University of Twente Student Theses
Uncertainty in LAI and fractional cover estimation from airborne imagery: Effects of viewing Geometry and Positional Uncertainty in the Case of Barrax SPARC Campaig
Maguma, Christabel Tendai Tandiwe (2012) Uncertainty in LAI and fractional cover estimation from airborne imagery: Effects of viewing Geometry and Positional Uncertainty in the Case of Barrax SPARC Campaig.
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| Abstract: | The purpose for this paper is to present a method using remote sensing measurement for improved retrieval of Leaf Area Index and fractional cover as input in the Surface Energy Balance Systems model. The method for estimation is based on comparing LAI based on the empirical relationship between LAI and vegetation Indices (NDVI) against Beer’s law derivative for LAI and Poisson derived model for factional cover estimation. Furthermore the influenced of correcting satellite data by accounting for the variability in the viewing angle is investigated. In comparison to the ground observation, both SEBS automated routine and Beer’s law derivative model under predicted LAI and thus exhibited a relatively weak predicting power on both the ASTER and the AHS data. The Aster data however showed a better R² 0.6249 and 0.6004 for the SEBS routines and the Beer’s law derivative model respectively with the scatter produced on the Aster data by the Beer’s law derivative model representing results more closely to the ground data. For fractional cover estimation subtle difference in the models’ estimation was observed with the major difference being observed at higher values of the viewing angle. Statistically the major difference is based on the R² (0.94) and the RMSE of the Poisson model derivative parameterization that showed the model performed better when multiplied by the cosine of the viewing zenith angle. This study is site specific and is achieved based on aircraft, satellite and field measurements made at the Barrax Agriculture Study Site in Spain during the SPARC campaign in 2004. |
| Item Type: | Essay (Master) |
| Faculty: | ITC: Faculty of Geo-information Science and Earth Observation |
| Programme: | Geoinformation Science and Earth Observation MSc (75014) |
| Link to this item: | https://purl.utwente.nl/essays/93660 |
| Export this item as: | BibTeX EndNote HTML Citation Reference Manager |
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