25 Years of Acoustic Tomography — and a New Device for Non-Destructive Tree Assessment
In addition to the signal’s transit time, the new impactor acoustic tomograph records other important characteristics that improve diagnosis.
Recent articles
Lasers instead of inclinometers alone: rethinking pulling tests
First post in a series on a laser-based pulling-test method. Peer-reviewed in Forests 2026, 17(5), 528 — Open Access.
Enhancing Tree Species Identification in Forestry and Urban Forests through Light Detection and Ranging Point Cloud Structural Features and Machine Learning
We demonstrate a novel computational efficient method to classify tree species in LiDAR point clouds.
Experimental Test of Non-Destructive Methods to Assess the Anchorage of Trees
Our results can provide a wider scientific basis for the pulling test method. They help to validate risk assessments and studies based on static load tests and increase their credibility and acceptance, thereby contributing significantly to the efficacy of research experiments as well as to the prospects of conserving valuable trees.
Accuracy and reproducibility of acoustic tomography significantly increase with precision of sensor position
To produce accurate and repeatable tomograms of trees with complex shapes, it is essential to measure the sensor positions precisely. Accuracy of the position of sensors affects estimated stress wave velocity, the shape of the tomogram, the size of the defect, and the estimated loss in load carrying capacity.
Using Artificial Intelligence to Assist Tree Risk Assessment
The use of AI in tree risk assessment not only supports the user but can also be used to disseminate knowledge and promote the standardization of decision-making in tree assessment.
Recent tree failures validate results of wind tipping curves
Tilt of > 0,2° at wind speed of 50-60 km/h leads to critical tilt values at gale winds
Reproducibility of Stress Wave and Electrical Resistivity Tomography for Tree Assessment
Provided that sensor positions are accurately recorded and documented, tomograms can reliably be repeated by different assessors over periods of years. Assessments based on complex calculations like loss of section modulus should be treated with caution, because they accumulate and amplify all sources of variation.
Static Pulling tests can be used for urban and forest trees
Static pulling tests were performed to compare the mechanical stability of Eurasian aspen (Populus tremula L.) and silver birch (Betula pendula Roth.) in both urban and peri-urban forests. The loading resistance of the species differed, with birch being more stable than aspen. Additionally, the mechanical stability of birch did not differ between trees growing in urban and peri-urban forests, suggesting static pulling tests are a suitable method for comparing trees from completely different growing conditions.
Comparison of methods to measure sensor positions for tomography
Precise sensor positions in tomography can be measured quickly.