Dr. David Roy of SDSU has research interests including the development of remote sensing and advanced computing methods to map and characterize terrestrial change, in particular the occurrence and spatial extent of vegetation fires; the causes and consequences of land cover and land use change; and fire-climate-vegetation interactions. He is also interested in development of methodologies to facilitate the transfer of remote sensing products into the user domain, particularly in developing countries.

Dr. Roy held post-doctoral research fellowships at the U.K. Natural Environment Research Council Unit for Thematic Information Systems, University of Reading, and at the Space Applications Institute, Joint Research Centre of the European Commission, Ispra, Italy. Before moving to South Dakota State University he was a research scientist in the Department of Geography, University of Maryland, and led the Moderate Resolution Imaging Spectroradiometer (MODIS) Land Data Operational Product Evaluation group at NASA's Goddard Space Flight Center for eight years.

Dr. Roy has a B.Sc. degree in Geophysics from the Department of Environmental Science, University of Lancaster, U.K. (1987), an M.Sc. degree in Remote Sensing and Image Processing from the Department of Meteorology, University of Edinburgh (1988), and a Ph.D. in Remote Sensing from the Department of Geography, Cambridge University (1994).

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Teaching

Quantitative Remote Sensing for Terrestrial Monitoring (GSE/GEOG-741-S01), Graduate level course offered as part of the Geospatial Science and Engineering Ph.D. program, Fall 2006, Fall 2007, Spring 2009.

This course describes the science, algorithms, and computational approaches to generate and assess derived satellite products for long term Earth system monitoring. Emphasis is on the principles of optical remote sensing (0.4-14 mm) and state-of-the-practice quantitative algorithms for estimating biophysical and geophysical land surface variables from remotely sensed observations.  Understanding of the fundamental principles of remote sensing, physics, calculus, statistics, and computer literacy is required.

2007 Syllabus (PDF, 33KB), Online Lectures

Advanced Remote Sensing Applications: Fire and other disturbances (GSE/GEOG-766-S01), Mark Cochrane & David Roy, Graduate level course offered as part of the Geospatial Science and Engineering Ph.D. program, Spring 2008.

This course describes the state-of-the-practice algorithms and sensors for remote sensing of drought stress, forest degradation and biomass burning, including the location and timing of these disturbances, the area affected, and the post-disturbance effects on the environment. The need for these information, in the context of ecological and climatological applications, is emphasized. Materials are presented in lectures and experienced in lab applications. Understanding of the fundamental principles of remote sensing, physics, ecology, and computer literacy is required.

Quantitative Remote Sensing (GEOG 485), Matt Hansen & David Roy, Undergraduate level course offered in the Geography Department, Spring 2008.

This course introduces the application of image processing techniques for analyzing remotely sensed images.  Students will learn the basics of image manipulation and analysis, including data sources, formats, statistics, interpretation, visualization, data transformations, image enhancement, data correction, characterization and accuracy assessment. The primary focus of the class will be on the application of multi-spectral remotely sensed data sets.  Lab activities will follow the aforementioned topics initially addressed through lectures.

Ph.D. Supervision

Chris Barnes, Ph.D. Title: United States Land Cover Land Use Change, Albedo and Radiative Forcing: Past and Potential Climate Implications [Funded by NASA Earth and Space Science Ph.D. Fellowship].

Amadou Dieye, Ph.D. Title: Land Use Land Cover Change and Soil Organic Carbon Under Climate Variability in Sahelian West Africa (1975-2055) [Funded by NASA Earth and Space Science Ph.D. Fellowship].

Sanath Kumar Sathyachandran, Ph.D. Title to be determined [Funded by Cochrane et al. NASA Biodiversity grant].

Research Supervision/Collaboration

Dr. Luigi Boschetti, Assistant Research Scientist.

Dr. Junchang Ju, Postdoctoral Fellow.

Currently Active Grants

Web-enabled Landsat data (WELD) - a consistent seamless near real time MODIS-Landsat data fusion for the terrestrial user community, Roy, D.P. (Principal Investigator), Hansen, M., Loveland, T., Vermote, E., Kline, K., Zhang, C., This 5 year co-operative agreement with NASA provides Earth science data products and services driven by NASA’s Earth science goals and contributing to advancing NASA’s “missions to measurements” concept. It is a formal collaboration between the United States Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS) and its academic partner, the South Dakota State University Geographic Information Science Center of Excellence (GIScE). The proposal contributes to NASA’s Land measurement theme; working at high spatial resolution and using state of the art and validated MODIS land products to systematically generate “seamless” consistent mosaiced Landsat ETM+ data sets with per-pixel quality assessment information and derived land cover characterization at monthly and longer time periods. This proposal will improve the consistency and quality of ETM+ data through a fusion with MODIS land products. The resulting high spatial resolution mosaic products will be generated for the conterminous USA and Alaska for a 7 year period, and made freely available to the user community. Funded by NASA NNH06ZDA001N Making Earth System data records for Use in Research Environments (MEASURES) program.

A Global Burned Area ESDR from MODIS and NPP VIIRS, Justice, C.O. (Principal Investigator at University of Maryland), Roy, D., Boschetti, L., Giglio, L., This 3 year grant is to continue and expand upon the current MODIS Burned Area Product research, developing an Earth Science Data Record (ESDR) through the following six tasks: i) to maintain the MODIS Burned Area Product and implement code refinement based on product QA, validation and user feedback, ii) to undertake targeted Stage 2 validation of the product, following the CEOS LPV burned area validation protocol, iii) to develop and provide enhanced user products, iv) to generate a multiyear assessment of global burned area at a national and continental scale from MODIS Collection 5 data, v) to integrate an active fire component in the burned area product to be run in MODIS Collection 6, to improve product performance for small fires and agricultural burning, vi) to design and prototype a burned area ESDR, providing product continuity from MODIS and NPP VIIRS and to scope the feasibility and cost of extending the ESDR retrospectively using data from previous moderate resolution satellites. Funded by NASA NNH06ZDA001N-EOS program.

Radiative Transfer Modeling for the characterization of natural burnt surfaces, Lewis, P. (Principal Investigator at University College London), Disney, M., Wooster, M., Pinty, B., Roy, D., This 18 month grant includes a work program developed to meets the requirements of the European Space Agency to be performed by a European-wide team of remote sensing, and vegetation modeling scientists, with links provided through existing UK Centre for Terrestrial Carbon Dynamics collaborative agreements with the developers of NASA funded fire products and associated research in the USA. Particular highlights are the inclusion of experienced radiative transfer modelers, appropriate field data sets and the incorporation of fire radiative energy estimates of Carbon release to constrain biomass burning estimates. Funded by European Space Agency (ESA) AO/1-5526/07/NL/HE.

A 0.05 degree global climate/interdisciplinary long term data set from AVHRR, MODIS and VIIRS instruments, Vermote, E. (Principal Investigator at the University of Maryland), Roy. D.P, Prince, S., Saleous, N., Masuoka, E., Privette, J., Tucker, C., Pinzon, J., This 5 year grant will create an improved AVHRR data set for the full record of AVHRR data starting in 1981, create an equivalent MODIS data set and use the AVHRR/MODIS overlap period to asses the uncertainties in the AVHRR data set and to address data continuity issues; and apply the same approach to study the MODIS/VIIRS continuity as VIIRS data becomes available. The science user community input on the requirements, algorithms used and evaluation of the produced data sets will be sought. Funded by NASA Earth Science REASoN - Research, Education and Applications Solutions Network solicitation.

Biodiversity Implications of Forest Disturbance and Related Landscape Dynamics in the Brazilian Amazon, Cochrane, M, (Principal Investigator at SDSU), Roy, D.P., Souza, C.M., Arima, E., Barlow J., This 3 year grant tests the hypothesis that Amazonian forest biodiversity levels are mediated by forest disturbance and time since last disturbance. Landsat and MODIS satellite data are used to create a 10 year spatial database (2000-2009) of major forest disturbances (selective logging, fire, fragmentation and deforestation) and to stratify and interpret field studies to investigate the disturbance response of four indicator taxa (understorey birds, dung beetles, trees and euglossine bees). Funded by NASA Interdisciplinary Research in Earth Science solicitation.

Using NASA’s Invasive Species Forecasting System to support National Park Service decisions on fire management activities and invasive plant species control, Benson, N. (Principal Investigator at National Interagency Fire Center National Park Service), Morisette, J., Welch, B. Roy, D. (Co-Investigator),  Storhlgren, T., Two major sources of interrelated ecological disturbance are fire and invasive species. Both are major issues affecting land management decisions through the National Park System. An invasive species habitat model and remote sensed fire products will be used to better understand fire - invasive species interactions in US park systems and adjacent USDA Forest Service land, including Yellowstone/Tetons, Sequoia/Kings Canyon, Denali, Gates of the Arctic, and Yukon-Charlie.  Funded by NASA Cooperative Agreement Notice: NN-H-04-Z-YO-010-C, Integrated System Solutions of Earth science for applications of national priority.

 
Fig. 2 A daily acquisition of MODIS data from Sept. 7, 2000. Creating internally consistent global composites over time requires rigorous production and quality assessment protocols. See (http://landweb.nascom.nasa.gov/browse).

Recent Publications

Roy, D.P., Boschetti, L., Justice C.O., Ju, J., 2008, The Collection 5 MODIS Burned Area Product – Global Evaluation by Comparison with the MODIS Active Fire Product, Remote Sensing of Environment, 10.1016/j.rse.2008.05.013 (PDF file 1.8MB)

Roy, D.P., Ju,  J., Lewis, P., Schaaf, C., Gao, F., Hansen, M., Lindquist, E., 2008, Multi-temporal MODIS-Landsat data fusion for relative radiometric normalization, gap filling, and prediction of Landsat data,  Remote Sensing of Environment, 112:3112-3130. (PDF file 6MB)

Boschetti, L., Roy, D.P., Justice, C.O., 2008, Using NASA’s World Wind Virtual Globe for Interactive Internet Visualisation of the Global MODIS Burned Area Product, International Journal of Remote Sensing, 29 (11):3067-3072. (PDF file, 355 KB). 

Barnes, C.A. and Roy, D.P., 2008, Radiative forcing over the conterminous United States due to contemporary land cover land use albedo change,  Geophysical  Research  Letters, 35, L09706, doi:10.1029/2008GL033567. (PDF file, 315KB), AGU Journal Highlight,  EOS , 89, 24, 10^th June 2008, p 221.

Hansen, M.C., Roy, D.P., Lindquist, E., Adusei , B., Justice, C.O., Altstaat, A., 2008, A method for integrating MODIS and Landsat data for systematic monitoring of forest cover and change and preliminary results for Central Africa, Remote Sensing of Environment, 112:2495-2513. (PDF file, 4.6MB)

Ju, J. and Roy, D.P., 2008, The Availability of Cloud-free Landsat ETM+ data over the Conterminous United States and Globally, Remote Sensing of Environment, 112:1196-1211. (PDF file, 2.1MB)

Boschetti, L., Roy, D.P., Barbosa, P., Boca, R., Justice, C., 2008, A MODIS assessment of the summer 2007 extent burned in Greece, International Journal of Remote Sensing, 29:2433 – 2436. (PDF file, 300KB)

Roy, D.P and Justice, C.O., 2007, “A burning question – the changing role of fire on Earth” in Our Changing Planet: A View From Space, Cambridge University Press, September 30th 2007, Editors Michael D. King, Claire L. Parkinson, Kim C. Partington, Robin G. Williams, 266-273.

Myneni, R.B., Wenze Yang, W., Nemani, R.R., Huete, A.R., Dickinson, R.E.,  Knyazikhin, Y.,  Didan, K., Fu, R., Negrón Juárez, R.I., Saatchi, S.S., Hashimoto, H., Ichii, K., Shabanov, N.V., Tan, B.,  Ratana, P., Privette, J.L., Morisette, J.T., Vermote, E.F., Roy, D.P., Wolfe, R.E., Friedl, M.A., Running, S.W., Votava, P., Saleous, N., Devadiga, S.,  Su, Y.,  Salomonson , V.V.,  2007,  Large Seasonal Swings in Leaf Area of Amazon Rainforests,  Proceedings of the National Academy of Sciences, March 13 2007; doi:10.1073/pnas.0611338104 (PDF file,  2.6MB)

Trigg, S.N and Roy D.P., 2007, A focus group study of factors that promote and constrain the use of satellite derived fire products by resource managers in southern Africa, Journal of Environmental Management, 82:95-110 (PDF file, 512KB)

In Press Publications

Boschetti, L. and  Roy, D.P., Defining a fire year for reporting and analysis of global inter-annual fire variability, Journal of Geophysical Research – Biogeosciences.

Archibald, S., Roy, D.P., Van Wilgen, B.W., Scholes, R.J., What Limits Fire?: An examination of drivers of burnt area in sub-equatorial Africa, Global Change Biology special issue on Fire Ecology and Climate Change.

Lindquist, E., Hansen, H., Roy, D.P., Justice, C.O., The suitability of decadal image data sets for mapping tropical forest cover change in the Democratic Republic of Congo: implications for the mid-decadal global land survey, International Journal of Remote Sensing.

Justice C.O., Giglio L., Roy D.P., Boschetti L., Csiszar I., Davies D., Korontzi S., Schroeder W., O’Neal K.J., Morisette J.T., “Global Fire Products from the MODIS instruments” in “Land Remote Sensing and Global Environmental Change: NASA’s EOS and the Science of ASTER and MODIS”,  B. Ramachandran, C. Justice and M. Abrams (Eds), Springer Verlag, New York, In Press.

Masuoka, E., Roy, D.P., Wolfe, R.,  Morisette, J., Teague, M., Saleous, N., Devadiga, S., Justice, C.,  Sinno, S.,  Nickeson, J., “MODIS Land Data Products: Generation, Quality Assurance and Validation”  in “Land Remote Sensing and Global Environmental Change: NASA’s EOS and the Science of ASTER and MODIS”,  B. Ramachandran, C. Justice and M. Abrams (Eds), Springer Verlag, New York, In Press.

Select Publications

Roy, D.P., Lewis, P., Schaaf, C., Devadiga, S., Boschetti, L., 2006, The Global impact of cloud on the production of MODIS bi-directional reflectance model based composites for terrestrial monitoring, IEEE Geoscience and Remote Sensing Letters, 3:452-456. (PDF file, 254KB)

Roy, D.P., Trigg, S.N., Bhima, R., Brockett, B., Dube, O., Frost, P., Govender, N., Landmann, T., Le Roux, J., Lepono, T., Macuacua, J., Mbow, C., Mhwandangara, K., Mosepele, B., Mutanga, O., Neo-Mahupeleng, G., Norman, M., Virgilo, S., 2006, The utility of satellite fire product accuracy information – perspectives and recommendations from the southern Africa fire network, IEEE Transactions on Geoscience and Remote Sensing, 44:1928-1930. (PDF file, 63KB)

Justice, C.O., Giglio, L., Roy, D.P., Csiszar, I., Boschetti, L., Korontzi, S., Wooster, M., 2006, A Community Land Earth System Data Record (ESDR) White Paper on Fire requested by NASA.

Roy, D.P., Boschetti, L., Trigg, S., 2006, Remote Sensing of Fire Severity: Assessing the performance of the Normalized Burn Ratio, IEEE Geoscience and Remote Sensing Letters, 3:112-116. (PDF file, 201KB)

Jin, Y. and Roy, D.P., 2005, Fire-induced albedo change and its radiative forcing at the surface in northern Australia, Geophys. Res. Lett., 32, L13401, doi:10.1029/2005GL022822. (PDF file, 210KB)

Roy, D.P., Frost, P., Justice, C., Landmann, T., Le Roux, J., Gumbo, K., Makungwa, S., Dunham, K., Du Toit, R., Mhwandagara, K., Zacarias, A, Tacheba, B., Dube, O., Pereira, J., Mushove, P., Morisette, J., Santhana Vannan, S., Davies, D., 2005, The Southern Africa Fire Network (SAFNet) regional burned area product validation protocol, International Journal of Remote Sensing, 26:4265-4292. (PDF file, 1.4MB)

Roy, D.P. and Landmann, T., 2005, Characterizing the surface heterogeneity of fire effects using multi-temporal reflective wavelength data,  International Journal of Remote Sensing, 26:4197-4218. (PDF file, 490 KB)

Privette, J.L. and Roy, D.P., 2005, Southern Africa as a remote sensing testbed: the SAFARI 2000 special issue overview, International Journal of Remote Sensing,  26:4141–4158. (PDF file, 362KB)

Roy, D.P., Jin, Y., Lewis, P.E., Justice, C.O., 2005, Prototyping a global algorithm for systematic fire-affected area mapping using MODIS time series data,  Remote Sensing of Environment, 97: 137-162. (PDF file, 4MB)

Trigg, S.N., Roy, D.P., Flasse, S.P., 2005, An in situ study of the effects of surface anisotropy on the remote sensing of burned savannah, International Journal of Remote Sensing, 26:4869-4876. (PDF file, 429KB)

Korontzi, S., Roy, D.P., Justice C.O., Ward, D.E., 2004, Modeling and sensitivity analysis of fire emissions in southern African during SAFARI 2000, Remote Sensing of Environment, 92:255-275.(PDF file, 1.9MB)

Roy, D., Lewis, P., Justice, C., 2002, 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. (PDF file, 2.3 MB)

Vermote E. and Roy D., 2002, Land surface hot-spot observed by MODIS over Central Africa, International Journal of Remote Sensing cover and letter, 23: 2141-2143. (PDF, 562 KB)

Roy, D., Borak, J, Devadiga, S., Wolfe, R., Zheng, M., Descloitres, J., 2002, The MODIS land product quality assessment approach, Remote Sensing of Environment, 83:62-76. (PDF, 1MB)

Wolfe, R., Nishihama, M., Fleig, A., Kuyper, J., Roy, D., Storey, J., Patt, F., 2002, Achieving sub-pixel geolocation accuracy in support of MODIS land science, Remote Sensing of Environment, 83:31-49. (PDF, 1MB)

Justice, C., Townshend, J., Vermote, E., Masuoka, E., Wolfe, R., Saleous, N., Roy, D., Morisette, J. 2002, An overview of MODIS Land data processing and product status, Remote Sensing of Environment, 83:3-15. (PDF, 359KB)

Schaaf, C., Gao, F., Strahler, A., Lucht, W., Li, X., Tsang, T., Strugnell, N., Zhang, X., Jin, Y., Muller, J-P., Lewis, P., Barnsley, M., Hobson, P., Disney, M., Roberts, G., Dunderdale, M., d'Entremont, R., Hu, B., Liang, S., Privette, J., Roy, D., 2002, First operational BRDF, albedo and nadir reflectance products from MODIS, Remote Sensing of Environment, 83: 135-148. (PDF, 1.3MB)

Roy, D.P., 2000, The impact of misregistration upon composited wide field of view satellite data and implications for change detection, IEEE Transactions on Geoscience and Remote Sensing, 38:2017-2032. (PDF, 436KB)

Roy, D., Giglio, L., Kendall, J., Justice, C., 1999, Multitemporal active-fire based burn scar detection algorithm, International Journal of Remote Sensing, 20:1031-1038. (PDF, 418KB)

Wolfe, R., Roy, D., Vermote, E., 1998, The MODIS land data storage, gridding and compositing methodology: L2 Grid, IEEE Transactions on Geoscience and Remote Sensing, 36:1324-1338. (PDF, 321KB)

Justice, C., Vermote, E., Townshend, J., Defries, R., Roy, D., Hall, D., Salomonson, V., Privette, J., Riggs, G., Strahler, A., Lucht, W., Myneni, R., Knyazikhin, Y., Running, S., Nemani, R., Wan, Z., Huete, A., van Leeuwen, W., Wolfe, R., Giglio, L., Muller, J-P., Lewis, P., Barnsley, M., 1998, The Moderate Resolution Imaging Spectroradiometer (MODIS): Land remote sensing for global change research, IEEE Transactions on Geoscience and Remote Sensing, 36:1228-1249. (PDF, 480KB)

Roy, D.P., 1997, Investigation of the maximum normalised difference vegetation index (NDVI) and the maximum surface temperature (Ts) AVHRR compositing procedures for the extraction of NDVI and Ts over forest, International Journal of Remote Sensing, 18:2383-2401. (PDF, 285KB)

Roy, D.P., Devereux, B., Grainger, B., White, S., 1997, Parametric geometric correction of airborne thematic mapper imagery, International Journal of Remote Sensing, 18:1865-1887.  (PDF, 7.5MB)