolution Imaging Spectroradiometer (MODIS): Land Remote Sensing for Global Change Research. IEEE Trans. Geosci. and Rem. Sens. 36(4), 1228-1249. (iISI cited by: 307)
    46. S. Liang, P. Lewis , R. Dubayah, W. Qin, and D. Shirey (1997) Topographic Effects on Surface Bidirectional Reflectance Scaling, Journal of Remote Sensing Vol. 1 (ISSN 1007-4619) 82-93. (ISI cited by: 0)
    47. W. Wanner , A. Strahler , B. Hu,, P. Lewis , X. Li , J-P. Muller M. Barnsley , (1997) Global BRDF and Albedo from the EOS MODIS and MISR Sensors, Journal of Remote Sensing Vol. 1 (ISSN 1007-4619) 143-148. (ISI cited by: 0)
    48. P. Lewis , and E. Vives de Lope , (1997) The Application of Kernel-driven BRDF models and AVHRR data to monitoring land surface Dynamics in the Sahel, Journal of Remote Sensing Vol. 1 (ISSN 1007-4619) 155-161. (ISI cited by: 0)
    49. W. Wanner , A. Strahler , B. Hu, P. Lewis , J-P. Muller X. Li , C. Schaaf , M. Barnsley, (1997), Global retrieval of Bidirectional reflectance and albedo over land from EOS MODIS and MISR Data: Theory and Algorithms.Journal of Geophysical Research, Vol. 102 , pp. 17,143 - 17,162. (ISI cited by: 112)
    50. M. Barnsley , P. Lewis , J-P. Muller , and M. Sutherland (1997), Estimating Land Surface Albedo in the HAPEX-Sahel Southern Super-Site: Inversion of Two BRDF Models against Multiple Angle ASAS Images. Journal of Hydrology. 188-189, pp. 749-778. (ISI cited by: 7)
    51. M. Barnsley , D. Allison , and P. Lewis (1997), On the Information Content of Multiple View Angle (MVA) Images, International Journal of Remote Sensing, 18(9), 1937-1960. (ISI cited by: 33)
    52. S. Liang and P. Lewis (1996), A Parametric Radiative Transfer Model for Sky Radiance Distribution. J. Quant. Spectrosc. Radiat.eTransfer, 55(2), 181-189.(pdf) (ISI cited by: 8)
    53. D.W. Burgess, P. Lewis and J-P. Muller (1995), Topographic Effects in AVHRR NDVI Data. Remote Sens. Environ, 54, 223-232. (ISI cited by: 23)
    54. S.D. Wall, T.G. Farr, J-P. Muller , P. Lewis and F.W. Leberl (1991), Measurement of Surface Microtopography. Photogrammetric Engineering and Remote Sensing, 57(8), 1075-1078. (ISI cited by: 7)

Books/Chapters:

    1. S. Quegan, P. Lewis, T. Quaife, G. Roberts, M. Wooster, M. Disney, (2008) Using Satellite Observations in Regional Scale Calculations of Carbon Exchange, In 'The Continental-Scale Greenhouse Gas Balance of Europe', Series: Ecological Studies , Vol. 203 Dolman, A. Johannes; Valentini, Riccardo; Freibauer, Annette (Eds.) 2008, XIII, 390 p. 69 illus., 27 in color., Hardcover ISBN: 978-0-387-76568-6, Springer-Verlag, New York.
    2. P. Lewis (2007) Canopy modelling as a tool in remote sensing research, In: Vos, J., Marcelis, L.F.M., de Visser, P.H.B., Struik, P.C. and Evers, J.B. eds. Functional Structural Plant Modelling in Crop Production. Springer, Dordrecht, pp.219-229.
    3. M. Barnsley , P. Lewis , J-P. Muller , and M. Sutherland (1997), Estimating Land Surface Albedo in the HAPEX-Sahel Southern Super-Site: Inversion of Two BRDF Models against Multiple Angle ASAS Images. in Goutorbe et al. (eds.), 1997, HAPEX-Sahel, Elsevier, 1079p. ISBN 0-444-82735-8. (reprints from Journal of Hydrology Special Issues on HAPEX-Sahel).

Reports:

    1. Final report of ESA project "Estimating surface lidar reflectivity for A-SCOPE", M. I. Disney and P. Lewis, ESA RFQ/3-12259/07/NL/JA.
    2. UK Emissions by Sources and Removals by Sinks due to Land Use, Land Use Change and Forestry Activities, Report, May 2004, June 2005, April 2006.
    3. P. Saich, P. Lewis, M. Disney, P. van Oevelen, I. Woodhouse, B. Andrieu, C. Fournier & S. Ljutovac (2003), Development of Architectural Vegetation Growth Models for Remote Sensing Applications", ESA Report contract 14940.
    4. A. Strahler , W. Wanner , C. Schaaf , X. Li , B. Hu, J-P. Muller , P. Lewis , M. Barnsley , (1995), MODIS BRDF/Albedo Product: Algorithm Theoretical Basis Document Version 4.0 MODIS Product ID: MOD09, Version 4.0, November 1996, 252pp.

Invited Lectures etc.

(not up to date ...)

  1. 2008, June 6, RSPSoc Lecture and Conversazione (in memory of Prof. Mike Barnsley) , BRDF - Varying perspectives on land surface monitoring

Conference Proceedings:

(not up to date ...)

  1. Jose Gomez-Dans, Martin Wooster, Philip Lewis, Allan Spessa, (2009), Probabilistic calibration of a coupled ecosystem and fire model using optical and thermal satellite data, IEEE Geosci Rem. Sens. Symp., Cape Town, S. Africa, July 2009.
  2. Ana Prieto-Blanco, Mathias Disney, Phillip Lewis, José Gómez-Da, (2009) Satellite monitoring of disturbances in acrtic ecosystems, IEEE Geosci Rem. Sens. Symp., Cape Town, S. Africa, July 2009.
  3. Crystal Schaaf, Alan Strahler, Zhuosen Wang, Miguel Román, Ziti Jiao, Yanmin Shuai, Qingling Zhang, Feng Gao, Jicheng Liu, Xiaoyang Zhang, Wolfgang Lucht, Shunlin Liang, Philip Lewis, Jan-Peter Muller, Michael Barnsley, Xiaowen Li, (2009), MODIS albedo and reflectance anisotropy products for climate and vegetation studies, IEEE Geosci Rem. Sens. Symp., Cape Town, S. Africa, July 2009.
  4. Philip Lewis, Jose Gomez-Dans, Mathias Disney, Martin Wooster, David Roy, Mathias Disney, (2009) Modelling the impact of wildfire on spectral reflectance, IEEE Geosci Rem. Sens. Symp., Cape Town, S. Africa, July 2009. <\li>
  5. P. Lewis, (2009) Vegetation Structure Measurement and Modelling for EO, ESA workshop: Remote Sensing of 3D-vegetation structures, Juelich, Germany, 2nd July, 2009.
  6. P. Lewis, T. Quaife, C.B. Schaaf, M. Roman, Z. Wang, Y. Shuai, (2009) BRF/albedo inversion constrained by temporal smoothness, The International Conference on Land Surface Radiation and Energy Budgets, Observations, Modeling and Analysis, Beijing, China, March 18-20 2009.
  7. Disney, M. I., Lewis, P. and Bouvet, M. (2008) Quantifying surface reflectivity for spaceborne lidar missions, in proc. IGARSS'08, 5-11 July, Boston, USA, 2008.
  8. M. De Kauwe, T. Quaife, P. Lewis, Disney, M. I. and M. Williams (2008) Estimating the spatial exchange of carbon through the assimilation of Earth Observation (EO) derived products using an Ensemble Kalman Filter, in proc. IGARSS'08, 5-11 July, Boston, USA, 2008.
  9. S. Hancock, Disney, M. I., P. Lewis, J.-P. Muller (2008) Exploring the measurement of forests with full waveform lidar through Monte-Carlo ray tracing, in proc. IGARSS'08, 5-11 July, Boston, USA, 2008.
  10. N. Macbean, Disney, M. I., Lewis, P. and P. Ineson (2008) Using remote sensing data to quantify changes in vegetation over peatland areas, in proc. IGARSS'08, 5-11 July, Boston, USA, 2008.
  11. Hancock, S., Lewis, P., Disney, M. I., Foster, M. and Muller, J. -P. (2008) Assessing the accuracy of forest height estimation with long pulse waveform lidar through Monte-Carlo ray tracing, in proc. SilviLaser 8th International Conference on LIDAR applications, 17-19 September, Edinburgh.
  12. C. Mutlow, P. Monks, R. Scott, D Matheson, S Rea, R Leigh, D Lobb, H Boesch, R M Jenkins, P Lewis, J-P Muller, M Foster, I H Woodhouse, J Jack, D Weidmann, K Smith, (2008) "Instrument Developments in the UK Centre for EO Instrumentation," Proceedings of the 59th International Astronautical Congress, Glasgow, Scotland, 29 Sep - 3 Oct 2008, IAC-08-B1.3.1
  13. Quaife, T,. Lewis, P., Disney, M. I., DeKauwe, M., Williams, M. and Law, B. (2007) Assimilating reflectance data into an ecosystem model to improve estimates of terrestrial carbon fluxes, in pro. IGARSS07, Barcelona, Spain, 23-27 July 2007.
  14. Disney, M. I. and Lewis, P. (2007) Spectral invariant behaviour of a complex 3D forest canopy, in proc. 10th ISPMSRS meeting, Davos, Switzerland, 12-14 March 2007.
  15. Pfeifer, M., Disney, M. I. and Lewis, P. (2007) Simulating gap fraction of complex forest scenes, in proc. 10th ISPMSRS meeting, Davos, Switzerland, 12-14 March 2007.
  16. Lewis, P. and Disney, M. I. (2007) Modelling Canopy reflectance with spectral invariants, in proc. 10th ISPMSRS meeting, Davos, Switzerland, 12-14 March 2007.
  17. Hancock, S., Lewis, P., Muller, J. P and Disney, M. I. (2007) Using Monte Carlo ray tracing to investigate the measurement of forest parameters with the Echidna laser scanner, in proc. 10th ISPMSRS meeting, Davos, Switzerland, 12-14 March 2007.
  18. Moreno, J.F., G.P. Asner, H. Bach, T. Belenguer, A. Bell, C. Buschmann, A. Calera, J. Calpe, P. Campbell, G. Cecchi, R. Colombo, L.A. Corp, A. Court, M.A. Cutter, M. Disney, A. Dudelzak, G. D'Urso, R. Fernandes, J. Flexas, P. Gege, B. Gielen, A. Gitelson, E.U. Gloor, J. Gower, R.O. Green, J. Hill, S. Jacquemoud, L. Jia, M. Kneubhler, T. Laurila, P. Lewis, D. Lobb, F. Magnani, S.W. Maier, M.V. Marek, A. Martinez, P. Martinez-Cobo, P. Mazzinghi, M. Menenti, R. Merton, E. Middleton, E. De Miguel, J. Miller, G. Mohammed, E.J. Milton, F. Morales, I. Moya, L. Nedbal, W. Knorr, C. Ottle, A. Olioso, S. Pace, A. Palucci, R. Pedros, J. Peltoniemi, J. Penuelas, A. Plaza, J. Polcher, U. Rascher, R. Reuter, A. Rosema, J.L. Roujean, Y. Saito, B. Saugier, M.E. Schaepman, J.B. Serrano, J.J. Settle, M. Sierra, J. Sobrino, M.P. Stoll, Z. Bob Su, C. Tobehn, N. Tremblay, R. Valcke, W. Verhoef, F. Veroustraete, M. Verstraete, and P. Zarco-Tejada. Fluorescence explorer (FLEX): An optimised payload to map vegetation photosynthesis from space. in AIAA 57th International Astronautical Congress, IAC 2006. 2006.
  19. Hancock, S., Disney, M. I., Lewis, P. and Muller, J.-P. (2006) Using lidar to characterise tree canopies, in proc. of IWMMM-4, 20-24th March 2006, Sydney, Australia.
  20. P. Lewis and M. Disney (2006), Prospects shoots and leaves: scaling relationships from within-leaf scattering to the canopy level, Proc. RSPSOC Conference, Sept. 2006, Cambridge (CDROM).
  21. D. Huang, S. Smolander, M. Rautianen, M. Schull, R. Myneni, P. Stenberg, Y. Knyazikhin, P. Lewis and M. Disney.The recollision probability and its potential use in ecological models, NASA MISR Team meeting Dec. 2005, NASA.
  22. P. Lewis, J. Hillier, J. Watt, B. Andrieu, C. Fournier, P. Saich, M. Disney, (2005) 3D dynamic vegetation modelling of wheat for remote sensing simulation and inversion, Proc. 9th Intl. Symp. on Physical Measurements and Signatures in Remote Sensing, Beijing, China, 17-19 Oct 2005 144-146
  23. T. Quaife, P. Lewis, M. Williams, M. Disney and M. de Kauwe (2005) Assimilating Earth Observation Data into a Vegetation Model using an Ensemble Kalman Filter, Proc. 9th Intl. Symp. on Physical Measurements and Signatures in Remote Sensing, Beijing, China, 17-19 Oct 2005 399-401
  24. M. Disney, P. Lewis, T. Quaife, C. Nichol, (2005) A spectral invariant approach to modelling canopy and leaf scattering, Proc. 9th Intl. Symp. on Physical Measurements and Signatures in Remote Sensing, Beijing, China, 17-19 Oct 2005 318-320
  25. L. Rebelo, P. Lewis and D. Roy (2005) A comparison of two temporal BRDF models with application to the identification of fire-affected areas, Proc. 9th Intl. Symp. on Physical Measurements and Signatures in Remote Sensing, Beijing, China, 17-19 Oct 2005 147-149
  26. T. Quaife, M. Lomas, P. Lewis, F.I. Woodward and M. Disney (2005). Testing carbon flux predictions from Dynamic Vegetation Models using data from Earth Observation satellites. In proceedings: RSPSoc 2005. Portsmouth,
    England.
  27. T. Quaife, P. Lewis, M. Williams, M. Disney and M. De Kauwe (2005). Assimilating Earth Observation Data into a Vegetation Model using an Ensemble Kalman Filter. NERC Earth Observation Conference. Portsmouth, England.
  28. Lewis et al. Compressed Interpolated Sparse LUT inversion of CHRIS-PROBA data. ESA ESRIN March 2004
  29. Lewis et al. 3D plant modelling for remote sensing simulation, Workshop on 3D modelling in EO, Avignon, France, March 2004
  30. L. Rebelo, P. Lewis & D. Roy, (2004) A temporal-BRDF model-based approach to change detection, IGARSS '04, Alaska USA, Page(s):2103 - 2106 vol.3
  31. Quaife T., Lomas M., Picard G., Disney M., Lewis P., Woodward F.I. "Forward Modeling Earth Observation Signals from the Sheffield Dynamic Global Vegetation Model", NERC EO meeting, Plymouth, June 2004.
  32. Quaife T., Lomas M., Picard G., Disney M., Lewis P., Woodward F.I.  "Coupling a Canopy Reflectance Model with a Global Vegetation Model", IGARSS '04, Alaska USA, Volume 1,  September 2004.
  33. M. Disney, M. Williams and P. Lewis (2004) The potential for assimilation of EO-measured radiance in terrestrial carbon studies: simulation of the canopy radiation regime, NERC EO conference, Plymouth, June 30 - July 1, 2004.
  34. M. Disney, P. Lewis and P. Saich (2004) 3D modelling of forest canopy structure for remote sensing simulation and parameter estimation, in proc. 4th International Workshop on Functional-Structural Plant Models, CIRAD, Montpellier, June 7-11, 2004, p 282.
  35. P.Lewis, P.Saich, M. Disney, B. Andrieu, C. Fournier, T. Macklin and J. Bodley (2004) Calibration of an L-system model of winter wheat for remote sensing modelling and inversion, in proc. 4th International Workshop on Functional-Structural Plant Models, CIRAD, Montpellier, June 7-11, 2004, pp 257-261.
  36. P. Lewis and M. Barnsley, (2004) CHRIS-PROBA conference paper April 2004, ESA ESRIN
  37. Quaife et al VGT conference paper
  38. P. Lewis, P. Saich, J. Hillier, M. Disney. B. Andrieu, C. Fournier, (2004),Estimation of Wheat Biophysical Parameters by Inverting Remote Sensing Data using 3D Models of Plant Dynamics at Optical and Microwave Wavelengths, plant modelling workshop, Halle, germany, Feb. 2004
  39. P. Lewis, Barnsley, M., Quaife, T., Thackrah, G., Disney, M. and Saich, P. (2003) Biophysical parameters from CHRIS/PROBA, in proc. SPECTRA Workshop, ESA/ESTEC Noordwijk, Netherlands, Oct. 28-30.
  40. Roy, D.P., Yufang, J., Justice, C.O., Giglio, L., Lewis P., (2003), Multi-year southern Africa MODIS burned area product generation and validation, Fall AGU Meeting, San Francisco, December 8-12, 2003. Session "Validation and Application of Land Surface Products From the MODIS Sensor".
  41. P. Lewis, P. Saich, M. Disney, B. Andrieu, C. Fournier, (2003) Modelling the radiometric response of a dynamic, 3D structural model of wheat in the optical and microwave domains. Proc. IEEE Geosci. and Rem. Sens. Symp. IGARSS'03 (Toulouse) Volume 6,  21-25 July 2003 Page(s):3543 - 3545 vol.6
  42. M. Disney, P. Saich P. Lewis, Modelling the radiometric response of a dynamic, 3D structural model of Scots Pine in the optical and microwave domains. Proc. IEEE Geosci. and Rem. Sens. Symp. IGARSS'03 (Toulouse) Volume 6,  21-25 July 2003 Page(s):3537 - 3539 vol.6
  43. P. Saich, P. Lewis, M. Disney (2003) Biophysical parameter retrieval from forest and crop canopies in the optical and microwave domains using 3D models of canopy structure. Proc. IEEE Geosci. and Rem. Sens. Symp. IGARSS'03 (Toulouse) Volume 6,  21-25 July 2003 Page(s):3546 - 3548 vol.6
  44. G. Thackrah and P. Lewis, An initial analysis of CHRIS-on-board-PROBA data for the purposes of biophysical parameter mapping over a variety of land cover types. Proc. IEEE Geosci. and Rem. Sens. Symp. IGARSS'03 (Toulouse)
  45. T. Quaife, P. lewis, M. Disney, M. Lomas, Intercomparison of phenological measures derived from medium and coarse resolution earth observation and implications for assimilation into vegetation growth models. Proc. IEEE Geosci. and Rem. Sens. Symp. IGARSS'03 (Toulouse)
  46. L. Rebelo, P. Lewis, and D. Roy (2003), Burn scar detection in southern Africa using a bi-directional reflectance model-based approach. Proc. IEEE Geosci. and Rem. Sens. Symp. IGARSS'03 (Toulouse)
  47. S. Dwyer and P. Lewis, Mechanisms for spectral variation in the range of semi-variograms
    Proc. IEEE Geosci. and Rem. Sens. Symp. IGARSS'03 (Toulouse) Volume 2,  21-25 July 2003 Page(s):979 - 981 vol.2
  48. S. Dwyer, P. Lewis, and JP Muller, (2003) An application of stereomatching to the problem of geo-referencing historical air-photos, Proc. IEEE Geosci. and Rem. Sens. Symp. IGARSS'03 (Toulouse) Volume 1,  21-25 July 2003 Page(s):170 - 172 vol.1
  49. S. Dwyer, P. Lewis, Buenos Aires ISPRS.
  50. Schaaf, C.; Strahler, A.; Feng Gao; Lucht, W.; Yufang Jin; Xiaowen Li; Xiaoyang Zhang; Tsvetsinskaya, E.; Muller, J.-P.; Lewis, P.; Barnsley, M.; Roberts, G.; Doll, C.; Shunlin Liang; Roy, D.; Privette, J.; (2002) Global albedo, BRDF and nadir BRDF-adjusted reflectance products from MODIS, Geoscience and Remote Sensing Symposium, 2002. IGARSS '02. 2002 IEEE International Volume 2,  24-28 June 2002 Page(s):1188 - 1190 vol.2
  51. P. Saich, P. Lewis, M. Disney and G. Thackrah, 2001. Comparison of Hymap/E-SAR data with models for optical reflectance and microwave scattering from vegetation canopies, in proc. Third International Workshop on Retrieval of Bio-and Geo-Physical Parameters from SAR data for Land Applications, Sheffield, September 2001.
  52. P. Lewis, M. Barnsley, and M. Cutter,  CHRIS-PROBA: Mission status and prospects for mapping biophysical parameters, Proc. Int. Geosci. Remote Sens. Symp. (IGARSS'01), Sydney, Australia, 9-13 July, 2001.
  53. Schaaf, C. B., A. H. Strahler, F. Gao, W. Lucht, X. Li, X. Zhang, Y. Jin, E. Tsvetsinskaya, J.-P. Muller, P. Lewis, M. Barnsley, G. Roberts, C. Doll, S. Liang, and J. L. Privette, (2001) MODIS Operational Bidirectional Reflectance and Albedo Products, Proc. Int. Geosci. Remote Sens. Symp. (IGARSS'01), Sydney, Australia, 9-13 July, 2001. Volume 5,  9-13 July 2001 Page(s):2227 - 2229 vol.5
  54. Schaaf, C. B., A. H. Strahler, F. Gao, W. Lucht, X. Li, X. Zhang, Y. Jin, E. Tsvetsinskaya, J.-P. Muller, P. Lewis, M. Barnsley, G. Roberts, C. Doll, S. Liang, and J. L. Privette, Operational Bidirectional Reflectance and Albedo Products from the MODerate Resolution Imaging Spectroradiometer (MODIS), Abstract, IGBP Global Change Open Science Conference in Amsterdam, Netherlands, 9-13 July, 2001.
  55. Schaaf, C. , A. H. Strahler, F. Gao, W. Lucht, X. Li, J.-P. Muller, P. Lewis, M. Barnsley, P. Hobson, M. Disney, G. Roberts, M. Dunderdale, C. Doll, Land Surface Spectral Bidirectional Reflectance and Albedo from the MODerate Resolution Imaging Spectroradiometer (MODIS), Abstract, American Geophysical Union Spring Meeting, Boston, MA, 29 May - 2 June, 2001.
  56. Schaaf, C. B., F. Gao, A. Straler, W. Lucht, T. Tsang, N. Strugnell, X. Li, X. Zhang, J-P. Muller, P. Lewis, M. Barnsley, P. Hobson, M. Disney, M. Dunderdale, G, Roberts, C. Doll and S. Liang. Temporal Characteristics of the MODIS BRDF/Albedo Product. Proceedings of the 8th International Symposium on Physical Measurements and Signatures in Remote Sensing, Aussois, France, 8-12 January, 233-238, 2001.
  57. Schaaf, C.B.; Feng Gao; Strahler, A.H.; Tsang, T.; Lucht, W.; Strugnell, N.; Xiaowen Li; Muller, J.-P.; Lewis, P.; Barnsley, M.; Hobson, P.; Disney, M.; Dunderdale, M.; Roberts, G., (2000) The Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF and albedo product, AGU Fall 2000 Meeting, San Francisco, Dec 2000.
  58. Schaaf, C. B., A. H. Strahler, F. Gao, W. Lucht, X. Li, J-P. Muller, P. Lewis, M. Barnsley, P. Hobson, M. Disney, M. Dunderdale, G. Roberts and C. Doll, (2000). The MODerate Resolution Imaging Spectroradiometer (MODIS) BRDF and Albedo Product, Abstract,American Geophysical Union Spring Meeting, San Francisco, CA, 15-19 Dec, 2000.
  59. Schaaf, C.B.; Feng Gao; Strahler, A.H.; Tsang, T.; Lucht, W.; Strugnell, N.; Xiaowen Li; Muller, J.-P.; Lewis, P.; Barnsley, M.; Hobson, P.;  Disney, M.; Dunderdale, M.; Roberts, G., (2000) Initial Results From the Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF and Albedo Product, AGU Spring 2000 Meeting, Washington DC, May 30-June 3
  60. D. Roy and P. Lewis (2000) Burned area mapping from multitemporal surface bidirectional reflectance, AGU Spring 2000 Meeting, Washington DC, May 30-June 3
  61. Schaaf, C.B.; Feng Gao; Strahler, A.H.; Tsang, T.; Lucht, W.; Strugnell, N.; Xiaowen Li; Muller, J.-P.; Lewis, P.; Barnsley, M.; Hobson, P.;Disney, M.; Dunderdale, M.; Roberts, G., (2000) The Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF and albedo product: preliminary results, IEEE International Geoscience and Remote Sensing Symposiun, 2000. Proceedings. IGARSS 2000. Volume: 7, 2000 Page(s): 3048 -3050 vol.7
  62. P. Hobson,, Barnsley, M., P. Lewis, M. Disney, and J-P. Muller (1999) Inversion of semi-empirical, kernel-driven models using POLDER on ADEOS data. ALPS '99, Meribel, France.
  63. P. Lewis(1999) The Botanical Plant Modelling System: a model for remote sensing simulation studies. XVI International Botanical Congress, 1-7 August 1999. Saint Louis, Missouri, USA.
  64. M. Disney and P. Lewis , (1999)  Towards a spectral kernel-driven BRDF model in proceedings of 25th Annual Remote Sensing Society Conference , 7-10th September 1999, Cardiff, UK.  377-384.
  65. P. Lewis  and M. Disney (1999) Application of the Botanical Plant Modelling System (BPMS) to the analysis of spatial information in remotely sensed imagery , in proceedings of 25th Annual Remote Sensing Society Conference , 7-10th September 1999, Cardiff, UK. 507-514.
  66. Roberts, G., and P. Lewis, (1999) Monitoring temporal dynamics of kernel-driven BRDF model paramters. in proceedings of 25th Annual Remote Sensing Society Conference , 7-10th September 1999, Cardiff, UK. 281-288.
  67. P.D. Hobson, M.J. Barnsley, P. Lewis and M. Disney (1999) Inversion of Kernel-Driven BRDF Models using POLDER-on-ADEOS Data. in proceedings of 25th Annual Remote Sensing Society Conference , 7-10th September 1999, Cardiff, UK. 371-376.
  68. P. Lewis, Izzawati, and J. McMorrow (1999) Sensitivity of 3D radar backscatter model to changing biophysical parameters of an oil palm plantation.  in proceedings of 25th Annual Remote Sensing Society Conference , 7-10th September 1999, Cardiff, UK. 37-44.
  69. P. Lewis  and M. Disney (1999) The development of spectral kernels to improve the linear kernel-driven approach to BRDF modelling. Abstract/poster presented at Second International Workshop on Multiangular Measurements and Models (IWMMM-2)  Ispra, Italy  September 15 - 17, 1999
  70. P. Lewis and P. Atkinson, (1998), A geostatistical Classifier for remotely sensed imagery. Kingston 1998 RGS-IGB Annual Conference. 5-8 Jan. 1998. Kingston UK. p. 89 (presented paper - abstract only)
  71. P. Lewis and M. Disney, (1998) The Botanical Plant Modelling System (BPMS): a case study of multiple scattering in a barley canopy. IGARSS'98, Seattle, USA Volume 3,  6-10 July 1998 Page(s):1481 - 1483 vol.3
  72. M. Disney and P. Lewis . (1998) An investigation of how linear BRDF models deal with the complex scattering processes encountered in a real canopy, Proc. IGARSS '98, Jul. 6th-10th, Seattle, USA. Volume 3,  6-10 July 1998 Page(s):1231 - 1233 vol.3
  73. M. Disney, P. Lewis . , Knott, R., Hobson, Evans-Jones, K. and Barnsley, M. J. (1998) Validation of a manual measurement method for deriving 3D canopy structure using the bpms, Proc. IGARSS '98, Jul. 6th-10th, Seattle, USA. Volume 3,  6-10 July 1998 Page(s):1249 - 1251 vol.3
  74. Izzawati, P. Lewis . and McMorrow, J. (1998) 3D model simulation of polarimetric radar backscatter and texture of oil-palm plantations., Proc. IGARSS '98, Jul. 6th-10th, Seattle, USA. Volume 3,  6-10 July 1998 Page(s):1502 - 1504 vol.3
  75. W. Lucht, C. Schaaf, A. Strahler, J-P. Muller, B. Hu, P. Lewis Y. Liu, A. Hyman, M.J. Barnsley, and N. Strugnell. (1998). At launch status of the MODIS BRDF/Albedo algroithm: implementation, AVHRR-based prototyping, and future plans. Proc. IGARSS '98, Jul. 6th-10th, Seattle, USA. Volume 3,  6-10 July 1998 Page(s):1289 - 1291 vol.3
  76. N. Akkal, P. Boissard, C. Chabanet, M.H. Jeuffroy, P. Lewis , and J.M. Meynard(1997), Nitrogen fertilization management in winter wheat based on early estimate of the cover fraction. 1st European Conf. on Precision Agriculture, Warwick University (U.K.), 7-10 Sept. 97, Vol 1. 405-412, BIOS Scientific Publishers
  77. P. Lewis and P. Boissard, (1997), The use of 3D plant modelling and measurement in remote sensing, 7th International Symposium Physical Measurements and Signatures in Remote Sensing, Courchevel, France, April 7-11, 1997. Vol. 1. pp 319-326. (ISBN 90 5410 9173)
  78. M. Disney , J-P. Muller , P. Lewis , M. Barnsley (1997), Production and validation of BRDF and albedo extracted from airborne and spaceborne data, 7th International Symposium Physical Measurements and Signatures in Remote Sensing, Courchevel, France, April 7-11, 1997. Vol. 2. pp 471-478. (ISBN 90 5410 9173)
  79. E. Vives de Lope and P. Lewis , (1996), The Application of Kernel-Driven BRDF Models and AVHRR data to monitoring land surface dynamics in the Sahel, 7th International Symposium Physical Measurements and Signatures in Remote Sensing, Courchevel, France, April 7-11, 1997. Vol. 2. pp. 599-606. (ISBN 90 5410 9173)
  80. P. Boissard, P. Valery, N. Akkal, J. Helbert, and P. Lewis (1997), Paremetrisation d'un modele architectural de ble au cours du tallage. Estimation des parametres de structure par photogrammetrie. Actes du Seminaire sur la Modelisation ArchitecturaleINRA Paris, 10-12 Mars 1997, 213-222
  81. P. Lewis (1997), The Botanical Plant Modelling System (B.P.M.S.). Actes du Seminaire sur la Modelisation ArchitecturaleINRA Paris, 10-12 Mars 1997, 45-54
  82. P. Lewis and M. Disney, (1997), Examining BRDF model operation with the botanical plant modelling system, Proc. Remote Sensing Society Conference, Reading, 1997. pp. 298-303.
  83. P. Lewis and M. Disney, (1997), Validation of kernel-driven BRDF models for monitoring albedo in the Sahel, Proc. Remote Sensing Society Conference, Reading, 1997. pp 304-309.
  84. Z. Hesley, P. Lewis , M. Barnsley , (1997), Dealing with BRDF heterogeneity thro' estimation of sub-pixel directional refl. assuming a linear mixture model, Proc. Remote Sensing Society Conference, Reading, 1997. pp. 434-439.
  85. Z. Hesley, M. Barnsley , and P. Lewis , (1996), The significance of angular sampling errors of the MODIS and MISR sensors on the retrieval of surface biophysical parameters from BRDF models. Proc. RSS 96, Durham, UK. 537-542
  86. M. Barnsley , M. Disney , P. Lewis ,Z. Hesley, and P. Muller (1996), On the intrinsic dimensionality of the BRDF: Implications for the retrieval of land surface biophysical properties. Proc. RSS 96, Durham, UK. 69-70
  87. P. Boissard, N. Akkal, P. Lewis , (1996), 3D Plant Modelling in Agronomy. Association of Applied Biologists: Modelling in Applied Biology: Spatial Aspects, 24/27 June 1996, Brunel, U.K.
  88. W. Wanner , P. Lewis , J-L Roujean, (1996), The Influence Of Directional Sampling On Bidirectional Reflectance Using Kernel-driven Models, Proc. IGARSS'96. Volume 3,  27-31 May 1996 Page(s):1408 - 1410 vol.3
  89. W. Wanner , A. Strahler , B. Zhang, and P. Lewis , (1996), Kilometer-Scale Global Albedo from MODIS, Proc. IGARSS'96. Volume 3,  27-31 May 1996 Page(s):1405 - 1407 vol.3
  90. P. Lewis , (1995), On the Implementation of Linear Kernel-Driven BRDF Models. Proc. RSS 95, "Remote Sensing in Action", Southampton, UK, 11-14 Sept, 333-340.
  91. M. Barnsley , D. Allison , and P. Lewis , (1995), On the Statistical Information Content of Multiple View Angle (MVA) Images. Proc. RSS 95, "Remote Sensing in Action", Southampton, UK, 11-14 Sept, 1298-1305.
  92. M. Sutherland , M. Barnsley , P. Lewis , and J-P. Muller , (1995), Derivation of Surface Biophysical Parameters through Inversion of a BRDF Model for HAPEX-Sahel. Proc. RSS 95, "Remote Sensing in Action", Southampton, UK, 11-14 Sept, 325-332.
  93. Z. Hesley, M. Barnsley , and P. Lewis , (1995), Effect of Angular Sampling Regimes on the Retrieval of Biophysical Parameters from BRDF Models.Proc. RSS 95, "Remote Sensing in Action", Southampton, UK, 11-14 Sept, 342-349.
  94. P. Boissard, N. Akkal, P. Lewis , P. Valery, and J-M Meynard, (1995), Linking a 3D Plant Model Database of Crop Structure to Models of Canopy Development. Int. Colloq. Photosynthesis and Remote Sensing, 28-31 Aug. 1995, Montpellier, Fr.
  95. P. Lewis , M. Barnsley , J-P. Muller , and M. Sutherland , (1995), Estimating land surface albedo in the HAPEX-Sahel experiment: model-based inversions using ASAS. Proc IGARSS'95, Firenze, Italy. Volume 3,  10-14 July 1995 Page(s):2221 - 2223 vol.3
  96. P. Lewis , (1995), The Utility of Linear Kernel-Driven BRDF Models in Global BRDF and Albedo Studies. Proc IGARSS'95, Firenze, Italy.Volume 2,  10-14 July 1995 Page(s):1186 - 1188 vol.2
  97. W. Wanner , A. Strahler , J-P. Muller , M. Barnsley , P. Lewis , X. Li , C. Schaaf , (1995), Global Mapping of Bidirectional Reflectance and Albedo for the EOS MODIS Project: The Algorithm and the Product. Proc IGARSS'95, Firenze, Italy. Volume 1,  10-14 July 1995 Page(s):525 - 529 vol.1
  98. P. Lewis and P. Boissard, (1995), A Botanical Plant Modelling System: a Model for Deriving and Describing Plant Form and Simulating the Canopy Shortwave Radiation Regime. Invited Paper (abstract only in proc.) RSS Meeting: "The Interaction of Vegetation Canopies with Radiation", Sheffield CEOS, May 24, 1995.
  99. D. Allison , M. Barnsley , P. Lewis , N. Dyble, and J-P. Muller , (1994), Precise Geometric Registration of ASAS Airborne Data for Land Surface BRDF Studies, Proc. IGRASS'94, Pasadena, Ca., USA, 8-12 Aug. 1994. Volume 3,  8-12 Aug. 1994 Page(s):1655 - 1657 vol.3
  100. D.W. Burgess and P. Lewis , (1994), The Topographic Effect on NDVI Measurements Derived from AVHRR Data, 7th Australaisian Remote Sensing Conference, 1-4 March 1994, Melbourne, Australia, 189-196.
  101. P. Lewis and M. Barnsley , (1994), Influence of the Sky Radiance Distribution on Various Formulations of the Earth Surface Albedo, Proc. Mesures Physiques et Signatures en Teledetection, Val d'Isere, France, 17-21 January, 1994, 707-716 [scanned pdf]
  102. P. Lewis and J-P. Muller , (1992), The Advanced RAdiometric RAy Tracer: ARARAT for Plant Canopy Reflectance Simulation, International Arch. Photogrammetry and Remote Sensing, XXIX, Comm. VII(B7), 26-34.
  103. P. Lewis , J-P. Muller and K. Morris, (1991), Quality Assessment of a Botanical Plant Modelling System for Remote Sensing Simulation Studies, Proc. IGARSS'91, Espoo, Finland, June 3-6th, 1917-1920.
  104. P. Lewis and J-P. Muller , (1990), Botanical Plant Modelling for Remote Sensing Simualtion Studies, Proc IGARSS'90, Washington D.C., USA, 1739-1782.
  105. S.D. Wall, T.G. Farr, J-P. Muller , P. Lewis and F.W. Leberl, (1989), Measurement of Surface Microtopography using Helicopter-Mounted Stereo Film Cameras and Two Stereo-Matching Techniques, Proc. IGARSS'89, July 10-14th, Vancouver, Canada, 1173-1176.

 

Research

Introduction

The main focus of my research is monitoring vegetation using Earth Observation methods. I have built a focus, in my own work and that of my research group, around developing and applying new methods in this area, with a key emphasis on moving the field from loose empirical correlations to making use of physically-based models. I have always sought to develop a strong, rigorous, capability in modelling within my own work and that of my group (research as well as training elements such as the MSc remote sensing). This has led to a wide range of fruitful collaborations over the years. The approach has provided practical solutions to operational monitoring (e.g. my work over the last 10+ years leading to the development of the NASA MODIS BRDF/albedo product with colleagues at BU1, NASA, UoW, Swansea2, and UCL) as well as providing for greater accuracy in spinoff applications such as model-based burn scar detection in Africa/change detection with colleagues at UMD3/NASA. Gaining a NERC EOSI Lectureship in the last few years (Dr Paul Saich, a microwave EO modeller) has allowed for rapid progress in the area of examining common links between information in the optical and microwave domains. Exploring and exploiting this synergy forms previous joint work for ESA and BNSC (in collaboration with BAE systems), as well as a focus for future developments in the NERC Centre of Excellence and other areas.

Developing fundamental understanding of radiation interactions

The basic approach of (robust) physically-based modelling developed has, and will continue to form a large component of my research focus. This has mainly been associated with developing models for 3D radiative transfer, of which our current model, drat, is an expression. This model has been applied to a wide range of canopy types, initially with the aim of developing a testbed simulation system, from which can be developed an understanding of the main factors affecting shortwave radiation scattering and absorption. We have participated with this model in model intercomparison exercises within the international framework of RAMI (Pinty et al., 2004).

The main directions of this work in the near future are (i) developing an understanding of the temporal dynamics of the radiation signal and synergy between optical and microwave scattered radiation through 3D dynamic modelling (see below), mainly through collaborations with INRA4 with ESA/BNSC/NERC funding; (ii) developing 'lumped parameter' models which encapsulate our understqanding of 3D scattering but which are able to accurately describe the radiation scattered with a small number of compound terms (see below); (iii) developing rapid methods for the inversion of physically-based models through sparse, compressed look-up tables (LUTs); (iv) developing system simulation tools to explore the possibilites of new sensor types and configurations.

Lumped parameter models

All of the streams of research in fundamental modelling are leading to the conclusion that whilst, in many ways, the remote sensing signal is a complex function of the details of canopy spatial arrangement and spectral properties, a decoupling of the structural and spectral aspects of scattering can provide significant insights into how a robust but simple model of radiation scattering and absorption can be constructed. Early evidence along these lines led to the development of so-called semi-empirical linear kernel-driven BRDF models which we helped developed and test and which form the basis of the NASA MODIS BRDF/albedo algorithm, a 16-day global 1 km product ( Schaaf et al., 2001). A spin-off application from these models has resulted in a set of 'signal tracking' models, one of which now forms the core of the NASA MODIS burned area detection algorithm. This product, which is soon to become operational, developed in collaboration with David Roy at UMD/NASA GSFC, allows the most accurate and robust mapping of burned areas so far developed (Roy et al., 2001, 2005). It has great potential for increasing our understanding of the impact of fire on Carbon budgets as well as in other areas (see fire below). Rebelo et al. (2005) show that semi-empirical signal tracking methods further developed from these models with an empirical temporal model allow for a more robust consideration of sudden changes in the reflectance signal, as well as more robust parameter mapping.

Whilst these semi-empirical models have allowed for a range of practical applications, the model parameters associated with them have no direct physical meaning. The 3D modelling work undertaken within my group (developing from Lewis & Disney, 1998 in Lewis et al., 2005; Disney et al., 2005) is pointing to the conclusion that if we separate the 'structural' aspects of scattering from the 'spectral' we can build much more meaningful 'lumped parameter' models, from which we can provide mappings of biophysical parameters, as well as more directly linking radiation scattering and absorption. This latter point is of particular importance if we are to use such models to drive vegetation/ecosystem growth models.

Monitoring and modelling photosynthesis from Space

A core stream of research within the CTCD is to develop improved modelling and monitoring of photosynthesis from space. We are doing this in several ways, using both simple models of Gross Primary Production (GPP) such as the Production Efficiency Approach (which more easily links to satellite observations) and more complex mechanistic models. This is currently developing in two main areas: (i) allowing for satellite observation-based estimates of GPP to be compared with mechanistic model predictions (Quaife et al., 2005); and (ii) allowing for the assimilation of satellite observations into mechanistic models to improve predictive capabilities and show model inadequacies. We are currently attempting this latter approach by assimilating satellite-derived products such as MODIS LAI, but we are also developing towards more directly linking the mechanistic model predictions to the observations through an 'EO operator', essentially a canopy scattering and absorption model driven by the mechanistic model state variables. This will use what we have learnt about simple parameterisatiuons of canopy scattering models and will allow for a clearer tracking of the uncertainties involved (thence uncertainties in Carbon flux prediction).

In addition, we are investigating new methods for measuring photosynthetic activity from space with methods ranging from simple band ratios (Photochemical Reflectance Index - PRI, which is linked to light-use efficiency through Xanthrophyll cycling), and more recently, passive detection of fluorescence.

Fire

Fire plays a major role in many ecosystem dynamics and is a large, dynamic and uncertain element of global Carbon bugets. One way in which Carbon release is estimated is by monitoring the area burned each year and multiplying this by factors associated with fuel load and fire intensity to arrive at estimates of Carbon released. We have therefore been working for several years to provide improved estimates of burned area from satellite data, building on our modelling expertise. As noted above, this has led to the development of the MODIS burned area product. An alternative and independent method for estimating Carbon release from biomass burning has been developed by Wooster (KCL). We have recently set up collaborative links with Wooster to combine these efforts with our improved burned area estimates and fire modelling activities within CTCD. We will be seeking NERC QUEST funding to follow this up.

Other

I have supervised around 20 MSc dissertations at UCL, and am currently responsible for four PhD students, three of whom are funded by NERC. I currently have three post-doctoral Research Fellows working for me on various NERC projects. I am involved in reviewing NERC and NASA grant applications, the former as a member of the NERC peer-review college, as well as reviewing papers for various journals including: RSE, RSR, IEEE GRS, IJRS, and New Phytologist.

1: BU = Boston University
2: UoW Swansea = University of Wales, Swansea
3: UMD = University of Marlyland
4: INRA = Institut Nationale de la Recherche Agronomique
5: CTCD = NERC Centre for Terrestrial Carbon Dynamics

Impact

 

Teaching

[GEOG2021] [GEOG3010] [UNIX] [ Scientific Computing: GeogG122][TERRESTRIAL CARBON: MODELLING and MONITORING]


Undergraduate Courses

Graduate Courses:

M.Sc. in Remote Sensing

 

Computing [1992-]
Computing on UNIX workstations: UNIX, X-windows etc. Shell programming. HTML; This is a ten week course offered to MSc students in Remote Sensing and Photogrammetry. Incorporates Image Processing [1999-]

Vegetation monitoring [1998-] (part of Climate course)
monitoring of global vegetation parameters - brief 3 hour introduction using examples from EOS/MODIS

Vegetation Science [1993-]
This is an intensive five week course which deals with models and methods for monitoring vegetation state from remote sensing data, mainly using physically-based models.

Renewable Natural Resources [2005-]
This is a 15 unit (1 term) MSc course designed to enable students to understand the physics and applications of monitoring renewable natural resources using remote sensing.

 

Previous undergraduate material
  • GEOG2004 Remote Sensing and GIS (1997-2000)
  • GEOG1002 Environmental Systems and Processes (1998+ material)
Previous postgraduate material
  • Vegetation Monitoring
    A previous course on the basics of vegetation monitoring from EO.
  • Renewable and Natural Resources [1992-93]
    This course was taught with Prof. Tony Allan of SOAS, and dealt with the use of remote sensing and GIS in monitoring renewable and natural resources (local, regional, global scales).
  • Image Processing [1992-1998]
    Image processing theory and practice; image processing under UNIX. (postscript: 7003885 bytes)

PhD Students

Doctoral Research Students

  • 1994-1998: NERC Studentship (with Mike Barnsley , University of Wales, Swansea)  (within 4 years)
    Trevor Tsang: Scaling Issues in Remote Sensing of Land Cover.

  • 1994-1998: NERC Studentship (with Mike Barnsley , University of Wales, Swansea)  (within 4 years)
    Zoltan Helsey: Scaling and BRDF Inversion with ATSR-2.

  • 1997-2001: NERC CASE Studentship (CASE partners: Matra Marconi, and NRSCL) (within 4 years)
    Mat Disney: Linear BRDF Modelling. [delayed through NERC problems with Airborne Remote Sensing Facility]

  • 1997-2002: Indonesian Govt./British Council sponsered (within 4 years)
    Izzawati: Microwave modelling and monitoring of tropical plantations (oil palm).[delayed through civil strife in Indonesia]

  • 1998- 2003: NERC Studentship (within 4 years)
    Gareth Roberts: Temporal BRDF dynamics in Southern Africa

  • 2001-2005: UCL Dept. Geog. Teaching Asst. (with Paul Saich, UCL and David Roy, UMD/NASA GSFC)
    Lisa Rebelo. Optical and Microwave Modelling for Change Detection in Southern Africa

  • 2003-: NERC tied studentship (with Paul Saich)
    Jane Matthews: Microwave Modelling of forest canopies

  • 2004-: NERC tied studentship
    Jillian Watt: Development and testing of a 3D dynamic model of winter wheat

  • <>2005-: NERC CTCD studentship
  • <>Martin de Kauwe: Assimilation of EO data into Carbon models

Recent Grants

  • Wales, Swansea, and J-P Muller, Dept. Photogrammetry and Surveying, UCL) - Extension of £ 35K to original £101K. GRADE - good.

Data funding/Science Teams:

  • 2000+: NASDA ALOS (3 projects)
  • 2000+: CHRIS-PROBA
  • 2000: NERC/BNSC SHAC Campaign (airborne SAR/Hyperspectral).
  • 1999+: ESA/EUMETSAT MSG data grant. Evaluation of MSG land surface products With Marc Leroy (CESBIO), Fred Baret (INRA), J-L Roujean (METEOFRANCE), Mike Barnsley (Swansea).
  • 1999+: POLDER-II data grant. POLDER-II Science team member With Mike Barnsley (Swansea) et al.
  • 1995+: SPOT VEGETATION data grant. VEGETATION Science team member. Determination and validation of Land Surface Biophysical properties using SPOT 4 VEGETATION and HRVIR. With Mike Barnsley (Swansea) et al.
  • 1995+: POLDER data grant. POLDER Science team member. With Mike Barnsley (Swansea) et al.
  • 2001-2004: ENVISAT-AO data grant.ID: 507. Global 1.2 km MERIS data for 3 years. Land surface albedo from MERIS reflectances using MODIS directional factors. with W. Lucht, PIK Potsdam (PI), A. Strahler, CRSA, Boston Univ. (C. Schaaf, CRSA Boston Univ. (awarded 1999)
  • 1995+: NASA EOS MODIS BRDF/Albedo product science team (incl. MODLAND).
  • 1992+: NERC Airborne Remote Sensing Facility/ NERC Equipment Pool for Field Spectroscopy.Various