Marcel Schwieder

Mr. Marcel Schwieder

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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1 September 2015 in Remote Sensing
Verified
Journal Article
Open access
PDF file
SLSebastian van der Linden
Sebastian van der Linden
ARAndreas Rabe
Andreas Rabe
MHMatthias Held
Matthias Held
BJBenjamin Jakimow
Benjamin Jakimow
PLPedro J. Leitão
Pedro J. Leitão
PHPatrick Hostert
Patrick Hostert
The EnMAP-Box is a toolbox that is developed for the processing and analysis of data acquired by the German spaceborne imaging spectrometer EnMAP (Environmental Mapping and Analysis Program). It is developed with two aims in mind in order to guarantee full usage of future EnMAP data, i.e., (1) extending the EnMAP user community and (2) providing access to recent approaches for imaging spectroscopy data processing. The software is freely available and offers a range of tools and applications for the processing of spectral imagery, including classical processing tools for imaging spectroscopy data as well as powerful machine learning approaches or interfaces for the integration of methods available in scripting languages. A special developer version includes the full open source code, an application programming interface and an application wizard for easy integration and documentation of new developments. This paper gives an overview of the EnMAP-Box for users and developers, explains typical workflows along an application example and exemplifies the concept for making it a frequently used and constantly extended platform for imaging spectroscopy applications.

1 October 2016 in International Journal of Applied Earth Observation and Geoinformation
Verified
Journal Article
Closed access
MSMarcel Schwieder
Marcel Schwieder
PLPedro J. Leitão
Pedro J. Leitão
MBMercedes Bustamante
Mercedes Bustamante
LFLaerte Guimarães Ferreira
Laerte Guimarães Ferreira
ARAndreas Rabe
Andreas Rabe
PHPatrick Hostert
Patrick Hostert

1 December 2018 in Remote Sensing of Environment
Verified
Journal Article
Closed access
SSStefan Suess
Stefan Suess
SLSebastian van der Linden
Sebastian van der Linden
AOAkpona Okujeni
Akpona Okujeni
PGPatrick Griffiths
Patrick Griffiths
PLPedro J. Leitão
Pedro J. Leitão
PHPatrick Hostert
Patrick Hostert

22 April 2014 in Remote Sensing
Verified
Journal Article
Open access
PDF file
MSMarcel Schwieder
Marcel Schwieder
PLPedro J. Leitão
Pedro J. Leitão
SSStefan Suess
Stefan Suess
CSCornelius Senf
Cornelius Senf
PHPatrick Hostert
Patrick Hostert
Anthropogenic interventions in natural and semi-natural ecosystems often lead to substantial changes in their functioning and may ultimately threaten ecosystem service provision. It is, therefore, necessary to monitor these changes in order to understand their impacts and to support management decisions that help ensuring sustainability. Remote sensing has proven to be a valuable tool for these purposes, and especially hyperspectral sensors are expected to provide valuable data for quantitative characterization of land change processes. In this study, simulated EnMAP data were used for mapping shrub cover fractions along a gradient of shrub encroachment, in a study region in southern Portugal. We compared three machine learning regression techniques: Support Vector Regression (SVR); Random Forest Regression (RF); and Partial Least Squares Regression (PLSR). Additionally, we compared the influence of training sample size on the prediction performance. All techniques showed reasonably good results when trained with large samples, while SVR always outperformed the other algorithms. The best model was applied to produce a fractional shrub cover map for the whole study area. The predicted patterns revealed a gradient of shrub cover between regions affected by special agricultural management schemes for nature protection and areas without land use incentives. Our results highlight the value of EnMAP data in combination with machine learning regression techniques for monitoring gradual land change processes.

1 October 2019 in International Journal of Applied Earth Observation and Geoinformation
Verified
Journal Article
Open access
Hugo do Nascimento BendiniHugo do Nascimento Bendini
Hugo do Nascimento Bendini
LFLeila Maria Garcia Fonseca
Leila Maria Garcia Fonseca
MSMarcel Schwieder
Marcel Schwieder
TKThales Körting
Thales Körting
PRPhilippe Rufin
Philippe Rufin
PHPatrick Hostert
Patrick Hostert

22 August 2018 in Ecosphere
Verified
Journal Article
Open access
PDF file
PLPedro J. Leitão
Pedro J. Leitão
MSMarcel Schwieder
Marcel Schwieder
FPFlorian Pötzschner
Florian Pötzschner
JPJosé R. R. Pinto
José R. R. Pinto
ATAna M. C. Teixeira
Ana M. C. Teixeira
PHPatrick Hostert
Patrick Hostert
In times of rapid global change, ecosystem monitoring is of utmost importance. Combined field and remote sensing data enable large‐scale ecosystem assessments, while maintaining local relevance and accuracy. In heterogeneous landscapes, however, the integration of field‐collected data with remote sensing image pixels is not a trivial matter. Indeed, much of the uncertainty in models that use remote sensing to map larger areas lies on the field data integration. In this study, we propose to use fine spatial resolution (5 × 5 m2) remote sensing data as auxiliary data for upscaling field‐sampled aboveground carbon data to target (meso‐scale, i.e., 30 × 30 m2) image pixels. In this process, we assess the effects of field data disaggregation and extrapolation, with and without the auxiliary data. We test this on three study sites in heterogeneous landscapes of the Brazilian savanna. We thus compare two methods that use auxiliary data—surface method, which uses a weighting layer, and regression method, which applies a regression model—with one method without auxiliary data—cartographic method. To evaluate our results, we compared observed vs. estimated aboveground carbon values (for known samples) at the pixel level. Additionally, we fitted a random forest regression model with the assigned carbon estimates and the target satellite imagery and assessed the influence of the fraction of extrapolated vs. sampled carbon values on model performance. We observed that, in heterogeneous landscapes, the use of fine spatial resolution remote sensing data improves the upscaling of field‐based aboveground carbon data to coarser image pixels. We also show that a surface method is more suitable for spatial disaggregation, while a regression approach is preferable for extrapolating non‐sampled pixel fractions. In our study, larger datasets, which included a higher proportion of estimated values, generally delivered better models of aboveground carbon than smaller datasets that are assumed to more reliably reflect reality. Our approach enables to link field and remote sensing data, which in turn enables the detailed mapping of aboveground carbon in heterogeneous landscapes over large areas through the optimized integration of field data and multi‐scale remote sensing data.