This study explores the use of structure from motion (SfM), a computer vision
technique, to model vine canopy structure at a study vineyard in the Texas Hill Country.
Using an unmanned aerial vehicle (UAV) and a digital camera, 201 aerial images (nadir
and oblique) were collected and used to create a SfM point cloud. All points were
classified as ground or non-ground points. Non-ground points, presumably representing
vegetation and other above ground objects, were used to create visualizations of the study
vineyard blocks. Further, the relationship between non-ground points in close proximity to
67 sample vines and collected leaf area index (LAI) measurements for those same vines
was also explored. Points near sampled vines were extracted from which several metrics
were calculated and input into a stepwise regression model to attempt to predict LAI. This
analysis resulted in a moderate R2 value of 0.567, accounting for 57 percent of the
variation of LAISQRT using six predictor variables. These results provide further
justification for SfM datasets to provide three-dimensional datasets necessary for
vegetation structure visualization and biophysical modeling over areas of smaller extent.
Additionally, SfM datasets can provide an increased temporal resolution compared to
traditional three-dimensional datasets like those captured by light detection and
ranging (lidar).