author = "Ponzoni, Fl{\'a}vio Jorge",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "Impact of topographic correction on soil and vegetation cover 
                         spectral characterization by TM/Landsat 5 imagery",
              journal = "Cerne",
                 year = "2016",
               volume = "22",
               number = "3",
                pages = "289--298",
                month = "July/Sept.",
             keywords = "C-correction, Spectral characterization, Topographic correction.",
             abstract = "Several topographic correction methods have been developed to be 
                         applied to orbital imagery. The main objective of these 
                         initiatives has been focused on improving land cover mapping. 
                         Despite of some discussions that include spectral approaches, no 
                         attention has been given to the impact of such correction on the 
                         spectral characterization of different targets. That impact can 
                         influence relationships commonly explored between radiometric data 
                         from orbital imagery and biophysical and/or geophysical 
                         parameters. TM/Landsat 5 images (orbit 218, row 76) from a 
                         mountainous region located between S{\~a}o Paulo, Minas Gerais 
                         and Rio de Janeiro states (Brazil) were converted to surface 
                         reflectance values. Two topographic correction methods considering 
                         different sampling strategies were applied. The local illumination 
                         was taking into account during the result analysis in order to 
                         evaluate the selective effect of the topographic correction on the 
                         spectral characterization of bare soils and vegetated surfaces. 
                         The results indicated that the sampling strategy influences both 
                         the visual aspect of the topographic corrected images and the 
                         spectral characterization of targets. Spectral distortions caused 
                         by the topographic correction procedures were higher at darker 
                         illumination conditions. The topographic correction is a procedure 
                         that deserves attention when exploring spectral characterization 
                         of different targets. Sometimes it contributes positively in 
                         qualitative approaches such as mapping or digital classification, 
                         but it can imply in severe influence on quantitative approaches 
                         that are dependent on the targets spectral characterization.",
                  doi = "10.1590/01047760201622032121",
                  url = "http://dx.doi.org/10.1590/01047760201622032121",
                 issn = "0104-7760",
             language = "en",
        urlaccessdate = "28 nov. 2020"