Daniel Clewley

Dan Clewley was at MiXIL from June 2012 – June 2014 as a post-doctoral researcher. He is now at Plymouth Marine Laboratory (Devon, UK) but still collaborates with MiXIL.

His research investigated uncertainty for time-series remote sensing classification in wetland areas, focusing on detecting decadal change using JERS-1 and PALSAR data. He was also involved in the Soil Moisture and Optimal Estimator (SoilSCAPE) project. His roles on the project include webmaster / database manager for the project website and data distribution server (soilscape.usc.edu), sensor placement, deployment and general GIS support.

Dan joined MiXIL in June 2012 after completing his PhD within the Institute of Geography and Earth Sciences (IGES) at Aberystwyth University (Wales, UK), externally supervised by Prof. Moghaddam. His research focuses on remote sensing of vegetation, primarily using Synthetic Aperture Radar (SAR) but often in combination with optical and LiDAR data.

Dan co-leads the Remote Sensing and GIS Library (RSGISLib; www.rsgislib.org) and writes a blog (spectraldifferences.wordpress.com) on open source software in remote sensing.

Main Research Areas
  • Remote sensing of vegetation.
  • Synthetic Aperture Radar.
  • Modelling / Inversion of radar backscatter from forests.
  • Software for processing large remote sensing datasets.
Education
  • Ph.D. “Retrieval of Forest Structure and Biomass from Radar Data using Backscatter Modelling and Inversion”. Aberystwyth University, UK. 2012. Thesis Advisers; Richard Lucas, Pete Bunting, Mahta Moghaddam
  • MSc. Geographical Information Systems and Remote Sensing. Aberystwyth University, UK. 2007. Thesis Adviser; Richard Lucas.
  • BSc. Physics, The University of Wales, Aberystwyth, UK. 2006
 Publications

Journal

  • Clewley, D.; Whitcomb, J.; Moghaddam, M.; McDonald, K.; Chapman, B.; Bunting, P. Evaluation of ALOS PALSAR Data for High-Resolution Mapping of Vegetated Wetlands in Alaska. Remote Sensing. 2015, 7, 7272-7297. (open access).
  • Lucas, R.M, Clewley, D., Accad, A., Butler, D., Armston, J., Bowen, M., Bunting, P., Carreiras, J., Dwyer, J., Eyre, T., Kelly, A., McAlpine, C., Pollock, S. and Seabrook, L. 2014 Mapping Forest Growth Stage in the Brigalow Belt Bioregion of Australia through integration of ALOS PALSAR and Landsat- derived Foliage Projective Cover (FPC) data. Remote Sensing of Environment. Volume 155. Pages 42-57. (link).
  • Clewley, D.; Bunting, P.; Shepherd, J.; Gillingham, S.; Flood, N.; Dymond, J.; Lucas, R.; Armston, J.; Moghaddam, M. A Python-Based Open Source System for Geographic Object-Based Image Analysis (GEOBIA) Utilizing Raster Attribute Tables. Remote Sensing 2014, 6, 6111-6135. (open access).
  • Bunting, P.J., Clewley, D., Lucas, R. M., Gillingham, S. 2014. The Remote Sensing and GIS Software Library (RSGISLib). Computers & Geosciences. 60, pp. 216-226 (link; pre-print)
  • Bunting, P.J., Armston, J., Lucas, R. M., Clewley, D. 2013. Sorted pulse data (SPD) library. Part I: A generic file format for LiDAR data from pulsed laser systems in terrestrial environments. Computers & Geosciences, 56, pp.197–206. (link)
  • Bunting, P.J., Armston, J., Clewley, D., Lucas, R. M.  2013. Sorted pulse data (SPD) – Part II: A processing framework for LiDAR data from pulsed laser systems in terrestrial environments. Computers & geosciences, 56, pp.207–215. (link)
  • Dickinson, C., Siqueira, P., Clewley, D., Lucas, R. (2013) Classification of forest composition using polarimetric decomposition in multiple landscapes. Remote Sensing of Environment, 131, pp 206-214. (link)
  • Clewley, D., R. Lucas, A. Accad, J. Armston, M. Bowen, J. Dwyer, S. Pollock, P. Bunting, T. Eyre, A. Kelly, J. Carreiras, and M. Moghaddam (2012). An Approach to Mapping Forest Growth Stages in Queensland, Australia through Integration of ALOS PALSAR and Landsat Sensor Data. Remote Sensing. 4(8) . (open access)
  • Bürgin, M., Clewley, D., Lucas, R.M. and Moghaddam, M. (2011). A generalized radar backscattering model based on wave theory for multilayer multispecies vegetation. IEEE Transactions on Geoscience and Remote Sensing, 49, pp. 4832–4845. (link)
  • Lucas, R.M., Armston, J., Fairfax, R., Fensham, R., Accad, A., Carreiras, J., Kelley, J., Bunting, P., Clewley, D., Bray, S., Metcalfe, D., Dwyer, J., Bowen, M., Eyre, T. and Laidlaw, M. (2010). An Evaluation of the ALOS PALSAR L-Band Backscatter—Above Ground Biomass Relationship Queensland, Australia: Impacts of Surface Moisture Condition and Vegetation Structure. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing. 3(4). (link)
  • Lucas, RM, Medcalf, K, Brown, A, Bunting, P, Breyer, J, Clewley, D, Keyworth, S and Blackmore, P (2011) Updating the Phase 1 habitat map of Wales, UK, using satellite sensor data. ISPRS Journal of Photogrammetry and Remote Sensing, 66(1), 81–102. (pdf)

Conference

  • Moghaddam, M., Clewley, D., Silva A., and Akbar, R. (2014) “The SoilSCAPE Network Multiscale In-situ Soil Moisture Measurements: Innovations in Network Design and Approaches to Upscaling in Support of SMAP” American Geophysical Union (AGU) Fall Meeting, San Francisco, December 2014.
  • Whitcomb, J., Moghaddam, M., Clewley, D., and McDonald, K.(2014) “Wetland Maps of Central Canada based on L-band SAR Imagery” American Geophysical Union (AGU) Fall Meeting, San Francisco, December 2014.
  • McDonald, K., Chapman, B., Azarderakhsh, M., Moghaddam, M., Whitcomb, J., Clewley, D., Schroeder, R., and Podest, E. (2014) “Satellite Remote Sensing of Inundated Wetlands: Data Record Assembly and Cross-Product Comparison” American Geophysical Union (AGU) Fall Meeting, San Francisco, December 2014.
  • Clewley, D., Lucas, R., Accad, A., Armston, J., Bunting., P., Moghaddam., M. (2014) “Mapping brigalow regrowth in Queensland, Australia using a combination of SAR and optical data” RSPSoc, Aberystwyth, UK, September 2014
  • Clewley, D., Whitcomb, J., Moghaddam, M., Bunting P. and McDonald, K. (2014) “Large-scale wetlands mapping in north America using L-band SAR data and open source software” RSPSoc, Aberystwyth, UK, September 2013
  • Clewley, D., Whitcomb, J., Moghaddam, M., McDonald, K. and Bunting P. (2014) “Decadal Changes in the type and extent of Wetlands in Alaska using L-band SAR data – a preliminary analysis” Proceedings, International Geoscience and Remote Sensing Symposium (IGARSS) 2014, Quebec, Canada, July 2014.
  • Whitcomb, J., Clewley, D., Moghaddam, M., McDonald, K. Podest, E. Chapman, B. and Bunting P. (2014) “Progress in Mapping Wetlands of Central Canada using L-band SAR data” Proceedings, International Geoscience and Remote Sensing Symposium (IGARSS) 2014, Quebec, Canada, July 2014.
  • Clewley, D., Whitcomb, J., Bunting, P., Moghaddam, M., Chapman, B. and McDonald, K. (2013) “Quantifying Uncertainty in Wetland Change Mapping for Alaska: Part I – Uncertainty in Input SAR Data.” American Geophysical Union (AGU) Fall Meeting, San Francisco, December 2013.
  • Whitcomb, J., Moghaddam, M., Clewley, D., McDonald, K., Podest, E. and Chapman, B. (2013) ” Wetlands Maps of Central Canada based on L-band SAR Imagery” American Geophysical Union (AGU) Fall Meeting, San Francisco, December 2013.
  • Moghaddam, M., Silva, A., Clewley, D., Akbar, R. and Entekhabi, D. (2013) ” SoilSCAPE in-Situ Observations of Soil Moisture for SMAP Validation: Pushing the Envelopes of Spatial Coverage and Energy Efficiency in Sparse Wireless Sensor Networks” American Geophysical Union (AGU) Fall Meeting, San Francisco, December 2013.
  • Devarakonda, R., Kefa, L., Palanisamy, G., Cook, B., Santhanavanna, S. Moghaddam, M. Clewley, D., Siva, A. and Akbar, R.. (2013) “Unified Science Information Model for SoilSCAPE using the Mercury Metadata Search System” American Geophysical Union (AGU) Fall Meeting, San Francisco, December 2013.
  • Clewley, D., Moghaddam, M., Lucas, R. and Bunting P. (2013) “Retrieval of Forest Structure and Moisture from SAR data using an Estimation Algorithm” Proceedings, International Geoscience and Remote Sensing Symposium (IGARSS) 2013, Melbourne, Australia, July 2013.
  • Lucas, R., Clewley, D., Carreiras, J., Bunting P., Armston, J., Scarth, P. and Accad, A. (2013) “Refocusing Remote Sensing towards the Restoration of Global Ecosystems” Proceedings, International Geoscience and Remote Sensing Symposium (IGARSS) 2013, Melbourne, Australia, July 2013.
  • Moghaddam, M., Silva, A., Akbar, R., Clewley, D., Bürgin, M., Castillo, A., Entekhabi, D. (2013) “SoilSCAPE In situ Network for Multiscape Validation of SMAP Data Products” Proceedings, International Geoscience and Remote Sensing Symposium (IGARSS) 2013, Melbourne, Australia, July 2013.
  • DeGrandi, E., Lucas, R., Clewley, D., Bunting P., and Mitchard, E., (2013) “Analysis of TanDEM-X InSAR Data Aimed at the Characterisation of Vegetation Vertical Structure: a Case Study in Injune (Queensland, Australia)” Proceedings, International Geoscience and Remote Sensing Symposium (IGARSS) 2013, Melbourne, Australia, July 2013.
  • Clewley, D., R. Lucas, P. Bunting and M. Moghaddam (2012) “Classification of Forest Regrowth Stage using Polarimetric Decomposition and FPC” American Geophysical Union (AGU) Fall Meeting, San Francisco, December 2012. (ePoster)
  • Clewley, D., R. Lucas, M. Moghaddam, and P. Bunting, (2012) “The effect of errors on model inversion for the retrieval of forest structure from SAR data,” Proceedings, International Geoscience and Remote Sensing Symposium (IGARSS) 2012, Munich, Germany, July 2012, 4 pages.
  • Bunting, P., Armston, J. D., Lucas, R. M., Clewley D.,  (2011). Sorted Pulse Data (SPD) Format: A new file structure for storing and processing LiDAR data. SilviLaser 2011, Oct. 17-19, 2011 – Hobart, Australia, pp. 1–10, Sep. 2011.
  • Bunting, P., Armston, J. D., Clewley D., and Lucas, R. M. (2011) “The Sorted Pulse Data Software Library (SPDLib): Open source tools for processing LiDAR data,” SilviLaser 2011, Oct. 17-19, 2011 – Hobart, Australia, pp. 1–10, Sep. 2011
  • Clewley, D., Lucas, R.M., Armston, J., Bunting, P. and Dwyer, J (2010). Retrieval of forest structure and biomass from ALOS PALSAR and Landsat derived FPC using backscatter inversion. Proceedings, 15th Australian Remote Sensing and Photogrammetry Conference, Alice Springs, NT, Australia, September, 2010.
  • Clewley, D., Lucas, R.M., Moghaddam, M., Bunting, P., Dwyer, J. and Carreiras, J. (2010). Forest parameter retrieval from SAR data using an estimation algorithm applied to regrowing forest stands in Queensland, Australia. Proceedings, International Geoscience and Remote Sensing Symposium (IGARSS), Honolulu, US, July, 2010.

Book Chapter

  • Clewley, D., J. Whitcomb, M. Moghaddam, and K. McDonald. 2014 “Mapping the State and Dynamics of Boreal Wetlands using Synthetic Aperture Radar”, to be published in Advances in Wetlands Mapping, M. Lang and R. Tiner (Eds.).
  • Lucas, R.M., Rosenqvist, A., Kellndorfer, J., Hoekman, D., Shimada, M., Clewley, D., Walker, W., and de Mesquita Jr H. N.,. 2012 “Global Forest Monitoring with Radar (SAR) Data” in Global Forest Monitoring from Earth Observation, Eds.  F. Achard, M. C. Hansen. CRC Press
  • Lucas, R.M., Armston, J., Lee, A.C., Carreiras, J., Viergever, K, Bunting, P., Clewley, D., Moghaddam, M., Siqueira, P. and Woodhouse, I. (2010). “Quantifying Carbon in Wooded Savannas: The Role of Active Sensors in Measurements of Structure and Biomass”. In: Ecosystem Function in Savannas: Measurement and Modelling at Landscape to Global Scales, Eds. M.J. Hill and N.P. Hanan, Taylor and Francis
 Other

Tutorials / Teaching Notes

  • Bunting and Clewley (2014) “Object-based image classification using RSGISLib + Stack” (notes and data available to download from here (zip 233 MB)).
  • Bunting and Clewley (2013) “Python tutorial for Spatial Data Processing”. MSc course at Aberystwyth University (available here).
  • Bunting and Clewley (2013) “RSGISLib Documentation” (available here).

Code

  • Bunting and Clewley “The Remote Sensing and GIS Software Library” (rsgislib.org). Main contributions include:
    • Zonal statistics utilities.
    • Inversion routines (from PhD).
    • Various additions / enhancements to vector / image utilities.
    • rsgiscmd command-to-xml interface.
  • Bunting and Clewley “RSGIS Scripts” – Assorted scripts for working with spatial data, text manipulation general utilities etc. Main contributions include:
    • A complete processing chain for batch processing ALOS PALSAR scenes using GAMMA (here).
    • A web based tool for generating training / validation points using Google Maps (here).
    • Numerous scripts for text processing.
  • Clewley “AirMOSS GDAL Utilities” – A collection of scripts for converting and working with AirMOSS data using GDAL.