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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - State space functional principal component analysis to identify spatiotemporal patterns in remote sensing lake water quality
AU - Gong, M.
AU - Miller, C.
AU - Scott, M.
AU - O’Donnell, R.
AU - Simis, S.
AU - Groom, S.
AU - Tyler, A.
AU - Hunter, P.
AU - Spyrakos, E.
PY - 2021/12/31
Y1 - 2021/12/31
N2 - Satellite remote sensing can provide indicative measures of environmental variables that are crucial to understanding the environment. The spatial and temporal coverage of satellite images allows scientists to investigate the changes in environmental variables in an unprecedented scale. However, identifying spatiotemporal patterns from such images is challenging due to the complexity of the data, which can be large in volume yet sparse within individual images. This paper proposes a new approach, state space functional principal components analysis (SS-FPCA), to identify the spatiotemporal patterns in processed satellite retrievals and simultaneously reduce the dimensionality of the data, through the use of functional principal components. Furthermore our approach can be used to produce interpolations over the sparse areas. An algorithm based on the alternating expectation–conditional maximisation framework is proposed to estimate the model. The uncertainty of the estimated parameters is investigated through a parametric bootstrap procedure. Lake chlorophyll-a data hold key information on water quality status. Such information is usually only available from limited in situ sampling locations or not at all for remote inaccessible lakes. In this paper, the SS-FPCA is used to investigate the spatiotemporal patterns in chlorophyll-a data of Taruo Lake on the Tibetan Plateau, observed by the European Space Agency MEdium Resolution Imaging Spectrometer.
AB - Satellite remote sensing can provide indicative measures of environmental variables that are crucial to understanding the environment. The spatial and temporal coverage of satellite images allows scientists to investigate the changes in environmental variables in an unprecedented scale. However, identifying spatiotemporal patterns from such images is challenging due to the complexity of the data, which can be large in volume yet sparse within individual images. This paper proposes a new approach, state space functional principal components analysis (SS-FPCA), to identify the spatiotemporal patterns in processed satellite retrievals and simultaneously reduce the dimensionality of the data, through the use of functional principal components. Furthermore our approach can be used to produce interpolations over the sparse areas. An algorithm based on the alternating expectation–conditional maximisation framework is proposed to estimate the model. The uncertainty of the estimated parameters is investigated through a parametric bootstrap procedure. Lake chlorophyll-a data hold key information on water quality status. Such information is usually only available from limited in situ sampling locations or not at all for remote inaccessible lakes. In this paper, the SS-FPCA is used to investigate the spatiotemporal patterns in chlorophyll-a data of Taruo Lake on the Tibetan Plateau, observed by the European Space Agency MEdium Resolution Imaging Spectrometer.
KW - AECM algorithm
KW - Functional principal component analysis
KW - Lake chlorophyll-a
KW - Remote sensing images
KW - State space model
KW - Chlorophyll
KW - Lakes
KW - Remote sensing
KW - Satellites
KW - Space optics
KW - Uncertainty analysis
KW - Water quality
KW - Environmental variables
KW - European Space Agency
KW - Medium resolution imaging spectrometers
KW - Principal Components
KW - Principal components analysis
KW - Satellite remote sensing
KW - Spatiotemporal patterns
KW - Quality control
U2 - 10.1007/s00477-021-02017-w
DO - 10.1007/s00477-021-02017-w
M3 - Journal article
VL - 35
SP - 2521
EP - 2536
JO - Stochastic Environmental Research and Risk Assessment
JF - Stochastic Environmental Research and Risk Assessment
SN - 1436-3240
IS - 12
ER -