Gerold Gerhard

Dr. Gerold Gerhard


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 May 2019 in Remote Sensing
Verified
Journal Article
Open access
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Flávia De Souza MendesFlávia De Souza Mendes
Flávia De Souza Mendes
DBDaniel Baron
Daniel Baron
GGGerold Gerhard
Gerold Gerhard
Veraldo LiesenbergVeraldo Liesenberg
Veraldo Liesenberg
SEStefan Erasmi
Stefan Erasmi
Mapping vegetation types through remote sensing images has proved to be effective, especially in large biomes, such as the Brazilian Cerrado, which plays an important role in the context of management and conservation at the agricultural frontier of the Amazon. We tested several combinations of optical and radar images to identify the four dominant vegetation types that are prevalent in the Cerrado area (i.e., cerrado denso, cerradão, gallery forest, and secondary forest). We extracted features from both sources of data such as intensity, grey level co-occurrence matrix, coherence, and polarimetric decompositions using Sentinel 2A, Sentinel 1A, ALOS-PALSAR 2 dual/full polarimetric, and TanDEM-X images during the dry and rainy season of 2017. In order to normalize the analysis of these features, we used principal component analysis and subsequently applied the Random Forest algorithm to evaluate the classification of vegetation types. During the dry season, the overall accuracy ranged from 48 to 83%, and during the dry and rainy seasons it ranged from 41 up to 82%. The classification using Sentinel 2A images during the dry season resulted in the highest overall accuracy and kappa values, followed by the classification that used images from all sensors during the dry and rainy season. Optical images during the dry season were sufficient to map the different types of vegetation in our study area.


9 December 2017 in Regional Environmental Change
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Journal Article
Open access
PDF file
GGGerold Gerhard
Gerold Gerhard
ECEduardo Guimarães Couto
Eduardo Guimarães Couto
BMBeata Emoke Madari
Beata Emoke Madari
HJHermann F. Jungkunst
Hermann F. Jungkunst
RARicardo Santos Silva Amorim
Ricardo Santos Silva Amorim
Claas NendelClaas Nendel
Claas Nendel

22 January 2010
Verified
Book Chapter
Closed access
PDF file
GGGerold Gerhard
Gerold Gerhard
CLConstanze Leemhuis
Constanze Leemhuis