Effects of sample size and model form on the accuracy of model-based estimators of growing stock volume
NRC Research Press (a division of Canadian Science Publishing), 2015
Online
academicJournal
Zugriff:
In this study we investigate the use of model-based inference in forest surveys where auxiliary data are available as a probability sample. We evaluate the effects of model form and sample size on estimators of growing stock volume, based on different types of remotely sensed auxiliary data. The study was performed through Monte Carlo sampling simulation using a two-phase sampling design within a simulated study area resembling the conditions in mid-western Finland. We show that the choice of model has a minor to moderate effect on the precision of model-based estimators. Similarly, the choice of estimator of the variance-covariance matrix of model parameter estimates, which is at the core of uncertainty assessment in model-based inference, also was found to have a minor to moderate effect on the precision. Regarding sample sizes, the model error contribution to the total variance remains the same regardless of first phase sample size (i.e. the size of the sample of auxiliary data); to reduce the model-error contribution there is a need to increase the second phase sample size (i.e. the size of the sample of field plots for developing regression models). As a baseline for comparisons, model-assisted estimators were applied and were found to be about equally precise as the model-based estimators, in accordance with the theory for the case when models are estimated from the sample data. ; The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.
Titel: |
Effects of sample size and model form on the accuracy of model-based estimators of growing stock volume
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Autor/in / Beteiligte Person: | Saarela, Svetlana ; Schnell, Sebastian ; Grafström, Anton ; Tuominen, Sakari ; Nordkvist, Karin ; Hyyppä, Juha ; Kangas, Annika ; Stahl, Göran |
Link: | |
Veröffentlichung: | NRC Research Press (a division of Canadian Science Publishing), 2015 |
Medientyp: | academicJournal |
ISSN: | 0045-5067 (print) |
DOI: | 10.1139/cjfr-2015-0077 |
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