Design and Application of Barcode Diameter-at-Breast-Height Tape in Forest Inventories

Abstract

Diameter at breast height (DBH) is one of the most important factors in forest inventories. A diameter tape is a traditional tool for measuring DBHs and is often used to obtain references when testing other DBH tools. However, reading measurements with this tool is subjective and may result in low-accuracy values. In this paper, two types of diameter tapes with barcoding (black & white tape and multicolour tape) were designed based the traditional diameter tape. A new algorithm was designed and developed as an application that can be installed on a smartphone with a wide-angle camera to decode and store readings of these new tapes. This system was tested in typical forest plots. The results showed that when comparing the mean values measured multiple times with reference values obtained with a traditional tape, the bias was not particularly significant (1.3 mm). The RMSE of measurements using these new tools (5.6 mm) was smaller than that obtained using a traditional tool (9.2 mm). Furthermore, this new approach reduced the subjectivity of different observers reading the data. Therefore, these new tapes may be better alternatives to a traditional tape.

Bayesian Evaluation of Smartphone Applications for Forest Inventories in Small Forest Holdings

“…With respect to accuracy and precision, we would like to note that accuracy tests usually (and this is also the case in this paper) do not refer to the closeness of the measurements to the "true" population value of a stand parameter. Instead, estimates obtained by an alternative method are used as a reference (e.g., [11,38]), meaning that the measurement error of the reference method is not accounted for (but see [10,39,40]).…”