Details zur Publikation

Referenztyp Zeitschriften
DOI / URL Link
Titel (primär) Efficient approximation of the spatial covariance function for large datasets – analysis of atmospheric CO2 concentrations
Autor Vetter, P.; Schmidt, W.; Schwarze, R.
Journal / Serie Journal of Environmental Statistics
Erscheinungsjahr 2014
Department OEKON
Band/Volume 6
Heft 3
Seite von 1
Seite bis 36
Sprache englisch
Keywords spatial covariance function; fixed rank kriging; covariance tapering; full-scale approximation; large spatial data sets; mid-tropospheric CO2; remote sensing; effcient approximation
UFZ Querschnittsthemen RU6;
Abstract Linear mixed effects models have been widely used in the spatial analysis of environmental processes. However, parameter estimation and spatial predictions involve the inversion and determinant of the n × n dimensional spatial covariance matrix of the data process, with n being the number of observations. Nowadays environmental variables are typically obtained through remote sensing and contain observations of the order of tens or hundreds of thousands on a single day, which quickly leads to bottlenecks in terms of computation speed and requirements in working memory. Therefore techniques for reducing the dimension of the problem are required. The present work analyzes approaches to approximate the spatial covariance function in a real dataset of remotely sensed carbon dioxide concentrations, obtained from the Atmospheric Infrared Sounder of NASA’s ”Aqua” satellite on the 1st of May 2009. In a cross-validation case study it is shown how fixed rank kriging, stationary covariance tapering and the full-scale approximation are able to notably speed up calculations. However, the loss in predictive performance caused by the approximation strongly differs. The best results were obtained for the full-scale approximation, which was able to overcome the individual weaknesses of the fixed rank kriging and the covariance tapering.
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=15903
Vetter, P., Schmidt, W., Schwarze, R. (2014):
Efficient approximation of the spatial covariance function for large datasets – analysis of atmospheric CO2 concentrations
Journal of Environmental Statistics 6 (3), 1 - 36