Thomas PurfürstUniversity of Freiburg | Albert-Ludwigs-Universität Freiburg · Chair of Forest Operations
Thomas Purfürst
B.Sc./M.Sc. Forestry; M.Sc. GIS; Dr. rer silv. habil.
Digitalisation of positions under forest canopy, digitalisation of wood stacks, timber logistic optimisation
About
60
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283
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Publications
Publications (60)
The aim of the study was to provide a comprehensive overview of global long-distance road transportation of industrial roundwood. The study focused on the maximum gross vehicle weight (GVW) limits allowed with different timber truck configurations, typical payloads in timber trucking, the road transportation share of the total industrial roundwood...
The roundwood measurement is an essential phase when acquiring that raw material. The accuracy requirements for the measurement process are very high, since small deviations in the measurement process when acquiring such high volumes of roundwood can lead to dramatical economic losses for the purchasing companies. Over the last decades in several E...
Im Zuge der Digitalisierung der Waldarbeit (Forst 4.0) werden umfangreiche Daten als Digitaler Zwilling des Waldes und den darin stattfindenden Prozessen erzeugt und digital abgelegt. Während die Aufnahme der Daten bisher stark untersucht wurde, stellt die effiziente Zurverfügungstellung der aufbereiteten digitalen Daten an den jeweiligen Nutzer Vo...
Die Rundholzvermessung spielt eine wesentliche Rolle in der Forstwirtschaft. Die Genauigkeitsanforderungen an den Messvorgang sind sehr hoch, da kleine Abweichungen zu wirtschaftlich relevanten Verlusten für beteiligten Akteure führen können. In zahlreichen europäischen Ländern wurden in den letzten Jahrzehnten sowohl traditionell manuelle als auch...
Traceability is the ability to follow the processes that a raw material or product goes through. For forestry, this means identifying the wood from the standing tree to the mill entrance and recording all information about the technical (production) and spatial (transportation) manipulation of the timber by linking it to the ID. We reviewed the lit...
The measurement of roadside wood stacks in the forest still plays an important role in many forestry operations. Traditional manual measuring methods can be laborious, inaccurate and error-prone. Therefore, the issue is whether 2.5D or 3D optical remote sensing measuring methods provide more precise or detailed results and advantages in further dat...
The Sustainable Development Goals, developed in 2015 by the United Nations, are a set of 17 internationally agreed-upon goals to be reached by 2030. The forest sector stands out as an important player in tackling climate change and strengthening sustainable initiatives. However, in addition to investigating the synergies and trade-offs between the...
In commercial transaction of stacked roundwood, the estimation of the stack net volume plays a key role. One generalized method to determine the net volume is using conversion factors that relate the gross and net volumes. In this literature review the developed methods to estimate the conversion factors as well as their influencing parameters were...
The measurement of roadside wood stacks in the forest still plays a decisive role in many forestry operations. Traditional manual measuring methods can be laborious, inaccurate and error-prone. Therefore, the issue is whether 2.5D or 3D optical remote sensing measuring methods can provide more precise or detailed results and advantages in further d...
Assessing the solid wood content is crucial when acquiring stacked roundwood. A frequently used method for this is to multiply determined conversion factors by the measured gross volume. However, the conversion factors are influenced by several log and stack parameters. Although these parameters have been identified and studied, their individual in...
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 spruc...
Determining the current position in a forest is essential for many applications and is often carried out using smartphones. Modern smartphones now support various GNSS constellations and multi-frequency analyses, which are expected to provide more accurate positioning. This study compares the static autonomous GNSS positioning accuracy under forest...
Working in the forest is dangerous, especially in the case of motor manual work, which represents a significant proportion of all forest work in Germany. Nevertheless, many accidents in the forest also happen during recreational activities. In the unfortunate case of an accident, rapid assistance is therefore crucial. For provision of this service,...
Real-time or timely digital product information is decisive to effect efficient logistical processes within the wood supply chain. Actually, harvesters and forwarders provide about two-thirds of the annual softwood supply in Germany. Report of work progress and product data (assortments) are sent automatically by machines to promote the logistical...
Working in the forest is always associated with dangers. Manual forestry work, which still accounts for between 20
and 33 % of all forest work in Germany, is hazardous. Nevertheless, many accidents also occur during recreational
activities in the forest. In the case of an accident, fast help is therefore crucial. Rural areas are usually not
charact...
Ausgehend von eigenen Untersuchungen, in der Literatur veröffentlichten Studienergebnissen und basierend auf Erfahrungen wird der aktuelle Stand der fotooptischen Poltervermessung vorgestellt. Dabei wird auf Einflussfaktoren während der Vermessung mit verschiedenen Messsystemen eingegangen. Darüber hinaus werden Perspektiven der fotooptischen Verme...
Rut formation is a clearly visible and easy to measure indicator to assess the impact of forest operations on soils. Uncertainties exist in assessing rut depth from driving on forest soils. The study aims to better understand rut formation assessment accuracy as a pre-condition for a continuous rut formation measurement during forest operations and...
Bei der Digitalen Transformation hin zu einer Forstwirtschaft 4.0 spielt das Smartphone eine immer entscheidendere Rolle. Es ist fast immer dabei und dadurch, dass es eine Vielzahl von Funktionen in sich vereint, entwickelt es sich in der Forst-Holz-Kette immer mehr zur Wunderwaffe der Digitalisierung in der Forstwirtschaft.
In der Präsentation so...
The influence that parameters crookedness and taper have on the stack volume was analyzed by using a 3D-simulation model in this study. To do so, log length, diameters at the midpoint and both ends, crookedness, bark thickness, taper and ovality were measured in 1000 logs of Scots pine. From this database, several data sets with different proportio...
Driving on forest soil with heavy machinery produces soil changes, which may conflict with sustainable forestry activities. To better understand the problem, a sensor system has been developed, tested, and applied to measure the contact pressure directly in the tires of forestry vehicles, using sunken force sensors. In this way, the contact surface...
Digitalization at Bavaria State Forest Enterprise
Nacrtak Human operators are key determinants of the performance of most production systems, so individual performance is of intrinsic interest when evaluating current and proposed sys-tems for forest operations. Such evaluations can be useful for diverse purposes, for instance, planning, incentive-setting, control and costing. Hence, various evalua...
It is well-known that machine operators vary in their performance when undertaking mechanized forestry harvesting operations. Nevertheless, the human factor is still largely disregarded in productivity calculations. In the present study, operator performance is evaluated by analysing archived production data collected automatically by computers on-...
Single grip harvesters may reach very high productivity levels but are very expensive forestry machines. Therefore, they have to work very efficiently. This paper will analyse the learning curves of harvester operators and the influence of human factors described in a qualitative and quantitative manner. Based on long term production logging files...
Productivity models provide information about the expected performance of a given procedure under specific conditions. In forestry, they are essential to planning and cost estimation. In hitherto existing productivity models of forest machinery, however, the human being as an important yet mostly unknown factor influencing productivity has been dis...
To calculate the time and costs for a technical forest production system - productivity models are needed. Though we know a lot mostly of them disregard one of the main factors. Practical experience indicates that the machine driver is a decisive factor for the system’s performance; therefore all those productivity models that do not consider this...
To calculate the time and costs for a technical forest production system - productivity models are needed. Though we know a lot mostly of them disregard one of the main factors. Practical experience indicates that the machine driver is a decisive factor for the system's performance; therefore all those productivity models that do not consider this...
Questions
Question (1)
I want to log GPS/GNSS data on an iPhone/iPad and look for a dedicated app. I want to log as much data as possible (DOPS, satellite data [strength, number, position,...], used constellations, frequencies...) over a longer period of time. Additional data from other internal sensors (IMU) would also be ideal. The recording should not depend on the position change, ideally in NMEA or RAW and stored locally. Other data formats are also possible if they contain the necessary information.
Does anyone know such an app for IOS? I have tried dozens and have not found one that meets the requirements.
Thanks
