A handheld device for measuring the diameter at breast height of individual trees using laser ranging and deep-learning based image recognition

Table 1 Measurement accuracy of the newly developed device

	Diameter values of standard cylinders measured by the device	Diameter values of individual trees measured by the device
aveRE (%)	1.76	3.38
BIAS (mm)	0.064	− 1.78
relBIAS (%)	0.32	− 0.77
RMSE (mm)	3.07	6.36
relRMSE (%)	2.11	4.22
Pearson correlation coefficient	0.999**	0.991**
sig. of independent sample test	0.808	0.772

**Correlation is significant at the 0.01 level (2-tailed). (Diameter values of standard cylinders measured by the device: reference is the known diameter values of standard cylinders; diameter values of individual trees measured by the device: reference diameter being the values measured using conventional tape)

ISSN: 1746-4811