Science

Scanning tree skeletons

If given the chance, Dr Alexander Bucksch would analyse an entire forest. Five years ago he started with some apple trees, party people and women’s breasts.

“I could scan a whole forest,” Bucksch says, “but for that I’d have to adapt my algorithm, and I’d also need access for months to a supercomputer like Sara (Stichting Academisch Rekencentrum Amsterdam).”

Dr Bucksch, who worked at the remote sensing department of the faculty of Aerospace Engineering, developed an algorithm to analyse laser scanning samples. Next week he will defend his thesis, titled ‘Revealing the skeleton from imperfect point clouds’.

With a laser scanner, an apparatus that slowly rotates and emits millions of laser beams, one can quantify the environment by creating point clouds, in which each point is a reflection of one of the leaser beams on an object. These point clouds can come in handy for monitoring construction sites, helping to verify that there is no subsidence of structures over time. Delft researchers have quite some experience with this application.

Bucksch however focused on something completely different: “I scanned six honey crisp apple trees in Canada. And I worked with a German ecologist, Stefan Fleck, who is interested in the exact structure of the trees, in order to better study the physiological processes.” 

To obtain all the available information about the tree structure, one must scan the tree from different angles. But owing to the scanned surface properties and the fine structure in orchard tree crowns, the result is blurry images. Bucksch’s algorithm solves this problem by extracting the skeletons of trees from the massive point cloud. 

With his portable laser scanner, Bucksch not only travelled to orchards: together with a colleague, he also used the scanner in a clinic to verify if breast implants had the desired results. And to help get people better acquainted with science, he also scanned people’s faces during special events in museums. 

Op de website van de Gouden Piramide wordt het tot BK City omgebouwde voormalige TU-hoofdgebouw ‘fleurig en flexibel’ genoemd. De prijs bestaat uit een bedrag vijftigduizend euro en een trofee.

Collegevoorzitter Dirk Jan van den Berg zei woensdag 26 mei tegen de ondernemingsraad het een leuk detail te vinden dat het een prijs is van het ministerie van Onderwijs, Cultuur en Wetenschappen. Datzelfde ministerie moet immers beslissen of Bouwkunde de 25 miljoen euro mag houden die de faculteit van minister Plasterk kreeg voor nieuwbouw. “We zijn er buitengewoon op gebrand om deze prijs binnen te slepen.”

Editor Redactie

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