Canadian Forest Service Publications
Considerations in simultaneous curve-fitting for repeated height-diameter measurements. 1994. Flewelling, J.W.; De Jong, R.J. Canadian Journal of Forest Research 24: 1408-1414.
Issued by: Pacific Forestry Centre
Catalog ID: 3576
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The problem of fitting height-diameter curves for repeated measurements on growth plots is addressed. The context of the problem is fitting historical data with varying sampling protocols and varying measurement accuracy. A key consideration is obtaining good estimates of top height and top-height increment. A particular model and objective function for fitting are presented. The model has two parameters for each measurement and one common parameter; limited crossovers in the height-diameter curves for the various measurements are allowed. The objective function minimizes errors in predicted height and in predicted change in height. The programming is described, and the availability of code is announced. Examples show both the strengths and weaknesses of this approach.