TY - JOUR A1 - Berendt, Ferréol A1 - de Miguel-Diez, Felipe A1 - Wallor, Evelyn A1 - Blasko, Lubomir A1 - Cremer, Tobias T1 - Comparison of different approaches to estimate bark volume of industrial wood at disc and log scale JF - Scientific Reports N2 - Within the wood supply chain, the measurement of roundwood plays a key role due to its high economic impact. While wood industry mainly processes the solid wood, the bark mostly remains as an industrial by-product. In Central Europe, it is common that the wood is sold over bark but that the price is calculated on a timber volume under bark. However, logs are often measured as stacks and, thus, the volume includes not only the solid wood content but also the bark portion. Mostly, the deduction factors used to estimate the solid wood content are based on bark thickness. The aim of this study was to compare the estimation of bark volume from scaling formulae with the real bark volume, obtained by xylometric technique. Moreover, the measurements were performed using logs under practice conditions and using discs under laboratory conditions. The mean bark volume was 6.9 dm3 and 26.4 cm3 for the Norway spruce logs and the Scots pine discs respectively. Whereas the results showed good performances regarding the root mean square error, the coefficient of determination (R2) and the mean absolute error for the volume estimation of the total volume of discs and logs (over bark), the performances were much lower for the bark volume estimations only. KW - Environmental sciences; Physics Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-1987 SN - 2045-2322 VL - 11 PB - Springer Nature ER - TY - CHAP A1 - de Miguel-Díez, Felipe A1 - Reder, Stefan A1 - Wallor, Evelyn A1 - Bahr, Henrik A1 - Mund, Jan-Peter A1 - Cremer, Tobias T1 - Long Range and High-Speed Personal Laser Scanning (PLS) and Simultaneous Localization and Mapping (SLAM) Technology in Roundwood Measurement T2 - Proceedings of the SilviLaser Conference 2021 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-4462 N1 - Proceedings of the SilviLaser Conference 2021, Vienna, Austria, 28–30 September 2021. Technische Universität Wien, 2021. DOI: 10.34726/wim.1861 ER - TY - JOUR A1 - de Miguel-Díez, Felipe A1 - Pettenkofer, Tim A1 - Wallor, Evelyn A1 - Tolosana-Esteban, Eduardo A1 - Purfürst, Thomas A1 - Cremer, Tobias T1 - Influence of log and stack parameters on the conversion factors for Norway Spruce wood stacks using a 3D simulation model JF - International Journal of Forest Engineering N2 - One method for estimating the solid wood content in a stack involves using conversion factors and multiplying these by the measured gross volume. The conversion factors can vary depending on several log and stack parameters. The aim of this study was to analyze eleven parameters using a 3D simulation model based on 541 measured logs of Norway spruce. To this end, 50 data sets were created from measured logs, where the parameters of interest in this study (e.g., length, crookedness, taper …) were classified according to different ranges. After that, 64 runs of simulations were carried out. In each simulation run, 150 stacks were modeled. The simulation results were compared with previous studies and with the measurement guidelines of several countries. This analysis revealed that the parameters midpoint diameter, length, crookedness, delimbing quality and the proportion of moderately and highly crooked logs in a stack have a considerable influence on the conversion factors. Taper, proportion of butt logs in a stack and stack height have a modest effect as do the proportion of tapered and crooked logs for low and high taper and low crookedness. In contrast, ovality and the proportion of logs stacked in opposite directions have a marginal influence on the conversion factors. Based on findings from these analyses, the current measurement guidelines of different countries can now be adapted to achieve a higher degree of accuracy. KW - Roundwood measurement; conversion factors; solid wood content; software development Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-4482 SN - 1494-2119 VL - 33 IS - 2 SP - 119 EP - 128 PB - Taylor & Francis ER - TY - JOUR A1 - de Miguel-Díez, Felipe A1 - Reder, Stefan A1 - Wallor, Evelyn A1 - Bahr, Henrik A1 - Blasko, Lubomir A1 - Mund, Jan-Peter A1 - Cremer, Tobias T1 - Further application of using a personal laser scanner and simultaneous localization and mapping technology to estimate the log’s volume and its comparison with traditional methods JF - International Journal of Applied Earth Observation and Geoinformation N2 - The aim of this study was the development of a methodical processing line for estimating the log’s volume from scanning logs using a long-range high-speed personal laser scanner (PLS) GeoSLAM ZEB HORIZON and simultaneous localization and mapping (SLAM) technology in an open-source software framework of Cloud Compare. Additionally, the accuracy and precision of using PLS and the suggested method when measuring roundwood volume was examined compared to measurements made using a xylometer and estimations obtained from applying the formulae of Huber, Smalian and Newton. For this purpose, several parameters were measured in 50 logs of Norway spruce with an average length of 2.53 m and a mean diameter of 19.97 cm. Afterwards, the volume of these 50 logs was measured with a xylometer. The results of these measurements served as reference values. The same 50 logs were subsequently scanned with the PLS. The scans were converted into point clouds and were analyzed in Cloud Compare to estimate the volume of the scanned logs. Next, the root mean square error (RMSE) and the mean bias error (MBE) as well as their relative values were calculated for the volumes determined in Cloud Compare and estimated with the above mentioned formulae. The calculated RMSE (and relative RMSE) determined a deviation of the logs' volumes estimated in Cloud Compare from the xylometric volumes of 2.88 dm3 (3.54%) whereas the deviations of the log’s volumes calculated applying the formulae of Huber, Smalian and Newton from the xylometric volumes were respectively 9.63 dm3 (11.83%), 10.33 dm3 (12.69%) and 4.69 dm3 (5.76%). The calculated MBE (and relative MBE) showed that the estimated volumes in Cloud Compare and those using the formulae were overestimated, with the lowest overestimation of 0.10 dm3 (0.12%) in Cloud Compare and the highest, 5.50 dm3 (6.75%), using the Smalian formula. Therefore, it can be stated that results of suggested methodical processing line came closest to the logs' volumes obtained with the xylometer, i.e., they were more accurate and precise compared to the conventionally formulae for log’s volume estimation. The implementation of this method has the potential filling a gap towards a wall-to-wall complete digitization of the roundwood commercialization and ensure transparency and acceptance between the stakeholders involved in the wood supply chain. KW - SLAM; Point cloud; Roundwood measurement; Wood supply chain Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:eb1-opus-4496 SN - 1872-826X IS - 109 PB - Elsevier ER -