Structure-from-Motion (SfM) and Multiview-Stereo (MVS) is emerging as a flexible, self-service, remote sensing tool for generating fine-grained digital surface models (DSMs) in the Earth sciences and ecology. However, drone-based SfM+MVS applications have developed at a rapid pace over the past decade and there are now many software options available for data processing. Consequently, understanding of reproducibility issues caused by variations in software choice and their influence on data quality is relatively poorly understood. This understanding is crucial for the development of SfM+MVS if it is to fulfil a role as a new quantitative remote sensing tool to inform management frameworks and species conservation schemes. To address this knowledge gap, a lightweight multirotor drone carrying a Ricoh GR II consumer-grade camera was used to capture replicate, centimetre-resolution image datasets of a temperate, intensively managed grassland ecosystem. These data allowed the exploration of method reproducibility and the impact of SfM+MVS software choice on derived vegetation canopy height measurement accuracy. The quality of DSM height measurements derived from four different, yet widely used SfM-MVS software – Photoscan, Pix4D, 3DFlow Zephyr and MICMAC, were compared with in-situ sward height data captured on the same day as image capture. Using the same replicate image dataset (n=3) as input we demonstrate that there are 1.7, 2.0 and 2.5 cm differences in RMSE (excluding one outlier) between the outputs from different SfM+MVS software using "High", "Medium" and "Low" quality settings, respectively. Furthermore, we show that there can be a significant difference, although of small overall magnitude between replicate image datasets (n=3) processed using the same SfM+MVS software, following the same workflow, with a variance in RMSE of up to 1.3, 1.5 and 2.7 cm (excluding one outlier) for “High”, “Medium” and “Low” quality settings, respectively. We conclude that SfM+MVS software choice does matter.
Photoscan High Quality Dataset 1
Photoscan High Quality point cloud, replicate image dataset 1.
THOneHQPS.ply
EcologyandEvolution_Material
Ground control points, 2D image measurements and sward height measurements.
Pix4D first image dataset, part 1
Pix4D point cloud HQ (part 1), first image dataset.
THOneHQPix_part_1.las
THTwoHQPS
Photoscan High Quality point cloud, replicate image dataset 2.
THThreeHQPS
Photoscan High Quality point cloud, replicate image dataset 3.
THOneHQPix_part_2
Pix4D point cloud HQ (part 2), first image dataset.
THOneHQPix_part_3
Pix4D point cloud high quality (part 3), replicate image dataset one.
THOneHQPix_part_4
Pix4D point cloud high quality (part 4), replicate image dataset one.
THOneMedPix
Pix4D medium quality point cloud, replicate image dataset one.
THTwoMedPix
Pix4D medium quality point cloud, replicate image dataset two.
THThreeMedPix
Pix4D medium quality point cloud, replicate image dataset three.
THOneHQMM
MICMAC high quality point cloud, replicate image dataset one.
THTwoHQMM
MICMAC high quality point cloud, replicate image dataset two.
THThreeHQMM
MICMAC high quality point cloud, replicate image dataset three.
THThreeHQPix
Pix4D high quality point cloud, replicate image dataset three.
THTwoHQPix
Pix4D high quality point cloud, replicate image dataset two.
THOneLQPix
Pix4D low quality point cloud, replicate image dataset one.
THTwoLQPix
Pix4D low quality point cloud, replicate image dataset two.
THThreeLQPix
Pix4D low quality point cloud, replicate image dataset three.
THOneMedMM
MICMAC medium quality point cloud, replicate image dataset one.
THTwoMedMM
MICMAC medium quality point cloud, replicate image dataset two.
THThreeMedMM
MICMAC medium quality point cloud, replicate image dataset three.
THOneLQMM
MICMAC low quality point cloud, replicate image dataset one.
THTwoLQMM
MICMAC low quality point cloud, replicate image dataset two.
THThreeLQMM
MICMAC low quality point cloud, replicate image dataset three.
THOneMedPS
Photoscan medium quality point cloud, replicate image dataset one.
THTwoMedPS
Photoscan medium quality point cloud, replicate image dataset two.
THThreeMedPS
Photoscan medium quality point cloud, replicate image dataset three.
THOneLQPS
Photoscan low quality point cloud, replicate image dataset one.
THTwoLQPS
Photoscan low quality point cloud, replicate image dataset two.
THThreeLQPS
Photoscan low quality point cloud, replicate image dataset three.
PhotoscanProcessingReports
Photoscan processing reports.
Pix4DProcessingReports
Pix4D processing reports.
3DFlowProcessingReports
3DFlow processing reports.
THOneHQDF
3DFlow high quality point cloud, replicate image dataset one.
THTwoHQDF
3DFlow high quality settings, second replicate image dataset.
THThreeHQDF
3DFlow high quality point cloud, replicate image dataset three.
THOneMedDF
3DFlow medium quality point cloud, replicate image dataset one.
THTwoMedDF
3DFlow medium quality point cloud, replicate image dataset two.
THThreeMedDF
3DFlow medium quality point cloud, replicate image dataset three.
THOneLQDF
3DFlow low quality point cloud, replicate image dataset one.
THTwoLQDF
3DFlow low quality point cloud, replicate image dataset two.
THThreeLQDF
3DFlow low quality point cloud, replicate image dataset three.