Konrad Wessels
- Associate Professor
Contact Info
- Name
- Dr. Konrad Wessels
- Job Title
- Associate Professor
- Phone Number
- Office Number
- Exploratory Hall, Room 2203, MSN 6C3
Affiliations
Departments
- Geography & Geoinformation Science Department (Instructional Faculty)
- Geography & Geoinformation Science Department (Research Faculty)
Current Research
I am dedicated to the application of earth observation and geospatial sciences to improve human well-being and environmental sustainability in the face of global change. My research focuses on deriving geospatial insight from large volumes of diverse remote sensing data.
Research interests:
- Measuring 3D vegetation structure and biomass using drone, airborne and space-borne LiDAR, and Synthetic Aperture Radar (SAR) for studying forest and savanna ecosystems.
- Using deep learning to extract land cover and socio-economic information from high resolution imagery.
Projects:
- NASA Decadal Survey Incubation Study Team for Surface Topography and Vegetation (STV) (NASA STV Incubation Study). The STV Study team is tasked with (i) systematically recording science questions along with detailed data product requirements in a Science and Application Traceability Matrix (SATM) and (ii) identify technology gaps that NASA may invest in to advance the technology readiness of required capabilities.
- SavannaBio: Biomass Estimation with New Spaceborne Missions for MRV in Dry Forests and Savannas. (NASA, University of Maryland)
- Monitoring long-term change in savanna vegetation structure with airborne LiDAR and SAR time-series data.
- The Impact of Investment on Irrigated Rice, Dryland Agriculture and Afforestation in Senegal using SAR and Optical Time-Series Imagery in Data Fusion Approaches. NASA Land Cover Land Use Change program. (NASA) (NASA Land-Use and Land-Cover Change Program)
- Scoping study for NASA Terrestrial Ecology long-term field and airborne campaign focused on Drylands: ARID.
Selected Publications
- Wessels, K., Li, X., Bouvet, A. Mathieu, M., Main, R., Naidoo, L., Erasmus, B., Asner, G. (2023) Quantifying the sensitivity of L-Band SAR to a decade of vegetation structure changes in savannas. Remote Sensing of Environment, 284, 113369.
- Thai, D.H., Fei, X., Le, M.T., Züfle, A., Wessels, K.J. (2023) Riesz-Quincunx-UNet Variational Auto-Encoder for Unsupervised Satellite Image Denoising. IEEE Transactions on Geoscience and Remote Sensing. 61: DOI: 10.1109/TGRS.2023.3291309
- Li, X., Wessels, K.J, Armston, Hancock, S.J. et al. (2023) First validation of GEDI canopy heights in African savannas. Remote Sensing of Environment, 285, 113402.
- Malherbe, J., Smit, I., Wessels K. & Beukes P. (2020) Recent droughts in the Kruger National Park as reflected in the extreme climate index, African Journal of Range & Forage Science, 37:1, 1-17, DOI: 10.2989/10220119.2020.1718755
- Wessels, K.; Mathieu, R.; Knox, N.; Main, R.; Naidoo, L.; Steenkamp, K. Mapping and Monitoring Fractional Woody Vegetation Cover in the Arid Savannas of Namibia Using LiDAR Training Data, Machine Learning, and ALOS PALSAR Data. Remote Sens. 2019, 11, 2633. https://doi.org/10.3390/rs11222633
- Mograbi, P.J., Witkowski, E.T.F., Erasmus , B.F.N., Asner, G.P., Fisher, J.T., Mathieu, R., Wessels, K.J. (2018). Fuelwood extraction intensity drives compensatory regrowth in African savanna communal lands. Land Degradation and Development. DOI: 10.1002/ldr.3210
- Mahlangu, P., Mathieu, R.,Wessels, K., Naidoo, L.,Verstraete, M., Asner, G., Main R. (2018) Indirect Estimation of Structural Parameters in South African Forests Using MISR-HR and LiDAR Remote Sensing Data. Remote Sensing. 10: 1537. https://doi.org/10.3390/rs10101537
- Wessels, K., van den Bergh, K., Roy, D., Salmon, B., Steenkamp, K., McAlister, B., Swanepoel, D., Jewitt, D. (2016). Rapid land cover map updates using change detection and robust Random Forest classifiers. Remote Sensing. 8, 888; doi:10.3390/rs8110888
- Mograbi, P.J., Asner, G.P., Witkowski, E.T.F., Erasmus, B.F.N., Wessels, K.J., Mathieu, R., Vaughn, N. (2017) Humans and elephants as treefall drivers in African savannas. Ecography 40: 001–011, 2017
- Main, R., Mathieu, R., Kleynhans W., Wessels, K., Naidoo, L., Asner G. (2016) Hyper-Temporal C-Band SAR for Baseline Woody Structural Assessments in Deciduous Savannas. Remote Sensing. 2016, 8, 661; doi:10.3390/rs8080661
- Naidoo, L., Mathieu, R., Main, R., Wessels, K., Asner, G.P. (2016). L-band Synthetic Aperture Radar imagery performs better than optical datasets at retrieving woody fractional cover in deciduous, dry savannahs. International Journal of Applied Earth Observation and Geoinformation. 52, pp 54-64.
- Fisher, J.T., Witkowski, E.T., Erasmus, B.F., Mograbi, P.J., Asner, G.P., Aardt, J.A., Wessels, K.J., & Mathieu, R. (2015). What lies beneath: detecting sub-canopy changes in savanna woodlands using a three-dimensional classification method. Applied Vegetation Science, doi: 10.1111/avsc.12160
- Kleynhans, W., Salmon, B., Wessels, K., & Olivier, J. (2015). Rapid detection of new and expanding human settlements in the Limpopo province of South Africa using a spatio-temporal change detection method. International Journal of Applied Earth Observation and Geoinformation, 40, 74-80
- Mograbi, P.J., Erasmus, B.F., Witkowski, E., Asner, G.P., Wessels, K.J., Mathieu, R., Knapp, D.E., Martin, R.E., & Main, R. (2015). Biomass Increases Go under Cover: Woody Vegetation Dynamics in South African Rangelands. PLOS One, DOI:10.1371/journal.pone.0127093
- Naidoo, L., Mathieu, R., Main, R., Kleynhans, W., Wessels, K., Asner, G., & Leblon, B. (2015). Savannah woody structure modelling and mapping using multi-frequency (X-, C-and L-band) Synthetic Aperture Radar data. ISPRS Journal of Photogrammetry and Remote Sensing, 105, 234-250
- Fisher, J.T., Erasmus, B.F., Witkowski, E.T., Aardt, J., Wessels, K.J., & Asner, G.P. (2014b). Savanna woody vegetation classification–now in 3D. Applied Vegetation Science, 17, 172-184
- Tsela, P., Wessels, K., Botai, J., Archibald, S., Swanepoel, D., Steenkamp, K., & Frost, P. (2014). Validation of the two standard MODIS satellite burned-area products and an empirically-derived merged product in South Africa. Remote Sensing, 6, 1275-1293
- Salmon, B.P., Kleynhans, W., van den Bergh, F., Olivier, J.C., Grobler, T.L., & Wessels, K.J. (2013). Land cover change detection using the internal covariance matrix of the extended Kalman filter over multiple spectral bands. Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of, 6, 1079-1085
- Mathieu, R., Naidoo, L., Cho, M.A., Leblon, B., Main, R., Wessels, K., Asner, G.P., Buckley, J., Van Aardt, J., & Erasmus, B.F. (2013). Toward structural assessment of semi-arid African savannahs and woodlands: The potential of multi-temporal polarimetric RADARSAT-2 fine beam images. Remote Sensing of Environment, 138, 215-231
- Wessels K.J., Colgan M.S., Erasmus B.F.N., Asner G.P., Twine W.C., Mathieu R., van Aardt J.A.N., Fisher J.T. and Smit I.P.J. (2013) Unsustainable fuelwood extraction from South African savannas. Environmental Research Letters 8: 014007
- Wessel, K.J., Van Den Bergh F., Scholes R.J. (2012) Limits to detectability of land degradation by trend analysis of vegetation index data. Remote Sensing of Environment. 125: 10-22
- Malherbe, J., Smit, I., Wessels K. & Beukes P. (2020) Recent droughts in the Kruger National Park as reflected in the extreme climate index, African Journal of Range & Forage Science, 37:1, 1-17, DOI: 10.2989/10220119.2020.1718755
- Wessels, K.; Mathieu, R.; Knox, N.; Main, R.; Naidoo, L.; Steenkamp, K. Mapping and Monitoring Fractional Woody Vegetation Cover in the Arid Savannas of Namibia Using LiDAR Training Data, Machine Learning, and ALOS PALSAR Data. Remote Sens. 2019, 11, 2633. https://doi.org/10.3390/rs11222633
Contact Info
- Name
- Dr. Konrad Wessels
- Job Title
- Associate Professor
- Phone Number
- Office Number
- Exploratory Hall, Room 2203, MSN 6C3