Thesis subject

MSc thesis topic: Modelling plant-height, growth and canopy dynamics using UAVRemote-Sensing

Plant responses to biotic and abiotic legacies left in soil by preceding plants is known as plant–soil feedback (PSF). Most PSF studies are short-term and small-scale due to practical constraints for field-scale quantification of PSF effects, yet field experiments are warranted to assess actual PSF effects under less controlled conditions in the field. We used unmanned aerial vehicle (UAV)-based optical sensors to test whether PSF effects on plant traits can be quantified remotely and in a non-destructive way. By combining repeated UAV observations over the growing season, canopy structure over the growing season can be modelled.

Canopy structure can be derived from UAV based
observations using the so-called Structure from Motion approach. This methods
calculates the Digital Surface Model from which 3D canopy information can be
derived of the crop canopy. From temporal observations, growth curves and
canopy dynamics can be derived. The UAV-based canopy measurement using RGB
images is a suitable alternative for quantifying canopy structure through fitting
a fitting a Weibull distribution to the 3-dimensional point cloud of a plant
structure or given region of interest. This method has been applied for tree
objects but also the relevance for agricultural plants and plots has been
indicated.

Objectives

Develop a processing chain to derive crop height using SfM applied on a time-series of UAV images
Evaluate the Weibull distribution approach for modelling growth and canopy dynamics

Literature

Jean-François Côté, Richard A. Fournier, Joan E.Luther and Olivier R. van Lier (2018): Fine-scale three-dimensional modeling of boreal forest plots to improve forest characterization with remote sensing, Remote Sensing of Environment, Volume 219.
Liang Han, Guijun Yang, Hao Yang, Bo Xu, Zhenhai Li and Xiaodong Yang (2018): Clustering Field-Based Maize Phenotyping of Plant-Height Growth and Canopy Spectral Dynamics Using a UAV Remote-Sensing Approach, Frontiers in Plant Science.
Bob van der Meij, Lammert Kooistra, Juha Suomalainen, Janna M. Barel, and Gerlinde B. De Deyn (2017): Remote sensing of plant trait responses to field-based plant–soil feedback using UAV-based optical sensors, Biogeosciences, 14.

Theme(s): Sensing & measuring; Integrated Land Monitoring

Bob van der Meij, Lammert Kooistra, Juha Suomalainen, Janna M. Barel, and Gerlinde B. De Deyn (2017): Remote sensing of plant trait responses to field-based plant–soil feedback using UAV-based optical sensors, Biogeosciences, 14.